Browsing by Author "Orhan, Nuri"

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    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.
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    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.
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    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.
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    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.