Effects of processing parameters on properties of selective laser melting Mg–9%Al powder mixture

Abstract

In the present study, selective laser melting (SLM) was used to sinter a powder mixture of Mg–9%Al. Both densification mechanism and microstructure evolution of laser sintered powder mixture were established. The effect of laser processing parameter on Mg–9%Al powder using SLM was also investigated. It can be found that a maximum relative density was 82% with preferable process parameters of v = 0.02 m/s, P = 15 W. An overlapped structure can be obtained when decreasing the laser energy density due to an incomplete melt. On the other hand, a severe particulate agglomeration appeared as the increase of the laser energy due to a balling effect. A critical scanning speed of 0.02 m/s can ensure that the particulates were well melted and not evaporated during the experiment. Moreover, the Mg and Al elements were dispersed uniformly in the samples. The microstructure and composition phase were studied through scanning electron microscopy (SEM) and X-ray elemental mapping (XRD) respectively.