Comparative study of laser remelting of plasma sprayed coatings on AISI1040 steel with different TiO ₂ –Al ₂ O ₃ and TiO ₂ –SiO ₂ –Cr ₂ O ₃ constituents

Abstract In this study, laser remelting was applied using Nd:Yag laser beam to plasma sprayed coatings that include Al 2 O 3 -43 % of TiO 2 for the first experiment series, 2.15 % of TiO 2 , 4.36 % of SiO 2 in Cr 2 O 3 for the second experiment series, and 4.31 % of TiO 2 , 2.15 % of SiO 2 in Cr 2 O 3 for the third experiment series. Wear tests and microstructural analyses were conducted to reveal characterization of the laser remelted specimens. According to the results, the fusion zone exhibited the highest hardest in the microstructure due to quick solidification inducing martensitic transformation in the microstructure. The pearlitic and ferritic structure were transformed into tempered martensite and bainite in heat affected zone, gradually increasing the micro-hardness. While the coefficient of friction in the first series of specimens was measured as 0.23, it was 0.31 for the second and third series of specimens. Although friction coefficient was higher than that of first series, the lowest weight loss was observed in the specimen that laser remelted at 350A plasma spray current level.