Substitution of Ni for Zn on microstructure and mechanical properties of Mg-Gd-Y-Zn-Mn alloy

This study analyzes the effect of substitution of Ni for Zn on microstructure and mechanical properties of Mg-Gd-Y-Zn-Mn alloy. Our results show that the volume fraction of Mg5(Gd, Y) and (Mg, Zn)3RE phase decreased and LPSO phase increased with more substitution of Ni. After homogenization, only α-Mg and LPSO phase existed. In Mg-Gd-Y-Zn-Mn alloys, the LPSO phases mainly consisted of the 14H type. While in Mg-Gd-Y-Ni-Mn alloy, the LPSO phases consisted of the 18R type. In addition, compared with Mg-Gd-Y-Zn-Mn alloy, the mechanical properties of as-extruded Ni-substitution alloys were improved due to the better refinement of the size of grains and LPSO phases. The tensile strength in as-extruded Mg-Gd-Y-Ni-Mn alloy could reach up to 400 MPa with 18% of the elongation to failure.