Al–Si/B4C composite coatings on Al–Si substrate by plasma spray technique

摘要: Abstract Plasma-sprayed coatings of Al–Si/B 4 C have been prepared on Al–Si piston alloys for diesel engine motors. The composite powders including 5–25 wt% B were by mixing and ball-milling processes. These deposited substrate using an atmospheric plasma spray technique. characterised with respect to phase composition, microstructure, microhardness, bond strength thermal expansion. It was found that Al, Si, Al 2 O 3 phases determined in the approximately 600 μm thick X-ray diffraction analysis. Scanning electron microscope observation revealed boron carbide particles uniformly distributed fully wetted alloy. Also, no reaction products observed coatings. surface roughness, porosity, expansion coefficient decreased increasing fraction particle. demonstrated higher content, hardness because is than Al–Si.