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采用粉末冶金方法制备体积分数为35%的Si Cp/2024 Al复合材料。利用高分辨透射电镜对复合材料中Si Cp与Al基体、析出相与Al基体之间的界面微结构进行表征,采用拉伸弹性模量和布氏硬度测试对界面状况进行评估。结果表明,所得复合材料中Si C与Al的界面整体状况良好。复合材料中SiC/Al界面分为3种类型:大部分干净界面、少量轻微反应型界面以及极少量的非晶层界面。在干净界面中,Si C和Al的结合机制为紧密原子匹配形成的半共格界面,且Si C和Al无固定或择优的取向关系。在轻微反应型界面中,MgA l2O4尖晶石与Si C和Al均形成半共格界面,作为中间媒介很好地连接Si C和Al。复合材料经510°C固溶2 h再在190°C时效9 h后,许多圆盘状纳米析出相和棒针状纳米析出相弥散分布于基体中,且与基体的界面为错配度较小的半共格界面。此时,复合材料的布氏硬度达到峰值。
The volume fraction of 35% Si Cp / 2024 Al composite was prepared by powder metallurgy. The interfacial microstructures of Si Cp and Al matrix, precipitated phase and Al matrix were characterized by high-resolution transmission electron microscopy and the interfacial conditions were evaluated by tensile modulus of elasticity and Brinell hardness. The results show that the interface between Si C and Al in the composites is in good condition. There are three types of SiC / Al interface in the composites: most clean interfaces, a few mild reactive interfaces and a very small amount of amorphous interface. In a clean interface, the bonding mechanism between Si C and Al is a semi-coherent interface formed by tight atom matching, and there is no fixed or preferential orientation between Si C and Al. In the slightly reactive interface, the MgAl2O4 spinel forms a semicontinuous interface with both SiC and Al, and serves as a good intermediary to connect SiC and Al. After the composite was solution-treated at 510 ° C for 2 h and then aged at 190 ° C for 9 h, many discoid nano-precipitates and rod-like nano precipitates diffusely distributed in the matrix, and the interface with the matrix is mismatched Semi-coherent interface. At this point, the Brinell hardness of the composite peaked.