Effects of La on Eutectic Microstructure and Corrosion Resistance of AZ81 Magnesium Alloy

Effects of La on the microstructure and mechanical properties of as-cast AZ81 magnesium alloy were studied by using optic microscope and mechanical property testing.The results show that the grain size is refined by the addition of La.When the La addition amount is 1.0wt%,the grains change into tiny equiaxial crystal from originally developed branches crystal,the mechanical performance achieve the best,the tensile strength increases up to 24.8% and achieves 242MPa,and the brinell hardness increase up to 36.54%.