Mustafa Boz - Academia.edu (original) (raw)

Papers by Mustafa Boz

DergiPark (Istanbul University), 2019

Bu çalışmada, gaz atomizasyonu yöntemi ile AM60 magnezyum alaşım tozunun üretimi deneysel olarak ... more Bu çalışmada, gaz atomizasyonu yöntemi ile AM60 magnezyum alaşım tozunun üretimi deneysel olarak araştırılmıştır. Deneyler 770 °C sabit sıcaklık, 35 bar atomizasyon gazı basıncı ve 4 farklı nozul çapında (2, 3, 4, 5 mm) yapılmıştır. Ergiyiği atomize etmek için argon gazı kullanılmıştır. Üretilen AM60 tozlarının şeklini belirleyebilmek için taramalı elektron mikroskobu (SEM), üretilen tozların iç-yapılarında oluşan fazları ve bu fazların % oranlarını belirleyebilmek için XRD ve XRF analizleri, toz boyut analizi için ise lazer ölçüm cihazı kullanılmıştır. Üretilen AM60 magnezyum alaşım tozlarının genel görünümlerinin karmaşık, ligament, çubuksu, damlamsı, flake (pul) ve küresel şeklinde olduğu, fakat nozul çapının küçülmesine bağlı olarak tozların şeklinin çoğunlukla damlamsı ve küresele doğru değiştiği görülmüştür. Elde edilen en ince tozun 770 °C sıcaklıkta, 2 mm nozul çapında 35 bar gaz basıncında oluştuğu ve tozların genelinin karmaşık şekilli olduğu tespit edilmiştir.

Sigma Journal of Engineering and Natural Sciences, Jun 1, 2019

In this study, the effect of gas pressure on the shape and size of the AZ31 alloy powder produced... more In this study, the effect of gas pressure on the shape and size of the AZ31 alloy powder produced by using the gas atomization method was investigated experimentally. Experiments were carried out at 840°C constant temperature, in 2 mm constant nozzle diameter and by applying 4 different gas pressures (5, 15, 25 and 35 bar). Argon gas was used to atomize the melt. Scanning electron microscope (SEM) to determine the shape of produced AZ31 powders, XRD and XRF analysis to determine the phases forming in the internal structures of the produced powders and the percentages of these phases and a laser measuring device for powder size analysis were used. The general appearances of AZ31 alloy powders produced had general appearances of complex, ligament, acicular, droplet, flake and spherical shape, but depending on the increase in gas pressure, the shape of the powders is seen to change mostly towards droplet and spherical.

DergiPark (Istanbul University), Sep 25, 2018

Al12Si tozlarının boyut ve şeklini belirleyebilmek için taramalı elektron mikroskobu (SEM) görünt... more Al12Si tozlarının boyut ve şeklini belirleyebilmek için taramalı elektron mikroskobu (SEM) görüntüleri ve Elek analizi yöntemiyle toz boyut analizleri yapılmıştır. Yapılan analizler sonucunda, nozul çapının küçülmesi ve gaz basıncının artmasıyla toz boyutunun küçüldüğü ve toz şeklinde genelinde ligament, damlamsı, çubuksu ve karmaşık şekilli olduğu tespit edilmiştir. Elde edilen en ince tozların 2 mm nozul çapında 35 bar gaz basıncı ile olduğu gözlemlenmiştir.

Uluslararası Teknolojik Bilimler Dergisi, 2019

Bu çalışmada, gaz atomizasyonu yöntemi ile AM60 magnezyum alaşım tozunun üretimi deneysel olarak ... more Bu çalışmada, gaz atomizasyonu yöntemi ile AM60 magnezyum alaşım tozunun üretimi deneysel olarak araştırılmıştır. Deneyler 770 °C sabit sıcaklık, 35 bar atomizasyon gazı basıncı ve 4 farklı nozul çapında (2, 3, 4, 5 mm) yapılmıştır. Ergiyiği atomize etmek için argon gazı kullanılmıştır. Üretilen AM60 tozlarının şeklini belirleyebilmek için taramalı elektron mikroskobu (SEM), üretilen tozların iç-yapılarında oluşan fazları ve bu fazların % oranlarını belirleyebilmek için XRD ve XRF analizleri, toz boyut analizi için ise lazer ölçüm cihazı kullanılmıştır. Üretilen AM60 magnezyum alaşım tozlarının genel görünümlerinin karmaşık, ligament, çubuksu, damlamsı, flake (pul) ve küresel şeklinde olduğu, fakat nozul çapının küçülmesine bağlı olarak tozların şeklinin çoğunlukla damlamsı ve küresele doğru değiştiği görülmüştür. Elde edilen en ince tozun 770 °C sıcaklıkta, 2 mm nozul çapında 35 bar gaz basıncında oluştuğu ve tozların genelinin karmaşık şekilli olduğu tespit edilmiştir.

Russian Journal of Non-ferrous Metals, May 1, 2020

Journal of The Faculty of Engineering and Architecture of Gazi University, Dec 25, 2019

Bu çalışma iki aşamadan oluşmaktadır. Birinci aşamada toz melalurjisi yöntemi ile bronz esaslı fr... more Bu çalışma iki aşamadan oluşmaktadır. Birinci aşamada toz melalurjisi yöntemi ile bronz esaslı fren balataları üretilmiş ve üretilen balataların sürtünme-aşınma özellikleri incelenmiştir. İkinci aşamada bronz esaslı balata malzemesine farklı oranlarda (0,5 - 4 %) sepiyolit tozu ilave edilerek, yeni balata numuneleri üretilmiş ve üretilen sepiyolit katkılı balata numunelerinin sürtünme aşınma davranışları belirlenerek bronz esaslı balata numuneleri ile karşılaştırılması yapılmıştır. Bu amaçla fren balata numunelerinin yoğunluk, sertlik, sürtünme katsayısı, sürtünme kuvveti ve aşınma miktarları tespit edilmiş, numunelerden sinterleme öncesi ve sonrası mikro yapı görüntüleri ile aşman yüzeylerden SEM görüntüleri alınmış ve farklı bileşimdeki numunelerin aşınma mekanizmaları tespit edilmiştir. Deneyler sonucunda, bu çalışmada kullanılan bronz esaslı metal tozundan üretilen fren balata numunelerinin optimum sürtünme-aşınma davranışlarının 350 MPa presleme basıncında ve 820 °C sinterleme ...

Russian Journal of Non-Ferrous Metals, 2020

The aim of this study is to investigate the AZ31 alloy powder production and characterization pro... more The aim of this study is to investigate the AZ31 alloy powder production and characterization processes experimentally using the gas atomization method. For this purpose, firstly, the design and production of gas atomization units were done at Karabük University Faculty of Technology Department of Manufacturing Engineering. In this gas atomization unit, the manufacturability of AZ31 powder from magnesium alloys was investigated by the gas atomization method which is one of the production methods by powder metallurgy. The parameters and the literature used in the production of materials similar to the AZ31 alloy are taken into account as producibility parameters. In the gas atomization method, parameters such as nozzle diameter, gas pressure, and temperature must be controlled in order to produce the desired properties in metal powder production. The diameter of the nozzle is crucial because it affects the gas pressure and temperature, the size of the powder, and the shape of the powders. Experimental studies were carried out using 3 different temperatures (790, 820, and 850°C), 4 different nozzle diameters (2, 3, 4, and 5 mm) and 4 different gas pressures (5, 15, 25, and 35 bar). In the molten metal atomization process and in the process of forming a protective gas atmosphere, argon gas was preferred. Scanning electron microscopy (SEM) was used to determine the shape of the AZ31 powders produced, XRD, XRF, and SEM-EDX analyses were used to determine the phases in the internals of the produced powders and percentages of these phases. Laser measurement devices were used for powder size analysis and hardness tests were performed to determine the mechanical properties of the produced powders. The powders produced were pressed into masses at 4 different pressing pressures (300, 400, 500, and 600 MPa). The best sinterability values of the bulked powders and sintering process were performed at 3 different temperatures (500, 550, and 600°C). Density measurements were made after pressing and sintering the powders. As a result of the experimental studies, it was found that the powder size decreased with the increase of the gas pressure but the nozzle diameter, and the powder shape changed to the dripping and the spherical in the ligament and complex form. It has been observed that the temperature has no significant effect on the powder size and shape.

Archives of Metallurgy and Materials, 2018

In this study, the effect of gas pressure on the shape and size of the AZ91 alloy powder produced... more In this study, the effect of gas pressure on the shape and size of the AZ91 alloy powder produced by using the gas atomization method was investigated experimentally. Experiments were carried out at 820°C constant temperature in 2-mm nozzle diameter and by applying 4 different gas pressures (0.5, 1.5, 2.5 and 3.5 MPa). Argon gas was used to atomize the melt. Scanning electron microscope (SEM) to determine the shape of produced AZ91 powders, XRD, XRF and SEM-EDX analysis to determine the phases forming in the internal structures of the produced powders and the percentages of these phases and a laser measuring device for powder size analysis were used. Hardness tests were carried out to determine the mechanical properties of the produced powders. The general appearances of AZ91 alloy powders produced had general appearances of ligament, acicular, droplet, flake and spherical shape, but depending on the increase in gas pressure, the shape of the powders is seen to change mostly towards...

Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi

Production of magnesium alloy AM60 Powder by gas atomization method  The effect of gas pressure ... more Production of magnesium alloy AM60 Powder by gas atomization method  The effect of gas pressure in powder production by gas atomization method  Powder characterization of magnesium alloy AM60 powder Figure A. Production process diagram and produced AM60 powder Purpose: In this study, AM60 magnesium alloy powder produced by gas atomization method is produced. As a result of the literature research, there is no study about the production of AM60 magnesium alloy powder by gas atomization method. For this purpose, AM60 magnesium alloy powder production was studied in order to fill this gap in literature. Theory and Methods: Experimental studies were carried out in the gas atomization unit in Karabuk University Technology Faculty Manufacturing Engineering Department. The experiments were carried out at a constant temperature of 820 ° C with a 2 mm nozzle diameter and 4 different gas pressures (5, 15, 25, 35 bar). Argon gas was used to atomize the melt. In order to determine the shape of the AM60 powder produced, scanning electron microscope (SEM), XRD, XRF and SEM-EDX analysis were used to determine the phases formed in the internal structures of the powders and the% ratios of these phases, and laser measuring device was used for the powder size analysis. Hardness tests were performed to determine the mechanical properties of the powders produced. Results: As a result of experimental studies, it was observed that the size of the powder decreased due to the increase of gas pressure. It has been found that gas pressure has a significant effect on powder size and shape in powder production by gas atomization method. Powder produced is generally observed in the form of ligament, droplet, acicular, flake and spherical shape. As a result of the XRD analysis, α (Mg main matrix) phase, β phase Mg17Al12 and very small amount of Mn were detected in the structure. The hardness of the powders produced is higher than the hardness of ingot material (67 HV0,025). Conclusion: In the gas atomization unit, the production of magnesium alloy AM60 powder was carried out by the gas atomization method, which is widely used in the production of powders. In the production of gas atomized magnesium alloy AM60 powder, the smallest powder size was measured as 820 °C, 2 mm nozzle diameter and 35 bar pressure as 41.95 µm. As a result of XRF analysis, it was determined that the AM60 powder produced and the chemical composition of the ingot material were close.

In this study, the production of AM60 magnesium alloy powder by gas atomization method was experi... more In this study, the production of AM60 magnesium alloy powder by gas atomization method was experimentally investigated. Experiments were carried out at a constant temperature of 770 °C, 35 bar atomizing gas pressure and 4 different nozzle diameters (2, 3, 4, 5 mm). Argon gas was used to atomize the melt. Scanning electron microscopy (SEM) was used to determine the shape of the AM60 powders produced, XRD and XRF analyzes were used to determine the internal phases of the produced powders and percentage of these phases, and laser measurement devices were used for powder size analysis. The overall appearance of the AM60 magnesium alloy powders produced is complex, ligament, rod, droplet, flake and spherical but the shape of the powder is mostly dripping and spherical depending on the reduction of the nozzle diameter. The finest powder obtained was found to have a gas pressure of 35 bar at a temperature of 770 °C, a diameter of 2 mm, and the overall shape of the powder was found to be co...

Journal of Magnesium and Alloys

Abstract This study intends to determine the pressability and sinterability of AZ91 powder produc... more Abstract This study intends to determine the pressability and sinterability of AZ91 powder production by gas atomisation method and that of the produced powder for partial production. Therefore, first, a gas atomisation unit has been designed and manufactured in the laboratories of the Karabuk University, Department of Manufacturing Engineering. Atomised powder production has been achieved at a temperature of 795 °C, with nozzle diameters of 2 and 4 mm and four different gas pressures (5, 15, 25, 35 bars). Argon gas has been used for atomisation and as a protective gas atmosphere. Scanning electron microscope (SEM) is used to determine the shape of the produced AZ91 powder, and a laser particle size analyzer is used to analyze the powder size. Additionally, a microhardness (HV0.025) measurement has been conducted to determine the hardness of the produced powders. To achieve a homogeneous distribution, the produced powders are mixed in a three-dimensional moving turbulator for 30 min. Mixed powders have been pressed at 300, 400, 500 and 600 MPa and have been sintered at 500 °C, 550 °C and 600 °C. Additionally, the density values have been determined before and after sintering of the materials. SEM images have been obtained from the fractured surfaces of the samples before and after sintering. XRD and EDX analyses have been performed to determine the chemical composition. Further, microhardness (HV0.5) is obtained from the pressure surfaces of the samples to determine the effects of the pressing pressure and the sintering temperature on the hardness. As a result of the experimental studies, it has been observed that the powder size decreases with the increase in gas pressure and that the powder shape generally changes from ligament and complex shape to droplet and spherical shape. From the XRD, XRF and EDX results, it has been determined that the structure comprises an α phase (Mg main matrix) and Mg17Al12 interphase, which is β phase, and very small amounts of MgO have been observed. The hardness of the produced powders increased based on the increase in gas pressure. The densities of the samples increased with both increasing pressing pressure and sintering temperature. It has been observed from the fractured surface SEM images that the number of pores formed in the samples decrease with an increase in the pressing pressure. It has been determined that the post-sintering structure exhibits a typical dendritic structure. In addition to the α-Mg matrix phase, β (Mg17Al12) intermetallic and α + β eutectic were formed in the structure. The microhardness values of the samples decreased depending on the sintering temperature; the highest hardness value was measured as 64,02 HV0.5 at a pressing pressure of 300 MPa and a sintering temperature of 500 °C, whereas the lowest hardness value was measured as 54,86 HV0.5 at a pressing pressure of 600 MPa and a sintering temperature of 600 °C.

Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi

Bu calismada, tozalti kaynak yontemi ile birlestirilen genel amacli yapi celigi ve hardoks hituf ... more Bu calismada, tozalti kaynak yontemi ile birlestirilen genel amacli yapi celigi ve hardoks hituf celik malzemeler kullanilarak uc farkli kaynakli baglanti yapilmistir. Butun kaynakli baglantilarda ayni kaynak parametreleri (325 A, 30-32 V) kullanilmistir. Birlestirilen parcalara sertlik testi uygulanmistir. Birlestirme bolgesinde meydana gelen makro ve mikroyapi degisimi tespit edilmistir. Sonuclarda hardoks hituf celik malzeme kullanilarak yapilan kaynakli baglantilarin daha yuksek sertlik gosterdigi tespit edilmistir. Ayrica yapilan makro ve mikroyapi calismalari sonucunda ITAB bolgesinin genel amacli yapi celiginde daha genis oldugu gorulmustur.

Sakarya University Journal of Science

In this study, SEM images of the samples taken from welded nick break tests of API 5L X65 pipe jo... more In this study, SEM images of the samples taken from welded nick break tests of API 5L X65 pipe joints, whose welding parameters were determined by Taguchi method, were examined. As a result of the investigations, the elongations and orientations exhibited by the grains showed that ductile and brittle fractures were observed in the welded joints. As it was observed from equiaxed, honeycomb like images that the fractures exhibited a ductile behavior. Brittle fractures that occurred due to cleavage breaks in some regions were detected. An apparent effect of welding direction was observed in fracture behavior. It was detected from the SEM images that a ductile fracture structure had occurred in all joints that were performed from bottom to top, while it was observed in the joints performed from top to bottom that generally cleavage planes had developed along with fibrous structures in places, therefore brittle fractures had occurred.

Steel and Composite Structures, 2013

ABSTRACT In this study, an electrolyzing device for the production of metal powders was designed ... more ABSTRACT In this study, an electrolyzing device for the production of metal powders was designed and fabricated. The production of copper powders was performed using a variety of current densities, anode-cathode distances and power removal times. The effect of these parameters on powder particle size and shape was determined. Particle size was measured using a laser diffraction unit while the powder shape was determined by SEM. Experimental results show that an increase in current density leads to a decrease in powder particle size. In addition particle shape changed from globular dendritic to acicular dendritic with increasing the current density. Distance between the cathode and anode also showed a similar influence on powder particle size and shape. An increase in time of powder removal led to an increase in powder particle size, as the shape changed from acicular dendritic to globular dendritic.

铁粉末被生产块的 15 wt % 取样使用粉末冶金学技术的 1 ~ 与石墨粉末混合。粉末为 20 min 在三维的掺合器被混合并且压缩了在一在由使用一个方向性的出版社的 500 MPa 下面的 ... more 铁粉末被生产块的 15 wt % 取样使用粉末冶金学技术的 1 ~ 与石墨粉末混合。粉末为 20 min 在三维的掺合器被混合并且压缩了在一在由使用一个方向性的出版社的 500 MPa 下面的 die。Sinterability 和有不同碳含量的样品的机械性质被调查。Sinteringprocess 在分裂的氨空气与火焰窗帘在一个带炉子上被执行。生产的块样品对 ASTM B-312 横向的破裂力量测试仪器合适并且在 100 g 负担下面在一个出版社与 0.050 kN/s 速度被测试。直到 2 wt % 的石墨数量增加了粒子的接触区域并且充当了润滑剂断然影响 sintering 行为，这被发现。结果显示包含直到 5 wt % 的样品由于珠泽铁数量的增加显示出好 sintering 行为和也好的坚硬。然而，包含石墨(超过 5 wt %) 的更高的数量的样品在 Fe 粉末附近由于免费石墨的解决否定地影响了 sintering 行为，它在坚硬和横向的破裂力量导致了减少。

ZrSiO4 的磨擦穿性质增强了样品被测量，与那些相比，平原，铜基于。为这个目的，密度，坚硬，磨擦系数穿样品的行为被测试。在 sintering 和穿的表面前后的样品的微观结构被扫描电子显微镜学... more ZrSiO4 的磨擦穿性质增强了样品被测量，与那些相比，平原，铜基于。为这个目的，密度，坚硬，磨擦系数穿样品的行为被测试。在 sintering 和穿的表面前后的样品的微观结构被扫描电子显微镜学(SEM ) 也调查，并且 wear 类型是坚定的。最佳磨擦穿行为在在最后的样品的 820 ° C .Density 在 500 MPa 和 sintered 压缩的样品被获得与增加在 sintering 以后在 pre-sintering.However 前增强元素(ZrSiO4 ) 的数量减少了，在包括增强元素(ZrSiO4 ) 的样品的密度没有变化。与增加磨擦表面温度，在样品的磨擦系数的减小被观察。然而，在磨擦系数的最高的减小在包含样品的 0,5% 增强的 ZrSiO4.The SEM 图象的同样收到的样品被观察当没有 ZrSiO4 的基于铜的裂缝衬里材料显示出磨料时，显示了那穿行为，增加 ZrSiO4 的数量结果在到粘合剂的磨料的一个变化穿机制。所有样品展出了磨擦穿价值，它在在 SAE-J661 标准显示出的价值以内。与增加增强 ZrSiO4 的数量，穿样品的抵抗被增加。然而，与 5% 和 6% ZrSiO4 增强的样品证明最好结果。

Metal Powder Report, 2001

Srudies of a range of Cu-Fe-Si-Sn-graphite alloys, with 5wt%C and 15.-18"/ porosity, were describ... more Srudies of a range of Cu-Fe-Si-Sn-graphite alloys, with 5wt%C and 15.-18"/ porosity, were described. Powders were pressed at 300 MPa and liquid phase sintered m H at 1150 "C. Structures were determined. PearliteCu matrices were found but no Fe&, which is derrimental to properties. The materials were shown to have good self-lubricating and tribologic.al properties at high pressures and low speeds. New materials with good anti-friction properties It was reported that new hearing alloys, based on Cu with small amounts of Sn and absence of Pb, had been developed. These were shown to have good anti-friction properties and did not require complex equipment for manufacture.

Materials & Design, 2004

In this study, Al 1080 alloy materials were welded using friction stir welding process. The influ... more In this study, Al 1080 alloy materials were welded using friction stir welding process. The influence of stirrer design on the welding process was investigated. For this purpose, five different stirrers, one of them square cross-sectioned and the rest were cylindrical with 0.85, 1.10, 1.40 and 2.1 mm screw pitched were used to carry out welding process. Bonding could be effected with the square, 0.85 and 1.10 mm screw pitched stirrers. Microscopic examination of the weld zone and the tension test results showed that the best bonding was obtained with 0.85 mm screw pitched stirrer. In addition, temperature distribution with in the weld zone was also determined.

Materials Science Forum, 2011

In this study, electrolyze unit, which is used for the production of metal powders, was designed ... more In this study, electrolyze unit, which is used for the production of metal powders, was designed and produced. The production of powder was carried out by using different parameter times of powder removal (5, 10, 20, 30 and 40 min.). The effect of time of powder removal on powder particle size and shape was examined. Laser particle measurement machine and SEM were also used to measure particle size and particle shape respectively. Experimental results indicated that an increase in time of powder removal caused an increase in powder particle size and its shape changed from acicular dentritic to globular dentritic.

DergiPark (Istanbul University), 2019

Bu çalışmada, gaz atomizasyonu yöntemi ile AM60 magnezyum alaşım tozunun üretimi deneysel olarak ... more Bu çalışmada, gaz atomizasyonu yöntemi ile AM60 magnezyum alaşım tozunun üretimi deneysel olarak araştırılmıştır. Deneyler 770 °C sabit sıcaklık, 35 bar atomizasyon gazı basıncı ve 4 farklı nozul çapında (2, 3, 4, 5 mm) yapılmıştır. Ergiyiği atomize etmek için argon gazı kullanılmıştır. Üretilen AM60 tozlarının şeklini belirleyebilmek için taramalı elektron mikroskobu (SEM), üretilen tozların iç-yapılarında oluşan fazları ve bu fazların % oranlarını belirleyebilmek için XRD ve XRF analizleri, toz boyut analizi için ise lazer ölçüm cihazı kullanılmıştır. Üretilen AM60 magnezyum alaşım tozlarının genel görünümlerinin karmaşık, ligament, çubuksu, damlamsı, flake (pul) ve küresel şeklinde olduğu, fakat nozul çapının küçülmesine bağlı olarak tozların şeklinin çoğunlukla damlamsı ve küresele doğru değiştiği görülmüştür. Elde edilen en ince tozun 770 °C sıcaklıkta, 2 mm nozul çapında 35 bar gaz basıncında oluştuğu ve tozların genelinin karmaşık şekilli olduğu tespit edilmiştir.

Sigma Journal of Engineering and Natural Sciences, Jun 1, 2019

In this study, the effect of gas pressure on the shape and size of the AZ31 alloy powder produced... more In this study, the effect of gas pressure on the shape and size of the AZ31 alloy powder produced by using the gas atomization method was investigated experimentally. Experiments were carried out at 840°C constant temperature, in 2 mm constant nozzle diameter and by applying 4 different gas pressures (5, 15, 25 and 35 bar). Argon gas was used to atomize the melt. Scanning electron microscope (SEM) to determine the shape of produced AZ31 powders, XRD and XRF analysis to determine the phases forming in the internal structures of the produced powders and the percentages of these phases and a laser measuring device for powder size analysis were used. The general appearances of AZ31 alloy powders produced had general appearances of complex, ligament, acicular, droplet, flake and spherical shape, but depending on the increase in gas pressure, the shape of the powders is seen to change mostly towards droplet and spherical.

DergiPark (Istanbul University), Sep 25, 2018

Al12Si tozlarının boyut ve şeklini belirleyebilmek için taramalı elektron mikroskobu (SEM) görünt... more Al12Si tozlarının boyut ve şeklini belirleyebilmek için taramalı elektron mikroskobu (SEM) görüntüleri ve Elek analizi yöntemiyle toz boyut analizleri yapılmıştır. Yapılan analizler sonucunda, nozul çapının küçülmesi ve gaz basıncının artmasıyla toz boyutunun küçüldüğü ve toz şeklinde genelinde ligament, damlamsı, çubuksu ve karmaşık şekilli olduğu tespit edilmiştir. Elde edilen en ince tozların 2 mm nozul çapında 35 bar gaz basıncı ile olduğu gözlemlenmiştir.

Uluslararası Teknolojik Bilimler Dergisi, 2019

Bu çalışmada, gaz atomizasyonu yöntemi ile AM60 magnezyum alaşım tozunun üretimi deneysel olarak ... more Bu çalışmada, gaz atomizasyonu yöntemi ile AM60 magnezyum alaşım tozunun üretimi deneysel olarak araştırılmıştır. Deneyler 770 °C sabit sıcaklık, 35 bar atomizasyon gazı basıncı ve 4 farklı nozul çapında (2, 3, 4, 5 mm) yapılmıştır. Ergiyiği atomize etmek için argon gazı kullanılmıştır. Üretilen AM60 tozlarının şeklini belirleyebilmek için taramalı elektron mikroskobu (SEM), üretilen tozların iç-yapılarında oluşan fazları ve bu fazların % oranlarını belirleyebilmek için XRD ve XRF analizleri, toz boyut analizi için ise lazer ölçüm cihazı kullanılmıştır. Üretilen AM60 magnezyum alaşım tozlarının genel görünümlerinin karmaşık, ligament, çubuksu, damlamsı, flake (pul) ve küresel şeklinde olduğu, fakat nozul çapının küçülmesine bağlı olarak tozların şeklinin çoğunlukla damlamsı ve küresele doğru değiştiği görülmüştür. Elde edilen en ince tozun 770 °C sıcaklıkta, 2 mm nozul çapında 35 bar gaz basıncında oluştuğu ve tozların genelinin karmaşık şekilli olduğu tespit edilmiştir.

Russian Journal of Non-ferrous Metals, May 1, 2020

Journal of The Faculty of Engineering and Architecture of Gazi University, Dec 25, 2019

Bu çalışma iki aşamadan oluşmaktadır. Birinci aşamada toz melalurjisi yöntemi ile bronz esaslı fr... more Bu çalışma iki aşamadan oluşmaktadır. Birinci aşamada toz melalurjisi yöntemi ile bronz esaslı fren balataları üretilmiş ve üretilen balataların sürtünme-aşınma özellikleri incelenmiştir. İkinci aşamada bronz esaslı balata malzemesine farklı oranlarda (0,5 - 4 %) sepiyolit tozu ilave edilerek, yeni balata numuneleri üretilmiş ve üretilen sepiyolit katkılı balata numunelerinin sürtünme aşınma davranışları belirlenerek bronz esaslı balata numuneleri ile karşılaştırılması yapılmıştır. Bu amaçla fren balata numunelerinin yoğunluk, sertlik, sürtünme katsayısı, sürtünme kuvveti ve aşınma miktarları tespit edilmiş, numunelerden sinterleme öncesi ve sonrası mikro yapı görüntüleri ile aşman yüzeylerden SEM görüntüleri alınmış ve farklı bileşimdeki numunelerin aşınma mekanizmaları tespit edilmiştir. Deneyler sonucunda, bu çalışmada kullanılan bronz esaslı metal tozundan üretilen fren balata numunelerinin optimum sürtünme-aşınma davranışlarının 350 MPa presleme basıncında ve 820 °C sinterleme ...

Russian Journal of Non-Ferrous Metals, 2020

The aim of this study is to investigate the AZ31 alloy powder production and characterization pro... more The aim of this study is to investigate the AZ31 alloy powder production and characterization processes experimentally using the gas atomization method. For this purpose, firstly, the design and production of gas atomization units were done at Karabük University Faculty of Technology Department of Manufacturing Engineering. In this gas atomization unit, the manufacturability of AZ31 powder from magnesium alloys was investigated by the gas atomization method which is one of the production methods by powder metallurgy. The parameters and the literature used in the production of materials similar to the AZ31 alloy are taken into account as producibility parameters. In the gas atomization method, parameters such as nozzle diameter, gas pressure, and temperature must be controlled in order to produce the desired properties in metal powder production. The diameter of the nozzle is crucial because it affects the gas pressure and temperature, the size of the powder, and the shape of the powders. Experimental studies were carried out using 3 different temperatures (790, 820, and 850°C), 4 different nozzle diameters (2, 3, 4, and 5 mm) and 4 different gas pressures (5, 15, 25, and 35 bar). In the molten metal atomization process and in the process of forming a protective gas atmosphere, argon gas was preferred. Scanning electron microscopy (SEM) was used to determine the shape of the AZ31 powders produced, XRD, XRF, and SEM-EDX analyses were used to determine the phases in the internals of the produced powders and percentages of these phases. Laser measurement devices were used for powder size analysis and hardness tests were performed to determine the mechanical properties of the produced powders. The powders produced were pressed into masses at 4 different pressing pressures (300, 400, 500, and 600 MPa). The best sinterability values of the bulked powders and sintering process were performed at 3 different temperatures (500, 550, and 600°C). Density measurements were made after pressing and sintering the powders. As a result of the experimental studies, it was found that the powder size decreased with the increase of the gas pressure but the nozzle diameter, and the powder shape changed to the dripping and the spherical in the ligament and complex form. It has been observed that the temperature has no significant effect on the powder size and shape.

Archives of Metallurgy and Materials, 2018

In this study, the effect of gas pressure on the shape and size of the AZ91 alloy powder produced... more In this study, the effect of gas pressure on the shape and size of the AZ91 alloy powder produced by using the gas atomization method was investigated experimentally. Experiments were carried out at 820°C constant temperature in 2-mm nozzle diameter and by applying 4 different gas pressures (0.5, 1.5, 2.5 and 3.5 MPa). Argon gas was used to atomize the melt. Scanning electron microscope (SEM) to determine the shape of produced AZ91 powders, XRD, XRF and SEM-EDX analysis to determine the phases forming in the internal structures of the produced powders and the percentages of these phases and a laser measuring device for powder size analysis were used. Hardness tests were carried out to determine the mechanical properties of the produced powders. The general appearances of AZ91 alloy powders produced had general appearances of ligament, acicular, droplet, flake and spherical shape, but depending on the increase in gas pressure, the shape of the powders is seen to change mostly towards...

Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi

Production of magnesium alloy AM60 Powder by gas atomization method  The effect of gas pressure ... more Production of magnesium alloy AM60 Powder by gas atomization method  The effect of gas pressure in powder production by gas atomization method  Powder characterization of magnesium alloy AM60 powder Figure A. Production process diagram and produced AM60 powder Purpose: In this study, AM60 magnesium alloy powder produced by gas atomization method is produced. As a result of the literature research, there is no study about the production of AM60 magnesium alloy powder by gas atomization method. For this purpose, AM60 magnesium alloy powder production was studied in order to fill this gap in literature. Theory and Methods: Experimental studies were carried out in the gas atomization unit in Karabuk University Technology Faculty Manufacturing Engineering Department. The experiments were carried out at a constant temperature of 820 ° C with a 2 mm nozzle diameter and 4 different gas pressures (5, 15, 25, 35 bar). Argon gas was used to atomize the melt. In order to determine the shape of the AM60 powder produced, scanning electron microscope (SEM), XRD, XRF and SEM-EDX analysis were used to determine the phases formed in the internal structures of the powders and the% ratios of these phases, and laser measuring device was used for the powder size analysis. Hardness tests were performed to determine the mechanical properties of the powders produced. Results: As a result of experimental studies, it was observed that the size of the powder decreased due to the increase of gas pressure. It has been found that gas pressure has a significant effect on powder size and shape in powder production by gas atomization method. Powder produced is generally observed in the form of ligament, droplet, acicular, flake and spherical shape. As a result of the XRD analysis, α (Mg main matrix) phase, β phase Mg17Al12 and very small amount of Mn were detected in the structure. The hardness of the powders produced is higher than the hardness of ingot material (67 HV0,025). Conclusion: In the gas atomization unit, the production of magnesium alloy AM60 powder was carried out by the gas atomization method, which is widely used in the production of powders. In the production of gas atomized magnesium alloy AM60 powder, the smallest powder size was measured as 820 °C, 2 mm nozzle diameter and 35 bar pressure as 41.95 µm. As a result of XRF analysis, it was determined that the AM60 powder produced and the chemical composition of the ingot material were close.

In this study, the production of AM60 magnesium alloy powder by gas atomization method was experi... more In this study, the production of AM60 magnesium alloy powder by gas atomization method was experimentally investigated. Experiments were carried out at a constant temperature of 770 °C, 35 bar atomizing gas pressure and 4 different nozzle diameters (2, 3, 4, 5 mm). Argon gas was used to atomize the melt. Scanning electron microscopy (SEM) was used to determine the shape of the AM60 powders produced, XRD and XRF analyzes were used to determine the internal phases of the produced powders and percentage of these phases, and laser measurement devices were used for powder size analysis. The overall appearance of the AM60 magnesium alloy powders produced is complex, ligament, rod, droplet, flake and spherical but the shape of the powder is mostly dripping and spherical depending on the reduction of the nozzle diameter. The finest powder obtained was found to have a gas pressure of 35 bar at a temperature of 770 °C, a diameter of 2 mm, and the overall shape of the powder was found to be co...

Journal of Magnesium and Alloys

Abstract This study intends to determine the pressability and sinterability of AZ91 powder produc... more Abstract This study intends to determine the pressability and sinterability of AZ91 powder production by gas atomisation method and that of the produced powder for partial production. Therefore, first, a gas atomisation unit has been designed and manufactured in the laboratories of the Karabuk University, Department of Manufacturing Engineering. Atomised powder production has been achieved at a temperature of 795 °C, with nozzle diameters of 2 and 4 mm and four different gas pressures (5, 15, 25, 35 bars). Argon gas has been used for atomisation and as a protective gas atmosphere. Scanning electron microscope (SEM) is used to determine the shape of the produced AZ91 powder, and a laser particle size analyzer is used to analyze the powder size. Additionally, a microhardness (HV0.025) measurement has been conducted to determine the hardness of the produced powders. To achieve a homogeneous distribution, the produced powders are mixed in a three-dimensional moving turbulator for 30 min. Mixed powders have been pressed at 300, 400, 500 and 600 MPa and have been sintered at 500 °C, 550 °C and 600 °C. Additionally, the density values have been determined before and after sintering of the materials. SEM images have been obtained from the fractured surfaces of the samples before and after sintering. XRD and EDX analyses have been performed to determine the chemical composition. Further, microhardness (HV0.5) is obtained from the pressure surfaces of the samples to determine the effects of the pressing pressure and the sintering temperature on the hardness. As a result of the experimental studies, it has been observed that the powder size decreases with the increase in gas pressure and that the powder shape generally changes from ligament and complex shape to droplet and spherical shape. From the XRD, XRF and EDX results, it has been determined that the structure comprises an α phase (Mg main matrix) and Mg17Al12 interphase, which is β phase, and very small amounts of MgO have been observed. The hardness of the produced powders increased based on the increase in gas pressure. The densities of the samples increased with both increasing pressing pressure and sintering temperature. It has been observed from the fractured surface SEM images that the number of pores formed in the samples decrease with an increase in the pressing pressure. It has been determined that the post-sintering structure exhibits a typical dendritic structure. In addition to the α-Mg matrix phase, β (Mg17Al12) intermetallic and α + β eutectic were formed in the structure. The microhardness values of the samples decreased depending on the sintering temperature; the highest hardness value was measured as 64,02 HV0.5 at a pressing pressure of 300 MPa and a sintering temperature of 500 °C, whereas the lowest hardness value was measured as 54,86 HV0.5 at a pressing pressure of 600 MPa and a sintering temperature of 600 °C.

Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi

Bu calismada, tozalti kaynak yontemi ile birlestirilen genel amacli yapi celigi ve hardoks hituf ... more Bu calismada, tozalti kaynak yontemi ile birlestirilen genel amacli yapi celigi ve hardoks hituf celik malzemeler kullanilarak uc farkli kaynakli baglanti yapilmistir. Butun kaynakli baglantilarda ayni kaynak parametreleri (325 A, 30-32 V) kullanilmistir. Birlestirilen parcalara sertlik testi uygulanmistir. Birlestirme bolgesinde meydana gelen makro ve mikroyapi degisimi tespit edilmistir. Sonuclarda hardoks hituf celik malzeme kullanilarak yapilan kaynakli baglantilarin daha yuksek sertlik gosterdigi tespit edilmistir. Ayrica yapilan makro ve mikroyapi calismalari sonucunda ITAB bolgesinin genel amacli yapi celiginde daha genis oldugu gorulmustur.

Sakarya University Journal of Science

In this study, SEM images of the samples taken from welded nick break tests of API 5L X65 pipe jo... more In this study, SEM images of the samples taken from welded nick break tests of API 5L X65 pipe joints, whose welding parameters were determined by Taguchi method, were examined. As a result of the investigations, the elongations and orientations exhibited by the grains showed that ductile and brittle fractures were observed in the welded joints. As it was observed from equiaxed, honeycomb like images that the fractures exhibited a ductile behavior. Brittle fractures that occurred due to cleavage breaks in some regions were detected. An apparent effect of welding direction was observed in fracture behavior. It was detected from the SEM images that a ductile fracture structure had occurred in all joints that were performed from bottom to top, while it was observed in the joints performed from top to bottom that generally cleavage planes had developed along with fibrous structures in places, therefore brittle fractures had occurred.

Steel and Composite Structures, 2013

ABSTRACT In this study, an electrolyzing device for the production of metal powders was designed ... more ABSTRACT In this study, an electrolyzing device for the production of metal powders was designed and fabricated. The production of copper powders was performed using a variety of current densities, anode-cathode distances and power removal times. The effect of these parameters on powder particle size and shape was determined. Particle size was measured using a laser diffraction unit while the powder shape was determined by SEM. Experimental results show that an increase in current density leads to a decrease in powder particle size. In addition particle shape changed from globular dendritic to acicular dendritic with increasing the current density. Distance between the cathode and anode also showed a similar influence on powder particle size and shape. An increase in time of powder removal led to an increase in powder particle size, as the shape changed from acicular dendritic to globular dendritic.

铁粉末被生产块的 15 wt % 取样使用粉末冶金学技术的 1 ~ 与石墨粉末混合。粉末为 20 min 在三维的掺合器被混合并且压缩了在一在由使用一个方向性的出版社的 500 MPa 下面的 ... more 铁粉末被生产块的 15 wt % 取样使用粉末冶金学技术的 1 ~ 与石墨粉末混合。粉末为 20 min 在三维的掺合器被混合并且压缩了在一在由使用一个方向性的出版社的 500 MPa 下面的 die。Sinterability 和有不同碳含量的样品的机械性质被调查。Sinteringprocess 在分裂的氨空气与火焰窗帘在一个带炉子上被执行。生产的块样品对 ASTM B-312 横向的破裂力量测试仪器合适并且在 100 g 负担下面在一个出版社与 0.050 kN/s 速度被测试。直到 2 wt % 的石墨数量增加了粒子的接触区域并且充当了润滑剂断然影响 sintering 行为，这被发现。结果显示包含直到 5 wt % 的样品由于珠泽铁数量的增加显示出好 sintering 行为和也好的坚硬。然而，包含石墨(超过 5 wt %) 的更高的数量的样品在 Fe 粉末附近由于免费石墨的解决否定地影响了 sintering 行为，它在坚硬和横向的破裂力量导致了减少。

ZrSiO4 的磨擦穿性质增强了样品被测量，与那些相比，平原，铜基于。为这个目的，密度，坚硬，磨擦系数穿样品的行为被测试。在 sintering 和穿的表面前后的样品的微观结构被扫描电子显微镜学... more ZrSiO4 的磨擦穿性质增强了样品被测量，与那些相比，平原，铜基于。为这个目的，密度，坚硬，磨擦系数穿样品的行为被测试。在 sintering 和穿的表面前后的样品的微观结构被扫描电子显微镜学(SEM ) 也调查，并且 wear 类型是坚定的。最佳磨擦穿行为在在最后的样品的 820 ° C .Density 在 500 MPa 和 sintered 压缩的样品被获得与增加在 sintering 以后在 pre-sintering.However 前增强元素(ZrSiO4 ) 的数量减少了，在包括增强元素(ZrSiO4 ) 的样品的密度没有变化。与增加磨擦表面温度，在样品的磨擦系数的减小被观察。然而，在磨擦系数的最高的减小在包含样品的 0,5% 增强的 ZrSiO4.The SEM 图象的同样收到的样品被观察当没有 ZrSiO4 的基于铜的裂缝衬里材料显示出磨料时，显示了那穿行为，增加 ZrSiO4 的数量结果在到粘合剂的磨料的一个变化穿机制。所有样品展出了磨擦穿价值，它在在 SAE-J661 标准显示出的价值以内。与增加增强 ZrSiO4 的数量，穿样品的抵抗被增加。然而，与 5% 和 6% ZrSiO4 增强的样品证明最好结果。

Metal Powder Report, 2001

Srudies of a range of Cu-Fe-Si-Sn-graphite alloys, with 5wt%C and 15.-18"/ porosity, were describ... more Srudies of a range of Cu-Fe-Si-Sn-graphite alloys, with 5wt%C and 15.-18"/ porosity, were described. Powders were pressed at 300 MPa and liquid phase sintered m H at 1150 "C. Structures were determined. PearliteCu matrices were found but no Fe&, which is derrimental to properties. The materials were shown to have good self-lubricating and tribologic.al properties at high pressures and low speeds. New materials with good anti-friction properties It was reported that new hearing alloys, based on Cu with small amounts of Sn and absence of Pb, had been developed. These were shown to have good anti-friction properties and did not require complex equipment for manufacture.

Materials & Design, 2004

In this study, Al 1080 alloy materials were welded using friction stir welding process. The influ... more In this study, Al 1080 alloy materials were welded using friction stir welding process. The influence of stirrer design on the welding process was investigated. For this purpose, five different stirrers, one of them square cross-sectioned and the rest were cylindrical with 0.85, 1.10, 1.40 and 2.1 mm screw pitched were used to carry out welding process. Bonding could be effected with the square, 0.85 and 1.10 mm screw pitched stirrers. Microscopic examination of the weld zone and the tension test results showed that the best bonding was obtained with 0.85 mm screw pitched stirrer. In addition, temperature distribution with in the weld zone was also determined.

Materials Science Forum, 2011

In this study, electrolyze unit, which is used for the production of metal powders, was designed ... more In this study, electrolyze unit, which is used for the production of metal powders, was designed and produced. The production of powder was carried out by using different parameter times of powder removal (5, 10, 20, 30 and 40 min.). The effect of time of powder removal on powder particle size and shape was examined. Laser particle measurement machine and SEM were also used to measure particle size and particle shape respectively. Experimental results indicated that an increase in time of powder removal caused an increase in powder particle size and its shape changed from acicular dentritic to globular dentritic.