采用热压烧结制备Al/50%Si复合材料。利用金相显微镜和扫描电子显微镜观察复合材料的微观组织。研究复合添加0.5~4%Cu和0.5%Mg对材料显微组织、力学性能和热物理性能的影响。结果表明:复合材料组织均匀细小,致密度高,综合性能好,当Cu添加量不超过1%,Mg添加量为0.5%时,Si颗粒没有粗化;当Cu添加量达到2%,Mg添加量为0.5%时,Si颗粒逐渐粗化。添加1%Cu和0.5%Mg后Al/50%Si复合材料的相对密度从98.5%上升到99.9%,抗拉强度和抗弯强度可分别达到293 MPa和412 MPa,热膨胀系数和热导率分别为11.0×10-6/K和138 W/(m·K),完全满足高性能雷达用电子封装材料的性能要求。

Al/50%Si composites are prepared by hot pressing. Metallographic microscope and scanning electron microscopy are employed to analyze the microstructures. The effects of combined additions of 0.5~4% Cu and 0.5%??Mg on the microstructures, mechanical properties and thermal physical properties of Al/50% Si composites are studied. The results show that the composites with high density have a refined and uniform microstructure as well as excellent comprehensive properties. The coarsening behavior of Si particles does not appear when the Cu content is below 1% and Mg content is 0.5%. However, the Si particles become coarsening when the Cu content is 2% and Mg content is 0.5%. The relative density of Al/50%??Si composite with 1%??Cu and 0.5%??Mg has improved from 98.5%??to 99.9%, the tensile strength and bending strength can achieve 293 MPa and 412 MPa respectively, and the coefficient of thermal expansion and thermal conductivity are 11.0×10-6/K and 138 W/(m·K) respectively, which can successfully satisfy requirements of the electronic packaging materials for high-performance radar.

TN405