SiC颗粒特性对无压熔渗SiCp/Al复合材料热物理性能的影响

Effect of SiC particles' characteristics on the thermophysical properties of SiCp/Al composites by powder injection and pressureless infiltration

采用粉末注射成形-无压熔渗相结合技术制备出了电子封装用高体积分数SiCp/Al复合材料.重点研究了SiC粒径、体积分数以及粒径大小等颗粒特性对所制备复合材料热物理性能的影响规律.研究结果表明,SiCp/Al复合材料的热导率随SiC粒径的增大和体积分数的增加而增加;SiC粒径的大小对复合材料的热膨胀系数(CTE)没有显著的影响,而其体积分数对CTE的影响较大.CTE随着SiC颗粒体积分数的增加而减小,CTE实验值与基于Turner模型的预测值比较接近.通过对不同粒径的SiC粉末进行级配,可以实现体积分数在53%～68%、CTE(20～100℃)在7.8×10-6～5.4×10-6K-1、热导率在140～190W.m.K-1范围内变化.

SiCp/Al composites with high volume fraction for electronic packaging were prepared by powder injection molding and pressureless infiltration. The effects of the particle size and volume fraction of SiC on the thermophysical properties of SiCp/Al composites were investigated. The results show that thermal conductivity of SiCp/Al composites increases with the increase of the particle size and volume fraction of SiC. The coefficient of thermal expansion （CTE） of the composites is not affected by the particle size of SiC but depends on the volume fraction of SiC. With the increase in volume fraction of SiC the CTE of the composites decreases, and it agrees well with the predicted values based on Turner＇ s model. By graduation of SiC particles with different sizes, it can be realized that the volume fraction ranges from 53% to 68%. As a result, the CTE（20 - 100℃ ） of the composites changes from 7.8 × 10^-6 to 5.4 × 10^- 6 K^- 1, and thermal conductivity from 140 to 190 W· m· K^- 1.