<正>研讨了铝基陶瓷复合材料的显微结构和性能之间的关系。采用7075铝合金为金属基,并加入体积为20％,粒度为F-1000或F-600的SiC颗粒增强。通过塑性和断裂韧性测量以及试样断口的TEM、SEM显微观察,分析断裂显微结构的细节。研究表明,当基体从时效状态到过时效状态时,断裂模式从SiC颗粒断裂转变为SiC颗粒和基体之间出现窝状断裂。由TEM观察证实,在过时效条件下基体和SiC界面上沉淀析出新相,这大大降低了材料的韧性。

This paper deals with the microstructure-property relationship in metal-ceramic particulate reinforced composites. Metal matrix was 7075 aluminum alloy and was reinforced with 20% by volume of either F-600 grade or F-1000 grade SiC particulates. Through tensile ductility and fracture toughness, and by means of frac-tography of TEM and SEM, the details of the fracture were investigated. The result showed that fracture tended to initiate in clustered regions. A tendency to shift the fracture mode from particle cracking to dimpled fracture was observed as the matrix temper was varied from underaged to overaged. While TEM revealed a new phase of precipitation at the particle/matrix interface in the overaged and it accompanied a substantial decrease in toughness.