Influence of Laser Scanning Speeds on Microstructure and Property of AZ91HP Magnesium Alloy

Laser melting treatment of AZ91 HP magnesium alloy was carried out under vacuum in order to improve the wear and corrosion resistance of magnesium alloy.In the case of fixing the laser power and spot diameter,the influence of laser scanning speeds on the microstructure and property of the melted layer was analyzed.The results show that with the increasing of laser scanning speeds,hard phaseβ-Mg17Al12 of the melted layer decreases,and the dendrite of the melted layer is gradually refined.Because of the effect of the fine-grained strengthening,the microhardness and wear resistance of the melted layer are increased compared with those of the received Mg alloy.With the increasing of the laser scanning speeds,the microhardness,wear and corrosion resistance of the melted layers are improved.