中文摘要：

通过向Al-20%Mg2Si合金中加入5%SiO2颗粒，利用高频磁场的电磁相分离法成功制备了Al-20%Mg2Si和Al-20%Mg2Si-5%Al2O3两种梯度复合材料。分析了两种复合材料的微观组织，讨论了加入SiO2颗粒对微观组织和机械性能的影响，并对两种合金沿径向进行了硬度测量，结果表明，硬度在径向呈梯度分布，满足梯度复合材料外硬内韧的性能特征。

英文摘要：

The paper introduces the method of producing the two graded composite material of Al-20%Mg2Si and Al-20%Mg2Si-5%Al2O3 by adding SiO2 particles into Al-20%Mg2Si alloy under the high frequency magnetic field.The microcosmic structures of two composite materials are analyzed and the effect on microcosmic structure and the mechanical property added with SiO2 particles are discussed.The hardness is tested along the radial way,the result shows that the hardness distributes in gradient way and meets the demand that the outer area is high intensity but the center area is flexile.