硅含量对高硅铝合金材料组织及性能的影响

针对航空航天电子封装用轻质高硅铝合金材料,采用空气雾化水冷与真空包套热挤压工艺相结合的方法,制备了Al-30Si和Al-40Si高硅铝合金,并利用金相显微镜、万能电子拉伸机、差热分析仪、TR-2热物性测试仪等设备系统测试和分析了该材料的显微组织、力学和热物理性能.结果表明:随着合金中硅含量的增加,经热挤压后的硅相尺寸相对要粗大一些;材料的热导率呈下降趋势,热导性能下降的幅度会随Si含量的增加而加大;热膨胀系数下降;材料的抗拉强度下降.

Effect of Si Content on Microstructure and Property of High Silicon Aluminum Alloy

Light high-silicon aluminum alloy is used for electronic packaging in the aviation and space-flight, here we call it hypereutectic high-silicon aluminum alloy.Al-30Si and Al-40Si can be fabricated with a method in which air-atomization is followed by vacuum canning hot-extrusion process.Optical microscopy,universal material testing machine,thermal analyzer and TR-2 thermal physics testing are used to study the microstructure,material thermal conductivity,thermal expansion coefficient and tensile strength.Experimental results show that,when Si content in alloy is increase,the size of silicon crystal is larger after hot-extrusion,material thermal conductivity is down,thermal expansion coefficient and the tensile strength is lower.