Influence of solidification conditions on mechanical properties of Mg-10Gd-3Y-0.5Zr magnesium alloy

Mg-10Gd-3Y-0.5Zr alloy was cast in a step-like mould with five different cooling rates. The as-cast microstructures of the different steps were examined with optical microscope（OM） and scanning electron microscope（SEM）. The room temperature mechanical properties were examined by tensile test. The results show that the microstructures are refined and the second phase particles are distributed much uniformly with the increase of cooling rate. The increase of yield strength, ultimate strength and elongation can be ascribed mainly to the strengthening effect of fine grains. The relationship between grain size and yield strength/hardness agrees with the Hall-Petch behavior.