▎ 摘　　要

NOVELTY - Preparing thermal crack resistant cast magnesium alloy comprises (i) selecting magnesium alloy system, heating and melting alloy at 30-100 degrees C above melting point to obtain magnesium alloy melt, (ii) introducing graphene into magnesium alloy melt using in-situ autogenous or external methods, where the graphene content in magnesium alloy melt is 0.01-1 wt.%, and (iii) casting magnesium alloy melt obtained by reaction to obtain magnesium alloy castings. USE - The method is useful in preparing thermal crack resistant cast magnesium alloy for manufacture automobile wheels (claimed). ADVANTAGE - The method: solve problem of obvious hot cracking phenomenon of magnesium alloy castings with high rejection rate; and is suitable for industrial production, and is applied to field of non-ferrous metal material manufacturing.