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Advancing Cutting Technology

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Abstract

This paper reviews some of the main developments in cutting technology since the foundation of CIRP over fifty years ago. Material removal processes can take place at considerably higher performance levels in the range up to Qw = 150 – 1500 cm3/min for most workpiece materials at cutting speeds up to some 8.000 m/min. Dry or near dry cutting is finding widespread application. The superhard cutting tool materials embody hardness levels in the range 3000 – 9000 HV with toughness levels exceeding 1000 MPa. Coated tool materials offer the opportunity to fine tune the cutting tool to the material being machined. Machining accuracies down to 10 μm can now be achieved for conventional cutting processes with CNC machine tools, whilst ultraprecision cutting can operate in the range < 0.1 μm. The main technological developments associated with the cutting tool and tool materials, the workpiece materials, the machine tool, the process conditions and the manufacturing environment which have led to this advancement are given detailed consideration in this paper. The basis for a roadmap of future development of cutting technology is provided.

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... According to [14], when milling high-temperature nickel alloys, it is recommended to use tools made of hard alloys for machining at low cutting rates (15-20 m/min) and a feed of 0.02 mm/tooth. However, when milling high-temperature alloys, more aggressive cutting regimes and hard-alloy tools with wear-resistant coating are recommended in the literature [15,16]. Specifically, machining should be carried out by climb milling at a cutting rate of 20 to 50 m/min and feeds of 0.10-0.15 ...
... Solid-carbide Ø8 mm end mill cutters were used as cutting tools. The main geometric parameters of the cutters are presented in Table 4. Based on the recommendations on the machining regimes of high-temperature alloys and the analysis of the literature [4,14,16], the feed per tooth of 0.04 mm/tooth and the cutting speed of 30 m/min were chosen for the experiments. The cutters were fixed in a collet chuck with identical overhang, 24 ± 0.5 mm. ...
... Solid-carbide Ø8 mm end mill cutters were used as cutting tools. The main geometric parameters of the cutters are presented in Table 4. Based on the recommendations on the machining regimes of high-temperature alloys and the analysis of the literature [14,16,4], the feed per tooth of 0.04 mm/tooth and the cutting speed of 30 m/min were chosen for the experiments. The cutters were fixed in a collet chuck with identical overhang, 24 ± 0.5 mm. ...
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This work studies the process feasibility of milling a metal-matrix composite based on Inconel 625 with added NiTi-TiB2 fabricated by direct laser deposition. The composite is intended for manufacturing turbine blades and it has strength characteristics on par with those of Inconel 625. However, the addition of TiB2 has improved its heat and wear resistance. This material is new, and its machinability has not been studied. The new composite was milled with end mill cutters, and recommendations were worked out on the cutting speed, feed per tooth, cutter flank angle, as well as depth and width of milling. The wear of cutter teeth flank was more intense. After the flank wear land on the back surface of a tooth had reached 0.11–0.15 mm, there was a sharp increase in the forces applied which was followed by brittle fracture of the tooth. Milling at a speed of 25 m/min ensured 28 min of stable operation. However, afterwards the critical wear value of 0.11 mm was quickly approached at a cutting speed of 50 m/min, and critical wear followed after 14 min. Dependencies of the cutting forces vs. time for all the selected cutting speeds and throughout the entire testing time period have a tendency to increase, which indicates the influence of cutter wear on the cutting forces. It was found that the durability of the cutters increases with an increase in the milling width and a decrease in the milling depth.
... O substrato determina a geometria e a tenacidade da ferramenta, enquanto as propriedades tribológicas dependem das características do revestimento. A zona intermediária entre o revestimento e o substrato, chamada de interface, determina a adesão do filme (BYRNE;DORNFELD;DENKENA, 2003). ...
... O substrato determina a geometria e a tenacidade da ferramenta, enquanto as propriedades tribológicas dependem das características do revestimento. A zona intermediária entre o revestimento e o substrato, chamada de interface, determina a adesão do filme (BYRNE;DORNFELD;DENKENA, 2003). ...
... O substrato determina a geometria e a tenacidade da ferramenta, enquanto as propriedades tribológicas dependem das características do revestimento. A zona intermediária entre o revestimento e o substrato, chamada de interface, determina a adesão do filme (BYRNE;DORNFELD;DENKENA, 2003). ...
Article
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Durante as últimas décadas, estudos envolvendo a estrutura bainítica tem atraído pesquisadores por combinar elevada resistência e alta ductilidade. Aços bainiticos são potencialmente úteis em estruturas que sofrem fadiga de rolamento e/ou deslizamento, por exemplo trilhos ferroviários, componentes de mineração, rolamentos e eixos. Essas propriedades mecânicas têm sido obtidas, elaborando cuidadosamente o projeto da liga e adequado tratamento térmico de austêmpera. No entanto, o material com essas propriedades tende a prejudicar a usinabilidade nos processos de manufatura, fazendo-se necessário usinar o material no estado recozido. Este trabalho tem por objetivo contribuir com a análise tribológica do contato entre aço fundido no estado recozido contra metal duro e cermet (revestidos com Nitreto de Titânio (TiN)), que são materiais amplamente encontrados em ferramentas de corte. Para isso, foram realizados ensaios de pino sobre disco (PSD), de modo a analisar as evoluções do coeficiente de atrito (µ), coeficiente de desgaste específico (k) e o comportamento de induzidas deformações. Os resultados indicaram que os menores valores de µ foram observados utilizando pinos com substrato de cermet, o que sugere ter sido influenciado pela composição química desse substrato. Em relação ao k e a espessura da camada deformada para ambos os substratos não houveram variação significativa nos valores encontrados. Superfícies lisas foram observadas para as trilhas desgastadas em todas as condições avaliadas e sinais de deformação plástica (ploughing) no qual sugere atuação de suaves mecanismos de abrasão. No entanto, foi observado que tanto o mecanismo de adesão quanto o mecanismo de abrasão influenciaram o µ para o substrato de cermet na condição réplica. O trabalho contribui para avaliar a influência de diferentes substratos e identificação dos mecanismos de desgaste presente.
... The mechanics of the milling process have been extensively studied; in this context, the cutting force is a considerable area of research interest. As a result of the high sensitivity and rapid response of the cutting force signal to changes in cutting condition [4][5][6][7][8], the force signal can be processed for various tasks to optimize machine tool usage, such as: (1) adaptive feed rate control to keep the applied force at a predetermined level [1-4]; (2) tool wear evaluation from a comparative force level [9][10][11][12][13]; (3) force monitoring for the detection of chatter vibrations [1,2,[4][5][6][7][8][9][10][11][12][13]; and (4) force monitoring for the detection of tool breakage in milling [9][10][11][12][13]. ...
... The mechanics of the milling process have been extensively studied; in this context, the cutting force is a considerable area of research interest. As a result of the high sensitivity and rapid response of the cutting force signal to changes in cutting condition [4][5][6][7][8], the force signal can be processed for various tasks to optimize machine tool usage, such as: (1) adaptive feed rate control to keep the applied force at a predetermined level [1-4]; (2) tool wear evaluation from a comparative force level [9][10][11][12][13]; (3) force monitoring for the detection of chatter vibrations [1,2,[4][5][6][7][8][9][10][11][12][13]; and (4) force monitoring for the detection of tool breakage in milling [9][10][11][12][13]. ...
... Under forced vibration, the dynamic properties of the dynamometer's limited bandwidth result in systematic errors which cause erroneous cutting force measurements that do not accurately reflect the physical machining process. The correction of the systematic errors caused by the dynamometer structural dynamics has been extensively researched [1,2,[4][5][6][7]. ...
Article
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This paper describes the dynamic stability evaluation of a constrained-motion dynamometer (CMD) with passive damping. The CMD’s flexure-based design offers an alternative to traditional piezoelectric cutting force dynamometers, which can exhibit adverse effects of the complex structural dynamics on the measurement accuracy. In contrast, the CMD system’s structural dynamics are nominally single degree of freedom and are conveniently altered by material selection, flexure element geometry, and element arrangement. In this research, a passive damping approach is applied to increase the viscous damping ratio and, subsequently, the stability limit. Cutting tests were completed and the in situ CMD displacement and velocity signals were sampled at the spindle rotating frequency. The periodic sampling approach was used to determine if the milling response was synchronous with the spindle rotation (stable) or not (chatter) by constructing Poincaré maps for both experiment and prediction (time-domain simulation). It was found that the viscous damping coefficient was increased by 130% and the critical stability limit was increased from 4.3 mm (no damping) to 15.4 mm (with damping).
... Recent developments in the machine tools domain are determined by the necessity for new and improved constructive solutions, in order to solve the inherent conflict between the precision and the productivity of the machine tools [1][2] [3]. ...
... In order to meet these ambitious demands, it is necessary to find solutions regarding the shortening of the process time, which can be accomplished by increasing the productivity of the manufacturing process, since increasing the precision of the procedures is in many cases limited by the physical principles which underly these procedures and by the performances of the mechanical part of the machine tool [3]. ...
... Also, magnesium alloy is abrasionfree, resulting in lower tool wear. Mg produces short-breaking chips because of the HCP crystal lattice, as it only offers a base plane for slip under shear stress at room temperature [177]. Machining of magnesium can be carried out at a higher cutting speed than aluminum and steel [178]. ...
... The schematic representation of machining of MMCs is shown in Fig. 32. During machining of MMCs, due to the presence of reinforcement, tool wear increases, which increases the total cost of machining [177,180]. The presence of coarse reinforcement increases tool wear produces poor surface finish and resists plastic deformation. ...
Article
The effort to use magnesium-based materials is gradually increasing in various structural applications of automobile and aerospace industries because of their lower specific weight. This paper reviews the recent development in magnesium-based metal matrix composites and analyzes their mechanical properties. The process involving the synthesis of reinforcement during the composite development (in-situ process) shows improved properties because of a clean reinforcement-matrix interface, thermally stable reinforcement, and better wettability. The wear resistance of the material improves by the minute addition of ceramic reinforcement into the magnesium alloy matrix. The solid-state joining process is suitable for joining magnesium matrix composites. It overcomes the defects like reinforcement segregation, irregular reinforcement distribution, porosity, and oxide formation that occurred during the conventional welding process. Machining of composites possesses certain difficulties like increased surface roughness and tool wear due to the presence of discontinuous ceramic particles. An effort to enhance the machinability of the materials has been illustrated based on contemporary literature.
... Nowadays, the manufacturing community is facing considerable challenges in dealing with excessive wear and premature failures of cutting tools governing the machining processes. Developing coating materials to improve the wear resistance of tool substrates could be a feasible strategy to cope with the harsh cutting conditions, which has become a topic of great interest in recent decades [1][2][3]. Tool coating refers to covering a thin layer of refractory metal or non-metallic compound with good wear resistance on the traditional tool substrate by vapor deposition methods [4]. As the coating can act as a chemical and thermal barrier, it avoids the direct contact between the tool and the workpiece and reduces the mutual diffusion at the tool-workpiece interface, thereby improving the antiadhesion and wear resistance of cutting tools [5]. ...
... Their outstanding characteristics can significantly improve the cutting conditions dominating the tool-chip and tool-work interactions during the material removal process. This can be evidenced by the remarkable reduction of cutting forces/temperatures, the improvement of cut surface quality as well as the extension of tool life [2,6,7]. To date, tool-coating materials are mainly compounds with high wear resistance, such as nitrides, carbides, oxides, carbonitrides, silicides, sulfides, borides, diamonds, etc. [3,6]. ...
Article
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Nowadays, the manufacturing community is facing considerable challenges in dealing with excessive wear and premature failures of cutting tools governing the machining processes [...]
... Turning has been traditionally identified as a finishing operation. It represented for years a flexible process able to satisfy different needs such as superior surface conditions, geometrical accuracy, and dimensional precision [1]. However, the classification of hard turning as a finishing process is limited by tool wear [2]. ...
... b is Burger's vector equal to 2.95E − 10 m, and i is the total dislocation density set as 1·10 14 [1]. ...
Article
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This paper presents a physics-based model able to simulate the flow stress behavior of the Ti6Al4V alloy during subsequent severe plastic deformation processes, namely turning and burnishing. All the physical and metallurgical mechanisms that accommodate the deformation were considered to describe the material strengthening and they were implemented via user subroutine in a commercial finite element software. Then, the proposed numerical model was used to investigate the effect of combined turning/burnishing processes on the surface integrity of manufactured Ti6Al4V components. Turning and roller burnishing experiments were conducted to validate the proposed finite element model and to analyze the microstructural phenomena and the output variables. The implemented model well fits experimental results, precisely predicting the evolution of grain size, dislocations, hardness, and residual stresses. Different process combinations can lead to similar microstructures and information on different contributions can be highlighted through physics-based modelling and simulated process combinations. Graphical abstract
... The material removal process is considered as one of the most important manufacturing procedures and there can be no doubt that it will remain very important in the foreseeable future of product manufacturing and assembly. It is estimated that machining accounts for almost 15% of all manufacturing industry volume [1]. Machining is most commonly used in making metal parts, tools and machine components, but can also be used to work materials such as plastic, ceramic and composite. ...
... Otherwise, grinding is one of the most versatile material removal machining processes in manufacturing industry. The advantages of grinding process include a high surface quality and dimensional accuracy as well as possibility of machining complex geometry and difficult to cut materials [1][2][3]. In the recent past, in addition to conventional grinding technology, there has been an introduction of high performance grinding process. ...
Article
The research presented in this paper deals with the modeling and optimization of heat transfer problem in the machining process. An inverse heat transfer model based on the measured temperature at some point in the surface layer of the workpiece was used. The developed inverse model determines temperature and heat flux distribution for the selected machining conditions. By optimizing relationship between the intensity and duration of heat on the boundary of the workpiece, the optimum machining parameters are determined to achieve high productivity and quality at the same time. The solution of the inverse heat transfer problem is obtained by formulating an approximate well-posed problem by minimizing an objective function. Since it is an ill-posed inverse problem that is very sensitive to errors in the input data, special attention is required in order to ensure the conditions of uniformity and stability. Therefore, in this work we investigated the influence of the temperature measurement noise, the accuracy of knowledge of thermophysical properties of the material and the effect of possible instability of the numerical solution. Stability analysis of the inverse optimization problem is shown on the example of high performance grinding. The stability results were verified by a series of experiments.
... The dimensional accuracy and surface roughness of precision hard turned workpieces can reach IT5 and 0.1 μm, respectively [33]. Jouini et al. [34] performed precision hard turning of GCr15 bearing steel, obtained an extremely low surface roughness of 0.1 μm, and found that its fatigue life increases with the decrease in the surface roughness. ...
Article
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The surface integrity of bearing steel materials largely determines the life of mechanical parts like bearings and gears. Optimizing the process parameters or applying surface modification technology can improve the surface integrity of materials. In this paper, the definitions and characteristics of the evaluation parameters of surface integrity and their influences on mechanical part performance were reviewed. The influences of machining processes (forging, cold rolling, heat treatment, turning, grinding, and super-finishing) for bearing steel materials on parameters related to surface integrity including metal streamline distribution, surface roughness, surface waviness, surface defects, micro-structure, residual stress, and micro-hardness were summarized. Several typical surface modification technologies applied to bearing steel materials were summarized, including surface coating technology, chemical heat treatment technology, ion implantation technology, reinforced grinding technology, shot peening technology, and composite modification technology. Finally, two new surface modification technologies which can be applied to bearing steel materials in the future were introduced (ultrasonic surface rolling process and laser shock peening). It can provide certain research directions and theoretical references for improving the surface integrity of bearing steel material in this paper.
... This presents new challenges for process reliability in the machining of hybrid materials due to the different material properties, chemical composition, and transitions. It is known that the process parameters, cutting tools, and machining strategies have to be selected individually for the material and the existing microstructure to achieve a high workpiece quality [4]. Unsuitable process parameters lead to poor chip formation, long process times, and high cutting forces, which can cause tool breakage and machine damage. ...
Article
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Hybrid material composites can meet the increasing demands for high strength and low weight due to their different workpiece properties. Usually, hybrid components require post-machining after their fabrication. Due to the different material properties, new challenges arise in the machining process. It is essential to recognize the course of the material boundary in order to adapt the process planning accordingly and to enable a uniform material transition during machining. This paper presents a method for automated material recognition and automatic adaptation of the process parameters considering a uniform force level during the milling of hybrid materials. This way, the load on the milling tool in the material transition area can be reduced by up to 71%, which prevents premature tool failure. An optical laser line scanner is used to localize of material transitions within hybrid components. This enables a digital mapping of the material distribution in the discretized workpiece model. In combination with an empirical force model, it is possible to predict the cutting forces of the different materials and determine the material transition area for adapting them to specified target values.
... Computational Fluid Dynamics (CFD) is the analysis of fluid flows using numerical solution methods that allows for the optimization and verification of design performance before costly prototypes and physical tests [57]. Many CFD models are developed to model the temperature profile, oil droplet behavior in the cutting zone, the heat transfer characteristics of the resultant nanocutting fluid, interactions between the cutting tool and workpiece, and resulting residual stress using NFMQL in machining processes [58,59]. One study developed a 2-D axisymmetric CFD to simulate the thermal effects of resultant nanomist and obtained the thermal characteristics of the nanofluid [60]. ...
Article
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Gaining grounds as a potential heat transfer fluid due to its superior thermal and tribological properties, Nanofluid Minimum Quantity Lubrication (NMQL) has been classified as an environmentally friendly technique and has already been successfully applied in several machining processes. This paper presents a review of the role of NMQL for different machining processes. The mechanisms of the MQL technique are thoroughly explained for achieving optimal performance based on parameters like nozzle feed position, angle of elevation, distance from the nozzle tip to cutting zone, flow rate, and air pressure. NMQL is shown to enhance cooling performance and lubrication, as well as the tribological properties of the fluid and cutting performance. With government legislative and public opinion pushing manufacturing companies towards sustainable production techniques and practices, the implementation of MQL-nanofluid can slowly prevent the adverse effects that conventional cutting fluids contribute.
... Therefore, it covers a wide range of manufacturing domain technologies [20] that can be classified according to their perspec-tives. For example, from the standpoint of manufacturing processes, these technologies include plastic forming technologies, cutting technologies, casting technologies, welding technologies, heat treatment technologies, and additive technologies, among others [21][22][23][24][25]. Machine intelligence technology is related to HCPS 2.0 cyber systems, which are based on the integration of AI technologies with manufacturing domain knowledge to achieve specific HCPS goals. ...
Article
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The next-generation intelligent smart factory system that is proposed in this paper could improve product quality and realize flexible, efficient, and sustainable product manufacturing by comprehensively improving production and management innovation via its digital network and intelligent methods that reflect the characteristics of its printed circuit board (PCB) manufacturing design and on-site implementation. Intelligent manufacturing systems are complex systems that are composed of humans, cyber systems, and physical systems and aim to achieve specific manufacturing goals at an optimized level. Advanced manufacturing technology and next-generation artificial intelligence (AI) are deeply integrated into next-generation intelligent manufacturing (NGIM). Currently, the majority of PCB manufacturers are firms that specialize in processing orders from leading semiconductor and related product manufacturers, such as Samsung Electronics, TSMC, Samsung Electro-Mechanics, and LG Electronics. These top companies have been responsible for all product innovation, intelligent services, and system integration, with PCB manufacturers primarily playing a role in intelligent production and system integration. In this study, the main implementation areas were divided into manufacturing execution system (MES) implementation (which could operate the system using system integration), data gathering, the Industrial Internet of Things (IIoT) for production line connection, AI and real-time monitoring, and system implementation that could visualize the collected data. Finally, the prospects of the design and on-site implementation of the next-generation intelligent smart factory system that detects and controls the occurrence of quality and facility abnormalities are presented, based on the implementation system.
... Nearly four decades ago, Norio Taniguchi forecasted the future development of machining accuracy by extrapolating historical data and predicted that by the turn of the millennium, ultraprecision machining could achieve an accuracy of 1 nanometer, or one-millionth of a millimeter [1]. Now, the future has become the past, and Taniguchi's forecasts have been proven to be correct [2][3][4]. In particular, the ultraprecise production of miniaturized, truly three-dimensional structures [5] or mesoscale components with microscale features [6] was made possible. ...
Article
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This article presents the application and evaluation of a cantilever with integrated sensing and actuation as part of an atomic force microscope (AFM) with an adjustable probe direction, which is integrated into a nano measuring machine (NMM-1). The AFM, which is operated in closed-loop intermittent contact mode, is based on two rotational axes that enable the adjustment of the probe direction to cover a complete hemisphere. The axes greatly enlarge the metrology frame of the measuring system by materials with a comparatively high coefficient of thermal expansion, which ultimately limits the achievable measurement uncertainty of the measuring system. Thus, to reduce the thermal sensitivity of the system, the redesign of the rotational kinematics is mandatory. However, in this article, some preliminary investigations on the application of a self-sensing cantilever with an integrated micro heater for its stimulation will be presented. In previous investigations, a piezoelectric actuator has been applied to stimulate the cantilever. However, the removal of the piezoelectric actuator, which is enabled by the application of a cantilever with an integrated micro heater, promises an essential simplification of the sensor holder. Thus, in the future it might be possible to use materials with a low coefficient of thermal expansion, which are often difficult to machine and therefore only allow for rather simple geometries. Furthermore, because of the creepage of piezoelectric actuators, their removal from the metrology frame might lead to improved metrological characteristics. As will be shown, there are no significant differences between the two modes of actuation. Therefore, the redesigned rotational system will be based on the cantilever with integrated sensing and actuation.
... The spindle speed of the milling cutter is generally above 3000 r/min and up to 24000 r/min (Zheng et al. 2008). High-speed milling enables wood processing with high productivity and smooth surface quality (Darmawan et al. 2001;Byrne et al. 2003;. ...
Article
Regression models and a neural net approach were used to predict the cutting performance during milling of Scots pine (Pinus sylvestris L.) by shank cutter. The influence of rake angle, spindle speed, and milling depth on surface roughness of the workpiece, as well as the connection between the milling force and the surface roughness, were thoroughly considered. Four approaches were used to predict the workpiece’s surface roughness based on the experimental data: Back Propagation Neural Network (BPNN), Radial Basis Function Neural Network (RBFNN), Support Vector Machines (SVM), and multiple linear regression. The comparative analysis of the predictive models showed that Neural Network (NN) had preferable performance for prediction of machined surface roughness, with an R2 of 0.98. The SVM had certain fluctuations and the R2 of the multiple linear regression was just 0.87, indicating that they did not fit well for prediction machined surface roughness. In summary, the effective trend of milling parameters on the machined surface roughness of Scots pine was similar to multiple nonlinear regression, and the accurate prediction by BPNN model can provide technical support for the surface roughness of the Scots Pine and enhance shank cutter performance.
... The increasing demands for Ti6Al4V alloys are due to their excellent intrinsic properties, such as low density, high strength, and corrosion resistance. Nevertheless, these factors lead to poor machinability of Ti6Al4V alloys because of its small elastic modulus, high chemical reaction activity, and low thermal conductivity [1]. A lot of heat generated is confined over the tool-chip contact interface during the machining process, which results in high cutting temperature that in turn facilitates the chip adhesion on the rake face of cutting tools. ...
Article
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The present study was to reduce the adhesion and wear that happened on the rake face during machining of Ti6Al4V alloys by employing volcano-like textured coated tools. A combination of experimental and simulative investigation was adopted. DEFORM-3D software with updated Lagrangian formulation was used for numerical simulation, and the thermo-mechanical analysis was performed using Johnson–Cook material model to predict the cutting forces, cutting temperature, chip morphology, and tool wear. In cutting experiments, volcano-like textures with different area densities (10%, 20%, 30%) were fabricated by fiber laser on the rake face of cemented carbide tools close to the main cutting edge. Then, these textured tools were deposited with CrAlN coating through cathodic vacuum arc ion plating technique. Experiments in cutting Ti6Al4V alloys were carried out with the textured coated tools and non-textured coated tool under dry and wet cutting conditions. Then, cutting forces, chip morphology, and tool wear were investigated. The results showed that textured coated tools were superior to the conventional tool. Especially in wet cutting, the main cutting force and radial force of the coated tool with texture area density of 20% (VCT2) were reduced by 11.6% and 21.25%, respectively. Surface morphology of VCT2 tool had lower workpiece adhesion on the rake face. Therefore, VCT2 tool showed a better cutting performance. Finally, the mechanisms of textured coated tools under wet cutting conditions were proposed.
... Antara lain mempengaruhi kekasaran permukaan benda kerja (Grzesik, 2008). Peningkatan performa material mata pahat dapat meningkatkan kualitas permukaan, toleransi yang lebih rapat, akurasi manufaktur serta mengurangi biaya produksi (Byrne et al., 2003). Penlitian yang dilakukan oleh Yallese menemukan bahwa perbedaan jenis mata pahat keramik yang digunakan memiliki hasil kekasaran permukaan yang berbeda-beda (Yallese et al., 2005). ...
Article
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Kekasaran permukaan merupakan salah satu aspek yang penting dalam proses pemesinan. Kekasaran permukaan mempengaruhi hasil kualitas pada spesimen benda kerja, dan kemampuannya dalam proses perakitan maupun kemampuan benda kerja ketika harus terjadi pergesekan. Kekasaran permukaan dapat dipengaruhi oleh parameter pemotongan yang salah satunya adalah kedalaman pemotongan. Penelitian ini memiliki tujuan untuk mengetahui tentang seberapa besar pengaruh dari kedalaman pemotongan terhadap kekasaran permukaan dalam proses pembubutan serta mengetahui faktor yang mempengaruhi nilai signifikansi dari pengaruh kedalaman pemotongan terhadap kekasaran permukaan. Penelitian dilakukan menggunakan material baja AISI 4140 dan baja AISI 4340 serta menggunakan mata potong berjenis material keramik alumina. Penilitian dilaksanakan menggunakan metode penelitian korelasional dengan melibatkan variabel terikat dan variabel bebas. Metode penelitian ini dipilih untuk melihat korelasi antar variabel bebas dan variabel terikat. Variabel bebas yang digunakan adalah kedalaman potong yang telah ditentukan yaitu sebesar 0.1 mm, 0.2 mm, dan 0,3 mm serta varibel terikat nya adalah kekasaran permukaan. Berdasarkan hasil analisis data maka diperoleh kesimpulan bahwa kedalaman potong memiliki pengaruh yang cukup signifikan terhadap kekasaran permukaan serta besarnya pengaruh kedalaman potong terhadap kekasaran permukaan dapat dipengaruhi oleh kekerasan material.
... Aluminum alloys are widely used in the aviation, automobile, marine, and machinery manufacturing industries [1] due to their excellent properties such as high corrosion resistance, high strength and stiffness to weight ratio, high electrical and heat conductivity and good formability [2]. Although aluminum alloys have good cutting properties because of their low strength, they adhere between tool and chip on the rake face in machining processes [3]. Cutting uids are conventionally used to lessen friction and adhesion at the cutting zone in the machining process; conversely, cutting uids are harmful to the machine operators, ruin the machine tool rails, and pollute the environment. ...
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This paper presents the effect of surface texturing and CNT enriched nanofluid lubrication on the cutting performance of cemented carbide cutting inserts during the turning of Aluminum 7075 alloy. This alloy is widely used in various industries due to its excellent properties such as high corrosion resistance, high strength to weight ratio, and good formability. Although aluminum alloys have good cutting properties because of their low strength, they adhere between tool and chip on the rake face in machining processes, and this results in the low surface finish of machined components. To solve this problem, the use of textured tools under nanofluid lubrication is proposed in this study. Firstly, different shape of textures was fabricated on the rake face, and effective texture was determined using experimental tests. Then, turning tests were carried out using the selected textured tool under CNT enriched nanofluid lubrication to enhance the cutting performance of the machining process. Results showed that the linear microgrooves perpendicular to chip flow direction have better performance in comparison to other shapes of texture. Our findings revealed that the main cutting force, built-up edge, and surface finish were reduced up to 32%, 37%, and 19% using the selected textured tool under CNT enriched nanofluid lubrication compared to dry turning condition.
... FIGURE 1 | Profile of stress distribution in the surface layer of hardened 100Cr6 steel after hard turning and ball burnishing (Byrne et al., 2003). (Yang et al., 2021). ...
Article
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Surface integrity is important factor for components exposed to wear, like cold working tools, which need to possess high hardness combined with high wear resistance. Surface treatments such as grinding, hard turning, and hard turning with slide burnishing have been developed for its improvement. Vancron 40 and Vanadis 8 tool steels, of different chemical composition and different types and amounts of carbides, were now investigated. Heat treatment was carried out in vacuum furnaces with gas quenching to hardness of Vancron 64 ± 1 HRC and of Vanadis 65 ± 1 HRC. 3D topography, optical and scanning electron microscopy, X-ray diffraction and ball-on-disc tribological tests against Al 2 O 3 and 100Cr6 balls as counterparts were used to examine wear and friction. For both steels, the lowest values of dynamic frictions and wear rates against Al 2 O 3 counterbodies were achieved after sequential process of hard turning with slide burnishing with a burnishing force of 180 N. For alumina balls, the increase of wear resistance, achieved after hard turning plus burnishing in comparison to grinding exceeds 50 and 60%, respectively for Vanadis 8 and Vancron 40 steels.
... WEDM is a spark erosion technique that oxidises the machined surface and creates micro-cracks and micro-pores, increasing corrosion [8]. The low density of Mg-alloys favours better machinability in terms of low power consumption, high tool life, and good surface quality [11]. Thus, the conventional milling process must be emphasised for the processing of Mg-alloys-based bone implants. ...
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Surface properties play a significant role in the biocompatibility and biodegradation of Mg-alloy implants which primarily depends on the manufacturing route followed. In the present work, the milling process has been optimized on ZM21 Mg-alloy to obtain the trade-off between the material removal rate (MRR), surface roughness (SR), and degradation rate (DR). Milling parameters vary the amount of force and pressure developed between the tool and work interface, thus, affecting the MRR and SR. The weight loss of machined samples was measured after seven days of immersion in simulated body fluid (SBF) to calculate the DR. L16 orthogonal array was used to study the effect of milling parameters such as tool rotation speed (TRS), feed rate (FR), and depth of cut (DoC). The result showed that the variation in the values of milling parameters significantly influences the surface integrity of Mg-alloy, thus affecting the DR. Chip morphology and surface cracks with scanning electron microscopy (SEM) were evaluated to correlate the influence of milling parameters on the machining performance of ZM21 Mg-alloy. The machined surface of Mg-alloy must be of very low SR and cracks-free to avoid fast corrosion. Therefore, grey relational analysis (GRA) has been employed for multi-optimization to get the best trade-off for higher MRR and lower SR and DR. The optimized setting suggested by GRA for milling of ZM21 Mg alloy is TRS; 2700RPM, FR; 25mm/min, and DoC; 1.25mm.
... The recent progress in the development of cutting tools and improved machine tools' performance made the milling process more flexible and eco-friendly, which can replace the grinding process shortly. Therefore, it is essential to know material behavior and its structural compositions in combination with technological adeptness to take advantage of its potential [1][2][3]. Ti-6Al-4V is one such alloy widely investigated by industrial prospects because of its outstanding combination of a particular high strength-to-weight proportion, exceptional corrosion resistance, and high fracture-resistance characteristics [4]. However, it is recognized as a kind of typical difficult-to-machine material because of its low elastic modulus and thermal conductivity [5]. ...
Article
Due to several inherent properties, Ti-6Al-4V alloy is a kind of typical difficult-to-machine material, especially during high-speed milling processes. The combined action of translation and rotation motion, as well as the short and variable undeformed chip thickness generation, make the milling process different from the turning process. Hence, it is essential to investigate the thermo-mechanical effect on serrated chip formation mechanism during the high-speed milling of Ti-6Al-4V alloy. The present paper investigates numerical methodology (i.e., the combined action of material constitutive with an energy-based ductile failure mechanism) for serrated chip formation in high-speed milling of Ti-6Al-4V alloy. First, a simplified 2D milling model was adopted based on the J-C constitutive equation combined with the energy density-based failure material model. Secondly, the proposed model was corroborated through experimentally obtained results. A good correlation was found between the numerically adopted model and experimentally obtained results. Thirdly, the physical phenomenon of the serrated chip formation and the effect of friction coefficient on shear stress is highlighted and discussed. Finally, the chip back surface's microstructural changes and phase transformation were investigated. The present investigation is beneficial to well understanding the serrated chips formation during high-speed milling of Ti-6Al-4V alloy as well as to optimizing process parameters and maintaining desirable machined surface integrity.
... Grzesik [18] studied the significant influence of surface topography produced by turning, grinding, honing, and isotropic finishing on the friction, fatigue, corrosion, and other functional properties, and highlighted the possibilities of generating precision surfaces with target features by some manufacturing processes. Additionally, Byrne et al. [19] found that dimensional accuracy and roughness could respectively achieve IT5 (Ra 0.1 μm) during the cutting process. Yao et al. [20,21] developed a CMP machining approach with both-sides mode for cylindrical bearing steel and obtained high-accuracy polishing surfaces. ...
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The application of a specific rheological polishing slurry is proposed first for high-efficiency machining of steel materials to achieve high-quality ultraprecision finished surfaces. The rheology of the polishing slurry was explored to show that the non-Newtonian medium with certain parameters of content components exhibits shear-thickening behavior. Then the new high-efficiency nano polishing approach is applied to process spherical surfaces of bearing steel. Several controllable parameters such as shear rheology, abrasive data, rotational speed, and processing time are experimentally investigated in this polishing process. A special finding is that the surface roughness and material removal rate can increase simultaneously when a small abrasive size is applied due to the thickening mechanism during the shearing flow of slurries. Excessive abrasives can decrease surface quality due to the uneven agglomeration of particles scratching the surface. Under optimized conditions, a high-accuracy spherical bearing steel surface with a roughness of 12.6 nm and roundness of 5.3 μm was achieved after a processing time of 2.5 h. Thus, a potential ultraprecision machining method for target materials is obtained in this study.
... Pure Magnesium is extremely susceptible to corrosion, wear, poor hardness and material compliance, which can be enhanced through optimized implant design, mechanical working, surface treatments and optimized compositions [3,4]. The characteristics of machining Mg alloys are low power consumption, best tool life, high surface quality, and small breaking chips [5]. Therefore, it is critical to machine the material with a high material removal rate and low surface roughness [6,7]. ...
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The effects of CNC end-milling process parameters on the machinability of Mg-alloy are discussed in the present investigation. The optimization of the process parameters namely cutting speed, feed rate and depth of cut has been carried out for material removal rate (MRR) and thermal stresses (TS) using Taguchi design of experiment and TOPSIS approach. The milling parameters have shown significant role towards the machining attributes. Analysis of variance (ANOVA) used to evaluate and analyse the relative importance of milling process parameters. For single response optimization, the most significant factor for MRR was feed rate and for thermal stress TS, it was cutting speed. However, feed rate has the greatest impact on preference value (PI), accounting for 71.85% of contribution to multi-response optimization. The recommended milling process parameters have determined to be optimum at cutting speed: 1200 RPM, feed rate: 100 mm/min and depth of cut: 1.25 mm by using the multi-response optimization technique.
... The use of carbide as a cutting tool in the processing of nickel-based heat resistant super alloys (HRSA) was due to their high ratio of hardness, tensile strength, and fracture toughness [123]. It should be noted that the basic research of physical and mechanical, chemical, and operational processing conditions of carbide instruments during turning and milling of various structural materials, including also machining of hard materials, began from the 1970s to the 1980s of the previous century [108,124]. ...
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Nickel-based superalloys are attractive to many industrial sectors (automotive, military, energy, aerospace, etc.). However, their physical properties make them difficult to machining using traditional tools. Therefore, new materials for the machining of Ni-based alloys are required. Ceramic-based composites could act as a tool to replace the current materials. The incentives for this paper are to provide an overview of existing ceramic composites and draw some conclusions that will help in solving the problem of choosing materials for the processing of Ni-based superalloys. Despite the diversity of ceramic composites in this work, the possibility of using the SiAlON ceramic for Ni-based alloy machining is highlighted.
... Due to advancements in coated tool technology, it is possible to accomplish the targeted machining accuracies according to the workpiece material. 16,17 The chip formation takes place over the tools rake face during the turning process. 18,19 Owing to the high coefficient of friction leads to the high-temperature zone near the cutting area, which undesirably affects the surface quality, dimensional integrity and tool life. ...
Article
The drive of this research is to examine the machinability of 100Cr6 bearing steel using advanced C-type cutting tools. Experimental studies investigated the effects of machining variables on the surface quality, chip reduction coefficient and cutting force. Seven advanced coated tools were checked for characterization by micro hardness (VHN), adhesion quality, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS). The experimental trials were planned by Taguchi’s L 18 orthogonal array using a mixed-level design. Two numerical machining variables feed rate and cutting speed, and one categorical machining variable tool type was taken into consideration while a constant depth of cut was kept for all trails. A combined Taguchi-Satisfaction function distance measure approach was implemented for multi-response optimization. The most promising machining parameter setting for minimization of surface roughness, cutting force, and chip reduction coefficient was identified. The most important process parameter was found to be tool-type. Ceramics tools are found to be best trailed by WC coated tools under most of the conditions. Lower tool wear was observed in the CBN tool as compared to others.
... Sub-micron or ultra-fine size grains (0.2-1 μm) are the hardest variant [22]. As a result, they display high hot hardness and tensile strength and can be used for positive and negative rake angle tools-with high cutting angles, allowing for better penetration of a workpiece surface [23]. The smaller grains also have better wear resistance when used in applications such as grinding as self-sharpening is easier. ...
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Polycrystalline diamonds, polycrystalline cubic boron nitrides and tungsten carbides are considered difficult to process due to their superior mechanical (hardness, toughness) and wear properties. This paper aims to review the recent progress in the use of lasers to texture hard and ultra-hard materials to a high and reproducible quality. The effect of wavelength, beam type, pulse duration, fluence, and scanning speed is extensively reviewed, and the resulting laser mechanisms, induced damage, surface integrity, and existing challenges discussed. The cutting performance of different textures in real applications is examined, and the key influence of texture size, texture geometry, area ratio, area density, orientation, and solid lubricants is highlighted. Pulsed laser ablation (PLA) is an established method for surface texturing. Defects include melt debris, unwanted allotropic phase transitions, recast layer, porosity, and cracking, leading to non-uniform mechanical properties and surface roughness in fabricated textures. An evaluation of the main laser parameters indicates that shorter pulse durations (ns—fs), fluences greater than the ablation threshold, and optimised multi-pass scanning speeds can deliver sufficient energy to create textures to the required depth and profile with minimal defects. Surface texturing improves the tribological performance of cutting tools in dry conditions, reducing coefficient of friction (COF), cutting forces, wear, machining temperature, and adhesion. It is evident that cutting conditions (feed speed, workpiece material) have a primary role in the performance of textured tools. The identified gaps in laser surface texturing and texture performance are detailed to provide future trends and research directions in the field.
... With the characteristics of low density, high strength and corrosion resistance, Ti6Al4V alloy are an important material in aerospace, shipbuilding and chemical industries. Nevertheless, these factors lead to poor machinability of Ti6Al4V alloy due to its small elastic modulus, high chemical reaction activity and low thermal conductivity [1]. A lot of heat generated is confined over the tool-chip interface during the machining process [2]. ...
Preprint
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In this work, the main aim is to reduce the adhesion and wear that happened during machining of the Ti6Al4V alloy by employing volcano-like texture on the rake face of coated tool. A combination of experimental and simulative investigation was adopted. DEFORM-3D software with updated Lagrangian formulation was used for numerical simulation, and the thermo-mechanical analysis was performed using Johnson-Cook material model to predict the cutting temperature, cutting forces, chip morphology and tool wear. In cutting experiments, volcano-like textures with different area densities (10%, 20%, 30%) were fabricated by fiber laser on the rake face of cemented carbide tools close to the main cutting edge. Then, these textured tools were deposited with CrAlN coating through cathodic vacuum arc ion plating technique. Experiments in cutting Ti6Al4V alloy were carried out with the textured coated tools and non-textured coated tool under dry and wet cutting conditions. Then, the chip morphology, chip size and tool wear were investigated. The results showed that textured coated tools were superior to conventional tool. Especially in wet cutting, compared with those of non-textured coated tool, the adhesion area and the chip curling radius of the coated tool with texture area density of 20% (VCT2) were reduced by 31.2% and 49.7%, respectively. Therefore, VCT2 tool showed a better cutting performance. Finally, the mechanisms of textured coated tools under dry and wet cutting conditions were proposed.
... Aluminum alloy has been widely used in aerospace industries, automobile manufacturing owing to its advantages in good welding performance and excellent corrosion resistance. However, the drawbacks of low melting point and high ductility tend to bring out a limitation in tool machinability, which make chips more likely to adhere on the tool surface, lowering tool resistance and the quality of products [1,2]. Therefore, in order to alleviate the defects, a variety of approaches in enhancement of cutting tools in the recent years have been a 2 pplied to reduce friction and wear between the tool and chip, such as cutting fluid [3], PVD coatings [4], surface texturing [5,6]. ...
Preprint
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When cutting aluminum alloy with WC/Co coated tools, severe adhesion and wear exist on the tool-chip contact interface, which are the major factors leading to failure of cutting tools. To address this problem and extend service life of cutting tools, this study introduced surface textures into coated tools, trying to integrate the anti-friction properties of micro-textures with the wear resistance properties of coatings to improve tribological characteristics of tools surface. Firstly, hybrid texture consisting of micro-scale pits and micro-scale grooves were fabricated on the rake surface close to the main cutting edge of carbide tools by picosecond laser. Subsequently, the textured tools were deposited with hard-coatings CrAlN via physical vapor deposition (PVD) technology and the hybrid textured CrAlN coated tool (MPG-T) was obtained eventually. Other texture combinations included micro-scale pits and micro-scale grooves distributed in the tool-chip contact zone. Wet cutting experiments were carried out on these prepared tools. Results showed that compared with micro-scale pitted coated tool (MP-T), micro-scale grooved (MG-T) and conventional coated tool (CCT), MPG-T tool performed better in cutting forces, friction coefficient, tool adhesion and wear on the rake face and the flank face, chip morphology. Moreover, the corresponding synergistic mechanisms of hybrid texture and coatings were proposed. It’s suggested that applying the results to actual industries can enhance the cutting performance of coated tools in machining of aluminum alloy.
... The use as a cutting tool of carbide when processing nickel-based HRSA due to their high ratio of hardness, tensile strength and fracture toughness [25]. ...
Preprint
Nickel-based superalloys are attractive to many industrial sectors (automotive, military, energy, aerospace etc.). However, their physical properties make them difficult to machining using traditional tools. Therefore, the new materials for the machining of Ni-based alloys are required. Ceramic-based composites could act as a tool to replace the current materials. The incentives for this paper are to provide an overview of existing ceramic composites and draw some conclusions that will help in solving the problem of choosing materials for processing of Ni-based superalloys. Despite the diversity of ceramic composites in this work the focus was on the SiAlON ceramic.
Preprint
Full-text available
This paper presents wet machining of wrought aluminium alloys with textured and non-textured tools. To improve the machining performance, textures were produced on rake face of uncoated cemented carbide by using femtosecond laser machining. Experiments were conducted on a computer numerical controlled lathe with each textured tool and then compared to conventional cutting tool. To evaluate the cutting performance of tested tools, the following criteria were considered: cutting forces evolution, rake face wear, flank face wear and chip formation. A significant decrease of flank wear about 90% is observed with textured tools with nanometric Laser Induced Periodical Surface Structures (LIPSS) and of 80% with double-scale structure (LIPSS + Dimples). Double-scale structured tool presents a lower cutting force in comparison with conventional cutting tool. An increase of shear angle value with tool textured with micrometric structure (Lines) is observed. A lower height of adhesion on rake face of the tool with LIPSS compared to other tested tools is found too. These results constitute another step in the purpose to design a new generation of tools for precision turning of aluminium alloys.
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In this study, the effect of cutting fluid on tool wear in finished surface formation area was investigated when turning alloy 304 with a TiN coated carbide tool under different lubricant conditions and the transition of surface roughness caused by tool wear was investigated. In the case of water-soluble cutting fluid, the higher concentration emulsion caused a smaller wear width VB and larger VB ’”. In the case of oily cutting fluid, the lower co-efficient of friction oil caused a smaller wear width VB and larger VB ’”. In both cases of water soluble and oily cutting fluid, the cutting fluid of lower coefficient of friction caused a larger wear width VB in milling at the feed rate of around tool edge roundness. This tendency was consistent with the wear width VB ” and VB ’” in turning. In both cases of water soluble and oily cutting fluid, the cutting fluid of lower coefficient of friction caused a larger cutting force volatility. The feed marks were more irregular in lower coefficient cutting fluids.
Conference Paper
This work investigates the effect of the influencing machining parameters and optimum input in the machinability characteristics of AZ31 magnesium alloy during face milling operation. The input parameters selected are depth of cut, feed rate and cutting speed. The output responses measured are surface roughness and tool nose radius deviation. Taguchi L9 orthogonal array was designed for the three input parameters and three level design. Based on Taguchi's S/N ratio, the ideal input factors were obtained for minimum surface roughness and tool nose radius deviation. The optimal combination of process parameters were determined using grey relational grading in order to obtain improved surface quality and reduced tool nose deviation. Confirmation studies showed that the optimum combination of input parameters resulted in considerable improvements in output quality. Grey relational Taguchi analysis is an excellent approach for determining feasible input parameters for a desired surface quality of AZ31 Alloy under dry conditions, according to the results of the confirmation experiment.
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Higher temperature and lower thermal conductivity between the tool-chip contact face easily result in adhesion and wear on the tool surface which negatively affects the tool life and the machining quality of the workpiece in the machining Ti-6Al-4V alloy process. To address these problems, the investigation, combining the simulation and experiment, introduced the volcano-like textures of different diameters with excellent anti-adhesion performance on the tool rake face. DEFORM-3D software with updated Lagrangian formulation was used for numerical simulation, and the thermo-mechanical analysis was performed using the Johnson-Cook material model to predict the cutting forces, cutting temperature and tool wear. In cutting experiments, volcano-like textures (VT) with different diameters were fabricated by fiber laser on the rake face of cemented carbide tools close to the main cutting edge. Experiments in cutting Ti-6Al-4V alloy were carried out with the textured tools and non-textured tool under rough machining, semi-finishing and finishing conditions. Then, cutting force, cutting temperature and tool wear were investigated. The results showed that textured tools generally perform better than non-textured tools. The cutting force of VT1 was reduced by 31.2% and 50%, respectively, compared with the non-textured tool under Semi-finishing and finishing conditions. With the refinement of machining, the cutting performance of the textured tools is improved, and the service life of the tool is extended. Therefore, the investigation can provide a basis for the surface texture design and optimization of the carbide tool.
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Due to high temperature strength (hot strength), excellent corrosion resistance and high strength-to-weight ratio, Ti-6Al-4V alloy is considered as a potential candidate for extensive applications in aerospace and biomedical engineering. But, alloy’s low thermal conductivity and extreme chemical affinity (towards tool substrate and coating materials) often cause an aggressive cutting environment with a tremendous rise in cutting zone temperature, premature tool wear, and disappointing surface integrity during conventional machining processes. In order to achieve desired machining yield without opting for any coolant, selection of proper cutting tool (based on their geometry and properties) is indeed vital. Thus, the present work examined the performance of MTCVD-TiCN-Al2O3-TiOCN multi-layer coated carbide and PVD TiN single layer coated composite ceramic (Al2O3/TiCN) tool inserts during dry machining of Ti-6Al-4V. Higher friction coefficient (of the coating system) was revealed for the ceramic tool which caused substantial temperature rise at tool-tip. On the other hand, carbide insert imparted lower cutting force (beyond v = 80 m/min) than ceramic insert due to its better thermo-chemical stability. Coating peel-off and tool flaking were witnessed for ceramic insert due to its thermal instability at higher cutting speeds; while carbide tool was mainly affected by material adhesion, abrasion, and chip fusion (adhesion of broken chip-fragments over tool surface due to high pressure and temperature). It was experienced that induced cutting heat significantly affected chip morphology under a dry cutting environment. Up to v = 130 m/min, ceramic tool exhibited lower flank wear than carbide tool.
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The paper identifies the meso scale (10 µ m to few millimeters) component size that can be manufactured by using both lithography and non-lithography based approaches. Non-lithography based meso/micro manufacturing is gaining popularity to make micro 3D artifacts with various engineering materials. Being in the nascent stage, this technology looks promising for future micro manufacturing trends. Currently, lithography based micro manufacturing techniques are mature, and used for mass production of 2D, 2.5D features and products extending to 3D micro parts in some cases. In this paper, both the techniques at state-of-the-art level for meso/micro scale are explained first. The comparison is arranged based on examples and a criterion is set in terms of achievable accuracy, production rate, cost, size and form of artifacts and materials used. The analysis revealed a third combined approach where a mix of both techniques can work together for meso scale products. Critical issues affecting both the manufacturing approaches, to advance in terms of accuracy, process physics, materials, machines and product design are discussed. Process effectiveness guideline with respect to the component scale, materials, achievable tolerances, production rates and application is emerged, as a result of this exercise.
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Vanadis 10 SuperClean is a high vanadium alloyed powder metallurgy tool steel offering a unique combination of an excellent abrasive wear resistance in combination with a good chipping resistance. Studies in the literature on the machinability of this powder metallurgical steel are limited. In addition, more studies are needed to examine the relationship between cutting tool vibration amplitude and cutting temperature, surface roughness, and cutting tool wear. Surface roughness is one of the most important parameters for the final product quality and cutting tool wear is a performance output that directly affects the cost. In this study, the effects of the eco‐friendly (100% biodegradable plant‐based) Minimum Quantity Lubrication (MQL) system on the cutting temperature, cutting tool vibration amplitude, tool wear, average surface roughness, and tool life in the turning of Vanadis 10 steel (50 HRC) used in the automotive industry were investigated. In the experiments, TiCN/Al2O3/TiN‐coated cemented carbide tools were used. Experimental results showed that, compared to Dry machining, MQL produced remarkable improvements in terms of cutting temperature, cutting tool vibration amplitude, tool wear, and surface roughness. In addition, the Taguchi experimental design, ANOVA, and linear and quadratic regression analyses were applied to the experimental data. The statistical analysis found the most effective parameter on average surface roughness to be the cutting environment (86.31%). It was determined that the cutting speed was the most effective on vibration amplitude and tool wear (46.22% and 32.41%). The correlation coefficients for the linear and quadratic regression analysis were 0.9 and 0.95, respectively. This article is protected by copyright. All rights reserved.
Article
The study of residual stresses induced during machining is of considerable importance due to their effect on fatigue life of machined components. The metallurgical changes occurred due to thermo-mechanical phenomenon in cutting process affects the distribution of residual stress in machined components. Ultrasonic vibration assisted turning (UVAT) is effective machining process for low thermal conductivity materials like Ti6Al4V alloy and improves the surface characteristics by reducing cutting force and cutting temperature. In this paper, experimental and finite element (FE) studies are conducted to study the circumferential and axial residual stress distribution in UVAT of Ti6Al4V alloy. FE model is developed to study the effect of vibrating parameter (ultrasonic power intensity) and cutting parameters (cutting speed, feed rate, and depth of cut) on the residual stress profiles of machined surface. The FE simulation results of cutting force and cutting temperature are validated with experimental results. The circumferential and axial surface residual stresses obtained from FE simulation are also compared with experimental results using X-ray diffraction method. The effect of thermo-mechanical loading on residual stress distribution is analyzed with respect to force components (cutting force and feed force) and cutting temperature. Finally, the effect of each cutting parameter on subsurface layer of machined component is analyzed.
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The paper presents the development of layered composite material, which includes a carbide substrate, a ceramic layer and a nano-scale multilayered coating. Each element of a layered tool material fulfills individual functions. The carbide layer provides raised toughness and strength of tool material, the ceramic layer provides resistance of a tool material to oxidation, corrosion and high-temperature weakening at elevated temperatures, the nano-scale multilayered coating decreases thermal-mechanical stresses on the rake face of the tool and eliminates superficial defects of the ceramic.
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Tool edge preparation is preferred in metal machining processes, which is strongly related to process reliability, tool cutting performance and surface integrity. Therefore, proper edge micro-geometry optimization and selection could be taken as a feasible approach to improve tool cutting performance, slow tool wear and ameliorate surface integrity. This review paper addresses the recent development in tool cutting performance (including cutting forces, temperature and tool wear), surface integrity (including surface geometrical characteristics, metallurgical behaviour and mechanical property) in the metal cutting processes considering the cutting insert with various designed micro-geometry. In addition, the prospective research issue and tool technology development in this field is also presented.
Chapter
An ultrasonic vibration-assisted turning tool system is studied using the Taguchi robust design method. An experiment is conducted to measure surface accuracy for ultrasonic-vibration assisted turning of AISI 1045 steel, establishing the following optimal parameters: frequency of 20 kHz, voltage of 75 V, cutting speed of 150 m/min, and feed rate of 0.05 mm/rev. The differences between surface roughness with and without ultrasonic vibration-assisted turning are examined. It shown that surface roughness is lower with ultrasonic vibration-assisted machining than without.KeywordsUltrasonic vibration-assisted turning tool systemUltrasonic vibration-assisted machiningTaguchi robust design method
Chapter
Application of novel engineering materials and advanced technology has been increasing tremendously in many industrial needs. Among those challenging manufacturing methods, conventional machining is one of the proven and prominent processes. Although, fast growing and newer developments in modern manufacturing industries are posses the tough fight on current requirements. On the other hand, continuously developing new technology and trends of advanced machining methods on modern technology for industries and academicians are not well established in the open web sources. Hence, this chapter will be eye opener for both industrialists and researchers about the various novel techniques, trends, and developments in conventional machining.
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Sustainatableble development assumes the meeting of humanity’s everyday needs and development goals while sustaining the ability of nature to provide the resources and ecosystem on which the economy and society depend. It means that an increase of economic benefit cannot be a single optimization problem anymore, instead, the multi-criteria approach is used with the accent on ecology and social welfare. However, it is not easy to harmonize these aims with machining, which is a well known industrial pollutant. On the other hand, new industrial paradigms such as Industry 4.0/5.0, are driving toward the smart concept that collects data from the manufacturing process and optimizes it in accordance with productivity and/or ecologic aims. In this research, the smart concept is used through the development of the multi-criteria decision support system for the selection of the optimal machining process in terms of sustainability. In the case of milling process selection, it has been demonstrated that green machining, without a multi-criteria approach, will always remain an interesting research option, but not a replacement for conventional machining. However, when applying realistic ecological and social criteria, green machining becomes a first choice imperative. The multi-criteria decision-making PROMETHEE method is used for the comparison and ranking, and validation of results is made through criteria weights sensitivity analysis. The contribution of this concept is that it could also be applied to other manufacturing processes.
Article
Traditional dry machining of ‘difficult-to-cut’ titanium alloy Ti-6Al-4V has always been a challenging task. This is due to its lower thermal conductivity, strong work-hardening tendency, and extreme chemical reactivity. These causes adverse machining effects including premature tool failure, evolution of huge cutting temperature, machine tool chatter, and disappointing surface integrity of the machined work part. Selection of compatible tool material, appropriate tool geometric parameters, and adequate control of cutting parameters are of vital importance towards achieving satisfactory machining yield. In this context, performances of MT-CVD TiCN/Al2O3 bi-layered coated carbide, PVD TiN/TiCN/TiN multi-layered coated cermet, and CVD TiCN/Al2O3 bi-layered coated SiAlON inserts are studied during dry machining of Ti-6Al-4V within cutting speed range 50-130 m/min; at constant feed ~ 0.1 mm/rev, and depth-of-cut ~ 0.35 mm. Approximate tool-tip temperature (maximum value) attained during operation, magnitude of tangential cutting force, and width of flank wear progression are measured. Detailed study on wear morphology of worn-out inserts, chip’s micro/ macro morphology, and surface integrity of the machined product are carried out. It is experienced that cermet tool performs better than remaining two counterparts in purview of lower tool-tip temperature, reduced flank wear, and better machined surface integrity.
Chapter
The primary goal of machining process modeling is to improve machining performance prediction. The most studied predictive methods are analytical, numerical, and artificial intelligence (AI) modeling, which are commonly validated with experimental data (Altintas in Manufacturing automation: metal cutting mechanics, machine tool vibrations, and CNC design. Cambridge University Press, Cambridge, 2012; Grzesik in Advanced machining processes of metallic materials: theory, modelling and applications, Elsevier, 2017). There are also many studies attempt to develop hybrid modeling techniques to integrate the benefits of the different approaches.
Chapter
We are now living in the new era of the fourth industrial revolution (Industry 4.0). The important sign of this era is the fast developing of 3C (computation, communication, control) and AI (artificial intelligence) technologies, as well as their pervasive applications uses in the manufacturing industry.
Thesis
La fonctionnalisation des surfaces des pièces plastiques permet de répondre à des cahiers des charges innovants sans utilisation de solvants ou de traitements chimiques. Une large gamme de propriétés est réalisable allant des propriétés optiques à des améliorations techniques concernant la mouillabilité, la gestion des frottements ou l’adhésion. La solution envisagée pour répondre à une production de masse à coût maîtrisé est la réplication par injection plastique d’une empreinte de moule microtexturée. Cependant, le principal challenge est le changement d’échelle qui existe entre une pièce de dimension dite « macro » (quelques cm3 et plus) et des microtextures de quelques dizaines de micromètres. Cette méthode de fabrication impose de contrôler la réplication des textures durant l’injection et donc de comprendre et maitriser le comportement de la matière durant sa mise en œuvre. Afin de répondre à cette problématique, un outillage de visualisation instrumenté, comportant deux empreintes de formes différentes, permettant une analyse in operando des paramètres de mise en œuvre a été conçu et développé. Une méthodologie de réglage originale a été utilisée et a permis de mettre en évidence qu’à partir d’une valeur seuil de vitesse d’injection, les paramètres température outillage et pression de maintien ont un rôle secondaire dans la réplication de microtextures de 30 µm de profondeur. En effet, la viscosité in opérando du polymère amorphe injecté, diminue fortement lors de l’augmentation de la vitesse de cisaillement. La prédiction de remplissage d’une microcavité en simulation rhéologique nécessite une analyse poussée des conditions limites du calcul. Une méthodologie d’ingénierie inverse, couplée à l’utilisation des mesures des vitesses d’écoulement effectuées avec le dispositif de visualisation développé, a permis la mise en évidence de l’importance de la détermination du coefficient d’échange thermique, htc. Une bonne corrélation, des hauteurs de remplissage d’une microrainure (de 370 µm de large et un rapport de forme de 3,6), entre les simulations numériques avec le logiciel Moldflow et les expérimentations, a été obtenue avec une valeur htc = 30 000 W.m-2.K-1 dans la phase de remplissage, affectée aux mailles de la microcavité.
Chapter
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The ability of a material to produce acceptable outcomes with respect to the tool wear, Metal Removal Rate (MRR), surface integrity, and power consumption when machined is called machinability. Machinability is often a qualitative than a quantitative assessment of the process. Evaluating machinability is considered important especially for materials that are challenging to machine [1]. Machinability factors or indicators are tool wear, MRR, dimensional accuracy, surface integrity, and power or energy consumption, and so on. [2]. Considering the earlier research studies on machining, there is high percentage of products manufactured using machining. It is highly advantageous to find ways for successful machining and processing of materials [2]. Some of the common problems encountered in machining are work surface deterioration and irregularity, rapid tool wear, lower MRR, and out-of-tolerance parts. This chapter is an attempt to identify and plug the research gaps by analyzing the existing literature and future requirements necessary for the growth and sustainability of the machinability research related to the selected materials i.e., Selective Laser Melted (SLM) titanium Ti6Al4V, and Super Austenitic Stainless Steel (SASS).
Article
This paper describes a two-step (additive + subtractive) hybrid manufacturing approach for a laser powder bed fusion 316L stainless steel constrained-motion cutting force dynamometer (PBF CMD). The purpose of the research is to produce a near-net shape metallic dynamometer via additive manufacturing (AM) with post-processing by machining and wire-EDM to achieve the desired surface finish and performance. A cutting force comparison is presented with a commercially-available dynamometer.
Chapter
Gun drilling is a process used to produce small-diameter holes at a high depth-to-diameter ratio, beyond what is capable using conventional tooling, especially for difficult-to-machine superalloys such as titanium, Inconel, Monel, etc. Presently, it often incapacitates by low productivity, rapid tool wear, frequent tool breakages, and straightness deviation. This chapter addresses the challenges of tackling these problems by employing game-changing approaches and technologies. Existing research in the advanced gun drilling technologies tends to focus on the choice of drilling parameters. There is little literature available for the cutting mechanics and workpiece deformation, tool geometry, wear and failure mechanism, especially in the deep hole drilling process for superalloys. Consequently, the aim of this chapter is to provide an overview of how the game-changing approaches and technologies for advanced gun drilling can be explored and utilized.
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A practical explicit 3D finite element analysis model has been developed and implemented to analyze turning hardened AISI 52100 steels using a PCBN cutting tool. The finite element analysis incorporated the thermo-elastic-plastic properties of the work material in machining. An improved,friction model has been proposed to characterize tool-chip interaction with the friction coefficient and shear flow stresses determined by force calibration and material tests, respectively. A geometric model has been established to simulate a 3D turning. FEA Model predictions have reasonable accuracy for chip geometry, forces, residual stresses, and cutting temperatures. FEA model sensitivity analysis indicates that the prediction is consistent using a suitable magnitude of material failure strain for chip separation, the simulation gives reasonable results using the experimentally determined material properties, the proposed friction model is valid and the sticking region on the tool-chip interface is a dominant factor of model predictions.
Article
Although active magnetic guides (AMG) can obtain an infinite static stiffness and high damping using sophisticated multi-degree-of-freedom control, still a non-negligible dynamic compliance is inherent. This is especially true when high controller gains cannot be achieved due to spill over effects. Several approaches are known to overcome this problem, repetitive control and frequency estimation being two of them. Both have drawbacks concerning flexibility, robustness and compensation quality. This paper proposes a smart frequency identification and compensation scheduling algorithm along with tracking compensation oscillators to cancel arbitrary periodic disturbances. The proposed algorithm has been implemented and tested on an AMG. The introduced smartness provides a very robust behavior and leads to an infinite steady state stiffness.
Article
Kurzfassung Am Fraunhofer IPT wurde eine hochdynamische Drehmaschine zur Unrundbearbeitung entwickelt und aufgebaut. Mit ihr ist das Herstellen nicht-rotationssymmetrischer Bauteile möglich, wie sie beispielsweise im Motorenbau in Form unrund gedrehter Kolben vorkommen.
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Kurzfassung Die Verfahren Hartdrehen und Schleifen stehen zunehmend in Konkurrenz zueinander, da Schneidstoff- aber auch Verfahrensentwicklungen für beide Fertigungsverfahren die Arbeitsgebiete erweitern konnten. Neben der flexiblen Schleifbearbeitung von Futterteilen durch das Längsschleifen bietet sich durch neue Maschinenkonzepte die kombinierte Bearbeitung durch Hartdrehen und Schleifen in einer Aufspannung an.
Chapter
Until recently, detection of chipping and other small-scale breakages in the milling process has presented formidable difficulties because of limitations in the traditional Fourier signal processing techniques. This paper explores the use of the Discrete Wavelet Transform (DWT) in detecting small tooth chipping in the milling process. We demonstrate that the DWT surpasses the FFT in recognizing the subtle, time-localized changes in the cutting force caused by chipping. The DWT uses wavelet functions which are localized in time and in frequency, in contrast to the sines and cosines of Fourier analysis which are localized in frequency but spread throughout the time spectrum. Like the FFT, the it can also be implemented using fast algorithms based on standard matrix methods.
Article
Knowledge of the machining parameters for titanium aluminides of the type gamma-TiAl is essential for the acceptance and application of this new heat-resistant light-weight material for high performance components in automobile and aircraft engines. This work evaluates drilling, turning, sawing, milling, electroerosion, grinding, and high-pressure water-jetting of primary castings. The results indicate that there is a potential for each machining process, but a high quality of surface finish can only be achieved by some of the processes.
Article
Steels with additions of lead, bismuth and tellurium comprise the high sulphur free cutting steels but also Al-killed grades such as carbon steels, cold heading and alloyed steels. Saarstahl is a major producer of these steels. Equipment for slag retention, for lead, bismuth and tellurium injection into the ladle and for EMF-oxygen measurements are important tools for the production of these steels. Collection of all lead, bismuth, tellurium and selenium emissions is an essential prerequisite. The effect of the metallurgy on machinability is discussed. Further, the roles of lead, bismuth, tellurium, selenium and tin are explained.
Article
In the recent years, an upcoming interest of the automotive industry can be noticed in the use of light metals as construction materials. Magnesium as one of the lightest metals for mass production of automotive components offers a great potential for weight reduction. Still, for a safe and economic machining of magnesium parts, there are some problems to solve. Especially in dry machining and at high cutting speeds, adhesion between tool and workpiece material leads to build-up edges. Experiments show, that tools, which are polycrystalline diamond coated (DP) by chemical vapor deposition (CVD), have a superior cutting performance. Excellent results regarding the workpiece surface roughness can be achieved when using new smooth CVD-DP coated tools.
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This paper illustrates the essential safety aspects of tools rotating at high speed. Based on a load analysis, the various types of tool failure are represented and are evaluated with respect to their hazard potential. Analytical calculation approaches and numerical methods are discussed as means for a safe design of such tools. On the basis of experimental results, concrete design aids for the tool design engineer are derived.
Article
The hard turning and grinding processes are increasingly finding themselves in competition with each other since cutting material - But also technique developments - Have been able to expand the fields of application for both production processes. Besides the flexible grind machining of clamping chuck parts by means of traverse grinding, new machine concepts offer the possibility of combined machining using hard turning and grinding together.
Article
Kurzfassung Das Potenzial weiterer Produktivitätssteigerungen für Werkzeugmaschinen durch die Verbesserung einzelner Parameter, wie Beschleunigung oder Geschwindigkeit der Antriebe, ist begrenzt. Nur durch die Anwendung von neuen Struktur- und Topologieoptimierungsmethoden, neuer kinematischer Konzepte und der konsequenten Nutzung moderner Berechnungs- und Simulationstechniken ist es möglich, die Produktivität und Zuverlässigkeit weiter zu steigern. Neben innovativer Technologien für Komponenten der Werkzeugmaschine muss auch die gestiegene Rechenleistung moderner Steuerungen konsequent genutzt werden, um zusätzliche Regelungs- und Überwachungsaufgaben zu integrieren.
Article
High temperatures at the tool/chip interface due to high cutting speeds and harder material in machining have created severe economical and technical problems. The tool-life and surface finish are affected by the interface temperature. In the present work, the spray cooling method which has a superior heat removal capacity than flood cooling has been applied to reduce temperatures at the tool/chip interface and in the chip. An air assisted nozzle was used to supply the spray onto the tool/chip interface when machining a stainless-steel 416 bar in turning. The spray cooling cut compared with dry cut shows numerous advantages: smoother surface finish, better chip breakability, and longer tool-life. The main reason for these benefits is shown as resulting from the stabilized lower temperature at the tool/chip interface.
Article
Cutting fluids are essential in metal cutting to increase the tool life and reduce the finished surface roughness. Due to increasingly strict legislation aiming at controlling environmental pollution, however, the cost of using cutting fluids is rising. Therefore, it is necessary to reduce the amounts of the cutting fluid used. In this study, we propose a method in which cooling and lubrication can be achieved using extremely small amounts of cutting fluids. The effect of the proposed method is investigated through experiment.
Article
In order to advance understanding of the burr formation process, a series of finite element models are introduced. First, a finite element model of the burr formation of two-dimensional orthogonal cutting is introduced and validated with experimental observations. A detailed and thorough examination of the drilling burr forming process is undertaken. This information is then used in the construction of an analytical model and, leads to development of a three-dimensional finite element model of drilling burr formation. Using the model as a template, related burr formation problems that have not been physically examined can be simulated and the results used to control process planning resulting in the reduction of burr formation. We highlight this process by discussing current areas of research at the University of California in collaboration with the Consortium on Deburring and Edge Finishing (CODEF).
Article
Dynamic plastic behavior of materials is influenced by internally generated temperature gradients. These gradients are a function of thermophysical properties as well as strain rate and shear strength. Criteria are presented for the prediction of catastrophic shear in materials. Catastrophic shear occurs when the local rate of change of temperature has a negative effect on strength which is equal to or greater than the positive effect of strain-hardening. Catastrophic slip is an influential deformation mechanism during high-speed machining and ballistic impact. Structural failure may occur during dynamic loading of components which are designed without regard to the specific sensitivity of certain materials to catastrophic shear.
Article
Simulation technology has been used in the gold industry for over two decades. It is firmly established in the engineering and design field, and is most commonly used to produce steady-state mass and energy balances. Process simulation involves building a model either of a single area of the gold recovery plant or of the whole operation, usually using specialized software tools. This model responds to given inputs much as the operation would be expected to behave in the real world. Using it, the engineer can experiment testing various ideas and options to get an understanding of how the actual operation would behave in certain situations. It is used to size new plant and equipment, trial new equipment or control strategies, and to see how the system will perform at different loads or ore blends. By simulating the process plant closely, the process engineer can remove a large amount of uncertainty from engineering decisions. Modeling for decision support is therefore becoming a project requirement in the gold industry.
Article
Knowledge of the machining parameters for titanium aluminides of the type γ-TiAl is essential for the acceptance and application of this new heat-resistant light-weight material for high performance components in automobile and aircraft engines. This work evaluates drilling, turning, sawing, milling, electroerosion, grinding, and high-pressure water-jetting of primary castings. The results indicate that there is a potential for each machining process, but a high quality of surface finish can only be achieved by some of the processes.
Article
In an attempt to overcome the deficiencies of existing theories of cutting, an experimental technique was developed for observing the cutting process during slow orthogonal cutting of mild steel. An attempt to find consistency between the observations and the ideal theory of plasticity failed. Consequently the theory was extended by including the effect of work- hardening and, in spite of the laborious nature of the analysis, it appeared that consistency had been regained. This led to a novel and physically consistent picture of the cutting process, which was taking place during the tests.
Article
The mechanics of chip segmentation, during machining of a cold rolled steel has been investigated from a phenomenological point of view using a high speed movie camera and an explosive quick stop device. The latter was used for obtaining chip root samples at various stages of segmentation for subsequent examination in the optical and scanning electron microscope. The chip segmentation process is found is arise as a result of instabilities in the cutting process and is further augmented by the dynamic response of part of the machine tool structure. This process involves a slow forward movement of the plastic boundary in the primary shear zone, forming a ramp on the free surface of the chip, followed by a rapid return of the plastic boundary back toward the tool, forming a step on the chip segment as a result of partial fracture at the free surface. This process is characterized by large strains, low shear angles that oscillate cyclically, and stick-slip friction on the rake face. The instability in the cutting process is proposed to be due to the negative stress-strain characteristics of certain materials at large strains, involving void formation around second-phase particles, their propagation into microcracks in the primary shear zone and the coalescence of these cracks leading to partial fracture.
Article
The process of turn-milling was a subject of intensive research in the late 1980s, which was followed by a number of practical applications. However, this process has not been investigated as extensively as other conventional cutting processes (turning). The main limitations preventing wider use have been the kinematics (smaller shape elements) and the dynamic instability. This paper presents guidelines showing how to avoid dynamic instability by using optimum entry—exit conditions which can be achieved through a proper set-up of the process parameters. As a result, a decision diagram is proposed. The paper also presents the results of comparison with turning, showing that, at the same productivity, turn-milling enables better surface roughness and is much more suitable for high-speed cutting (HSC) machining than turning, where the centrifugal force restrains the process.
Article
The description of cutting processes using FEM based simulations offers a lot of advantages compared to analytical models. In this paper the simulation of high speed orthogonal turning (HSC) of AISI 1045 steel using the commercial software DEFORM 2D is described. Additionally high speed turning experiments are conducted and analyzed. It is investigated whether the comparison of simulated and experimental results is permissible. Therefore, the input parameters of the simulation are evaluated. It is shown that for the modelling of the cutting process by FEM simulation several assumptions regarding the material properties have to be made. Despite these limitations the comparison of simulation and experiment shows good agreement. To enable this comparison a simulation routine for potentially endless continuous cutting simulations is presented.
Article
A cost minimization procedure for the drilling operation was developed based on a Drilling Burr Control Chart and Bayesian statistics. The cost of a drilling operation consists of the cost of drilling (hole making) and the cost of deburring. The drilling burr control chart is a tool that is based on experimental data and shows a specific distribution of burr types on the space defined by process variables developed for the chart. Bayesian statistics were applied to predict the probability of formation of certain types of burrs. Probabilistic burr type prediction is more feasible and, potentially, more effective in a mass production environment because drilling burr formation has considerable variation at certain ranges of process parameters. The procedure developed in this study can be effectively used to estimate and minimize the total cost of a drilling operation without sacrificing the productivity and hole quality.
Article
Machining of composite materials is difficult to carry out due to the anisotropic and non-homogeneous structure of composites and to the high abrasiveness of their reinforcing constituents. This typically results in damage being introduced into the workpiece and in very rapid wear development in the cutting tool. Conventional machining processes such as turning, drilling or milling can be applied to composite materials, provided proper tool design and operating conditions are adopted. An overview of the various issues involved in the conventional machining of the main types of composite materials is presented in this paper.
Article
The fact that the design of equipment and machines can no longer be separated from the concept of human safety has led to the definition of criteria which is linked to the equipment's exploitation and must be taken into account during their design. Firstly, this paper looks at the problem of integrating safety into design as early as possible, reviews the state of the art and examines the research carried out on this subject to date. The area of application of our research is then presented. The production system analyzed is an offset printing line. We propose a system model by defining the working situation and the elements characterizing this situation as well as the concepts relative to these elements. The model is presented and the method is illustrated by the results of an experiment carried out in the design department of an industrial partner. The ultimate aim is to provide designers with the means of integrating information about the potential work context into the equipment's design process from the onset.
Article
Point grinding and electrical discharge machining (EDM) are detailed on high speed machining centres. A Taguchi design was employed to evaluate operating parameters when point grinding (plunge) nickel-based superalloys with 15 mm diameter electroplated diamond and cubic boron nitride (CBN) wheels using speeds up to 60,000 rpm provided by an ancillary spindle. Material removal of up to 120 cm3 and roughness values down to 1.2 μm Ra were obtained when machining Inconel 718. A retrofit EDM servo head unit was designed for die sinking and workpiece surface texturing. When texturing 2D and 3D workpieces, surfaces were produced with an Ra of 1-10 μm, depending on operating parameters.
Article
In 1995 CIRP STC “Cutting” started a working group “Modelling of Machining Operations” with the aim of stimulating the development of models capable of predicting quantitatively the performance of metal cutting operations which will be better adapted to the needs of the metal cutting industry in the future. This paper has the character of a progress report. It presents the aims of the working group and the results obtained up to now. The aim is not to review extensively what has been done in the past. It is basically a critical assessment of the present state-of-the-art of the wide and complex field of modelling and simulation of metal cutting operations based on information obtained from the members of the working group, from consultation in industry, study of relevant literature and discussions at meetings of the working group whit the aim to stimulate and pilot future developments. For this purpose much attention is given to a discussion of desirable and possible future developments and planned new activities.
Article
This paper describes an intelligent data base system which performs an intelligent task like a skilled operator. The system consists of a grinding data base, a grinding rule base, a learning module and a reasoning module. The learning module extracts relationships between set-up parameters and results from grinding examples stored in the grinding data base using genetic algorithms. These relationships are expressed in the form of a fuzzy production rule and stored in the grinding rule base. The reasoning module provides suitable dressing and grinding parameters using those rules. A computer simulation is performed to confirm the effectiveness of the proposed system.
Article
The high speed milling process places completely new demands on the dynamic behaviour of machining centres. This paper describes the causes of vibrations in high speed milling. It includes a quantification of vibrations due to imbalances, accelerations and cutting forces. The effects on the quality of workpieces are simulated by a dynamic model of the machine. Therefore, also the mechanical structure and the axis control system are taken into account. The results of the simulation are verified by some cutting examinations. To improve the quality of workpieces suggestions are made to avoid vibrations or to compensate the effects on vibrations due to imbalance.
Article
The historical progress of machining accuracy is plotted and its probable further development is shown by extrapolation, both in the micro-technology and nano-technology regions. Single point “mirror machining” of soft metals and the ultraprecision polishing of hard and brittle materials are discussed. The concept of “atomic-bit” chip removal first by elastic emission machining, etc. is introduced. Photolithography for LSI wafer processing and electron beam processing/lithography for IC photo masks are then described. Ion beam sputtering, a promising atomic-bit machining process for the near future, is also described. Finally, analysis is made of the problems to be addressed and solved in achieving true accuracies of 0.1 μm - 0.05 μm for electronic, optical and mechanical workpieces; measuring resolution and random errors in the required ultra-precision processing machines will have to be no worse than 0.01 μm (10 nm).
Article
This publication deals with advantages and characteristics of linear drives in comparison with the conventional electromechanical drives and discusses suitable applications. Due to their high cost per axis, linear drives are mainly appropriate for some special applications such as high speed machining.
Article
A quantitative model of burr formation for ductile materials which does not include fracture during orthogonal machining is proposed. The burr formation mechanism is divided into three parts-initiation, development, and formation of the burr with appropriate assumptions. The mechanisms proposed are based on the observation of the behavior of workpiece material during orthogonal machining on commercial plasticine. To validate the model, orthogonal machining inside a scanning electron microscope at low speed was done with a copper workpiece and A16061-T6, A12024-T4 and A1390 were cut on a modified milling machine over a range of cutting speeds.
Article
Parallel kinematics have recently attracted attention as machine tools because of their conceptual potentials in high motion dynamics and accuracy combined with high structural rigidity due to their closed kinematic loops. This paper, prepared with input from CIRP colleagues as well as of machine manufacturers and end-users involved in PKM, attempts to review the development of parallel kinematics for machine tools, their practical application and their performance compared to classical machine tools.
Article
A piezo actuator based fast tool servo is presented for precision turning of cylindrical shafts. The monolithic actuator housing transmits motion to the tool assembly using solid flexures. The actuator has a stroke of 36 μm, 3200 Hz natural frequency, and 370 N/μm stiffness. Two sets of additional piezo actuators are placed in the transverse direction to clamp the tool for increased stiffness during hard turning operations. A sliding mode controller rejects cutting forces and compensates the piezo stack nonlinearities. The tool position is controlled to within 10 nm during finish hard turning on a conventional CNC lathe.
Article
Besides the technological problems in the dry grinding process such as the development of grinding tools and the adaptation of grinding parameters there is another problem which deals with the emissions and immissions of grinding dust. During the dry grinding process chips and grinding wheel particles cannot be bounded and transported by cooling lubricants. As a result there are grinding dust emissions that have a negative impact on the working security and the health of the machine tool operator. For these reason emission analysis has been carried out. The analysis is based on the rules of VDI 2066 and DIN 689. The emissions of the dry grinding process when working without suction was compared with the emission working with point and chamber suction. As the main result the investigations revealed, that during dry grinding only with suction the registered emissions were uncritical for the environment. Without suction the emissions exceed the threshold values. In this case due to the dangerous particle size distribution a severe health hazard for the operator is likely to occur.