This invention discloses a method for preparing low-cost heat-resistant Mg
alloy containing
rare earth, which is prepared by: adding Mg /
rare earth intermediate
alloy into molten AZ91D, AM50B or AM60B Mg
alloy, and die-
casting. The
rare earth content of the heat-resistant Mg alloy is 0.1-3.0 wt.%, and the rare earth is one of La, Pr, Sm, Eu, Tb, Ho, Er, Tm, Dy, Gd, Ce, Y, Ce-rich mixed rare earths and Nd-rich mixed rare earths. The method comprises:
smelting Mg / rare earth intermediate alloy
ingot (rare earth content = 10-60 wt.%), pressing into wire or rod, melting AZ91D, AM50B or AM60B Mg alloy,
cutting Mg / rare earth intermediate alloy wire or rod, preheating, adding into molten AZ91D, AM50B or AM60B Mg alloy, and die-
casting into heat-resistant Mg alloy. The heat-resistant Mg alloy has largely increased
creep resistance at 120-200 deg.C, and can be used in cylinder body, automatic gear box,
oil pump and
crankcase.