The as-cast microstructure and mechanical properties of AlSi10 MgMn alloy with different rare earth（La

Ce） contents were investigated by means of optical microscope

SEM

Vickers hardness and tensile test at room temperature. The results show that rare earth（La

Ce） can refine α-Al

eutectic silicon

AlMnSi and Mg

2

Si phases in the alloy

and eliminate β-AlFeSi phase. When the content of added rare earth（La

Ce） is 0.1%

the hardness

tensile strength and yield strength of the alloy reach 82.76 HV、373.05 MPa and 281.37 MPa

respectively

which are 12.95%、17.29% and 43.44% higher than those of ones without rare earth

while the elongation is reduced to 2.26%

decreased by 11.37%. Furthermore

the addition of rare earth（La

Ce） has little effect on the fracture mode of the alloy.