Browsing by Author "Islak, Serkan"

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Aşınnmayı Önlemede Termokimyasal işlem Olarak Borlamanın Kullanılması
(MetalMakina, 2009) Islak, Serkan; Uzun, Arif
BOR KARBÜRLÜ ELMASLI KESİCİ SOKETLERİN MİKROYAPI VE MEKANİK ÖZELLİKLER
(6. ULUSLARARASI TOZ METALURJİSİ KONFERANSI ve SERGİSİ, 2011) Islak, Serkan; Kır, Durmuş; Çelik, Halis; Çelik, Ertuğrul
Bu çalışmada, doğal taş kesme işlerinde kullanılan elmaslı kesici soketlere bor karbür (B4C) ilavesinin mikroyapı ve mekanik özellikleri üzerine etkisi araştırılmıştır. Bu amaçla, deneylerde B4C ağırlıkça % 2, 5 ve 10 oranlarında kullanıldı. Tüm deneylerde sıcak presleme işlemi 35 MPa basınçta, 700 °C sıcaklıkta ve 3 dakika süreyle yapılmıştır. Soketlerin mikroyapı ve faz bileşimi taramalı elektron mikroskobu (SEM), X-ışın difraktogramı (XRD), X ışını enerji dağılım spektrometresi (EDS) ile belirlenmiştir. Mikrosertlik ve eğme dayanımı değerleri ise sırasıyla sertlik ve üç noktalı eğme test cihazıyla ölçülmüştür. Soketlerin sertlik ve eğme dayanımları bor karbürün oranına bağlı olarak değişmiştir. In this study, effect of boron carbide (B4C) addition on microstructure and mechanical properties of diamond cutting segments that are used in cutting works of natural stones were investigated. For this purpose, the boron carbide was changed as 2, 5 and 10 wt. % percents. In all of the experiments, hot pressing process was carried out at 35 MPa pressure, at 700 °C temperature and 3 minutes sintering time. Microstructure and phase composition of segments were determined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis. Microhardness and bending strength values were measured by hardness and three-point bending test devices, respectively. Hardness and bending strength values of segments changed depending on boron carbide rate.
DOĞAL TAŞ KESME İŞLERİNDE KULLANILAN ALTERNATİF KÜBİK BOR NİTRÜRLÜ KESİCİ TAKIMLARIN MİKROYAPI VE MEKANİK ÖZELLİKLERİ
(INTERNATIONAL POWDER METALLURGY CONFERENCE & EXHIBITION, 2011-05-11) Kır, Durmuş; Islak, Serkan; Çelik, Halis; Çelik, Ertuğrul
Bu çalışmada, doğal taş kesme işlerinde kullanılan elmaslı kesici takımlarda elmasın yerine alternatif olarak kübik bor nitrürün (cBN) kullanılabilirliği araştırılmıştır. Bu amaçla soketlere farklı oranlarda kübik bor nitrür ilave edildi. Tüm soketler 35 MPa basınç altında, 600 °C sıcaklıkta ve 3 dakika sinterleme süresinde sıcak preste üretildi. Soketlerin mikroyapı ve faz bileşimi taramalı elektron mikroskobu (SEM), X-ışın difraktogramı (XRD), X ışını enerji dağılım spektrometresi (EDS) ile belirlenmiştir. Soketlerin mekanik özellikleri üç noktalı eğme testi kullanılarak tespit edilmiştir. Eğme testi sonuçları kübik bor nitrürlü soketlerin eğme mukavemetlerinin elmaslı soketlerinkinden daha yüksek çıktığını göstermiştir.
Effect of boron carbide on the microstructure and the mechanical properties of segments produced using hot pressing method
(Academic Journals Scientific Research and Essays Vol. 7(23), 2012) Islak, Serkan; Kır, Durmuş; Çelik, Ertuğrul; Çelik, Halis
In this study, effect of boron carbide (B4C) addition on microstructure and mechanical properties of diamond cutting segments was investigated. For this purpose, the boron carbide addition quantity was changed as 2, 5 and 10 wt%. In all of the experiments, hot pressing process was carried out at 35 MPa, at 700°C and sintering time of 3 min. Microstructure and phase composition of segments were determined by Scanning Electron Microscopy, Energy Dispersive Spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis. Hardness and bending strength values were measured by hardness and three-point bending test devices, respectively. Hardness and bending strength values of segments changed depending on boron carbide rate.
Effect of boron carbide on the microstructure and the mechanical properties of segments produced using hot pressing method
(Academic Journals Scientific Research and Essays Vol. 7(23), 2012) Islak, Serkan; Kır, Durmuş; Çelik, Ertuğrul; Çelik, Halis
In this study, effect of boron carbide (B4C) addition on microstructure and mechanical properties of diamond cutting segments was investigated. For this purpose, the boron carbide addition quantity was changed as 2, 5 and 10 wt%. In all of the experiments, hot pressing process was carried out at 35 MPa, at 700°C and sintering time of 3 min. Microstructure and phase composition of segments were determined by Scanning Electron Microscopy, Energy Dispersive Spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis. Hardness and bending strength values were measured by hardness and three-point bending test devices, respectively. Hardness and bending strength values of segments changed depending on boron carbide rate.
Effect of the cBN Content and Sintering Temperature on the Transverse Rupture Strength and Hardness of cBN/Diamond Cutting Tools
(Science of Sintering, 44 (2012) 235-243, 2012) Kır, Durmuş; Islak, Serkan; Çelik, Halis; Çelik, Ertuğrul
The aim of this work was to investigate the effect of cBN content and sintering temperature on the transverse rupture strength (TRS) of cBN/diamond cutting tools produced by hot pressing. The segments containing different cBN content were manufactured under 35 MPa pressure at 600, 650 and 700 °C with a 3 minutes sintering time. The TRS of segments were determined using three-point bending test. Microstructure and phase composition of fracture surface of segments were determined by scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The obtained results show that the TRS of the segments with cBN were higher than that of the segments with diamond.
Effect of the cBN Content and Sintering Temperature on the Transverse Rupture Strength and Hardness of cBN/DiamondCutting Tools
(Science of Sintering, 2012) Kır, Durmuş; Islak, Serkan; Çelik, Halis; Çelik, Ertuğrul
The aim of this work was to investigate the effect of cBN content and sintering temperature on the transverse rupture strength (TRS) of cBN/diamond cutting tools produced by hot pressing. The segments containing different cBN content were manufactured under 35 MPa pressure at 600, 650 and 700 °C with a 3 minutes sintering time. The TRS of segments were determined using three-point bending test. Microstructure and phase composition of fracture surface of segments were determined by scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The obtained results show that the TRS of the segments with cBN were higher than that of the segments with diamond
Effect on microstructure of TiO2 rate in Al2O3-TiO2 composite coating produced by plasma spray method
(ptoelectronics and Advanced Materials – Rapid Communications, Volume: 6, No: 9-10, 2012, p. 844-849., 2012) Islak, Serkan; Buytoz, Soner; Ersöz, Emine; Orhan, Nuri; Stokes, Joseph; Somunkıran, İlyas
In this study, Al2O3-TiO2 composite coatings were thermally sprayed on the SAE 1040 steel using atmospheric plasma spray (APS) process of mixed different rates micron–sized TiO2 and micron-sized Al2O3 powders. The effects of TiO2 addition on the microstructure, phase compositions and microhardness of the coatings were investigated by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD) and microhardness tester. The results show that the Al2O3-TiO2 composite coatings consists of both fully melted regions and partially melted regions, and the fully melted region has a lamellar-like structure. Phase transformations from mainly stable α-Al2O3 and anatase-TiO2 in the powders to predominant metastable γ-Al2O3, rutile-TiO2 and Al2TiO5 phase in the Al2O3-TiO2 composite coatings were observed. It was determined that the pore content decreased with the increased in the TiO2 powder rate. The microhardness of the coating layers was 3-4.5 times higher than substrate material. The average microhardness values of the coatings were found to reach 650-860 HV.
Effect on microstructure of TiO2 rate in Al2O3-TiO2 composite coating produced by plasma spray method
(ptoelectronics and Advanced Materials – Rapid Communications, Volume: 6, No: 9-10, 2012, p. 844-849., 2012) Islak, Serkan; Buytoz, Soner; Ersöz, Emine; Orhan, Nuri; Stokes, Joseph; Somunkıran, İlyas
In this study, Al2O3-TiO2 composite coatings were thermally sprayed on the SAE 1040 steel using atmospheric plasma spray (APS) process of mixed different rates micron–sized TiO2 and micron-sized Al2O3 powders. The effects of TiO2 addition on the microstructure, phase compositions and microhardness of the coatings were investigated by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD) and microhardness tester. The results show that the Al2O3-TiO2 composite coatings consists of both fully melted regions and partially melted regions, and the fully melted region has a lamellar-like structure. Phase transformations from mainly stable α-Al2O3 and anatase-TiO2 in the powders to predominant metastable γ-Al2O3, rutile-TiO2 and Al2TiO5 phase in the Al2O3-TiO2 composite coatings were observed. It was determined that the pore content decreased with the increased in the TiO2 powder rate. The microhardness of the coating layers was 3-4.5 times higher than substrate material. The average microhardness values of the coatings were found to reach 650-860 HV.
FeW -SiC Esaslı Kompozit Kaplamaların Mikro Yapı ve Aşınma özellikleri
(International Advanced Technologies Symposium (IATS’11), 16-18 May 2011, Elazığ, Turkey, 2011) Eski, Özkan; Islak, Serkan; Buytoz, Soner
In this paper, FeW+SiC based metal matrix composite (MMC) coating layer on the AISI 304 stainless steel were formed by gas tungsten arc (GTA) weld process. Rate of SiC in the produced coating was changed as 10, 25 and 50 wt. % in order to investigate the effect of silicon carbide (SiC) on the microstructure, hardness and abrasive wear properties. Optical microscope (OM), scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS) and X-ray diffraction (XRD) were employed for studying the microstructure and elemental analysis of the coatings. Optical and SEM observations showed that coating layer was uniformly bonded to substrate. The formation of Fe2C, Cr7C3 , W2C carbides ve Fe2Si, CrSi2 silicides has been determined in the microstructure. It was concluded that FeW-25 % SiC composite coating was the most suitable combination as a result of the study on the properties of hardness and wear performance.
GTA YÖNTEMİ KULLANILARAK ÜRETİLEN SiC(p) ESASLI KAPLAMALARIN AŞINMA DAVRANIŞLARININ İNCELENMESİ
(e-Journal of New World Sciences Academy, 2009-03) Islak, Serkan; Yıldırım, M.Mustafa
Bu çalışmada, GTA yöntemi kullanılarak alt tabaka malzemesi olarak seçilen 45Mn5 çeliğinin yüzeyine silisyum karbür (SiC) tozu kaplanmıştır. Farklı kaplama tozu miktarları kullanılarak yapılan kaplama işleminde numunelerin abrasiv aşınma özellikleri pim-disk test yöntemi ile belirlenmiştir. Kaplama bölgesinde oluşan mikroyapıların ve üretim parametrelerinin abrasiv aşınma üzerine etkileri araştırılmıştır. En iyi aşınma direnci 41.3 kJ/cm enerji girdisinde, 0.44 mmsn-1 üretim hızında ve 2.5 gr SiC ilavesinde elde edilmiştir. Ayrıca en yüksek mikro sertlik değeri 1250 HV0.2 olarak ölçülmüştür. Mikroyapıda oluşan M7C3, M2C ve FeSi2 fazlarının varlığında parçaların aşınma direncinde ve sertlik değerlerinde yükselme olduğu tespit edilmiştir.
Is›l Püskürtme Yöntemi
(MetalMakina, 2008) Islak, Serkan
Günümüzde metal yüzeyinde deforme olayının yoğun bir şekilde meydana gelmesi, bilim adamlaı ve araştırmacıları yüzey mühendisliği konusunda araştırma yapmasını sağlamıştır. Bu araştırmalar sonucunda da çeşitli yüzey modifiye yöntemleri gelişltirilmiş olup; bunlardan biri de ısıl püskürtme (thermal spray) yöntemidir. Bu literatür çalıflmasında metal kaplama yöntemi olan ısıl püskürtme yöntemi hakkında bilgi verilmiştir.
Mermer kesme takımlarında metal matris seçimi
(Metal Makina Dergisi 188, 256-259, 2011, 2011) Islak, Serkan
Microstructural and wear properties of FeW-SiC based composite coatings produced by tungsten inert gas (TIG) surfacing process
(Optoelectronics and Advanced Materials – Rapid Communications, Volume: 5, No: 6, 2011, p. 65-72, 2011) Islak, Serkan; Eski, Özkan; Buytoz, Soner
In this study, SiC reinforced and FeW based metal matrix composite (MMC) was produced on substrate of AISI 304 stainless steel using tungsten inert gas (TIG) surfacing process. In order to examine the effect of SiC on microstructure, hardness and abrasive wear properties inside FeW matrix, SiC was changed by ratios of 10, 25, and 50% by weight. Phase compound and microstructure of coating layers were examined using X-ray diffractometer (XRD) and scanning electron microscope (SEM). Wear behaviours of samples were evaluated using pin-on disc sliding wear tests. It was found that Fe2C, Cr7C3, W2C carbide and Fe2Si, CrSi2 silica were formed in the microstructure. The studies conducted concluded that FeW-25 wt. % SiC composite coating was the most appropriate combination in terms of hardness and wear performance.
Microstructural andWear Characteristics of High Velocity Oxygen Fuel (HVOF) Sprayed NiCrBSi–SiC Composite Coating on SAE 1030 Steel
(Arabian Journal for Science and Engineering, 2011) Buytoz, Soner; Ulutan, Mustafa; Islak, Serkan; Kurt, Bülent; Çelik, O. Nuri
In this paper, wear properties of NiCrBSi–SiC coatings were investigated using the ball-on-disk wear test. In experimental study, NiCrBSi–SiC powders were sprayed using a high-velocity oxygen fuel technique on an SAE 1030 steel substrate. Powder mixtures with different weight mixing ratios, NiCrBSi + 10 wt% SiC, NiCrBSi + 20 wt% SiC and NiCrBSi + 40 wt% SiC coatings were prepared. The deposited coatings are compared in terms of their phase composition, microstructure and hardness. It is proved that the degree of mixing of the NiCrBSi and SiC components in the powder has a massive effect on the phase composition, microstructure and hardness of the coatings.Wear tests were conducted on both the uncoated and coated substrates at same normal load, speed, and wear distance. It has been determined that the coated substrates exhibit a very good tribological performance in comparison to the uncoated substrate. The increase in the adhesive wear resistance provided by the coating has been attributed to the presence of a large amount of dispersed Ni and Cr carbide and/or borides in the Ni matrix.
Microstructural Characteristics of High Velocity Oxygen Fuel (HVOF) sprayed NiCrBSi-SiC Composite Coating on a Low Alloy Steel
(6th International Advanced Technologies Symposium (IATS’11), 16-18 May 2011, 13-21, Elazığ,, 2011) Islak, Serkan; Buytoz, Soner; Kurt, Bülent
In this study, NiCrBSi-SiC powders were sprayed using a high velocity oxygen fuel technique on AISI 1030 steel substrate. Powder mixtures with different weight mixing ratios, NiCrBSi+10 wt.% SiC, NiCrBSi+20 wt.% SiC and NiCrBSi+40 wt.% SiC coatings were prepared. The deposited coatings are compared in terms of their phase composition, microstructure and hardness. It is proved that the degree of mixing of the NiCrBSi and SiC components in the powder has massive effect on the phase composition, microstructure and hardness of the coatings. The structure and morphologies of Ni-based coatings were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) and optical microscope (OM). Microstructures of the coatings have been revealed to the presence of a large amount of dispersed Ni and Cr carbide and/or borides in the Ni matrix. Microhardness of the coatings is found to in the range of 550–830 Hv, which is higher than the substrate material
Microstructure and microhardness characterization of Cr3C2-SiC Coatings Produced Using the Plasma Transferred Arc Metho
(MP-Materials Testing-Materials and Components Technology and Application, 54 (11-12), pp. 793-799, 2012, 2012) Islak, Serkan; Eski, Özkan; Buytoz, Soner; Karagöz, Muzaffer; Stokes, Joseph; Ireland, Dublin
Microstructure and microhardness characterization of Cr3C2-SiC Coatings Produced Using the Plasma Transferred Arc Methot
(MP-Materials Testing-Materials and Components Technology and Application, 54 (11-12), pp. 793-799, 2012, 2012) Islak, Serkan; Eski, Özkan; Buytoz, Soner; Karagöz, Muzaffer; Stokes, Joseph; Ireland, Dublin
Plazma Püskürtme Yöntemiyle AISI 304 Paslanmaz Çelik Yüzeyinde Elde Edilen ZrO2 / Al2O3- % 13TiO2 Kompozit Kaplamasının Mikroyapı Özellikleri
(6th International Advanced Technologies Symposium (IATS’11), 16-18 May 2011, Elazığ, 2011) Islak, Serkan; Buytoz, Soner
In this study, ZrO2 /Al2O3 -13 % TiO2 composite coatings that various proportions of Al2O3 -13 wt. % TiO2 were reinforced into ZrO2 matrix powder were formed on the AISI 304 stainless steel surface by plasma spray. Microstructure and phase composition of coatings was determined by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis. Lamellae and porous microstructures were obtained in the coatings. In addition, a small amount of unmelted particles, partially melted and fully melted regions in microstructure of coatings were observed. With the increasing addition of Al2O3 - TiO2 , a decrease in the pores was observed. XRD analysis results showed the formation of ZrO2 , Al0.52Zr0.48O1.74, ZrTiO4 , Al0.18Zr0.82O1.91, Al2O3 , Al2Zr3 , Al3Ti and Ti2O3 phases in the coating layer. In compare to the substrate, microhardness of coating layer is 4-5 times more. Maximum
PLAZMA PÜSKÜRTME YÖNTEMİYLE OLUŞTURULAN AL2O3- TİO2 KOMPOZİT KAPLAMALARIN MİKROYAPI KARAKTERİSTİKLERİ
(International Iron & Steel Symposium, 02-04 April 2012, Karabük, Türkiye, 2012) Buytoz, Soner; Ersöz, Emine; Islak, Serkan; Orhan, Nuri; Kurt, Bülent; Somunkıran, İlyas
Yapılan çalışmada, SAE 1040 çeliğine plazma püskürtme yöntemiyle, Al2O3 tozu ve değişen oranlarda TiO2 tozu ilave edilerek Al2O3/TiO2 kompozit kaplamaları oluşturuldu. Elde edilen kaplama tabakalarının metalografi incelemeleri neticesinde lamelli bir mikroyapı içerisinde az miktarda ergimemiş partiküller, kısmi ergimiş ve tamamen ergimiş bölgeler gözlendi. Al2O3-TiO2 kompozit kaplamalarında TiO2 toz miktarının artmasına karşı gözenek miktarının azaldığı tespit edildi. XRD analizi sonuçları, kaplama tabakasında γ -Al2O3, α-Al2O3, Al2TiO5, ve TiO2 (rutil) fazlarının oluştuğunu göstermiştir. Kaplama tabakasının mikrosertliği alt malzemeye göre 3-4.5 kat daha fazladır. Kaplama tabakalarının ortalama mikrosertlik değerleri 650-850 HV arasında değişmiştir. In this study, Al2O3-TiO2 composite coatings were thermally sprayed on the SAE 1040 steel using atmospheric plasma spray (APS) process of mixed different rates of micron–sized TiO2 and micron-sized Al2O3 powders. The effects of TiO2 addition on the microstructure, phase compositions and microhardness of the coatings were investigated by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD) and microhardness tester. The results show that the Al2O3-TiO2 composite coatings consist of both fully melted regions, partially melted regions, and the unmelted particles in regions of lamellar-like structure. Phase transformations from mainly stable α-Al2O3 and anatase-TiO2 in the powders to predominant metastable γ-Al2O3, rutile-TiO2 and Al2TiO5 phase in the Al2O3-TiO2 composite coatings were observed. It was idendified that the pore content was decreased with increase of TiO2 powder ratio. The microhardnesses of the coating layers were found to be 3-4.5 times higher than that of substrate material. The average microhardness values of the coatings were changed as 650-860 HV.