(上海交通大学 金属基复合材料国家重点实验室，上海 200030)
摘 要: 用UMHT-3型超显微硬度仪测试SiCp/LD2复合材料界面附近基体中的硬度值，结果表明，由于热膨胀系数差异，复合材料中的热残余应力超过基体的屈服极限，导致界面附近基体内存在热残余应变，并使基体应变硬化，因而超显微硬度值的变化可以反映热残余应变的分布状况。界面附近基体的超显微硬度随颗粒尺寸、距界面的距离和颗粒的尖锐程度而变化，与有关复合材料中热残余应变分布的计算结果吻合。
关键字: 金属基复合材料；超显微硬度；热残余应力；热残余应变
（State Key Lab of MMCs, Shanghai Jiao Tong University, Shanghai 200030）
Abstract:UMHT-3 ultra-microhardness tester was used to measure the hardness of the matrix near the interface in SiCp/LD2 composites. Because of thermal residual stress (TRSs) caused by the different coefficients of thermal expansion (ΔCTE ) between the reinforcer and the matrix in a composite exceeds the yield strength of the matrix, there is a thermal residual strain (TRSn) in the matrix near the interface resulting in strain-hardening of the matrix. Therefore, the change of ultra-microhardness can reflect the distribution of TRSn in the matrix. Ultra-microhardness of the matrix near the interface varies with particle size, the distance from the interface and the sharpness of particle. The results are consistent with some theoretical calculations about distribution of TRSn in composites.
Key words: metallic matrix composites; ultra-microhardness; thermal residual stress; thermal residual deformation
