Islak S.Buytoz S.Ersoz E.Orhan N.Stokes J.Hashmi M.S.Somunkiran I.Tosun N.2023-04-122023-04-122012-01-0118426573https://hdl.handle.net/20.500.12597/6129In 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 a-Al2O3 and anatase-TiO2 in the powders to predominant rnetastable y-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.falseCeramic coating | Plasma spray | Rutile-Tio2 | Y-Al2o3Article2-s2.0-84872256947