Broad-beam laser cladding of Al–Si alloy coating on AZ91HP magnesium alloy

In the present study, an attempt was made to improve the wear resistance and the corrosion resistance of AZ91HP magnesium alloy by laser cladding Al–Si eutectic alloy. The results showed that the clad layer mainly consisted of Mg2Si, Mg17Al12 and Mg2Al3 phases. The microstructure of the bonding zone changed from columnar grains to equiaxial grains along the direction of heat-flow. The heat-affected zone consisted of α-Mg and α-Mg + β-Mg17Al12 eutectic. The formation of multiple Mg intermetallic compounds allowed the clad layer to exhibit higher hardness, better wear resistance and corrosion resistance.