Improving wear resistance of magnesium by droplet spraying of Al-Si alloy

Abstract

In order to improve the surface hardness and wear resistance of magnesium, Al-13%Si (mass fraction) alloy coating was deposited on pure magnesium by droplet spraying process. The microstructure was studied by electron probe microanalysis and X-ray diffraction. The micro-hardness and wear resistance of coating were investigated in comparison with those of the substrate. It is found that the coating layer is composed of α-Al cellular due to rapid solidification. Formation mechanism of the coating is due to the obstruction of diffusion by in-situ formed Mg₂Si in interfacial layer. The coating exhibits higher hardness compared to that of the Mg substrate. As result of its high hardness, the wear resistance of the coating layer is about ten times that of the substrate. The droplet spraying process demonstrates that the magnesium surface can be strengthened by using the existing Al-Si alloys.

Keywords

droplet spraying / Al-Si eutectic alloy / coating / magnesium / hardness / wear resistance / rapid solidification

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