无压浸渗法制备SiC-Al复合材料的断口分析

Study on the Fractograph of SiC/Al Composites by Pressureless Infiltration Technique

采用SEM、EDX等分析技术对无压浸渗法制备SiC/Al复合材料的断口形貌进行了分析。结果表明,该类材料的断裂包括基体韧断、界面脱开和增强体颗粒断裂三种方式,该类复合材料的强化效果取决于基体与界面结合的关系;对该复合材料的断裂机理进行了分析讨论,SiC颗粒断裂和SiC颗粒相互搭接处与基体界面脱粘是微裂纹萌生的主要原因。

The fracture morphology of SiC/Al composite was studied using SEM and EDX. The results showed that fracture evolution experiences a process of microvoid nucleation, growth and coalescence; there exhibit three models of fracture： toughness fracture of the metal matrix, boundary separation and SiC particle rupture. The fracture is mainly dimple fracture, accompanied by a few intergranular rupture. The failure mechanism is also analyzed and discussed. The results indicated that the cracking of SiC particle and interface debonding of particle-matrix are probably responsible for the initiating of microcracks in the composites materials.