M.Cemal Cakir

Uludag University · Department of Mechanical Engineering

Shaping of aluminum alloys by chip removal has increased significantly in the industry.Accordingly, issues aiming to reduce friction between the tool and the workpiece and to increasetool life have gained importance. As a result, despite the common use of coolant, minimal lubrica-tion, and cryogenic cooling, it is expected that studies for dry proc...

In this study, a ball collet chuck holder and a standard collet holder were compared. In order to increase the rigidity of the ball collet holder, the number of balls was increased and the gaps between the balls were reduced. The effect of two different holders on the machined surface quality was examined.

This study examined the impact of asymmetric spherical end mills with altered center points on surface quality, utilizing asymmetric tools designed to enhance mold surface quality.

In this study, self-lubricating Aluminum Metal Matrix Composites (AMMC) production was carried out by reinforcing graphite material with solid lubricant feature into Al6061 alloy. Self-lubricating composites were turned in a dry environment without the use of cutting fluid. The effects of solid lubricant reinforcement on cutting temperatures, tool...

In the aggregate and mining industry, an excessive flow rate of raw material from the feeder, caused by irregularities in the raw material being processed by crushers, can lead to blockages or excessive strain on the crusher. Conversely, a low flow rate of raw material can result in high energy consumption by the crusher, despite operating at a low...

Machine learning is widely used in several scientific domains for data prediction. Predicting cutting forces and temperature distribution in the domain of machining, a subdivision of manufacturing techniques, is crucial for enhancing production procedures. Studies in this topic frequently employ experimental methods and the finite element method, a...

As in many other fields, it's important to guess the data that will change how efficiently the machine industry attempts to reduce the costs of both the cutting tools and the finished product itself. For many years, the finite element method has been used to guess the results of machining, such as the cutting forces, the temperature distribution du...

Carbon nanotubes (CNTs) and their composites are gaining popularity due to their exceptional strength qualities. It is well known that adding CNTs to metal foam composites boosts compressive strength. On the other hand CNT addition is still a costly process due to high cost of the CNTs. This study presents a novel and cost-effective solution by sel...

This study investigated how image processing technology and cooling/lubrication methods affect the change in chip color and chip shape when milling Ti6Al4V alloy. The focus was on solving the high temperature problem in the machining of titanium alloys, which are hard and have limited thermal conductivity. The experiment was carried out under the s...

Printed circuit boards (PCBs) can be in various sizes depending on the application. In addition, depending on the application, the microelectronic components (transistors, capacitors, resistors, integrated circuits, etc.) and the location of these components on the PCB may vary. This situation makes it very difficult to define the design concept of...

Printed circuit boards (PCBs) can differ in terms of the electronic components, such as transistors and integrated circuits, as well as the types of solder leads used to link these components to the PCBs. The variations rely on the specific purpose of the PCB. When designing a prototype PCB, it is crucial to carefully select the type of solder lead...

The manufacture of polymers has experienced significant growth since the 1900s due to their favorable attributes such as ease of manufacturing, cost-effectiveness, desirable chemical and physical qualities, as well as their lightweight nature. The escalating utilization of plastic has begun to inflict damage upon the environment, organisms, and hum...

Polymers have rapidly replaced the utilization of glasses, ceramics, metals, and organic textiles due to their cost-effectiveness, lightweight nature, and enhanced functionality. Nevertheless, as a consequence of their chemical composition, polymers undergo a protracted degradation process in natural environments, resulting in a significant accumul...

Printed circuit boards (PCBs) have a sandwich structure consisting of an insulating composite layer between conductive copper layers. The material property of the PCB cannot be defined as isotropic due to this special structure. In addition, variables such as the types of hundreds of components on the PCB, material properties, types of solder leads...

With the new manufacturing technologies, it has been possible to machine hard metals efficiently. During high-speed machining (HSM) of high-strength steel, the poor surface integrity of the workpiece affects the performance of the process. Surface roughness, microstructure, microhardness and residual stress are key performance indices for surface i...

In this study, the performance of the front collision zone of the vehicle, reinforced with an S-shaped front collision rail, was compared to that of the classic straight front collision rail. In order to create a safe living cage in automobiles, half vehicle model was used and the collision performances of two different front collision zone models...

In this study, the performance of the front collision zone of the vehicle, reinforced with an S-shaped front collision rail, was compared to that of the classic straight front collision rail. In order to create a safe living cage in automobiles, half vehicle model was used and the collision performances of two different front collision zone models...

Hemming is a technology used in the automotive industry to join inner and outer closure panels together (hoods, doors, tailgates, etc.). It is the process of bending/folding the flange of the outer panel over the inner one by plastic deformation. Hemming of closure parts in the automotive industry is a complex engineering process that has a lot of...

In this study, an automatic vision-based defect inspection and sorting system has been developed for a plastic injection mold component called side passenger airbag, which is a critical component in automotive safety. In order to detect the defects on the plastic part, the necessary mechanical and automation system for the industrial image processi...

Binek araçlarda yakıtın iletimi ve geri beslemesi, yakıt taşıma sisteminin bir parçası olan yakıt boruları ile gerçekleştirilmektedir. Günümüzde plastik ve fluoraplastik yakıt boruları yaygın olarak kullanılmaktadır. Çalışma kapsamında PA12 malzemesi kullanılarak imal edilmiş üç katmanlı yakıt borusunun sıcaklık girdisi ile şekillendirilmesi ile an...

Bu çalışmada, günümüzde önemi her geçen gün artan ve üzerine yeni çalışmalar gerçekleştirilen insansı robotlar geliştirmek, insan mimiklerini gerçekçi şekilde simüle edecek mekanizmalar tasarlamak ve bu tasarımları gerçekçi boyutlarda bir araya getirerek insansı bir yapı oluşturmak amaçlanmıştır. Türkiye'de benzer konudaki araştırmalar çok kısıtlı...

A novel cold-walled CVD reactor has been designed for low-cost CNT synthesis. Aim was to eliminate the need for electric furnace, carbon-containing gas tanks and flowmeters, reducing energy consumption and gas emissions. Iron nanoparticles emulsion dip coating was preferred to simplify the catalyst preparation process. As carbon precursor, ethanol...

The most attractive aspect of metal foams is that they can combine the properties of metallic materials (e.g., strength, high melting temperature) with the properties of porous materials (e.g., light-weightiness, sound/heat energy absorption). This makes them favorable in aerospace applications where multifunctional lightweight materials are requir...

The closed-cell metal foams are utilized in various industrial applications due to their impact and energy absorption capacity, noise cancelation, and lightweight properties. Additionally, the manufacturing methods of stochastic foams with blowing agents or inert gas injection are well known. However, the poor mechanical strength and high brittlene...

The sub-components that are used in automotive lighting products are coated with aluminum by PVD method due to their aesthetic appearance and reflectivity needs. The PVD coating process is the evaporation of atoms or molecules from the liquid or solid phase under low pressure and condensation of the steam on the substrate.[1] Maintaining the requir...

Negatif Poisson oranına sahip olan öksetik yapılar, mekanik enerji/darbe sönümleme açısından iyi özelliklere sahiptir. Bu yapılar; havacılık-uzay ve savunma sektörlerindeki sandviç yapılı kompozitlerde, zırh üretiminde veya koruyucu spor ekipmanı üretiminde uygulama alanı bulmuştur. Bu çalışmada, öksetik bal peteği yapısının darbe yüklemesi altında...

Bu çalışmada, endüstriyel seri üretimde en çok kullanılan kaynak prosesi olan sıcak plaka kaynağı ele alınmış, Lupolen 4261AG malzemeden üretilmiş plastik parçalara uygulanan sıcak plaka kaynağı araştırılmıştır. Sıcak plaka kaynağı, ısıtılmış takım plakası kullanılarak iki plastik parçanın kaynaştırılması işlemidir. İşlemde her bileşen üzerindeki b...

Emniyet kemeri sistemleri, otomotiv endüstrisinde kullanılan standart güvenlik ekipmanlarındandır. Emniyet kemeri kullanımı sayesinde araç içerisindeki yolcuların güvenlik seviyeleri arttırılmış ve ciddi yaralanmaların önüne geçilmiştir. Özellikle emniyet kemerinin hava yastığıyla birlikte kullanımı sonucunda, yolcuların kafalarının araç kokpitine...

Bu çalışmada, rijit duvar testi sanal ortamda simule edilerek yüksek mukavemetli düşük alaşımlı çelik ön çarpışma kolu et kalınlığının aracın çarpışma performansına etkisi incelenmiş ve en uygun et kalınlığı tespit edilmiştir. Ön çarpışma kollarında HSLA (High-Strength Low-Alloy) çelik grubundaki FEE340 malzemesi kullanılmış ve altı farklı et kalın...

Bu çalışmada, otomotiv endüstrisinde çok sık kullanılan iki farklı çelik malzeme için yarım araç modeli kullanılarak önden çarpışma senaryosu (rijit duvar testi) bilgisayar ortamında simule edilmiştir. Ön çarpışma kollarında kullanılan HSLA (High-Strength Low-Alloy) çelik ailesi grubundaki FEE340 ve DP (Dual Phase) çelik ailesi grubundaki DP600 mal...

zet Çarpışma-kutuları otomobillerde, kaza anında çarpışma enerjisini sönümleyerek aracın ve yolcuların en az zararı almasını sağlayan önemli elemanlardır. Bu çalışmada, öncelikle, alüminyum köpük malzemesinin yarı-statik basma testleri gerçekleştirilerek malzeme modeli oluşturulmuştur. Bu malzeme modeli; farklı oranlarda alüminyum köpük takviyesi y...

In order to absorb the kinetic energy of the crash and provide a sufficiently low deceleration, crash-boxes are employed in vehicles. Occupants and the vehicle body itself are protected in this way. For this purpose, thin-walled steel or aluminum crash-boxes are widely used in automotive industry. Besides, aluminum foam-filling of thin-walled struc...

Crash-boxes are used in vehicles for absorbing the kinetic energy of the crash and providing a sufficiently low deceleration with the help of the crush forces. Occupants and the vehicle body itself (the components behind the crash-box and the bumper) are protected in this way. Thin-walled steel or aluminum crash-boxes are widely used in automotive...

In this work; HMDSO (that is used as protective film layer in PVD metallization processes) releasing is analyzed with the help of computational fluid dynamics to achieve optimized and equal concentration release into the high vacuum chamber. On the other hand, HMDSO that is released to high vacuum chamber, is analyzed in terms of substrate rotation...

In vehicle design, crash-boxes are employed on bumpers for a number of reasons. Among them are absorbing the kinetic energy of the crash, ensuring sufficiently low forces, and providing a sufficiently low deceleration. By achieving these; they protect the passengers, the other body in the crash, and the vehicle body itself (the high cost components...

Literally, hard machining describes machining of parts having hardness over 45 HRC. Besides its advantages like high metal removal rate, easiness of adapting to complex part geometries, possibility of dry cutting; this operation, which can substitute grinding in most cases, has some disadvantages. One of them is the significant increase of surface...

This paper presents a new cooling method to be used in dry metal cutting. This new cooling method is based on a tool holder with cooling fluid circulating inside a closed internal cooling system. A prototype that facilitates the cooling from inside the tool holder was specifically designed and manufactured. For this study, a series of cuttingtrials...

TOFAŞ ve FIAT'da ilk  Daha hafif  Darbenin yönünden etkilenmeksizin yüksek darbe ve titreşim sönümleme  Yerli tedarikçi ile yurt-dışına bağımlılığın önüne geçilmesi  Daha ucuz ve rekabetçi  Patentlenebilir Arka sigorta çarpma testi performans beklentisini karşılayabilen, yüksek enerji emilimi özelliği olan, ve % 30 oranında ağırlık düşüşü sağl...

The life of a tool is affected by many factors such as cutting speed, depth of cut, chip thickness, tool geometry, workpiece material, cutting fluid and the rigidity of the machine tool. This paper introduces the innovative turning strategy of variable feed turning. The workpiece material was AISI 1050, and two types of TiN-coated insert (CNMG-1204...

In this research, the tool-chip interface temperature (TCTI), the tool temperature (TT) and the average surface roughness (Ra) were measured experimentally during the turning of AISI 4140 alloy steel with TiAlN-TiN, PVD-coated, WNVG 080404-IC907 tungsten carbide inserts using an IR pyrometer technique, a K-type thermocouple and a portable surface-r...

Waspaloy, as a nickel superalloy, is a difficult-to-machine material used for gas turbine engine components that require considerable strength and corrosion resistance at high operating temperatures. The machining of nickel-based alloys generates high temperatures at the cutting tool edge. This research investigated the relationship between cutting...

Die springs with rectangular cross section (rectangular die springs) are common in the industry. However, the production of rectangular die springs is difficult, and the cost of production is high. In this study, we examined the use of die springs with circular cross section (circular die springs), which are both easier to produce and less costly,...

This paper presents a new cooling method to use internally cooled cutting tool in orthogonal metal cutting. Internally cooled cutting tool in turning based in a tool holder with cooling fluid flowing inside. In this research, a series of cutting trials was carried out to investigate the practicality and the effectiveness of this internally cooled c...

In machining processes, heat energy comes up because of plastic deformation and friction effects between tool and work piece. This heat energy cause temperature increase on tool so mechanical properties of the tool affected negatively. Rapid wear of the tool is shorten the tool life and also lower the quality of the machined surface. To reduce of t...

Waspaloy is difficult-to-machine material used for gas turbine engine components that call for considerable strength and corrosion resistance at high operating temperatures. The machining of nickel-based alloys generates high temperatures at the cutting tool edge. In this research, the correlation between cutting parameters and cutting temperature...

ÖZET Bu çalışmada, çekirdeğine kadar 62 HRC sertliğine sertleştirilmiş soğuk iş takım çeliği iş parçalarının (AISI D2) seramik takımlarla (CNGA 120404 KY4400) tornalanması işlemlerinde takım ömrü – işleme parametreleri (Vc, f, ap) ilişkisinin tepki yüzeyi metodolojisinde kullanılan merkezi bileşik tasarım yardımıyla modellenmesi ve analizi yapılmış...

The life of tool is affected by many factors such as cutting speed, depth of cut, chip thickness, tool geometry, workpiece material or the cutting fluid and rigidity of machine tool. In this paper, an innovative turning strategy, variable feed turning, was introduced and a thorough investigation has been carried out to study the effect of gradual f...

Bu çalışmada, 55 HRc sertliğe sahip DIN1.2344 ESR kalıp çeliğinden hazırlanan deney numunelerine cep açma işlemi CNC dik işleme tezgahında gerçekleştirilmiştir. 3 farklı kesme hızı ve 5 farklı diş başı ilerleme değeri kullanılmıştır. İşleme sonunda takım aşınmaları mikroskop yardımıyla tespit edilmiştir. Ardından deney numuneleri üzerindeki kalıcı...

In metal cutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature me...

Endüstride yaygın olarak kullanılan geleneksel imalat yöntemleri talaşlı imalat yöntemleri olarak tornalama, frezeleme, delme, vargelleme, taşlama vb, talaşsız imalat yöntemleri olarak da döküm, plastik şekil verme ve kaynak olarak genelleştirilebilir. Bunların dışında elektroerozyon, lazer, ultrasonik, basınçlı su jeti ve plazma ile işleme gibi al...

Bu çalışmada köpük malzemelerin genel yapısı incelenmiş, kapalı hücre yapılı ve sandviç tip alüminyum köpük malzemeler lazer ve tel erezyon yöntemleri ile kesim denemelerine tabii tutulmuş ve sonuçları değerlendirilmiştir. Saniyede sahip olduğu özelikleri ile kendine yer bulmaya çalışan metal köpük malzemeler için ikincil işlemler her geçen gün dah...

Bu çalışmada bir çift vidalı eksturder makinesinde Poliamid malzemesinin kompaund edilmesinde ekstrüzyon işlemi sonlu elemanlar ve sonlu hacimler yöntemi kullanılarak modellenmiş ve sonuçlar gerçek koşullarla karşılaştırılmıştır. Ayrıca birden fazla çıkış ağzına sahip olan çıkış kafasında polimer akışının homojen olup olmadığı araştırılmıştır. Newt...

In this paper, ductile irons with different microstructures were machined in a group of experiments using standard testing procedure and the effect of microstructure on the machinability was investigated. Bars (diameter 90mm×320mm) of ferritic/pearlitic, tempered martensitic, and lower ausferritic microstructures were produced by various heat treat...

The work presented in this paper examines the effects of cutting parameters (cutting speed, feed rate and depth of cut) onto the surface roughness through the mathematical model developed by using the data gathered from a series of turning experiments performed. An additional investigation was carried out in order to evaluate the influence of two w...

Austempered ductile iron (ADI) has found enormous applications in recent years due to its high strength and hardness, coupled with substantial ductility and toughness. The high strength and hardness of ADI have caused many researchers and engineers to doubt the machinability of this material. In the present work a series of test were conducted in o...

Machining processes have various restrictions related to cost, material, production method etc. and design for manufacturability is the key success factor for constructing the best equilibrium between the different aspects of production. In the present paper, to improve manufacturability of a part design, a research on design recommendations for tu...

Heat treating the ductile cast iron produced austempered ductile iron (ADI), which has outstanding mechanical properties that can be varied over a wide range by varying the heat treatment parameters. In the present work a series of test were conducted and the effects of austempering temperature and times onto the material properties was investigate...

In metal cutting, the problems need to be well analyzed in order to take precautions before any unexpected results are encountered. This process plays a significant role in achieving consistent quality and in controlling the overall cost of manufacturing. However, it is a difficult task that needs an expert who has a great deal of information and e...

Bu çalışmada, alüminyum köpük malzemelerin ikincil işlemleri sonlu elemanlar yöntemiyle (FEM) modellenmiştir. Kapalı hücre ve sandviç yapılı numuneler CO2 lazer kesme teknolojisi, tel erozyonla kesim (EDM) yöntemi ve mekanik dairesel döner testere ile kesilmiş; sandviç yapılı alüminyum köpük malzeme numuneleri farklı bir metot (metal dolgulu epoksi...

In this work cutting FEA of cutting tools prior to fracture is investigated. Fracture is the catastrophic end of the cutting edge that should be avoided for the cutting tool in order to have a longer tool life. This paper presents finite element modelling of a cutting tool just before its fracture. The data used in FEA are gathered from a tool brea...

In the modern manufacturing of sophisticated parts with 3D sculptured surfaces, die and mold making operations are the most widely used machining processes to remove unwanted material. To manufacture a die or a mold, many different cutting tools are involved, from deep hole drills to the smallest ball nose end mills. Since the specification of each...

Tool life and condition monitoring systems can be used effectively in cutting processes. Since no exact and reliable mathematical models exist for the cutting process which are able to predict tool wear, tool breakage, cutting temperature and forces, the development of tool condition monitoring systems are highly requested by industry, especially i...

The aim of this work is to define computer-aided optimum operation and tool sequences that are to be used in Generative Process Planning System developed for rotational parts. The software developed for this purpose has a modular structure. Cutting tools are selected automatically using the machinability data, workpiece feature information, machine...

the variables affecting the economics of machining operations are numerous and include machine tool cpacity, required workpiece geometry, cutting tool conditions of velocity, feed rate, depth of cut and many others. This paper describes a procedure to calculate the machining conditions for milling operations according to minimum production cost as...

This paper describes a procedure to calculate the machining conditions, such as the cutting speed, feed rate and depth of cut for turning operations with minimum production cost or the maximum production rate as the objective function. The optimum number of machining passes and the depth of cut for each pass is obtained through the dynamic programm...

Industry requires that all or a sample of the products manufactured are inspected in order that some measure of quality and reliability is attained. For a complex manufactured object the inspection process will have many stages - from testing the compatibility of each component to testing the performance and acceptance of the finished product. The...

In this study, an expert system (ES) has been developed for diagnosing faults causing breakdowns in computer numerical controlled (CNC) machine tools.The knowledge-base (KB) for ES has been established using structural, conceptual and heuristic knowledge. Generic design information for mechanical, electrical and hydraulic structural elements of CNC...

When components have been made they need to be inspected. In this paper some newly devised automatic methods are described that compare a set of measurements of an engineering componenet taken by a coordinate measuring machine with a master solid model of the measured component obtained from a CAD system. Once matched, the two may then be compared...