Microstructures and Properties of Extruded Mg-Gd-Y-Zr Alloys Containing Zn

Microstructure and mechanical properties of Mg-10Gd-3.8Y-xZn-0.5Zr (x = 0, 1, 3 wt.%) alloys during extrusion and following isothermal aging at 200 A degrees C were investigated using digital microhardness testing, mechanical testing, optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray diffraction (XRD). The results showed that Zn can refine grains of the alloy, and improved mechanical properties of the as-extruded alloys. In T5 (peak-aging) condition, the average grains of the alloy without Zn addition were about 20.10 mu m; the average grains of the alloys with 1 wt.% Zn addition and 3 wt.% Zn addition were about 15.35 and 10.04 mu m, respectively. For the alloy with 1 wt.% Zn addition in as-extruded and peak-aged states, the values of tensile strength reached 345 and 429 MPa, yield strength reached 260 and 342 MPa, as well as ductility rate reached 10.8 and 5.7%, respectively, exhibiting superior mechanical properties.