微观结构对Al-SiC封装材料热膨胀系数的影响

The influence of the microstructure of SiC particles on the coefficient of thermal expansion of Al-SiC composites

为了进一步降低Al-SiC封装材料的热膨胀系数,借助挤压浸渍工艺进行复合材料的制备,并研究了SiC颗粒微观结构对膨胀系数的影响。实验结果表明:在保持SiC颗粒尺寸和体积分数不变的情况下,通过颗粒排列的类晶界结构设计,可实现Al-SiC封装材料的热膨胀系数减小8.6%,且热导率保持在201 W·m^(-1)·K^(-1)的水平。基于模拟结果,分析认为热膨胀系数的降低归功于微结构对内应力状态的影响。

In order to further decrease the coefficient of thermal expansion of Al/SiC composites while thermal conductivity keeping the same level,the Al/SiC composite with grain-grain boundary-like structure were produced by pressure infiltration technique.Experiment results indicate that the coefficient of thermal expansion of composite with novel microstructure was reduced by 8.6%compared to that of composite with traditional structure with the same volume and particle size of SiC particles.In this case,the thermal conductivity of these two kinds of composites keeps at the same level.The improvement may be attributed to the variation restriction effect of different microstructure on release approach of internal stress.