高体分SiC颗粒增强镁基复合材料的显微组织与力学性能

Microstructure and Mechanical Properties of High Volume SiC_p Reinforement Magnesium Matrix Composites

预先对SiC颗粒增强体进行表面氧化处理,然后采用压铸浸渗法制备了体积分数为51.5%的SiCp/Mg-6Al-0.5Mn复合材料。通过压缩性能测试、扫描电镜、透射电镜等方法,研究了复合材料的显微与力学性能。结果表明,在基体Mg-6Al-0.5Mn合金掺入51.5%体积分数的SiC颗粒预制块后,复合材料的组织致密,分布均匀,其断裂方式包括界面脱开、基体韧断和增强体开裂。SiC颗粒与基体之间发生了界面反应,生成了纳米级的Mg2Si化合物。同时,适度的预氧化可以提高基体与颗粒之间的界面结合强度,从而使复合材料抗拉强度得到提高。

51.5vol.% SiCp/Mg-Al-Mn matrix composites billets were fabricated by squeeze pressurized infiltration.Microstructure and mechanical properties of the composites reinforced with the preoxidation of SiC particle has been investigated using compression testing,scanning electron microscopy(SEM) and transmission electron microscopy(TEM).It was found that the composites appear to be free of pores,and the SiC particles distribute uniformly in the composites.The ultimate compression strength of the composites can be improved as a result of the appropriate preoxidation of SiC particle.The mechanisms of fracture of the composites are the boundary separation,toughness fracture of the matrix and article beak.However,there is the nano-size Mg2Si compounds between SiC and the matrix alloy.