Wear behavior of plasma-sprayed Al-Si/TiB 2/h-BN composite coatings

In this study, mechanically alloyed Al-12Si/TiB 2/h-BN composite powder was deposited onto aluminum substrates by atmospheric plasma spraying. Wear performance of the coating was investigated with respect to the structural evolution of the composite powder coating. Non-lubricated ball-on-disk tests were used to examine the wear resistance of the coatings. The worn surfaces were examined using scanning electron microscopy and energy dispersive spectroscopy to elucidate the wear mechanisms operating at the sliding interface. It has been observed that TiB 2 and in situ formed AlN and Al 2O 3 phases in combination with h-BN solid lubricant strongly affect the wear performance of the coating. © 2009 ASM International