碳化硅颗粒增强石墨/铝复合材料的热物理性能  

Thermophysical properties of SiC particles reinforced graphite flakes/Al composites

作　　者：曾凡坤 孟正华[1,2] 郭巍[1,2] ZENG Fankun;MENG Zhenghua;GUO Wei(Hubei Key Laboratory of Advanced Technology for Automotive Components,Wuhan University of Technology,Wuhan 430070,China;Hubei Collaborative Innovation Center for Automotive Components Technology,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学现代汽车零部件技术湖北省重点实验室,武汉430070 [2]武汉理工大学汽车零部件技术湖北省协同创新中心,武汉430070

出　　处：《复合材料学报》2022年第10期4918-4926,共9页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金青年基金(51605356)。

摘　　要：片层石墨/铝复合材料具有低密度、高热导率的优点,但力学性能较差,目前无法作为一种可商业化应用的电子封装材料。为了改善片层石墨/铝复合材料的热物理性能,采用真空热压法制备了碳化硅颗粒增强石墨/铝复合材料,研究了碳化硅的含量对复合材料热导率、热膨胀系数和抗弯强度的影响。结果表明,经过高频振荡工艺,碳化硅-石墨/铝复合材料中石墨的排列取向良好。添加碳化硅颗粒能明显降低复合材料的热膨胀系数,提高抗弯强度,略微降低热导率。随着碳化硅颗粒体积分数增加,碳化硅-石墨/铝复合材料内部会逐渐出现孔洞缺陷,相对密度下降。当碳化硅和石墨的体积分数分别为15vol%、50vol%时,碳化硅-石墨/铝复合材料具有最优热物理性能,此时x-y方向热导率为536 W/(m·K)、热膨胀系数为6.4×10^(-6)m/K,抗弯强度为102 MPa,是一种十分具有商业前景的电子封装材料。The graphite flakes/Al composite has the advantages of low density and high thermal conductivity, but it cannot be used as a kind of commercial electronic packaging material due to its poor mechanical properties at present. In order to improve the thermophysical properties of graphite flakes/Al composite, the SiC particles reinforced graphite flakes/Al composites were prepared via vacuum hot-pressing process. The effect of the different content of SiC on the thermal conductivity, coefficient of thermal expansion, and flexure strength of the SiC-graphite flakes/Al composites were studied. The result shows that the high-frequency vibration process contributes to the good orientation of graphite flakes in the composites. The SiC particles can significantly reduce the coefficient of thermal expansion, increase the flexure strength, and slightly decrease the thermal conductivity of the composites.However, as the volume fraction of SiC particles increases, many pores and defects are gradually foamed in the SiCgraphite flakes/Al composites, causing the decrease of the relative density. When the volume fraction of SiC and graphite flakes are 15vol% and 50vol%, respectively, the thermal conductivity in x-y plane, coefficient of thermal expansion and flexure strength of the SiC-graphite flakes/Al composite are 536 W/(m·K) and 6.4×10^(-6)m/K and102 MPa, respectively, exhibiting the best comprehensive thermophysical properties, which can be a kind of electronic packaging material with very commercial prospect.

关 键 词：碳化硅-石墨/铝 热导率 热膨胀系数 抗弯强度 复合材料 

分 类 号：TB333[一般工业技术—材料科学与工程]