The Effect of Mixed RE Elements on Microstructure and Mechanical Properties of Die-Cast AZ91D Alloy

The effect of mixed RE elements (Y, Nd, Gd ) on the microstructure and tensile properties of die-cast AZ91D alloy were investigated. The results indicated that the content of mixed RE elements lead to the change of the formation of Al▔RE compounds and reduction of the fraction of β-Mg17Al12 phase. The grain size of the alloy added 1.0wt. % RE became smaller than die-cast AZ91D and AZ91D+2.0wt. % RE alloys. The UTS of die-cast AZ91D+xRE(x=0 wt. %, 1.0wt. %, 2.0 wt. %) alloys were 204MPa, 194MPa, 203.6MPa at room temperature, respectively. Moreover, RE addition resulted in fracture behaviors changed.