The microstructure and mechanical properties of alloy ZL104 modified by rare earth are a little inferior to three-component modifier

but the alloy can come up to the State Standard （GB） and the Factory Standard. The hardness of the castings after T6 treatment is high which is advantageous to rigidity

thereby the castings possess good machinability. Because the Rare earth modification gives lone effective time

reduces the rejects due to coarse grain and dross hole

hence the casting’s qualified rate is raised. Rare earth modification solves the problem that the crucible is difficultly protected by coating from the etching by three-component natrium salt which leading the aluminium-liquid to pick up iron. Rare earth metals have good degasification effect

reducing the degree of dross hole. This technology is suitable to low pressure die casting.