(1. 北京工业大学 新型功能材料教育部重点实验室，
北京 100022;
2. 中国科学院 金属研究所 固体原子像开放研究实验室，
沈阳 110015)
摘 要: 用透射电子显微术研究了(SiCw+B4Cp)/Mg(AZ91)复合材料的界面特征。结果表明：B4Cp/Mg界面区反应生成物混乱，而在SiCw/Mg界面区较为规则。SiCw/Mg界面生成了两种反应物，其中MgO与SiC具有180°旋转孪晶关系，孪晶面为｛111｝SiC，MgO，而MgB2一般以SiC表面一薄层MgO为基底生长成较大且完整的晶形， MgB2与MgO之间的晶体学取向关系为：(-111)MgO∥(000-1)MgB2，［110］MgO∥［11-20］MgB2。 高分辨观察结合计算机模拟确定了MgO/MgB2界面有两种原子占位方式，一种为界面处有两层Mg原子分别属于两相，另一种为界面处只有一层Mg原子为两相共享。此外，基体中第二相Mg17(Al，Zn)12和未知弥散小颗粒均与基体Mg非共格。
关键字: 镁基复合材料；SiC晶须；B4C颗粒；界面结构
Mg(AZ91) magnesium alloy composite
（1.The Key Laboratory of Advanced Function Materials,
Ministry of Education，Beijing Polytechnic University，
Beijing 100022, China;
2.Laboratory of Atomic Imaging of Solids，
Institute of Metal Research，The Chinese Academy of
Sciences，Shenyang 110015, China）
Abstract:The interfacial structure of (SiCw+B4Cp)/Mg(AZ91) magnesium alloy composite was studied by CTEM and HREM. The results show that there are a lot of chemical reaction products formed at the B4C/Mg interfaces and their distributions are mingle-mangle. Thin interfacial products MgO co-existing with the products MgB2 was found at the SiC/Mg interfaces. The orientation relationships between SiC and MgO is 180° rotation-twinning， while the relationships of (-111)MgO(000-1)MgB2，［110］MgO［11-20］MgB2 exist between MgO and MgB2. Two atomic structure models for the Mgo/MgB2 interface were defined by the HREM image and computer simulation. Besides， the HREM also show the interfaces between the matrix and the coarse second phase Mg17(Al，Zn)12 as well as a fine unknown particle are un-coherent.
Key words: magnesium matrix composite；SiC whisker；B4C particle；interfacial structure
