SiC颗粒增强LD_2基复合材料界面反应产物研究

Interface Reaction Products of SiC Particle Reinforced LD_2 Based Composite

本文利用金相显微镜、透射电镜及能谱仪研究了SiC颗粒增强LD_2基复合材料的界面微观结构。分析观察结果表明,SiC颗粒与α-Al固溶体发生了界面反应,反应产物为Al_4C_3与Mg_2Si。Al_4C_3呈棒状,晶内存在孪晶亚结构,孪晶面为(0003),棒的长轴方向即晶体生长方向为[1010].SiC颗粒间距过小及与液态金属接触时间过长会导致反应层厚度增加,因此适当降低SiC颗粒体积含量,避免SiC颗粒与液态金属接触时间过长,可以进一步改善材料的力学性能。

The interface microstructure of SiC particle reinforced LD2 based composite has been investigated u-tilizing optical microscope,TEM and EDAX. The reaults show that there exists interface reaction between SiC Particle and α-Al solution with the reaction products of A14C3 and Mg2Si. A14C3 is stick-like crystal, and its longitudinal direction [1010] is the crystal growth direction. There is twin substructure inside the crystal with the twin plan of (0003). The shorter SiC particle distance is and the longer SiC contacting time with liquid metal is,the thicker the reacting layer is. So both decreasing SiC particle content properly and avoiding SiC particle contact too long with liquid metal will further improve the mechanical property of the composite.