(上海交通大學(xué) 金屬基復(fù)合材料國家重點實驗室，上海 200030)
摘 要: 用UMHT-3型超顯微硬度儀測試SiCp/LD2復(fù)合材料界面附近基體中的硬度值，結(jié)果表明，由于熱膨脹系數(shù)差異，復(fù)合材料中的熱殘余應(yīng)力超過基體的屈服極限，導(dǎo)致界面附近基體內(nèi)存在熱殘余應(yīng)變，并使基體應(yīng)變硬化，因而超顯微硬度值的變化可以反映熱殘余應(yīng)變的分布狀況。界面附近基體的超顯微硬度隨顆粒尺寸、距界面的距離和顆粒的尖銳程度而變化，與有關(guān)復(fù)合材料中熱殘余應(yīng)變分布的計算結(jié)果吻合。
關(guān)鍵字: 金屬基復(fù)合材料；超顯微硬度；熱殘余應(yīng)力；熱殘余應(yīng)變
（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
