挤压温度对高硅铝合金材料物理性能的影响

EFFECT ON EXTRUSION TEMPERATURE FOR PHYSICAL PROPERTIES OF HIGH-SILICON ALUMINUM ALLOY

针对航空航天电子封装用轻质高硅铝合金,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过共晶高硅铝合金,并通过排水法对其进行了密度测试,同时测定了材料的导热性、气密性和热膨胀系数,得到了挤压温度与其性能的关系。结果表明:利用粉末冶金热挤压技术所制备的高硅铝合金,其致密度高达99．64％;材料的密度随挤压温度的升高而增加;随挤压温度的升高,热导率在104～140 W／(m·K)内变化,热膨胀系数逐渐增加,但均小于13×10-6(在100℃时);材料的气密性达10-9数量级。

Light weight high-silicon aluminum alloys are used for electronic packaging in the aviation and space-flight. Al-30Si and Al-40Si are fabricated with air-atomization and vacuum canning hot-extrusion process. Material density, thermal conductivity, henneticity and thermal expansion coefficient are also measured, and the relationship of extrusion temperature and properties are obtained. Experimental results show that the density of high-silicon aluminum alloys prepared with the method is high to 99.64% of the theory density, and it increases with elevating extrusion temperature, at the same time, thermal conductivity which varies between 104-140 W/（m ·K） with the extrusion temperature and thermal expansion coefficient also increases, but it is within 13×10^-6（at 100℃）, and the hermeticity of the material is high to 10^-9.