Olcay EKŞİ - Academia.edu (original) (raw)

Papers by Olcay EKŞİ

Taha Toros Arsivi, Dosya No: 44-Cetin-Aydin-Ragip Emec. Not: Metin ekli dokumanin 19. sayfasinda ... more Taha Toros Arsivi, Dosya No: 44-Cetin-Aydin-Ragip Emec. Not: Metin ekli dokumanin 19. sayfasinda yer almaktadir.

Latin American Applied Research - An international journal

AISI 304L steel is widely preferred in many fields such as pipe sector, biomedical and nuclear in... more AISI 304L steel is widely preferred in many fields such as pipe sector, biomedical and nuclear industry due to its wear behavior and good machinability. In this experimental study, temperature-dependent wear properties and worn surface structures of AISI 304L steel were investigated. All tests were conducted by using pin-on-disc test equipment under unlubricated conditions. As ambient temperatures, 25°C, 50°C, 100°C, 150°C, and 200°C were selected. The results indicated that the main friction properties, wear mechanisms, and wear rate of the worn steel samples were significantly affected by altering the test temperatures. It was observed that the friction coefficient oscillated at lower temperatures, but this case was quite different at higher temperatures. Micro observations showed that mixed deformation characteristic dominated by adhesive wear was observed between 25°C and 150°C while abrasive wear became more effective between 150°C and 200°C. Moreover, wear rate and sp...

Journal of Polymer Engineering

In this study, three-dimensional (3D) printed polylactic acid (PLA) samples are annealed at sligh... more In this study, three-dimensional (3D) printed polylactic acid (PLA) samples are annealed at slightly above the glass transition temperature to enhance the mechanical properties. Tensile and Izod impact tests are conducted to investigate the mechanical properties of 3D printed PLA specimens. Influence of different infill patterns on tensile strength and impact resistance are also observed. Porous structure of 3D printed PLA specimens is examined and average void area densities are determined via scanning electron microscope (SEM) images. Influence of void area density on mechanical properties is investigated. Tensile behaviour of 3D printed PLA parts is simulated with proposed nonlinear autoregressive with exogenous and transfer function models. While stress data and determined void area densities are used as inputs, strain data obtained from tensile tests used as output for the model structures.

Usak University Journal of Material Sciences, 2014

In this study, 5% and 15% in weight carbon fiber reinforced polypropylene (PP) sheets were formed... more In this study, 5% and 15% in weight carbon fiber reinforced polypropylene (PP) sheets were formed under appropriate vacuum and temperature conditions by using truncated cone-shaped thermoforming mold. In addition to this, 5% in weight glass fiber reinforced High Density Polyethylene (HDPE) sheets were formed using truncated cone-shaped, cylindrical, and cubic shaped thermoforming molds by thermoforming. Composite sheets used in this work were produced with a laboratory-type plastic extruder which has a screw diameter of 50 mm. In production of HDPE composite sheets, as a reinforcing material, chopped glass fibers (E-glass) which were provided from glass fiber manufacturer SISECAM A.S. Company were used. Using the same procedure PP (Borealis BE50-7032) thermoplastic granules were used as a matrix material in production of carbon fiber composite sheets. In carbon fiber reinforced sheets, chopped fibers were added during manufacturing. After thermoforming, composite semi-products were examined by visual inspection. Visual defects that affect product quality were obtained. Also carbon fiber distribution was investigated on different sections which were taken from the thermoformed semiproducts by Scanning Electron Microscopy (SEM). Through this experimental study, it is aimed to investigate the effect of defects during plastic extrusion on thermoformed product quality.

Journal of Polymer Engineering, 2021

Acrylonitrile-butadiene-styrene test specimens were additively manufactured by fused deposition m... more Acrylonitrile-butadiene-styrene test specimens were additively manufactured by fused deposition method to investigate the effects of infill pattern and density on wear rate, coefficient of friction, wear mechanisms, and microscopic wear characterization. The surface morphology of specimens was characterized using a scanning electron microscope. Under constant parameters of applied load, sliding speed, and sliding time, wear tests were carried out at room temperature. The study revealed that a grid pattern of high infill density and a honeycomb pattern of low infill density showed the lowest wear rate and lowest coefficient of friction compared to the rectilinear pattern. Infill pattern and density affected the wear rate behavior of specimens directly. Moreover, adhesion between additively manufactured layers along with surface texture affects the wear behavior and wear rate. Increasing infill density allowed poor cooling of previously built layers. Longer process time results in rou...

Materials Testing, 2020

Fused deposition modeling is one of the most well-known additive manufacturing methods. It might ... more Fused deposition modeling is one of the most well-known additive manufacturing methods. It might be considered the easiest way to produce particle reinforced composites or unreinforced sheets which are biodegradable and used in the packaging industry as well as for custom products. In this study, polylactic acid (PLA) sheets were produced by 3D printing and thermoformed using a lab-scale thermoforming machine. This article aims to determine the deformation behavior of 3d printed PLA sheets during thermoforming. In addition to experimental work, finite element analysis was performed to investigate the prediction capabilities of Mooney-Rivlin and Ogden models for PLA sheets. In addition, the initial thickness of the sheet was optimized using FEA and a python script to obtain final uniform thickness distribution. Thanks to 3D printing’s capability for printing sheets of variable thickness, sheets of variable thickness were printed to verify the material models. As a result, based on th...

Strojniški vestnik – Journal of Mechanical Engineering, 2014

Thermoforming is widely used in manufacturing industries to produce large and labour-intensive pr... more Thermoforming is widely used in manufacturing industries to produce large and labour-intensive products. Compared to other manufacturing techniques, thermoforming is an extremely efficient process that is suitable for high-efficiency mass production. In this paper, experimental thermoforming operations were carried out using a lab-scale, sheet-fed thermoformer. Carbon fibre-reinforced PP and unreinforced PS thermoplastic sheets were used in experimental thermoforming operations. The processing parameters were determined for each thermoformed material. Furthermore, a simulation of the thermoforming process was performed using LS-Dyna TM software. The thickness distributions obtained from the experiments were compared with the simulation results. The results show that the parameter that most affects the wall thickness distribution is the geometry of the clamping ring. To produce thermoformed products that have a more uniform thickness distribution, the clamping tool geometry must be selected according to the geometry of the product being thermoformed.

Özet Bu çalışmada, enjeksiyon kalıplama yöntemiyle Polipropilen(PP) ve Poliamit(PA) 6.6 kullanıla... more Özet Bu çalışmada, enjeksiyon kalıplama yöntemiyle Polipropilen(PP) ve Poliamit(PA) 6.6 kullanılarak üretilmiş bir parçanın boyutsal kararlılığının, kalıp yüzey sıcaklığı, ergimiş polimer sıcaklığı gibi parametrelerin değişiminden nasıl etkilendiği Moldflow Plastics Insight yazılımı ile araştırılmıştır. Buna ek olarak, farklı takviye elemanları(cam elyaf, talk pudrası) ilavesinin boyutsal kararlılık üzerine etkisi de araştırılmıştır. Artan takviye elemanı miktarının toplam büzülmeyi azalttığı tespit edilmiştir. Kalıp yüzey sıcaklığının kademeli olarak düşürülmesi, PP ve PA 6.6 malzemeler için boyutsal sapmayı ve hacimsel büzülmeyi azalttığı görülmüştür. Ergimiş polimer sıcaklığının düşürülmesi ise yine her iki türden malzeme için hacimsel büzülme ve boyutsal sapmayı azaltmıştır. Abstract In this work, effect of mold surface temperature and polymer melt temperature on dimensional stability of a plastic part which is produced with Polypropylene and Polyamide 6.6 granules by injection ...

Bu calismada, AISI 1040 celik malzemeden talasli sekil verme ile uretilmis bir robot tutucunun yo... more Bu calismada, AISI 1040 celik malzemeden talasli sekil verme ile uretilmis bir robot tutucunun yorulma hasari, SolidWorks Simulations yazilimi kullanilarak arastirilmistir. Tutucunun kati modeli SolidWorks yaziliminda olusturulmus, SolidWorks Simulations ile lineer gerilme analizi ve yorulma hasari kontrolu yapilmistir. Tutucunun tasarimi degistirilerek alternatif tasarimlar arastirilmistir. Sonuc olarak tutucunun tasarimi geri beslemeli bir surec sonrasinda degismistir. Tutucunun agirliginda yaklasik % 20 azalma saglanmistir. Yapilan tasarim degisikligi sonrasinda tutucuda olusan maksimum gerilmelerin azaldigi ve simulasyon sonuclarina gore parcanin calisma omrunun arttigi belirlenmistir.

Copper shows promising characteristics for applications in electrical sliding contacts. In this s... more Copper shows promising characteristics for applications in electrical sliding contacts. In this study, copper reinforced polylactic acid (PLA-copper) composites manufactured by fused deposition modeling (FDM). Wear behaviour of PLA-copper composites under dry sliding conditions at three different temperature conditions (20C, 50C, 70C) was evaluated by using pin-on-disc wear test equipment with attached heating module with 5N load applied at a sliding velocity of 104.7 mm/s. Tests have presented for 1040 steel bead interacting with polymer composite. Specific wear rates and coefficient of frictions of PLA-Cu polymer composites were evaluated. EDX analysis were conducted to examine the microstructure and scanning electron microscopy is used for the characterization of the worn surfaces.

In this study, wall thickness distribution in a thermoformed product was determined comparatively... more In this study, wall thickness distribution in a thermoformed product was determined comparatively. Firstly thickness distribution was achieved by a thermoforming simulation. In addition to this, thickness profile was created by using Areal Draw Ratio. Obtained two distinct thickness distributions were analysed comparatively. Thermoforming simulation in this study uses thermoformed polymer material properties and process parameters. In contrast, Areal Draw Ratio which is independent of polymer properties and thermoforming process parameters, only works according to product or thermoforming mould geometry. As a result, wall thickness distribution profiles obtained by Areal Draw Ratio show slightly agreement to results obtained by thermoforming simulation. But the weakest point or the thinnest area of the thermoformed product was determined accurately according to both methods. It is apparent that to employ Areal Draw Ratio is not appropriate for determination of thickness distribution...

Advances in Science and Technology Research Journal

In this work, Polystyrene (PS) sheets were thermoformed in predetermined conditions. Wall thickne... more In this work, Polystyrene (PS) sheets were thermoformed in predetermined conditions. Wall thickness distributions obtained by experimental method in PS thermoformed products. Then the same thickness distributions were predicted by using Geometric Element Analysis (GEA). The thickness results were obtained experimentally, compared to thickness distributions which were predicted by GEA. It has been found that GEA does not precisely reveal thickness distributions.

INTERNATIONAL REFEREED JOURNAL OF ENGINEERING AND SCIENCES, 2015

Key Engineering Materials, 2011

Forming conical parts is one of the complex and difficult fields in sheet metal forming processes... more Forming conical parts is one of the complex and difficult fields in sheet metal forming processes. These parts are normally formed in industry by spinning, explosive forming or multistage deep drawing processes. In this paper, forming pure copper conical–cylindrical cups in the hydrodynamic deep drawing process was studied using finite element (FE) simulation and experiment. In this study, the effect of cone angle and punch tip radius on bursting and thickness distribution of the parts and also the effect of pressure path on thickness distribution were examined. Using the measurements of strains and thickness variations on the cup wall, the quality of the drawn cups was evaluated. The results demonstrated that increasing cone angle will lead to higher drawing ratio and uniform thickness distribution. Also, it was concluded that in the conical-cylindrical part the punch tip radius region is the most critical zone. At this zone, the more the cone angle the less the possibility of tear...

Balıkesir Üniversitesi Fen Bilimleri Enstitüsü Dergisi

Copper shows promising characteristics for applications in electrical sliding contacts. In this s... more Copper shows promising characteristics for applications in electrical sliding contacts. In this study, copper reinforced polylactic acid (PLA-copper) composites manufactured by fused deposition modeling (FDM). Wear behaviour of PLA-copper composites under dry sliding conditions at three different temperature conditions (20 o C, 50 o C, 70 o C) was evaluated by using pin-on-disc wear test equipment with attached heating module with 5N load applied at a sliding velocity of 104.7 mm/s. Tests have presented for 1040 steel bead interacting with polymer composite. Specific wear rates and coefficient of frictions of PLA-Cu polymer composites were evaluated. EDX analysis were conducted to examine the microstructure and scanning electron microscopy is used for the characterization of the worn surfaces.

Plug, a type of male mould in thermoforming, is mostly produced by conventional processes such as... more Plug, a type of male mould in thermoforming, is mostly produced by conventional processes such as machining. However, in this study, plugs that are used in thermoforming were produced using Fused Deposition Modelling (FDM). Plugs were produced using Polylactic Acid (PLA) and Aluminium (Al) particle reinforced PLA filaments by a 3d printer. Plugs that are produced by FDM, were polished using 800, 1000, 1200, 1600 and 2000 grit sandpapers to reduce friction. Also, thermal effects such as temperature distribution on the region where the plug touches the plastic sheet, were investigated. It has been found that FDM can be a significant alternative for male mould production in thermoforming. Additionally, PLA filaments have great potential for tool production in thermoforming.

Gümüşhane Üniversitesi Fen Bilimleri Enstitüsü Dergisi

Isil sekillendirme prosesi, gerek otomotiv gerekse ambalaj sanayiinde en cok kullanilan prosesler... more Isil sekillendirme prosesi, gerek otomotiv gerekse ambalaj sanayiinde en cok kullanilan proseslerden biridir. Bu calismada, Polivinil klorur (PVC) filmlerin, erkek kalipla isil sekillendirme sonrasi kalinlik dagilimlari belirlenmistir. Erkek kalibin capi ve erkek kalibin disi kalip icerisindeki dalma derinligi artirilarak bir dizi isil sekillendirme islemi yapilmis ve numuneler elde edilmistir. Bu numunelerdeki kalinlik dagilimi karsilastirmali olarak grafik yontemle incelenmistir. Erkek kalip capinin ve erkek kalibin disi kalip icerisindeki dalma derinliginin artirilmasinin isil sekillendirilen yari mamullerde ozellikle yan duvar ve taban kalinlik dagilimini degistirdigi tespit edilmistir.

Taha Toros Arsivi, Dosya No: 44-Cetin-Aydin-Ragip Emec. Not: Metin ekli dokumanin 19. sayfasinda ... more Taha Toros Arsivi, Dosya No: 44-Cetin-Aydin-Ragip Emec. Not: Metin ekli dokumanin 19. sayfasinda yer almaktadir.

Latin American Applied Research - An international journal

AISI 304L steel is widely preferred in many fields such as pipe sector, biomedical and nuclear in... more AISI 304L steel is widely preferred in many fields such as pipe sector, biomedical and nuclear industry due to its wear behavior and good machinability. In this experimental study, temperature-dependent wear properties and worn surface structures of AISI 304L steel were investigated. All tests were conducted by using pin-on-disc test equipment under unlubricated conditions. As ambient temperatures, 25°C, 50°C, 100°C, 150°C, and 200°C were selected. The results indicated that the main friction properties, wear mechanisms, and wear rate of the worn steel samples were significantly affected by altering the test temperatures. It was observed that the friction coefficient oscillated at lower temperatures, but this case was quite different at higher temperatures. Micro observations showed that mixed deformation characteristic dominated by adhesive wear was observed between 25°C and 150°C while abrasive wear became more effective between 150°C and 200°C. Moreover, wear rate and sp...

Journal of Polymer Engineering

In this study, three-dimensional (3D) printed polylactic acid (PLA) samples are annealed at sligh... more In this study, three-dimensional (3D) printed polylactic acid (PLA) samples are annealed at slightly above the glass transition temperature to enhance the mechanical properties. Tensile and Izod impact tests are conducted to investigate the mechanical properties of 3D printed PLA specimens. Influence of different infill patterns on tensile strength and impact resistance are also observed. Porous structure of 3D printed PLA specimens is examined and average void area densities are determined via scanning electron microscope (SEM) images. Influence of void area density on mechanical properties is investigated. Tensile behaviour of 3D printed PLA parts is simulated with proposed nonlinear autoregressive with exogenous and transfer function models. While stress data and determined void area densities are used as inputs, strain data obtained from tensile tests used as output for the model structures.

Usak University Journal of Material Sciences, 2014

In this study, 5% and 15% in weight carbon fiber reinforced polypropylene (PP) sheets were formed... more In this study, 5% and 15% in weight carbon fiber reinforced polypropylene (PP) sheets were formed under appropriate vacuum and temperature conditions by using truncated cone-shaped thermoforming mold. In addition to this, 5% in weight glass fiber reinforced High Density Polyethylene (HDPE) sheets were formed using truncated cone-shaped, cylindrical, and cubic shaped thermoforming molds by thermoforming. Composite sheets used in this work were produced with a laboratory-type plastic extruder which has a screw diameter of 50 mm. In production of HDPE composite sheets, as a reinforcing material, chopped glass fibers (E-glass) which were provided from glass fiber manufacturer SISECAM A.S. Company were used. Using the same procedure PP (Borealis BE50-7032) thermoplastic granules were used as a matrix material in production of carbon fiber composite sheets. In carbon fiber reinforced sheets, chopped fibers were added during manufacturing. After thermoforming, composite semi-products were examined by visual inspection. Visual defects that affect product quality were obtained. Also carbon fiber distribution was investigated on different sections which were taken from the thermoformed semiproducts by Scanning Electron Microscopy (SEM). Through this experimental study, it is aimed to investigate the effect of defects during plastic extrusion on thermoformed product quality.

Journal of Polymer Engineering, 2021

Acrylonitrile-butadiene-styrene test specimens were additively manufactured by fused deposition m... more Acrylonitrile-butadiene-styrene test specimens were additively manufactured by fused deposition method to investigate the effects of infill pattern and density on wear rate, coefficient of friction, wear mechanisms, and microscopic wear characterization. The surface morphology of specimens was characterized using a scanning electron microscope. Under constant parameters of applied load, sliding speed, and sliding time, wear tests were carried out at room temperature. The study revealed that a grid pattern of high infill density and a honeycomb pattern of low infill density showed the lowest wear rate and lowest coefficient of friction compared to the rectilinear pattern. Infill pattern and density affected the wear rate behavior of specimens directly. Moreover, adhesion between additively manufactured layers along with surface texture affects the wear behavior and wear rate. Increasing infill density allowed poor cooling of previously built layers. Longer process time results in rou...

Materials Testing, 2020

Fused deposition modeling is one of the most well-known additive manufacturing methods. It might ... more Fused deposition modeling is one of the most well-known additive manufacturing methods. It might be considered the easiest way to produce particle reinforced composites or unreinforced sheets which are biodegradable and used in the packaging industry as well as for custom products. In this study, polylactic acid (PLA) sheets were produced by 3D printing and thermoformed using a lab-scale thermoforming machine. This article aims to determine the deformation behavior of 3d printed PLA sheets during thermoforming. In addition to experimental work, finite element analysis was performed to investigate the prediction capabilities of Mooney-Rivlin and Ogden models for PLA sheets. In addition, the initial thickness of the sheet was optimized using FEA and a python script to obtain final uniform thickness distribution. Thanks to 3D printing’s capability for printing sheets of variable thickness, sheets of variable thickness were printed to verify the material models. As a result, based on th...

Strojniški vestnik – Journal of Mechanical Engineering, 2014

Thermoforming is widely used in manufacturing industries to produce large and labour-intensive pr... more Thermoforming is widely used in manufacturing industries to produce large and labour-intensive products. Compared to other manufacturing techniques, thermoforming is an extremely efficient process that is suitable for high-efficiency mass production. In this paper, experimental thermoforming operations were carried out using a lab-scale, sheet-fed thermoformer. Carbon fibre-reinforced PP and unreinforced PS thermoplastic sheets were used in experimental thermoforming operations. The processing parameters were determined for each thermoformed material. Furthermore, a simulation of the thermoforming process was performed using LS-Dyna TM software. The thickness distributions obtained from the experiments were compared with the simulation results. The results show that the parameter that most affects the wall thickness distribution is the geometry of the clamping ring. To produce thermoformed products that have a more uniform thickness distribution, the clamping tool geometry must be selected according to the geometry of the product being thermoformed.

Özet Bu çalışmada, enjeksiyon kalıplama yöntemiyle Polipropilen(PP) ve Poliamit(PA) 6.6 kullanıla... more Özet Bu çalışmada, enjeksiyon kalıplama yöntemiyle Polipropilen(PP) ve Poliamit(PA) 6.6 kullanılarak üretilmiş bir parçanın boyutsal kararlılığının, kalıp yüzey sıcaklığı, ergimiş polimer sıcaklığı gibi parametrelerin değişiminden nasıl etkilendiği Moldflow Plastics Insight yazılımı ile araştırılmıştır. Buna ek olarak, farklı takviye elemanları(cam elyaf, talk pudrası) ilavesinin boyutsal kararlılık üzerine etkisi de araştırılmıştır. Artan takviye elemanı miktarının toplam büzülmeyi azalttığı tespit edilmiştir. Kalıp yüzey sıcaklığının kademeli olarak düşürülmesi, PP ve PA 6.6 malzemeler için boyutsal sapmayı ve hacimsel büzülmeyi azalttığı görülmüştür. Ergimiş polimer sıcaklığının düşürülmesi ise yine her iki türden malzeme için hacimsel büzülme ve boyutsal sapmayı azaltmıştır. Abstract In this work, effect of mold surface temperature and polymer melt temperature on dimensional stability of a plastic part which is produced with Polypropylene and Polyamide 6.6 granules by injection ...

Bu calismada, AISI 1040 celik malzemeden talasli sekil verme ile uretilmis bir robot tutucunun yo... more Bu calismada, AISI 1040 celik malzemeden talasli sekil verme ile uretilmis bir robot tutucunun yorulma hasari, SolidWorks Simulations yazilimi kullanilarak arastirilmistir. Tutucunun kati modeli SolidWorks yaziliminda olusturulmus, SolidWorks Simulations ile lineer gerilme analizi ve yorulma hasari kontrolu yapilmistir. Tutucunun tasarimi degistirilerek alternatif tasarimlar arastirilmistir. Sonuc olarak tutucunun tasarimi geri beslemeli bir surec sonrasinda degismistir. Tutucunun agirliginda yaklasik % 20 azalma saglanmistir. Yapilan tasarim degisikligi sonrasinda tutucuda olusan maksimum gerilmelerin azaldigi ve simulasyon sonuclarina gore parcanin calisma omrunun arttigi belirlenmistir.

Copper shows promising characteristics for applications in electrical sliding contacts. In this s... more Copper shows promising characteristics for applications in electrical sliding contacts. In this study, copper reinforced polylactic acid (PLA-copper) composites manufactured by fused deposition modeling (FDM). Wear behaviour of PLA-copper composites under dry sliding conditions at three different temperature conditions (20C, 50C, 70C) was evaluated by using pin-on-disc wear test equipment with attached heating module with 5N load applied at a sliding velocity of 104.7 mm/s. Tests have presented for 1040 steel bead interacting with polymer composite. Specific wear rates and coefficient of frictions of PLA-Cu polymer composites were evaluated. EDX analysis were conducted to examine the microstructure and scanning electron microscopy is used for the characterization of the worn surfaces.

In this study, wall thickness distribution in a thermoformed product was determined comparatively... more In this study, wall thickness distribution in a thermoformed product was determined comparatively. Firstly thickness distribution was achieved by a thermoforming simulation. In addition to this, thickness profile was created by using Areal Draw Ratio. Obtained two distinct thickness distributions were analysed comparatively. Thermoforming simulation in this study uses thermoformed polymer material properties and process parameters. In contrast, Areal Draw Ratio which is independent of polymer properties and thermoforming process parameters, only works according to product or thermoforming mould geometry. As a result, wall thickness distribution profiles obtained by Areal Draw Ratio show slightly agreement to results obtained by thermoforming simulation. But the weakest point or the thinnest area of the thermoformed product was determined accurately according to both methods. It is apparent that to employ Areal Draw Ratio is not appropriate for determination of thickness distribution...

Advances in Science and Technology Research Journal

In this work, Polystyrene (PS) sheets were thermoformed in predetermined conditions. Wall thickne... more In this work, Polystyrene (PS) sheets were thermoformed in predetermined conditions. Wall thickness distributions obtained by experimental method in PS thermoformed products. Then the same thickness distributions were predicted by using Geometric Element Analysis (GEA). The thickness results were obtained experimentally, compared to thickness distributions which were predicted by GEA. It has been found that GEA does not precisely reveal thickness distributions.

INTERNATIONAL REFEREED JOURNAL OF ENGINEERING AND SCIENCES, 2015

Key Engineering Materials, 2011

Forming conical parts is one of the complex and difficult fields in sheet metal forming processes... more Forming conical parts is one of the complex and difficult fields in sheet metal forming processes. These parts are normally formed in industry by spinning, explosive forming or multistage deep drawing processes. In this paper, forming pure copper conical–cylindrical cups in the hydrodynamic deep drawing process was studied using finite element (FE) simulation and experiment. In this study, the effect of cone angle and punch tip radius on bursting and thickness distribution of the parts and also the effect of pressure path on thickness distribution were examined. Using the measurements of strains and thickness variations on the cup wall, the quality of the drawn cups was evaluated. The results demonstrated that increasing cone angle will lead to higher drawing ratio and uniform thickness distribution. Also, it was concluded that in the conical-cylindrical part the punch tip radius region is the most critical zone. At this zone, the more the cone angle the less the possibility of tear...

Balıkesir Üniversitesi Fen Bilimleri Enstitüsü Dergisi

Copper shows promising characteristics for applications in electrical sliding contacts. In this s... more Copper shows promising characteristics for applications in electrical sliding contacts. In this study, copper reinforced polylactic acid (PLA-copper) composites manufactured by fused deposition modeling (FDM). Wear behaviour of PLA-copper composites under dry sliding conditions at three different temperature conditions (20 o C, 50 o C, 70 o C) was evaluated by using pin-on-disc wear test equipment with attached heating module with 5N load applied at a sliding velocity of 104.7 mm/s. Tests have presented for 1040 steel bead interacting with polymer composite. Specific wear rates and coefficient of frictions of PLA-Cu polymer composites were evaluated. EDX analysis were conducted to examine the microstructure and scanning electron microscopy is used for the characterization of the worn surfaces.

Plug, a type of male mould in thermoforming, is mostly produced by conventional processes such as... more Plug, a type of male mould in thermoforming, is mostly produced by conventional processes such as machining. However, in this study, plugs that are used in thermoforming were produced using Fused Deposition Modelling (FDM). Plugs were produced using Polylactic Acid (PLA) and Aluminium (Al) particle reinforced PLA filaments by a 3d printer. Plugs that are produced by FDM, were polished using 800, 1000, 1200, 1600 and 2000 grit sandpapers to reduce friction. Also, thermal effects such as temperature distribution on the region where the plug touches the plastic sheet, were investigated. It has been found that FDM can be a significant alternative for male mould production in thermoforming. Additionally, PLA filaments have great potential for tool production in thermoforming.

Gümüşhane Üniversitesi Fen Bilimleri Enstitüsü Dergisi

Isil sekillendirme prosesi, gerek otomotiv gerekse ambalaj sanayiinde en cok kullanilan prosesler... more Isil sekillendirme prosesi, gerek otomotiv gerekse ambalaj sanayiinde en cok kullanilan proseslerden biridir. Bu calismada, Polivinil klorur (PVC) filmlerin, erkek kalipla isil sekillendirme sonrasi kalinlik dagilimlari belirlenmistir. Erkek kalibin capi ve erkek kalibin disi kalip icerisindeki dalma derinligi artirilarak bir dizi isil sekillendirme islemi yapilmis ve numuneler elde edilmistir. Bu numunelerdeki kalinlik dagilimi karsilastirmali olarak grafik yontemle incelenmistir. Erkek kalip capinin ve erkek kalibin disi kalip icerisindeki dalma derinliginin artirilmasinin isil sekillendirilen yari mamullerde ozellikle yan duvar ve taban kalinlik dagilimini degistirdigi tespit edilmistir.