The invention discloses a high-
toughness rare earth heat-resistant
magnesium alloy. The high-
toughness rare earth heat-resistant
magnesium alloy comprises the following chemical components of, in percentage by
mass, 8.0%-10.8% of Gd, 3.1%-4.0% of Y, 1.8%-2.2% of Zn, 0.4%-0.5% of Zr and the balance
magnesium and inevitable
impurity elements, the invention further discloses a preparation method of the high-
toughness rare earth heat-resistant
magnesium alloy, the preparation method sequentially comprises the following steps of (1) preparing a
magnesium alloy casting rod; (2) homogenization of the bar, specifically, heating a
magnesium alloy bar and preserving heat by adopting a grading homogenization
system, then heating and reheating, preserving heat and carrying out homogenization treatment; (3) upsetting-extruding composite deformation, specifically, putting the bar into a heated upsetting-extruding composite die, and obtaining a high-toughness deformation state rare earth heat-resistant magnesium
alloy material after multiple times of cyclic upsetting-extruding. (4)
solid solution and aging treatment, specifically, enabling heat treatment to adopt
solid solution and aging treatment and heat preservation, adopting hot water
quenching after discharging, and after cooling to
room temperature, conducting aging and preserving heat. The magnesium alloy prepared by the solution is good in quality, and has more obvious high tensile strength and high elongation compared with common magnesium alloys in the market.