Article

Environment-Friendly Technological Advancements to Enhance the Sustainability in Surface Grinding- A Review

Authors:
  • University institute of Engineering & Technology, Panjab University SSG Regional centre, Hoshiarpur
  • Sardar Beant Singh State University (formerly Beant College of Engineering and Technology) Gurdaspur
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Abstract

Surface grinding is a widely used machining process for finishing of materials. Industry is looking for materials and techniques which are more productive as well as environment friendly. Researchers have worked upon various aspects to improve the overall performance of surface grinding in context of environmental and economic issues. But no comprehensive review on surface grinding, which covers all technological issues related to the process, including modelling and simulation, has been reported yet. This review is on research and technological advancements in surface grinding. It discusses critical findings pertaining to these advancements and gives recommendations related to surface grinding.

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... Machining is the most essential component of the manufacturing sector to manufacture high-quality precision spares, tools, equipment, etc [4]. Grinding is mostly the finishing process of machining to impart the required functional and quality features like dimensional and geometrical tolerances, surface texture, etc [5][6][7]. The intense heat generated while grinding generates thermal stresses that impair the product's mechanical properties, grain structure, and surface quality [8][9][10]. ...
... Step 4: The degree of dominance of the input variable I i over the input variable I j is computed using equation (6). ...
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The current work advocates the use of Cashew Nut Shell Liquid/Oil (CNSL), an oil extract of the leftover cashew nut shells, as a novel environment-friendly cutting fluid in sustainable machining operations. The tribological characteristics of CNSL obtained on a pin-on-disc tribometer are found to be better compared to the traditionally used cutting fluid. Experiments are conducted on the surface grinder with EN8 material, considering input parameters, such as cutting fluid type, grinder speed and grade, work speed, and depth of cut, with Surface Roughness (Ra) and Grinding Temperature (Temp) being the responses. Input parameter optimization is performed using Taguchi’s statistical models. A total of 36 investigative and six validation experiments are conducted, and a prediction model is proposed. When Ra and Temp are optimized simultaneously, the prediction value of Ra is 0.071 μm, and the corresponding value of Temp is 31.6 °C for which the experimental values are 0.072 μm and 32 °C respectively. This work also applies the TODIM (TOmada de Decisao Interativa Multicriterio, in the Portuguese language), a multi-attribute decision-making method for ranking the input parameter settings. The study reveals that the performance of CNSL is better than that of a traditional cutting fluid, and the TODIM method can be successfully applied to rank the input parameter settings.
... In surface grinding wheel having hard abrasive particles are generally used. Cubic boron nitride (CBN) super abrasive grinding wheel has been widely used for grinding of Ti-6Al-4V alloys because of its high hardness, good thermal conductivity and very good thermo-chemical stability (Dogra et al., 2018). But machining of Ti-6Al-4V is very difficult due to its poor thermal conductivity (Singh et al., 2020a). ...
... From the literature, it is clear that apart from grinding environment like flood, MQL and dry, the wheel material also plays a significant role in enhancing the grinding performance. Lot of work has been reported on surface grinding of Titanium under different cooling/ lubricating environment using CBN wheel (Dogra et al., 2018;Singh et al., 2019a;Singh et al., 2019b). But the work pertaining to comparing the performance of CBN wheel under dry and MQL surface grinding of titanium is scant. ...
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Nowadays the use of sustainable/environment friendly methods are rising in surface grinding process. In this work, the surface grinding of Ti-6Al-4V alloy with cubic boron nitride (CBN) grinding wheel under dry and minimum quantity lubrication (MQL) environment was performed. Experiments under MQL condition enhanced the overall grinding performance in terms of surface roughness and tangential cutting forces. Efficient lubrication under MQL environment due to presence of high anti-oxidation mono-saturated fatty acid percentage and lesser poly-saturated fatty acid percentage (easily oxidized) provides excellent lubrication and cooling action at the grinding zone in comparison to dry condition. Under dry grinding as the number of grinding passes increased from 2nd to 8th pass surface roughness increased by 166%. At higher grinding pass (8th) surface roughness decreased by 24% in contrast to 1st pass. Further, cutting force under dry grinding case with 8th pass got increased by 18% in contrast to MQL condition. © The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted distribution provided the original author and source are cited.
... To attain surfaces, which are smooth and precise, conventional machining needs the addition of lubricating agents at the toolework interfaces [7,8]. If applied, this addition has benefits on reduction of friction which also contribute to the lessening of temperature of the cutting zone [9,10]. In order to solve this problem, the flood cooling system are frequently used in machining industries [11]. ...
... Now this has ability of cooling as well as providing sufficient lubrication to the cutting zone [20,21]. Moreover, it will help in cleaning the machined surface and take away the chips from main cutting zone [10,22,23]. Many researchers around the globe is working on MQL and its upgraded version like MQCL [18,24,25]. ...
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The application of metalworking fluids (MWFs) are helpful in improving the tribological characteristics while machining difficult to cut materials like duplex stainless steel. However, the adverse effect of commonly used MWFs limits its application in the area of clean and sustainable manufacturing. The strict environmental concerns, policies and regulations allow the usage of green cooling systems that positively effects the environment. Therefore, this study concerns the parametric evaluation of the surface induced tribological characteristics obtained after machining of difficult to cut stainless steel under dry and minimum quantity cooling lubrication conditions (MQCL). The various surface roughness parameters were evaluated with latest microscopes and the analysis was made under dry and MQCL conditions. In the end, the surface tribology has been studied and the results are compared with dry and MQCL conditions. The research reveals that the two-dimensional roughness analysis of the machined surface is very often limited to the one evaluated surface profile parameter. The outcomes also demonstrated that the MQCL produces smooth surfaces with less irregularities and could be considered in the context of sustainable manufacturing.
... These detrimental effects can largely be controlled by applying suitable cutting fluids, selecting proper work-tool combination, delivery technique [12][13][14][15], process parameters, dressing parameters and adopting some special techniques like painted wheel [16,17], rexene pasted wheel [17], multi-nozzle cooling systems, etc. [18][19][20]. There are certain hybrid processes like nanoparticles based minimum quantity lubrication and ultrasonic assisted grinding that have shown superior grinding performance [21][22][23]. ...
... While applying cutting fluids, the cutting forces have lessened substantially. The fundamental functions of application of cutting fluid are to provide lubrication and cooling in the cutting zone and the secondary functions include cleaning of machining zone and protection of nascent finish surface [21]. Presence of lubrication and cooling in the processing zone should effectively control the grinding force requirement and figure 3(b) indicates the same. ...
Article
The experimental study is designed towards performance evaluation of unalike non-conventional and environment friendly cutting fluids viz. sodium nitrite, propylene glycol and soap water, while grinding Ti-6Al-4V through an economic SQL-based delivery system in drop-by-drop mode. The study is aimed at finding alternate cutting fluids that are both economic and environment friendly. These fluids have been applied separately during up-grinding of Ti-6Al-4V for 20 consecutive passes using identical alumina wheels and process parameters. Performances of these fluids are compared with conventional grinding fluid and dry grinding under three different cutting depths of 5, 10 and 15 µm. Through the critical and exhaustive analyses of germane factors of considerations like cutting force and specific cutting energy, average surface roughness, grinding ratio, SEM of the ground surface and chip-forms, the performances of the different unconventional fluids are evaluated and presented here. The results suggest that unconventional fluids are better suited compared with conventional fluids for grinding Ti-6Al-4V. Propylene glycol exhibits the most satisfactory results while reducing the grinding force requirement by 25 to 30%, specific energy by 25 to 32%, surface roughness by 35 to 40% and improving grinding ratio by 3 to 5 times compared with dry grinding and grinding using conventional coolant.
... In order to understand the impact or otherwise of the compressed air in grinding, a comparative study between dry air machining and compressed air is studied in this research. Currently, manufacturers are looking for materials and methods which are more productive, relatively cheaper and more environment friendly [19]. In this research, the optimum depth of cut for surface grinding under controlled grinding parameters using compressed air technique will be investigated. ...
... In this research, the optimum depth of cut for surface grinding under controlled grinding parameters using compressed air technique will be investigated. This is important because optimisation of the machining parameters can help to increase the productivity without significant loss of tool life thus minimising the overall cost of manufacturing [19]. Therefore, the effects of compressed air cooling technique on tool life will also be evaluated. ...
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The abundant use of cutting fluids in surface grinding process and the corresponding costs and energy consumption have been a major sustainability concern. This paper identified the optimum depth of cut for surface grinding under controlled grinding parameters using compressed air cooling technique and dry cutting. The surface morphology and subsurface defects of the workpiece material (AISI 304 stainless steel) were measured and compared. It was observed that lower depth of cut had a better surface morphology than higher depth of cut. The effects of compressed air on tool life were equally evaluated. The heat dissipations on the grinding wheels were observed and analysed for both grinding conditions. In addition, the influence of compressed air on the surface integrity of the workpiece was also investigated. The results showed that lower depth of cut proved to have a better quality surface compared to higher depth of cut.
... To address these issues and optimize the operation, textured abrasive tools have been proposed [21]. By introducing grooves into a grinding wheel, it was possible to achieve a 61% reduction in energy consumption and double the material removal rate compared to what achieved with a non-textured tool [22][23][24]. Regarding the ability to enhance heat dissipation by incorporating microgrooves in grinding wheels, a temperature reduction of 105 • C and a 60% decrease in lubricant fluid consumption were observed during the grinding of aluminum [8,25]. The grooves in abrasive wheels serve as pockets, strategically designed to concentrate the jet towards the contact zone while effectively containing the fluid within [5]. ...
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This work discusses challenges in conventional grinding wheels: heat-induced tool wear and workpiece thermal damage. While textured abrasive wheels improve heat dissipation, the current surface-only methods, such as those based on laser and machining, have high renewal costs. The proposed manufacturing technology introduces an innovative 3D cooling channel structure throughout the wheel, enabling various channel geometries for specific abrasive wheel applications. The production steps were designed to accommodate the conventional pressing and sintering phases. During pressing, a 3D organic structure was included in the green body. A drying cycle eliminated all present fluids, and a sintering one burnt away the structure, revealing channels in the final product. Key parameters, such as binder type/content and heating rate, were optimized for reproducibility and scalability. Wear tests showed a huge efficiency increase (>100%) in performance and durability compared of this system to conventional wheels. Hexagonal channel structures decreased the wear rates by 64%, displaying superior wear resistance. Comprehensive CFD simulations evaluated the coolant flow through the cooling channels. This new design methodology for three-dimensionally structured grinding wheels innovates the operation configuration by delivering the coolant directly where it is needed. It allows for increasing the overall efficiency by optimizing cooling, reducing tool wear, and enhancing manufacturing precision. This 3D channel structure eliminates the need for reconditioning, thus lowering the operation costs.
... Despite the better performance of the conventional method, the reduction in oil used compensates for higher values of grinding power and tangential cutting forces. The application of WCJ also contributes to minimizing energy consumption and elevates the efficiency of the grinding process by breaking the air barrier formed around the cutting wheel [73]. ...
Article
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Climate actions have been gaining prominence in discussions about the industrial future due to the need to reduce the amounts of residual pollutants in manufacturing processes. Although the grinding process is widely applied in the industry for its finishing capabilities and dimensional and geometric precision, it is significantly polluting and detrimental to workers’ health. This is attributed to the quantity of mineral oil used in conventional flood lubrication-cooling systems. With these demands in mind, this work proposes alternative methods by comparing the performance of the alumina grinding wheel with the conventional method of lubrication-cooling using MQL, with and without the WCJ auxiliary system, and distinguishing the direction angles of the air jet in the cylindrical grinding process. The workpieces are made of VP50 steel, and the analyzed output parameters include surface roughness (Ra), with confocal microscopy used on the workpiece surface, roundness error, diametrical wheel wear, G-ratio, grinding power, tangential cutting force, and cost and pollution analysis.
... Ultrasonic vibration assisted machining is one such technique. Ultrasonic vibration has been introduced into a variety of processing methods (e.g., turning, drilling, milling, and grinding) to achieve high surface quality and cost-effectiveness [15][16][17]. The advantages of this technique include a reduction in the cutting force and tool wear [18] and an enhancement of dynamic stability [19]. ...
Article
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The integral blisk has been widely used in aerospace, and its structural performance is inextricably linked to the blade surface quality. To improve the surface integrity of polished surface, ultrasonic vibration assisted belt flapwheel flexible polishing (UBFP) is proposed. In this study, the polishing principle of UBFP and the effects of vibration on surface generation are investigated, and kinematic analyses and trajectory simulations are performed. Furthermore, the influences of the main processing parameters on the polishing force and surface roughness in UBFP are explored experimentally, and the sensitivity of the main parameters is distinguished by multi-parameter relative sensitivity analysis based on Monte Carlo simulation. The results show that the ultrasonic vibration contributes to the polishing process primarily through kinematic state changing and trajectories interlacing of abrasives. Compared with conventional belt flapwheel flexible polishing, the polishing force decreases by 15.72% and the surface roughness decreases by 17.39%. The compression depth is the most sensitive parameter in the process of UBFP. This study demonstrates the feasibility of UBFP and provides a theoretical and experimental reference for improving the polishing surface quality of the blisk blade.
... Finally, the flood method was the one that presented the worst emission results, with 1.115 kg of CO 2 released in the grinding of each workpiece, a release of carbon dioxide 446% higher when compared to the MQL system, thus showing that this is a highly polluting method that goes against world trends. This high emission is mainly due to the large amount of cutting oil used, since in its production, heavy amounts of CO 2 are released into the atmosphere and at its disposal because it is incinerated [72,73]. ...
Article
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In machining processes, cutting fluid presents itself as a fundamental component, as they are responsible for the refrigeration and lubrication of the cutting interface. This is especially true for grinding processes, as the heat generated is so intense that it can cause thermal damage to the workpiece, changing its microstructure and mechanical properties. The application of the fluid in the process also helps with a better surface finishing and integrity of the workpiece with little geometric inaccuracies. However, its usage may cause damage to the health of the operators and the environment, as there is presence of toxic additives to improve the cutting fluid’s efficacy. While the most common method used with cutting fluid is the flood method, which consists in applying large quantities of pure oil or oil emulsified in water, one of the more eco-friendly alternatives is the minimum quantity lubrification (MQL) that uses a small amount of oil pulverized in the cutting surface with the usage of a jet of compressed air, achieving, in many cases, results similar to the flood method due to the technique’s excellent lubricating capability. On the other hand, this method presents some challenges to overcome, such as the lower cooling capacity and wheel clogging due to hot chips. To circumvent such obstacles, two techniques were found: adding water to the cutting fluid and a wheel cleaning system (jet of compressed air aimed at the surface of the grinding wheel to remove the chips clogged in the wheel pores). This paper analyzes the use of water paired with the MQL method in the external cylindrical plunge grinding of alumina (Al2O3) to minimize the flaws of the technique. The parameters evaluated include surface roughness (Ra), roundness error, diametrical wheel wear, grinding power, pollution analysis, and cost analysis for flood method, MQL with pure oil (1:0), and MQL with water in 1:1, 1:3, and 1:5 oil–water proportions, with and without wheel cleaning jet. MQL with pure oil generated the worst results, while diluted MQL presented better results. The use of diluted MQL 1:5 with wheel cleaning jet (WCJ) brought results that approximated most of the conventional method, with a fraction of the pollution and cost, showing the potential for using MQL with WCJ as an alternative to the flood method in the industry. However, high cutting temperatures and wheel clogging in MQL still pose obstacles, requiring more research in this method to improve it even further its efficiency.
... Given its immense pollution potential, the oil used in the flood method necessitates incineration, as it poses significant harm to both aquatic and terrestrial ecosystems. Consequently, alternative disposal methods are not feasible [31,53]. ...
Article
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Grinding is a machining process used to achieve high geometric accuracy and excellent surface finish for parts in various industries. In this process, a tool called a grinding wheel interacts with the workpiece’s surface, facilitating the removal of material. Due to the lack of defined geometry, multiple cutting edges engage with the material during machining, leading to a significant rise in temperature within the cutting zone. This temperature increase can jeopardize the process, potentially resulting in damage or even the loss of the workpiece. To address these issues, a technique has been developed involving the use of an emulsion comprising oil and water. This fluid is generously applied to the workpiece to provide lubrication and cooling during the machining process. However, the use of cutting oil raises environmental concerns due to its high pollution potential and its adverse effects on the health of machine operators. In this context, the minimum quantity lubrication (MQL) method was introduced, employing a spray nozzle and a compressed air system to directly apply oil to the cutting zone, facilitating lubrication. Nonetheless, this approach revealed limitations in effectively dissipating heat, leading to a phenomenon known as “clogging,” where machining chips adhere to the tool surface, obstructing the abrasive grains. To combat this issue, an auxiliary system was developed to complement MQL. This system directs a compressed air jet at a 30° angle onto the grinding wheel, dislodging the lodged materials from the tool. Hence, the objective of this study was to assess the effectiveness of these lubrication-cooling methods in machining VP50IM steel—a high-hardness material used in mold die manufacturing. For this purpose, the VP50IM ring-shaped workpieces were machined on a CNC cylindrical grinder RUAP515H, under different feed rates (0.25, 0.50, and 0.75 mm/min), using various lubricooling methods (flood, MQL, and MQL + WCJ). After each machining operation, measurements of roughness, roundness error, tool wear, and acoustic emission were conducted. Additionally, G-ratio, cost, and pollution analyses were also carried out to determine the performance for each case. Across various feed rates, the conventional system showed superior efficiency in most cases. However, it also exhibited the highest application cost and associated pollution. In contrast, the MQL + WCJ system emerged as a highly competitive alternative to the flood method, with comparable surface finish and roundness error, along with lower costs and a significantly reduced environmental impact. In terms of feed rates, the 0.25 mm/min feed rate provided the best surface finish for the workpieces; however, this slowness in the process led to an increase in cost and pollutant emissions. On the other hand, the 0.5 mm/min feed rate yielded the most balanced results. Meanwhile, for the 0.75 mm/min feed rate, the disparity between the lubricooling methods became more pronounced.
... Moreover, the cutting fluids are used in machining for two primary reasons: to reduce the generated cutting temperatures in shear zone and to decrease friction at the tool-to-workpiece contact. Several investigations have shown that the MQL is an alternate to flood cooling that reduces the amount of cutting fluid provided to the cutting region[58]. Further, the nano-fluids can be used to improve the MQL's cooling and lubricating properties by enhancing the thermal and wettability features of the base fluid[59]. ...
Article
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The term "sustainability assessment" refers to a set of practices that "guide the planning and decision-making process to realize sustainable development." Sustainability is becoming an increasingly central notion for many businesses. However, the current sustainability assessment techniques are being heavily criticized for a number of reasons, including a lack of interdependence and consistency, the predominance of subjectivity, and financial biases. Therefore, the present study applies the fundamental conceptual framework for sustainability evaluation to enhance the process performance of machining Bohler K490 steel using minimum quantity lubrication (MQL) and hBN-enriched nano-MQL cooling/lubrication. Power consumption and machining parameters such as tool wear, surface roughness, and chip morphology were taken into account while developing the sustainability assessment model. Then, the sustainability performance indicator (SPI) was determined. This global SPI supports the claim that using nano-MQL improves both sustainability and machining performance. The findings of tool wear clearly illustrated that applying hBN-enriched nano fluids from both the rake and flank surface reduced the tool wear values by up to 26.9%.
... Firstly, the atomized lubricant and the high-pressure (0.4 ~ 0.65 MPa) airflow can effectively break the boundary layer of air and enter the grinding zone for lubrication and cooling (as shown in Fig. 5(a)-(b)). Then, the high-pressure airflow and the air environment in the grinding zone constitute convection heat exchange, which reduces the grinding temperature [55]. In addition, high-pressure airflow can remove the generated chip and prevent material coating or blockage of grinding wheels etc. ...
Article
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Nickel-based superalloys, as typically difficult-to-machine materials, are mainly used in aero-engine, ship, chemical industry, and other fields. To further enhance the surface quality of nickel-based superalloys, prolong the life of wheels, save the related costs, and achieve sustainable development, many exploratory works on eco-friendly sustainable grinding technology have been carried out by relevant researchers. Based on the action and material properties of nickel-based superalloys, the lubrication mechanism and research results of MQL are first summarized. Then, the latest research progress of micro-lubrication technology and its synergism technology is introduced briefly. In addition, the relationship between MQL penetration characteristics, grinding process characteristics, and eco-friendly sustainability is established. Finally, the technical mechanism and latest achievements of Cryo-MQL, NMQL, and EMQL are summarized. The aim of those works is to reveal the MQL synergistic mechanism and provide a theoretical basis and technical guidance for its grinding engineering application of nickel-based superalloys.
... In this context, the use of nanoparticles dispersed in the fluid has been studied to improve MQL technique (also known as traditional MQL method, which there is no solid particles), since it tends to enhance, a priori, booth cooling and lubrication capacities of the base fluid [14][15][16]. This type of fluid with nanoparticles as additives is commonly known as nanofluid [17]. ...
... Above all, the traditional cooling way is liquid coolant. But the cooling way increased the coolant treatment cost and had risks to human health and the environment [34,35]. In order to reduce the usage of coolant, the MQL is advised. ...
Article
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Due to the enclosed working environment and inadequate cooling, it is easy to produce excessive local temperatures in the double-face grinding machining process. Excessive local temperatures lead to a number of issues, including grinding wheel wear, workpiece burns, and surface quality degradation. In order to reduce the temperature with little coolant, a study on coolant distribution is necessary. This paper studies the effects of grinding wheel speed and workpiece speed on the coolant distribution law. The unidirectional flow field model in double-face grinding is established based on the contact equation of computational fluid dynamics, the Navier‒Stokes equation, and the turbulence equation. This model also considers the pores on the grinding wheel surface, the equivalent height of the abrasive particles, the geometric boundary, and the equivalent gap between the workpiece and the wheel. The results show that the component surface fluid velocity gradually rises from the inner to the outside diameter of the grinding wheel. The grinding area pressure distribution in different parameters is analyzed. The variance analysis of coolant distribution is carried out. It is found that there is a positive linear correlation between the grinding fluid flowing into the grinding zone and the grinding wheel speed. With the increase of wheel speed, the more liquid concentrates on the area where the coolant enters. And it is observed that 60 rad/s wheel speed leads to a more even coolant distribution and a flatter machined surface.
... As their primary objective, business administrators maximize profits, and often, the initial path is to reduce costs [76,77]. From this perspective, it is known that the wheel cost for the grinding process represents a large portion of this totality. ...
Article
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The grinding process manufactures parts with geometric and dimensional precision and surface finish. During the procedure, material removal requires high energy and generates heat in the cutting zone. The grinding of advanced ceramics, such as alumina (Al2O3, 97% purity), is even more complex and economically expensive due to its mechanical properties. Thus, cooling and lubrication techniques are needed to control temperatures. The conventional flood technique is currently the most used, but it has a high environmental impact combined with unhealthy chemical agents in the cutting fluid. As a result, cutting fluids are the inputs that pose the most significant risks and damage to the environment and human health. Applying atomized and pressurized cutting fluid directly to the cutting zone has shown manufacturing potential compared to the conventional flood technique to solve these problems. Despite this, the minimum quantity of lubricant (MQL) technique does not provide good thermal dissipation compared to traditional methods, requiring the inclusion of auxiliary systems. In addition, one of these techniques deals with adding different proportions of water to the mixture, aiming to improve the heat transfer of the process and minimize the phenomenon of clogging the surface of the grinding wheel. Thus, this study analyzed the performance of a diamond grinding wheel in the advanced process of ceramic grinding using different proportions of cutting fluid applied to the MQL system, as follows: MQL + Pure (Pure—100% cutting fluid), MQL + 50% (50% cutting fluid and 50% water), MQL + 25% (25% cutting fluid and 75% water), and MQL + 15% (15% cutting fluid and 85% water) compared to the flood technique. Thus, surface roughness, soil surface topography by confocal microscopy analysis, roundness error, diametral grinding wheel wear, G-ratio, grinding cost analyses, and CO2 pollution analyses were evaluated. In addition, MQL applications revealed fewer pollutants. Furthermore, they were more economical application conditions from the grinding cost analysis, making them a great eco-friendly alternative for use in the industrial sector.
... Dogra et al. reviewed the eco-friendly techniques in grinding operations. They stated that MQL is a sustainable, cleaner production system during the grinding process, as it can enhance the heat transfer rate at the cost of a lower amount of coolants [38]. Zhang et al. have investigated the performance of a cryogenic air nano-fluid MQL (CNMQL) system during surface grinding of Ti-6Al-4V. ...
Article
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The presence of abrasive particles in ceramic reinforced composite materials makes the machining complicated by generating friction at elevated temperatures. Lubricants can be used to prohibit the hazard of higher temperatures. This research work is focused on examining the effects of lubricants on the grinding performances of Al matrix composites reinforced with nano-SiC particles under minimum quantity lubrication (MQL). A cylindrical grinding machine is used to perform the grinding experiments by employing a Box–Behnken design. Multiple performances, such as surface roughness, grinding forces and temperature, are optimized by considering the depth of cut, speed of the workpiece, wheel speed and wt % of nano-SiC using response surface methodology (RSM)-based artificial bee colony (ABC) algorithm. Atomic force microscope (AFM) and scanning electron microscopy (SEM) are used to observe the morphologies of the machined surfaces and the wheel.
... With the increase in the linear speed of the grinding wheel, the number of abrasive grains involved in material removal per unit of time increases, resulting in a reduction in the plastic deformation of the surface metal of the workpiece. At the same time, the increase of linear speed will also accelerate the flow of the coolant in the abrasive zone, which enhances the scouring and lubricating effect of coolant in the grinding zone, and eventually makes the surface roughness decreased [41] . ...
Article
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The traditional flood cooling method is hard to dissipate the massive amount of heat accumulated in the grinding zone during the high-efficiency grinding process, which easily causes burnout of the workpiece that limits the increase of the processing efficiency. Employing an abrasive phyllotaxy arrangement and an internal cooling grinding wheel (ICGW) can augment the heat transfer of the coolant in the grinding zone to lower the grinding temperature. An abrasive phyllotaxy arrangement internal cooling grinding wheel that is a combination of an ICGW and abrasive phyllotaxy arrangement was proposed in this study. To optimize geometric dimensions and phyllotaxy coefficient of the abrasive phyllotaxy arrangement ICGW, simulation and experimental investigations were carried out to explore the effects of coolant (water-based ILs-MWCNTs/MoS2 hybrid nanofluids), grinding wheel diameters, and phyllotaxy growth coefficient on the heat transfer capability of the wheels. Within a specific range, the ICGWs with a smaller diameter and larger phyllotaxy growth coefficient show an advantage in fluid flow and heat transfer. Experimental results exhibit that, compared with the typical orderly arrangement, the grinding temperature and surface roughness of the ICGWs with the phyllotaxy pattern was reduced by about 20% and 50%, respectively. Under the same phyllotaxis coefficient, the grinding temperature and surface roughness obtained by the ICGWs with a smaller diameter were reduced by 10% and 22.3%, respectively. The residual compressive stress was elevated by 10.94%.
... After a literature analysis of the cutting process of difficult-to-machine materials, we found that problems still exist regarding the deterioration of workpiece surface integrity and tool wear caused by friction damage, suggesting challenges in meeting the requirements of engineering practice. Scholars have recently conducted a systematic review of sustainable machining technology, including metal cutting fluid replacement technology [30][31][32][33][34][35], MQL technology [36][37][38], and sustainability evaluation of cooling methods [7,[39][40][41][42]. Other scholars have ventured on research from the viewpoint of materials, such as titanium alloys [43][44][45][46], and Inconel alloys [47,48]. ...
Article
The tribological behavior of cutting is a decisive factor in changing the production cycle, cost, and quality of parts. Minimum quantity lubrication (MQL) based on environmentally friendly biolubricants can convert contact conditions in cutting zones, but it cannot meet the manufacturing requirements of difficult-to-machine materials in the continuous friction turning process. Under the boundary conditions of high temperature, high cutting speed, and high pressure at the tool–workpiece interface, the scientific issue of performance enhancement remains unclear and thus has been the focus of academic and industry research. Moreover, under the continuous cutting boundary condition, technology enhancement as a development trend has not yet been systematically reviewed. Wetting, friction reduction, and heat transfer mechanisms have also not yet been investigated. In this study, the cooling lubrication mechanism and technical iteration motivation of MQL were initially analyzed. Subsequently, a quantized comparative assessment of cutting force, cutting temperature, tool wear, and surface quality under enhanced environmentally friendly lubrication turning, including parts enhanced by nanoparticles, cryogenic medium, ultrasonic vibration, and textured tools, was performed. The technical performance, parameter optimization, and mechanism of enhanced MQL were comprehensively studied, and the development stages of biolubricant MQL turning (MQLT) were fully reviewed. Finally, the development trend of the theory and application of MQLT for difficult-to-machine materials was prospected. This study may be used by scientists to deeply understand the mechanism, tribological behavior, and development trend of lubrication in relation to continuous cutting.
... Grain refinement can be realised by many mechanical treatment technologies via severe plastic deformation, such as SMAT [8], shot peening [219], deep rolling [220], grinding [221]. Indeed, synthesis of nanocrystalline material by severe plastic deformation has gained a great interest in recent years. ...
Thesis
This work focuses on the local experimental characterization of the gradient microstructure of 316L steels treated by SMAT. The gradient microstructure could be roughly divided into a top surface nanostructured layer, a transition layer and the bulk region. Grain refinement, compressive residual stress and strain hardening are three major SMAT-induced parameters as a result of severe plastic deformation induced by SMAT. Consequently, the enhanced mechanical properties of the gradient microstructure are due to the combined effects of these SMAT-induced changes. However, emphasis was mainly placed on the global properties of the gradient microstructure in previous studies and little effort was devoted to the individual characterization of each layers. The aim of this work is thus to investigate individually the mechanical properties of each layer by means of various characterization techniques. Characteristics of the gradient microstructure are first highlighted by EBSD which reveals the formation of a top surface nanostructured layer. The grain size for this layer ranges from 50 to 300 nm. As for the mechanical properties, nanoindentation and micro-pillar compression tests were carried out for the individual characterization of each layer of the gradient microstructure. The local mechanical properties could be subsequently derived according to the corresponding mechanical reponse. Another part of this work consisted of using Finite element method for the simulation of the mechanical behaviour of nanocrystalline materials. A two-dimensional crystal plasticity model was thus used for the simulation.
... In UVADG, vibrational energy produced by the ultrasonic transducer in the higher frequency range of 16-40 kHz. Further, this energy was transferred in the longitudinal direction towards workpiece or grinding wheel with lower amplitude in the range of 2-30 lm [10]. UVADG is a hybrid machining technique involving ultrasonic oscillation and CDG, which was employed for both brittle and ductile materials [11]. ...
Article
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As a cold working tool steel, AISI D2 tool steel is widely adopted in the tooling and automotive industries because of its excellent thermo-mechanical properties. However, the mechanism of chip removal is more intricate by conventional machining owing to its work straining phenomena. Besides, this material can be effectively machined and finished by advanced grinding such as brittle fracturing mechanism. Hence, the present experimental study attempts to compare the surface integrity characterization of AISI D2 tool steel upon conventional dry grinding (CDG), and ultrasonic vibration assisted dry grinding (UVADG) using non-destructive magnetic technique, i.e., hysteresis loop (HL). The surface integrity of ground sample was evaluated in terms of surface roughness, 2-D surface profile, microstructure, and microhardness. These surface integrity outcomes were compared with HL outcomes such as average permeability, remanence, coercivity, and core loss. The experimental results revealed that minimum phase transformation and microhardness variation were observed in the ground surface under UVADG compared to CDG mode due to intermittent shearing action of abrasive grits over work material, which restricts excessive heat penetration. The lower surface roughness was found under UVADG mode, which is Ra: 0.118 µm and Rz: 0.671 µm, respectively. Furthermore, excellent correlation was observed in magnetic response, i.e., significant changes in HL profile and better HL outcomes, and it was associating well with the microstructure and variations in microhardness, resulting from UVADG of ground sample.
... In UVADG, vibrational energy produced via the ultrasonic transducer is of higher frequency in the range of 16-40 kHz and the lower amplitude of vibration in the range of 2-30 µm in the longitudinal direction toward the workpiece or the grinding wheel. 6 UVADG is basically a composite technique involving both ultrasonic vibration and traditional grinding; it can be applied equally for ductile and brittle materials. Li et al. 7 conducted an ultrasonic vibration-assisted grinding experiment on zirconia ceramics; the results obtained indicate improvement in the workpiece surface quality and better tribological properties compared with precision grinding. ...
Article
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Ultrasonic vibration-assisted dry grinding is a sustainable hybrid manufacturing technology that decreases the negative environmental impact of coolant, reduces manufacturing costs, and improves surface integrity. The present investigation analyses the mechanisms associated with ultrasonic vibration-assisted dry grinding of AISI D2 tool steel with an alumina grinding wheel. It also compares the influence of traditional dry grinding and traditional wet grinding modes with the ultrasonic vibration-assisted dry grinding mode at different ultrasonic vibration amplitudes. Ultrasonic vibration was applied to the sample in the longitudinal feed direction. Further, kinematics of the abrasive grit path during the traditional grinding and ultrasonic vibration-assisted dry grinding is presented schematically. In this research, the impacts of ultrasonic vibration amplitude as well as the depth of cut on the process yields such as ground surface topography, grinding force, specific grinding energy, force ratio, surface finish, microstructure, and hardness were investigated experimentally. Experimental results revealed that the highest decline in tangential and normal grinding forces in ultrasonic vibration-assisted dry grinding at ultrasonic vibration amplitude 10 µm and the reduction in surface roughness parameter ( R a , R q , and R z ) in ultrasonic vibration-assisted dry grinding was 43.23%, 42.59%, and 33.69%, respectively, in comparison to those in traditional dry grinding and 26.35%, 26.94%, and 27.48%, respectively, in comparison to those in traditional wet grinding. It was observed that ultrasonic vibration-assisted dry grinding is beneficial as the profile produced by ultrasonic vibration-assisted dry grinding has a comparatively flat tip, and profile points are shifted to the bottom of the mean line. This study is expected to assist ultrasonic vibration-assisted dry grinding of hard materials.
... Comparing with other machining processes, e.g. turning, drilling and milling, the grinding process consumes more power/energy to remove the same material volume (Dogra et al., 2018). For example, the specific energy of 30-50 J/mm 3 is required in grinding the steels, typically higher than that (10 J/mm 3 ) in melting iron or nickel (Tian et al., 2017). ...
Article
A large amount of global power consumption and environmental pollution problems are attributed to manufacturing industries. Grinding is one of the most energy intensive precision machining processes. Stimulating energy-saving potential in grinding to improve energy efficiency will be great helpful to accelerate energy and environmental sustainability. However, the energy utilization and efficiency problem has not been fully considered in traditional grinding strategies for production benefits. Therefore, a Pareto optimal design method is proposed to obtain optimal grinding parameters under the dual drive of energy management and machining performance. A nonparametric model based on the improved adaptive artificial neutral network (aANN) has been built to predict the surface quality, machining time, total and active power consumption. Parametric studies of the aANN model have been performed to achieve more accurate predictions. Accordingly, the multi-objective optimization problem searching a trade-off among energy and time efficient criteria, as well as product quality, has been solved using non-dominated sorting genetic algorithm II (NSGA II). Moreover, an energy efficiency benchmark has been suggested to indicate eco-friendly ability of grinding. Experimental results of the AISI 1045 steel have demonstrated that the optimal solution could improve energy efficiency by 89.52% and reduce machining time by 174.36% keeping the same product quality. Similar procedures will be performed to build the energy efficient grinding database towards sustainable and intelligent manufacturing.
... Результаты согласуются с данными работы [12], где доказана эффективность технологии CAMQL при более низких величинах воздушного потока. Существует некая оптимальная концентрация наночастиц в составах -не всегда большое их количество обеспечивает хороший результат [14,15] Наличие наночастиц в зоне контакта изменяет механизм смазывания, снижается адгезия пары абразивный материал-металл, так как между абразивным зерном и обрабатываемым материалом имеется «третье тело», что в итоге отражается на качестве обрабатываемой поверхности. Эффект снижения следов адгезионного взаимодействия при использовании составов с наночастицами зарегистрирован также в работе [16]. ...
Article
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Introduction. In terms of environmental issues, the most significant problem in the metal finishing process is the use of lubricating cooling fluids (coolant). As an alternative of coolant using in the world practice are integrating an environmentally determined engineering of minimum lubrication (MQL minimum quantity lubrication). Though the use of MQL process in the abrasion with the highest contact temperatures is not effective enough. Due to this a set of measures has been suggested in the scientific community such as, the additional cooling action of the cutting area by cold air (CAMQL - cold air with minimum quantity lubrication). As part of our paper the researches of using these methods, both separately and in synthesis, in order to assessment of capability for increasing the MQL efficiency when grinding Ni-based alloy are carried out. The purpose of the work is to quantify the influence of the MQL and CAMQL input processes on the operational factors of the grinding process and the properties of a thin surface. Vegetable soy oil is used as a lubricant. including the addition of Al2O3 nanoparticles. Research methods. The surface roughness is controlled with Mitutoyo Surfest SJ=410 profilometr. Component cutting forces are measured using a six-component force-measuring complex Amti MC36-1000. Elemental analysis and surface morphology rating are carried out using a FEI Versa 3D LoVac dual-beam raster electron microscope with an X-ray microanalysis attachment. The contact potential difference is measured by atomic-force microscopy using the Kelvin's probe method. Results and discussion. The better application conditions for MQL and CAMQL are established, these are the dosing regimens of lubricating at 30 mill and the air low range for CAMQL equals to 12 m(3)/h. The measurement results of cutting forces showed the using of soy oil lubricant only is more effective for CAMQL. On addition of Al2O3 nanoparticles with an optimal concentration of 0.4 wt. % there is observed the dramatic decline of the cutting forces, in particular P(y )Component (by 30 % relative to grinding process without coolant), and the force values are almost the same when using both MQL and CAMQL. The machined surface roughness is reduced averagely 1.5 times. While using lubricant compositions with nanoparticles, there is a tendency to lower the surface roughness values when grinding with CAMQL. The states research of a thin surface layer after grinding process showed the use of CAMQL, regardless of the lubricant type, provides reduction of surface oxidation and improvement of its properties. When using compositions with Al2O3 nanoparticles, the decrease of adhesive interaction traces of machine surface is observed.
... In study [6], mineral oil is used, which somewhat contradicts the concept of environmentally-friendly grinding. Vegetable oil has excellent biodegradability, meets the requirements for the properties of lubrication, and has great potential for use in MQL [7][8][9][10]. ...
Chapter
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Modern trends in mechanical engineering are associated with the introduction of green technologies, in particular the use of a minimum quantity lubrication (MQL) in abrasive processing operations. However, due to the low cooling capacity of this technology, the use of cold air (CAMQL) is used increasingly often. This article summarizes the results of comparative tests of the application of this technology, using soy oil as a lubricant. The properties of the surface layer of a nickel alloy obtained after grinding have been studied using electron microscopy, X-ray diffraction analysis, and evaluation of the electron yield by the Kelvin probe method. It was found that when using CAMQL, there is a decrease in oxidative and adhesive processes, while the level of micro-stresses in the surface layer is reduced twice. The results obtained indicate an improvement in the quality of the surface layer when grinding a nickel alloy with CAMQL.
... * Wenfeng Ding dingwf2000@vip.163.com and milling. Most of the energy is converted into grinding heat at the wheel/workpiece interface [19], which would lead to the occurrence of surface burn, especially for the titanium alloys featuring high strength and low thermal conductivity. Some research has been conducted on the grinding-induced surface burn behavior of difficult-to-cut metallic materials, mainly including nickel-based superalloys (e.g., Inconel 718 [20] and K417 [21,22]) and conventional titanium alloys (e.g., Ti-6Al-4V [22,23]). ...
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This article presents the surface burn behavior when creep-feed grinding gamma titanium aluminide (γ-TiAl) intermetallic. First, the main characteristics of burnt surface morphology were detected. Subsequently, surface burn mechanism was revealed by analyzing compositional changes in the surface layer via X-ray photoelectron spectroscopy. Lastly, the effects of grinding temperature on grinding force and surface integrity were discussed. Finding showed that a high grinding temperature would lead to a heavy color, from light brown to hyacinthine, on the burnt surface. The burning process was dominated by oxidation of Ti and Al. Ti was generally in the state of TiO2 on the ground surface, whereas lower valence oxide of Ti was found on the subsurface. This oxide layer could produce a reduced ratio of the tangential grinding force to the normal one. Elevated temperature would produce grinding and quenching cracks on a burnt surface, and tensile residual stress might be developed if the temperature is extremely high. Surface morphology and topography characteristics indicated that, unlike conventional titanium alloys (e.g., Ti-6Al-4V), a marginal physical reaction occurred on the workpiece surface during the burning process of γ-TiAl intermetallics due to poor material ductility.
... In MQL regularly (20-150 ml/hr) measure of biodegradable oil alongside pressurized air having a weight lies in the middle of 4 bar-6.5 bar is required, henceforth it is a practical substitute to customary flood oil [11]. Liquid as fog is utilized to perform cooling/oil activity at the cutting zone [23,33]. ...
Article
The machining of hard to cut work materials produced lot of heat produced at the cutting zone resulted in generation of high cutting temperature at the tool-chip/tool-workpiece interface. Further, the high amount of tool wear (flank wear, crater wear), escalates the cutting forces, residual stresses as well as energy consumption and reduces the life of tool during turning process. To overcome these negative effects minimum quantity lubrication (MQL) as sustainable manufacturing technique has been largely used by researchers. High velocity mist droplets after penetration at the cutting zone, formed vapour blanket and give more effectual heat transfer than flood cooling. MQL process enhanced the turning performance in terms of low tool wear, excellent surface finish, and minimum cutting forces, lessen cutting temperature. This study, attempts to vitally evaluate the research scenario during turning of difficult-to-cut materials under environment friendly MQL technique.
... Among all the alternatives, dry machining would be ideal, since there is no fluid application. However, in high-energy generation processes, such as grinding, the absence of fluids leads to elevated temperatures at the cutting interface, which deteriorates workpiece quality and tool life, thus preventing its industrial application [19,20]. ...
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The application of the minimum quantity lubrication (MQL) technique in grinding processes is still limited due to the frequent occurrence of overheating and wheel clogging. In this context, this research evaluates a cooled wheel cleaning jet (CWCJ) under different temperatures, applied simultaneously to MQL in the cylindrical grinding of AISI 4340 quenched and tempered steel, using a CBN wheel. For comparison, tests with the MQL, MQL + WCJ, and conventional techniques were also performed. Surface roughness, microhardness, and roundness deviation of the workpieces, wheel wear, and grinding power were the assessed output parameters. The machined workpieces were evaluated by optical, confocal, and scanning electron microscopies. The MQL + WCJ outperformed MQL and MQL + WCJ in all the tested conditions. The application of the cooled wheel cleaning jet reduced by up to 79% the surface roughness, 82% the wheel wear, 76% the roundness deviation, and 37% the grinding power, regarding MQL and MQL + WCJ techniques, contributing towards a sustainable and high-quality grinding process.
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Minimum quantity lubrication (MQL) is an effective method for addressing technical challenges associated with high cutting loads during machining. Although much research has explored the ability of MQL to reduce cutting forces, intuitive analyses of its developmental trends, leading researchers, and research hotspots remain limited. To address this, a bibliometric analysis was conducted on studies related to MQL and its role in cutting force reduction. Data from the Web of Science Core Collection database, covering the period from January 1, 2008, to December 31, 2023, were analyzed. Bibliometric tools such as VOSviewer, Scimago Graphica, and Bibliometrix were used to visually assess publication trends, source journals, countries, institutions, authors, references, and keywords. The results show that India leads in publication output with 231 papers, while Li CH from China is the most cited author, with 3200 citations. A detailed clustering analysis of keywords and their representative research areas was performed, summarizing the current findings on the effects of processing parameters on cutting forces. The study also analyzed the optimization of machining parameters to minimize cutting forces, identifying relatively optimal conditions. Finally, challenges and potential solutions were discussed, providing theoretical and technical guidance for the industrial application of MQL.
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This work uses an alumina wheel to investigate the eco-benign grinding for better surface integrity of Inconel 625 (IN 625). To achieve this, applying nanofluids (NFs) with the minimum quantity lubrication (MQL) principle has been adopted, aiming at eco-benign grinding practices. In this work, MoS 2 (prepared by mixing MoS 2 NFs, MWCNTs NFs and hybrid NFs and MWCNTs in a 1:1 ratio) prepared using deionized water as the base fluid have been used. An in-house developed MQL setup is used to aim the NFs inside the grinding zone. The first attempt has been made to grind IN 625 in these environments. The characterisation of NFs in terms of nanofluid stability, dynamic viscosity, thermal conductivity and surface wettability have been performed before their utilization in grinding operations. A comparison has been made between the results obtained from NFs grinding and those from dry and soluble oil-based MQL grinding. It has been found that hybrid NFs provide excellent lubrication and cooling effects, reducing grinding forces and improving surface quality. Moreover, scanning electron microscopy, energy-dispersive spectroscopy and X-ray photon spectroscopy are applied to investigate the ground surfaces under different grinding conditions. Also, residual stress (with the help of X-ray diffraction and electron backscattered diffraction) and microhardness have been determined to gain further insights into the grinding behaviour. The wheel and chip morphology analyses have been performed to support the findings. The findings from this investigation lead to the conclusion that applying nano-MQL improves grinding effectiveness and promotes cleaner grinding outcomes. Hybrid NFs prove especially effective, as the physical synergistic effect enhances and safeguards the surface integrity of the produced ground components.
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The adoption of environmental, social, and governance reporting (ESGR) varies among nations due to the influence of various factors, specific to countries. Previous research has focused primarily on the institutional factors, revealing a gap in understanding the role of macroeconomic factors in the adoption of ESGR at the national level. The current study investigates various factors (including their interrelationship) that influences the successful adoption of ESGR at the country level. The study also proposes an empirical model for the efficient and effective adoption of ESGR. This pioneering study employs a structural model using Total interpretive structural modeling (TISM) method to explore the hierarchical relationship among factors. Further, Matrice d’Impacts Croisés Multiplication Appliquée áun Classement (MICMAC) analysis is administered to identify driver-dependent relationship among the factors. The study categorizes key factors influencing countries’ ESGR adoption for sustainable development at three levels (1) strategic factors which require action at the grassroots level as political stability, the attitude of elected government, and natural and human Resources, (2) operational factors which support and strengthen the adoption process as economic development, competitive landscape, technical awareness, and public behavior, and (3) performance factors directly responsible for the adoption as regulatory framework and public administrative structure of a country. The study contributes to academic knowledge by advancing theoretical perspectives, enabling comparative analyses, and fostering methodological advancements. It provides assistance to government and policymakers in establishing a robust and comprehensive ESGR landscape that supports sustainable and responsible business practices globally.
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Grinding is a critical surface-finishing process in the manufacturing industry. One of the challenging problems is that the specific grinding energy is greater than in ordinary procedures, while energy efficiency is lower. However, an integrated energy model and analysis of energy distribution during grinding is still lacking. To bridge this gap, the grinding time history is first built to describe the cyclic movement during air-cuttings, feedings, and cuttings. Steady and transient power features during high-speed rotations along the spindle and repeated intermittent feeding movements along the x-, y-, and z-axes are also analysed. Energy prediction models, which include specific movement stages such as cutting-in, stable cutting, and cutting-out along the spindle, as well as infeed and turning along the three infeed axes, are then established. To investigate model parameters, 10 experimental groups were analysed using the Gauss-Newton gradient method. Four testing trials demonstrate that the accuracy of the suggested model is acceptable, with errors of 5%. Energy efficiency and energy distributions for various components and motion stages are also analysed. Low-power chip design, lightweight worktable utilization, and minimal lubricant quantities are advised. Furthermore, it is an excellent choice for optimizing grinding parameters in current equipment.
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This work explores the grinding performance of Inconel 625 by comparing tangential forces and surface roughness under dry, wet, and minimum quantity lubrication (MQL) environments. Response surface methodology (RSM) and machine learning (ML) techniques establish correlations between inputs and outputs. RSM shows the quadratic regression model effectively captures experimental variability. Four ML models, namely: multilayer perceptron, KNN, and SVM with two kernels, were implemented to predict outcomes, among which KNN appeared as a better-suited model. Lower tangential forces and better ground surface quality support the suitability of MQL grinding compared with dry and wet grinding. Micro-graph investigations of the ground surfaces and chip morphology findings also upkeep the emergence of MQL grinding as a sustainable alternative for Inconel 625 grinding.
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In this study, a CBN liquid-body-armor-like grinding wheel was developed for high-shear and low-pressure (HSLP) grinding of Inconel718 alloy. The material removal mechanism of the novel CBN liquid-body-armor-like wheel was introduced in detail. Particle clustering effect of the new wheel was studied via the finite element method. A series of grinding tests were carried out to investigate the grinding performance under the various conditions. It was shown that the surface roughness Ra of the ground workpiece decreased from initial 0.3 to 0.094 μm. Simultaneously, the specific material removal rate of 1.069 × 10 ⁵ μm ³ /mm·s was attained. The power spectral density function (PSDF) was employed to reveal the percentage of waviness and roughness of the surface profile, which was mainly concentrated in 0–40k Hz as compared with 60–120k Hz before grinding. It indicated that particle clustering effect was generated in the grinding zone. Besides, the maximum peak amplitude of the cross-correlation function coefficient of the ground workpiece surfaces before and after grinding was less than 0.3. The original scratches were completely removed. New and smooth textures generated after grinding. The experimental results demonstrated that the newly developed CBN liquid-body-armor-like grinding wheel was effective for surface finishing of the Inconel718 workpiece.
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Grinding plays an important role in ensuring the final machining quality in the manufacturing process of composite parts. Problems such as grinding damage, grinding wheel wear and loading undermine the grinding efficiency and quality. This review presents relevant research progress in the field of composites grinding in recent years from the aspects of material removal mechanisms, surface integrity, and advanced grinding technologies. It further discusses the common problems of composites grinding and summarizes grinding process strategies to suppress damage. It can provide an in-depth understanding of the fundamental mechanisms involved in composites grinding and solutions to the composites grinding problems.
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Accuracy design is an important and essential step for CNC machine tools, and traditional methods always focus on the accuracy optimization itself and ignore other objectives, such as low-carbon manufacturing. With the increasing concern about resources and the environment, energy consumption and carbon emissions should be taken into consideration in accuracy design optimization. This paper takes a novel CNC slider grinding machine with dual-head-dual-lead structure as an example to build an accuracy design model considering sustainable development. Specifically, the feed system of the machine tool is examined, which presents significant accuracy design challenges and has a great impact on the machine's positioning accuracy. By using the improved Sobol method, a sensitivity analysis is conducted to extract the critical geometric error terms, and the sensitivity indices of these terms are utilized to guide the optimization process. By considering manufacturing cost, quality loss, and carbon emissions of the grinding process with long period and high energy consumption, a more comprehensive accuracy design model is built and optimized by using the NSGA-II algorithm. Moreover, the Pareto optimal solution for balancing the objectives is selected through combining entropy-weight and technique for ordering preferences by the similarity of the ideal solution (TOPSIS). The optimization results demonstrate that the accuracy level of the machine tool can be ensured while reducing carbon emissions and total cost up to 30.2% and 18.4% respectively, which is important for promoting clean production in machine tool manufacturing. Besides, the proposed accuracy design framework has the potential to apply to other components and manufacturing processes of CNC machine tools to enhance sustainability and reduce carbon emissions.
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This work employs an eco-friendly lubrication approach of biodegradable soybean oil with air-assisted delivery mode to surface grind AISI 1045. Mixed model nested factorial design followed by balanced ANOVA (analysis of variance) at 95% confidence level has been used for evaluating the effect of lubricant/air mixing ratio, lubricant-laden air flow rate and grinding wheel speed on surface roughness, microhardness, and residual stress of the machined workpiece. It is found that compared to dry grinding baseline scenario, a mixing ratio of 1:2, flow rate of 4.53 g/s and grinding wheel speed of 1100 rpm, produce 72% better surface roughness and comparable microhardness value with minimum introduction of residual stresses which are recorded as −108 MPa (Compressive). It is also determined that only lubricant-laden air flow rate is statistically significant parameter at 95% confidence level for surface roughness; its higher value is seen to provide favorable results for surface roughness. Flow field analysis performed to better understand the ensuing flow dynamics show that parameters resulting in best combination of output measures enable the lubricant to reach the grinding zone and help form a uniform lubricant layer on the surface being machined which explains the betterment in surface integrity aspects obtained in the present work.
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Grinding is a machining process applied in the manufacture of components that require an excellent surface finish and high geometric and dimensional precision, being applied in the final stages of component manufacturing. Due to its high heat generation, grinding needs adequate lubrication and cooling methods, aiming to meet the demands of the ground component as well as to mitigate the environmental impacts resulting from the application of cutting fluids. Allied with this, the growing demand for new materials, such as advanced ceramics, has become a new challenge for grinding. In addition to being chemically and thermally stable, advanced ceramics are highly resistant to wear, making grinding this type of material difficult. Traditionally, cutting fluids have alkanolamines, nitrosamines, volatile organic compounds, mineral oils, hydrocarbons and heavy metals in their composition. Thus requiring proper disposal to inhibit groundwater and soil contamination, reducing immediate and long-term damage to the planet and society. That said, it is extremely important that scientific and technological advances in machining processes, especially grinding, allow for cleaner machining through techniques that reduce the need to apply large volumes of cutting fluid. In this sense, the minimum quantity lubrication technique (MQL) consists of applying a small amount of oil through a jet of compressed air, achieving results similar to the flood method in many cases. However, the lower cooling capacity of MQL is an obstacle to overcome. Thus, this work analyzed advanced grinding ceramics using a diamond grinding wheel combined with a new technology responsible for cleaning the grinding wheel (WCJ) under four different angles (0°, 30°, 60° and 90°). Surface roughness, roundness error, diametral wear of the grinding wheel, G ratio, grinding power, grinding cost analysis, and pollutant CO2 emissions involving each application were evaluated. As a result, the flood lubri-refrigeration method showed the best performance in roughness and surface roundness error values. However, the MQL + WCJ 30° presented similar results about the flooding method, proving competitive for industrial use. Furthermore, MQL applications led to lower CO2 pollution values than the flood method, making it a great green alternative for the environment.
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Metal cutting fluids (MCFs) under flood conditions do not meet the urgent needs of reducing carbon emission. Biolubricant-based minimum quantity lubrication (MQL) is an effective alternative to flood lubrication. However, pneumatic atomization MQL has poor atomization properties, which is detrimental to occupational health. Therefore, electrostatic atomization MQL requires preliminary exploratory studies. However, systematic reviews are lacking in terms of capturing the current research status and development direction of this technology. This study aims to provide a comprehensive review and critical assessment of the existing understanding of electrostatic atomization MQL. This research can be used by scientists to gain insights into the action mechanism, theoretical basis, machining performance, and development direction of this technology. First, the critical equipment, eco-friendly atomization media (biolubricants), and empowering mechanisms of electrostatic atomization MQL are presented. Second, the advanced lubrication and heat transfer mechanisms of biolubricants are revealed by quantitatively comparing MQL with MCF-based wet machining. Third, the distinctive wetting and infiltration mechanisms of electrostatic atomization MQL, combined with its unique empowering mechanism and atomization method, are compared with those of pneumatic atomization MQL. Previous experiments have shown that electrostatic atomization MQL can reduce tool wear by 42.4% in metal cutting and improve the machined surface R a by 47% compared with pneumatic atomization MQL. Finally, future development directions, including the improvement of the coordination parameters and equipment integration aspects, are proposed.
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This paper describes experimental studies that were carried out to assess the enhancement in grinding productivity of AISI D2 tool steel by adopting the ultrasonic vibration-assisted dry grinding (UVADG) mode. Experimental works were conducted on a UVADG setup that was indigenously developed and manufactured. The grinding productivity in the UVADG mode was assessed by comparing the grinding forces, force ratio, surface roughness, bearing area curve (BAC), BAC ratio, ground surface morphology, and topography achieved in conventional dry grinding (CDG) and conventional wet grinding (CWG) modes. The UVADG mode at optimized amplitude and frequency results in lesser grinding forces and better surface integrity than CDG and CWG modes. With UVADG mode, the impact of overlapping induced by ultrasonic vibration resulted in a higher BAC ratio (88.71%) and a steeper BAC. This BAC ratio reflects the ground surface in UVADG mode, which is less susceptible to antifriction and antiwear characteristics than CDG and CWG modes. The experimental outcomes revealed that the UVADG mode has a greater potential for improving the grindability of AISI D2 tool steel. The current study also promotes the need for a sustainable grinding method for ''difficult-to-machine'' materials adopting UVADG mode.
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Based on the particle size distribution and surface physicochemical characteristics of coal particles, a micro-energy consumption model of coal particles in the ultrafine grinding process was proposed. This model explained the microscopic mechanical behavior of the ultrafine grinding process by defining factors such as agglomeration between particles and the change in particle surface properties as the microscopic constraint energy of particles. Under the multi-domain fractal law of particle size distribution, the truncated particle size was introduced to eliminate the mutual interference between size grades, and the expression of the micro-energy consumption law in the ultrafine grinding process of coal particles was derived by combining with the surface area theory of macroscopic crushing. Through scanning electron microscopy and infrared spectroscopy analysis, it was confirmed that the evolutionary process of coal particle surface morphology and the fracture law of chemical bonds were in line with the viewpoint of the micro-energy consumption model.
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Undesirable hydrodynamic properties are inevitable in the traditional grinding process, which often provides a harsher lubrication environment. This paper introduces combinatorial bionics to optimize the hydrodynamic properties of grinding tools innovatively. Two bionic prototypes (phyllotaxis arrangement and fish scale) with special hydrodynamic properties are organically integrated to help design a combinatorial bionic grinding wheel (CBGW). The CBGW can more effectively inhibit the adverse effects of air turbulence on the grinding process and maintain a higher useful flow rate with a maximum improvement rate of 290.47%. This study enhances the effectiveness of grinding fluids from the perspective of grinding wheel structure and provides an excellent tribological basis for green and high-efficiency grinding.
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Grinding is considered as a rather environmental-unfriendly process, where the aspects involving the high demanding process energy input and required fluid application can lead to severe environmental impacts while achieving high product quality. However, the reduction of the cutting fluids raises the cutting temperature, leading to negative alterations of the ground subsurface. Such detrimental aspects are usually not factored into a life cycle inventory analysis. Therefore, this study introduces a new sustainability indicator based on the rolling contact fatigue life of the component, as determined by the grinding process. A method for calculating this indicator is presented, and a case study is illustrated. The subsurface damage thickness can be loosely correlated with fatigue life aThe authors would like to thank the Braziliannd introduced as a new indicator. The selected indicators were used as decision-making parameters to showcase the potential of the product life factor as an aggregate sustainability indicator.
Conference Paper
Nowadays, the minimum quantity lubrication method has become the eye apple of many manufacturing industries. MQL is a cooling procedure in which a very small volume of high quality refrigerant / lubricant is sprayed directly onto the work piece-tool interface. MQL machining has gained popularity over other cooling techniques due to its ability to produce superior surface quality, lower machining temperature, lower tool wear and lower coolant / lubricant consumption. Several researchers are continuing their work on new methods to strengthen the properties of coolants / lubricants. In this paper, efforts are being made to present important work by different researchers on the role of different coolant / lubricant in enhancing MQL environmental capability. A detailed overview of the functions of various processing fluids is presented in this text. such as vegetable oils, mineral oils, synthetic oils and nano-fluid-based machining fluids, in improving the machinability of MQL in spinning, milling and grinding operations. This paper also addresses the role of machining fluids in the enhancement of machining aspects such as surface strength, machining temp erature, tool wear and cutting insert life.
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Machining of carbon fiber-reinforced polymer (CFRP) with less damage remains to be a challenge because of anisotropy and inhomogeneity issues. Flood cooling will reduce the mechanical properties of CFRPs due to its hygroscopicity, however, dry grinding will result in thermal damage and deterioration of surface integrity, which cause it not suitable in aeroengine and aerostructure applications. Aiming to resolve the above gaps, the grinding mechanics for a single grain of CFRPs involving CNT nano-lubricant minimum quantity lubrication (MQL) is explored. To reveal the various fundamental mechanisms in machining CFRP of special transversal grinding and lubrication conditions, four sub-models were developed based on the unique geometries of grain and fiber in contact due to the random fiber arrangements and grain edge shapes under different undeformed chip thicknesses. Specifically, the models account ⅰ) the contact force model between the grain tip and fibers, ⅱ) the local contact stress model of elliptical region between the spherical grain edge and cylindrical fiber, ⅲ) the tensile fracture force model of single fiber regarded as an bending beam fixed at both ends and constrained on the elastic foundation, and ⅳ) the extrusion and shearing force model on the cut fiber section at the grinding groove. Furthermore, the grinding force model is obtained by integrating these sub-models, in which the grain-fiber friction coefficient and grinding mechanics are accurately introduced. Finally, the model is numerically simulated and the trend of force along the entire grinding arc length is obtained. Experimental verifications demonstrate the approach for predicting the grinding force have acceptable accuracy and can successfully capture the mechanics of CFRPs. The model reveals that the tensile fracture force of single fiber has the most contributions to the grinding force.
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Bio-ceramics are biocompatible ceramic materials that are widely used for biomedical engineering applications due to their excellent properties. Because of their inherent hardness and brittleness properties, bio-ceramics are difficult to machine. Abrasive machining such as diamond grinding is one of the most widely used machining for bio-ceramic materials. However, one of the key technical challenges resulted from grinding is edge chipping. The presence of edge chipping in a workpiece affects its dimensional accuracy, machining cost, and potential service time. It is, therefore, crucial to develop a new cost-effective manufacturing process relevant to control edge chipping in diamond grinding of bio-ceramics. In this paper, an ultrasonic vibration-assisted grinding (UVAG) system is developed to investigate the effect of ultrasonic vibration on edge chippings. Hertzian indentation tests are also conducted to validate the experimental results. Results reveal that edge chipping of bio-ceramic materials can be reduced significantly with the assistance of ultrasonic vibration. The results of this study can be applied to other manufacturing process when edge chippings of brittle materials are expected to be controlled.
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Abrasive machining is one of the most important processes used in manufacturing engineering. It is key to removing unwanted material, as well as to obtain the desired geometry and surface quality in manufacturing. "Machining with Abrasives" discusses the fundamentals and advances in the abrasive machining processes, and provides a complete overview of newly-developing areas in the field. Abrasive machining processes where material is removed from a work piece using a multitude of hard angular abrasive particles or grains which may or may not be bonded to form a tool are discussed at length. Also covered are: -Laser-based and diamond dressing techniques -High-efficiency deep grinding -Peel grinding and new grinding wheels -A comprehensive discussion of the latest in micro- and nano-grinding "Machining with Abrasives" collects contributions from leading researchers in the field, and is a must-read for any researcher or engineer working in manufacturing engineering.
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A novel grinding technique is proposed with the goal of improving the grindability of the titanium alloy Ti–6Al–4V. This technique is a combination of ultrasonic-assisted grinding and plasma-electrolytic oxidation. To determine its performance in the grinding of Ti–6Al–4V, experiments were conducted to investigate the effect of ultrasonic vibration on grinding forces and work-surface roughness under the presence of plasma oxidation. The results showed that the technique drastically reduced the normal and tangential grinding forces by 60% and 70%, respectively, and decreased the work-surface roughness by 46% compared to conventional grinding, which uses neither ultrasonic assisted grinding nor plasma-electrolytic oxidation.
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In this paper, an innovative approach for the description of the functional properties of a grinding wheel surface is discussed. First, the state of the art in the description of grinding wheel topographies is summarized. Furthermore, the fundamentals for a new approach for the quantitative description of grinding wheel topographies are provided. In order to analyze the functional properties of a grinding wheel's topography depending on its specification, grinding experiments were carried out. For the experimental investigations vitrified, synthetic resin bonded and electroplated grinding wheels with varied compositions were analyzed. During the experiments, the topographies of the investigated grinding wheels have been analyzed by means of the TOPOTOOL in detail. The developed software tool allows a detailed description of the kinematic cutting edges depending on the grinding process parameters and the grinding wheel specification. In addition to the calculation of the number of kinematic cutting edges and the area per cutting edge, a differentiation of the cutting edge areas in normal and tangential areas of the grinding wheel's circumferential direction is implemented. Furthermore, the TOPOTOOL enables to analyze the kinematic cutting edges shape by calculating the angles of the grain in different directions. This enables a detailed analysis and a quantitative comparison of grinding wheel topographies related to different grinding wheel specifications. In addition, the influence of the dressing process and wear conditions to the grinding wheel topography can be evaluated. The new approach allows a better characterization of the contact conditions between grinding wheel and workpiece. Hence, the impact of a specific topography on the grinding process behavior, the generated grinding energy distribution, and the grinding result can be revealed.
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Vegetable oil is employed as base fluid in precision grinding because of its biodegradability and non-pollutant properties. Castor oil exhibits superior lubrication performance to other vegetable oils, but its high viscosity and poor flow limit its application in industrial production. In this study, castor oil was used as base oil and individually mixed with six other kinds of vegetable oils (i.e., soybean, maize, peanut, sunflower, palm, and rapeseed oils) at a ratio of 1:1 to change the rheological properties of the former. Each mixture was obtained as base oil for minimum quantity lubrication grinding. The high-temperature nickel-based alloy GH4169 was used as workpiece to evaluate the lubrication performance at the grinding wheel/workpiece interface. The mechanism of lubrication was also studied based on the molecular structure of vegetable oil. Specific grinding force, specific grinding energy, surface roughness, surface microtopography, and grinding debris were compared among the experimental and comparison groups (castor oil). The workpiece surface profile was analyzed using the correlation function and cross-correlation coefficient. Results indicated that the comprehensive lubricating performance of mixed oil was superior to that of castor oil, and soybean/castor oil exhibited the optimal performance. The specific tangential grinding force and specific normal grinding force were 0.664 and 1.886 N/mm, respectively, with 27.03% and 23.15% reduction, respectively, with respect to those of castor oil. The surface profile curves of the workpiece obtained from four kinds of working conditions (castor oil, castor/soybean oil, castor/maize oil, and castor/palm oil) were also analyzed. The amplitude of the surface profile curve in castor/soybean oil is larger and the correlation coefficient is higher (0.51) than those under other mixed oils; hence, the workpiece showed the optimal surface quality.
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Grinding low carbon steel with diamond is regarded to be not feasible due to its chemical affinity to iron. A workpiece with comparable low hardness 330 HV30 and low-carbon content is selected. Therefore, cBN is a suitable choice of a superabrasive and thus employed. Its advantages compared to conventional abrasives are higher material removal rate and less wear. The thermal behaviour of the cBN grinding wheel in different environmental conditions is examined. The dry grinding process with a cBN grinding wheel is discussed and compared to wet grinding, grinding with minimum quantity lubrication and CO2 cooling. Increase in material removal rate and low wear rates are targeted. An electroplated, monolayer cBN grinding wheel with open structure design guarantees higher cooling ability and enlarged space for chips. The wear behaviour of the grinding wheel and the thermal damage on the workpiece surface are investigated. Cutting forces and temperatures are measured during the process for different high feed rates and depth of cuts. The thermal damages are evaluated by microscopic texture analysis. Grinding wheel dust contamination and loading connected with a significant temperature increase could be observed under dry environment. Cleaning impact of cooling nozzle on grinding wheel surface led to decreased normal forces and better surface roughness. Cooling impact of minimum quantity lubrication and CO2 cooling appeared less significant than emulsion.
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A tiny amount of cutting fluid is atomised and consumed at a very low rate in SQCL (small quantity cooling lubrication) grinding process and delivered in grinding zone. Grindability is significantly influenced by aerosol characteristics. In the present work, CFD (computational fluid dynamics) based modelling of the aerosol (air atomised water) produced by an internal-mix nozzle was carried out and validated. Various parameters, which are significantly pertinent to grindability, like droplet diameter, droplet velocity and heat transfer coefficient, were in the focus of the study. The model suggests that the SQCL technology can be effectively used at comparatively high atomising pressure with reduced flow rate for achieving adequate level of heat transfer coefficient. It was further concluded that higher flow rates or atomising pressure increases the wettable area, helping in reduction of the grinding zone temperature. Intensity of the tensile residual stress and tangential grinding force were found to be reduced in both cases but the former one was more sensitively influenced by increase in atomising pressure.
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An adaptive control is proposed for dry surface grinding to extend the use of the wheel without needing to be dressed, preserving at the same time the surface integrity of the workpiece. The implementation of this adaptive control needs to use predictive models of thermal damage, as in the case of Malkin's model, which calculates the allowable grinding power before the workpiece gets burnt for any working condition. In this latter case, the adaptive control of the cutting depth condition requires solving a quartic equation. Since the analytical procedures for solving quartics given in the literature are quite cumbersome to implement in the numeric control of the grinding machine, we propose a closed analytic formula in order to compute directly the unique positive solution. Moreover, we can enhance Malkin's model in order to consider an arbitrary heat flux profile entering into the workpiece and the kinematical correction to the geometrical contact length, in such a way that we can still using the latter solution to the quartic equation.
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To improve the quality of grinding processes, nanofluids can replace traditional cutting fluids, improving cooling, lubrication, and surface finish. However, a disadvantage of nanofluids is that a suspension of nanoparticles tends to agglomerate in the course of a long machining process, leading to cooling performance degradation. Although adding surfactants can improve nanoparticle dispersion, this may pollute the nanoparticles. The present research aims to solve these problems using ultrasonic assistance, first taking advantage of the excellent thermal conductivity of multi-walled carbon nanotubes in nanofluids, with vegetable oil as a cutting fluid, and second, devising an effective ultrasonic-assisted oscillator set-up for Minimum Quantity Lubrication. The oscillator agitates the nanofluid through ultrasonic cavitation to keep the nanoparticles dispersed. This experiment uses NAK80 mold steel as a material for grinding, with four different lubrication methods: dry, MQL, nanofluid (0.25 wt%)/MQL, and nanofluid (0.25 wt%)/ultrasonic MQL. The grinding performance and effects of ultrasonic-assisted dispersion are discussed. The results show that nanofluid/ultrasonic MQL grinding can effectively reduce the agglomeration of nanoparticles, and reduce grinding forces, grinding temperature, and surface roughness to a greater degree than other lubrication methods.
Article
In small quantity cooling lubrication (SQCL) grinding, small quantity of cutting fluid is air-atomized to serve the purpose of cooling and lubrication during the process. As the flow rate of cutting fluid is intended to be set as low as possible, it is essential to develop high performance cutting fluids. In the present work, it has been attempted to enhance cooling-lubrication and wetting characteristics of a bio-degradable flower seed extracted oil, namely sunflower oil, with suspension of multi-walled carbon nano tubes (MWCNT). The suspension was realized by ultrasonic agitation provided through a 700 W probe sonicator. This new generation fluid was used as a cutting fluid in small quantity cooling-lubrication (SQCL) mode; for grinding hardened AISI52100 steel by a vitrified bonded alumina wheel. Thermal conductivity, anti-frictional properties and therefore the cooling-lubrication characteristics of sunflower oil could be enhanced significantly by the dispersion of nanoparticles. Similarly, wettability of the ordinary sunflower oil was substantially improved with nano-suspension. Augmentation of its overall quality by such nano particle suspension subsequently led to remarkable reduction in requirement of specific energy in the grinding process, as compared with the values obtained by using ordinary sunflower oil (SQCL mode) and soluble oil (delivered in conventional flood and SQCL mode). The wear rate of wheel was also significantly minimized and Ft/Fn ratio could be kept at steady and lower level, which depict the better sharpness retention of grits under nano-SQCL environment. Surface quality was superior under the nano-SQCL environment. Compressive residual stress could be achieved on the ground surface along with acceptable surface roughness.
Article
Ag-Cu-Ti/TiX (TiX=TiB2, TiN or TiC) composite filler materials, instead of pure Ag-Cu-Ti alloy, were developed to improve the comprehensive mechanical performance of brazed joints of cubic boron nitride (CBN) grains/bonding layer/steel matrix. This article mainly concerns the effects of TiX addition on the joining interface and compressive strength of brazed CBN grains. The results demonstrate that, due to the variation of chemical activity of Ti atoms induced by TiX addition into the brazing system, the brazing reactions, especially chemical resultants produced at the joining interface between CBN grain and Ag-Cu-Ti alloy, are restrained to some extents. In general, the TiN particles show the greatest suppression effect on the brazing resultants, while the TiC particles have the weakest effect, and TiB2 particles have the medium effect. The optimum reinforcement of the composite filler is finally determined as the TiB2 particles with the content of 8 wt.%, with which the average compressive strength of brazed CBN grains reaches 15 N, which is nearly the same high as that of original CBN grains.
Article
Optimization of grinding process from the viewpoint of surface integrity and production cost is of the primary interest in grinding technology. Previous studies have shown that ultrasonic vibration assisted grinding (UAG) improves the grinding performance. These improvements are attributed to the change of the nature of the cutting process in UAG. On the other hand, minimum quantity lubrication (MQL) method has also been shown to increase the effect of lubrication characteristics of cutting fluid, and to minimize consumption of cutting fluid and reduce its environmental impact. Furthermore, it is perceived that adding nanoparticles to the cutting fluid, will improve its effectiveness. This paper reports an experimental investigation of the vibration assisted grinding process combined with MQL using oil-based nanofluids with MoS2 nanoparticles. Results are presented in terms of normal and tangential forces, force ratio and ground surface roughness. The results show that imposed horizontal ultrasonic vibration significantly decreases the grinding normal force. Also, MQL using nanofluid significantly decreases the grinding tangential force. Finally, simultaneous application of both techniques reduced forces by around 60%, which is very substantial. It also improved the surface quality.
Article
Abstract In any metal cutting operation, the cutting fluid plays a vital role by cooling the surface of the work piece and the cutting tool, removing chips from the cutting zone and by lubricating the tool-work piece interface. However, misuse of the cutting fluid and wrong methods of its disposal can affect human health and the environment badly. Also, it accounts for 16 - 20% of the total cost of manufacturing in the production industry. Among various techniques available on application of the coolant, researchers, of late, have been focussing on Near Dry Machining (NDM)/Minimum Quantity Lubrication (MQL) as it minimizes the use of coolant by spraying the mixture of compressed air and cutting fluid in an optimized manner instead of flood cooling. The MQL technique has proved to be suitable because it complies with the requirements of ‘green’ machining. This paper presents a review of the important research papers published regarding the MQL-based application of mineral oils, vegetable oils and nanofluid-based cutting fluids for different machining processes, such as, drilling, turning, milling and grinding, etc. The paper explains the mechanism of the MQL technique. In a systematic manner, the present work also discusses its effect on the performance parameters of different machining processes. Most of the experimental studies have shown that application of MQL produces surface better than dry machining and similar to that as produced under wet machining. Its application also reduces cutting forces, cutting zone temperature, tool wear, friction coefficient in comparison to dry and wet machining. Therefore, MQL technique has proved to be a viable alternative to the flood lubrication under similar performance parameters.