环境友好型Si_p/LD11复合材料的显微组织及性能

来源期刊：中南大学学报(自然科学版)2006年第6期

论文作者：修子扬 武高辉 张强 宋美慧

文章页码：1060 - 1064

关键词：Si/Al复合材料;显微组织;热膨胀;热导率;力学性能

Key words：Si/Al composite; microstructure; thermal expansion; thermal conductivity; mechanical properties

摘    要：选用粒径为20μm的高纯Si粉,采用挤压铸造方法制备Si体积分数为65%的Si_p/LD11复合材料。研究结果表明:复合材料组织致密,颗粒分布均匀;透射电镜观察发现,在Si颗粒内部存在高密度的层错,同时还存在孪晶和位错; Si-Al界面结合状况良好,无界面反应物; LD11铝合金中存在位错和析出的共晶Si;复合材料具有低密度(2.4 g/cm³),低热膨胀系数(8.1×10^-6/K),高热导率(161.3 W/(m·K))的特性,可以通过退火处理进一步降低其热膨胀系数,提高热导率。该材料具有较好的力学性能。

Abstract: The environmental-friendly Si_p/LD11 composites with high volume fraction of 65% silicon particles were fabricated by squeeze-casting method. The results show that the composite is dense and silicon particles are distributed uniformly. Transmission electron microscope observations show that stacking faults with high density, twins and dislocations are found in silicon particles. The Si-Al interfaces are well-bonded and no interface reactants are found. The dislocations and eutectic silicon precipitates are observed in LD11 matrix. Si_p/LD11 composite has low density of 2.4 g/cm³, low coefficient of thermal expansion (CTE) of 8.1×10^-6/K, high thermal conductivity of 161.3 W/(m·K), and the annealing treatment can reduce the CTE and improve the thermal conductivity. Moreover, the composite has excellent special strength and special modulus.