高频磁场下制备颗粒增强铝基梯度复合材料

摘要

A kind of reinforced composite of Al-14.9％Mg2Si-10.3％Si-11.8％MgAl2O4 were made by adding SiO2 particles into Al-20％Mg2Si-5％Si mother alloy. Then, the two kinds of particle reinforced graded composite materials, Al-20％ Mg2Si-5％Si (Sample-1) and Al-14.9％ Mg2Si-10.3％Si-11.8％MgAl2O4 (Sample-2), were fabricated by the remelting of the mother alloy and the reinforced composite based on the electromagnetic separation of the phases under the high frequency magnetic field. It is found that the SiO2 added acts with aluminum and magnesium in the melt and forms the particles MgAl2O4 that accumulated in periphery of specimen, which is proved by result of EPMA analysis. Besides, the primary phases of Mg2Si and Si also enrich on the surface of specimen. At last the hardness was tested along the radial of specimens, and the results show that the hardness distributes in gradient along the radial direction, which meets the demand on property of material that with a hard external and ductile internal.%通过向Al-20%Mg2Si-5%Si母合金中加入10%SiO2颗粒,制得颗粒增强复合材料Al-14.9%Mg2Si-10.3%Si-11.8%MgAl2O4,然后重熔母合金和复合材料,利用高频磁场的电磁相分离法分别成功制备了Al-20%Mg2Si-5%Si(样品1)和Al-14.9%Mg2Si-10.3%Si-11.8%MgAl2O4(样品2)两种颗粒增强梯度复合材料.发现加入的SiO2与铝熔体中的铝镁反应形成了MgAl2O4,并通过电子探针证实了该相的存在,除此之外,初生的Mg2Si、Si也富集于试样表面.在此基础上,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.