粒度组合对SiC_p/Al复合材料组织与性能的影响

Effects of SiC Particles with Varied Granularity Combination on Microstructure and Properties of High Volume SiC_p/Al Composites

采用粉末触变成形法制备了SiCp体积分数为50%的SiCp/Al复合材料,研究了不同SiCp粒度组合对复合材料组织、性能的影响。结果表明,不同粒度组合的复合材料中SiCp分布均匀,无明显偏聚现象,组织致密,致密度达到95%以上;采用多粒径组合能明显提高复合材料的致密度和抗弯强度,断口以脆性断裂为主;SiCp/Al复合材料抗弯强度在270~382 MPa之间,室温时热导率为111~146 W·m-1·℃-1,室温至200℃时平均热膨胀系数小于6×10-6℃-1。

50%SiCp/Al composites were prepared by powder thixoforming method,and effects of different SiC particle size combinations on microstructure and properties of the composites prepared were expounded.The results show that the SiC particles with different particle size combinations in the composites are distributed uniformly with absence of obvious conglomeration,and the density reaches more than95% with compact structure.The density and bending strength can be improved obviously by the proportioning of different particle sizes,and the main fracture mode is characterized by the brittle fracture.Bending strength of the SiCp/Al composites is in range of 270~382 MPa with the thermal conductivity at 111~146W·m-1·℃-1.Meanwhile,the mean linear coefficient of thermal expansion of composites from room temperature to 200℃is less than 6×10-6℃-1,meeting the requirement of electronic packaging.