Microstructure evolution and mechanical properties of wire arc additively manufactured Mg-Gd-Y-Zr alloy by post heat treatments

A detailed and systematic investigation on the effect post heat treatment has microstructure evolution resultant mechanical properties of wire arc additive manufacturing processed Mg-5.9Gd-2.8Y-0.7Zr alloy is conducted in this work. The as-built sample composed mainly fine equiaxed α-Mg grain Mg24(Gd, Y)5 phase. solution (400°C × 1 h) relatively little size, but it can effectively reduce content phase, which leads to a significantly improved elongation with slightly decreased strength. Further ageing at 200°C induces prismatic βʹ precipitates formation does not influence other phases size. samples directly following peak process demonstrate best tensile yield strength 227 ± 9 MPa, ultimate 350 4 MPa 5.5 0.6%.