Al2O3/Al复合材料的界面结构特征

利用高分辩透射电子显微镜研究挤压铸造法制备的亚微米 Al 2O 3颗粒增强 Al 基复合材料的界面微观结构。结果表明 : Al基体的 (200) 和 (111) 面优先沿 Al 2O 3颗粒表面生长 , 在复合材料界面处 Al 基体与 Al 2O 3颗粒具有 Al (200) ∥Al 2O 3 (101 2) 、Al 011 ] ∥Al 2O 3 0221 ] 的晶体学位向关系并形成半共格界面 , 且界面存在 Al (111) / / Al 2O 3 ( 1120) 的共格关系。界面干净无任何反应物。接近界面的 Al 基体中出现了柏氏矢量为 b= 1/ 3 111 ] 弗兰克不全刃位错 , 该刃位错引起界面附近基体中明显的晶格应变场 , 位错周围晶格变形场的范围约为 20～30 层原子面宽度 , 而在 Al 2O 3颗粒靠近界面的区域中未观察到位错等缺陷。并从晶体学角度对界面的形成机制进行了分析。

Structural features of the interfaces within Al2O3/Al composite

The microst ructures at the interfaces of the aluminum mat rix composite reinforced by Al 2O 3 particles were characterized by means of high resolution t ransmission elect ron microscopy ( HRTEM) . It was revealed that Al(200) and Al (111) planes of the Al mat rix should first grow along the surfaces of the Al 2O 3 particles , such orien2tation relationship as Al (200) ∥Al 2O 3 (101 2) and Al 011 ] ∥Al 2O 3 0221 ] , and partial2 coherent interface exist in one of the interfaces between the Al mat rix and the Al 2O 3 particles , a coherent relationship with Al(111) / / Al 2O 3 (1120) appears in another interface , but no resultant production is found along those interfaces. Frank partial edge dislocation with 1/ 3 111 ] Burgers vector , which is responsible for forming of remarkable lat tice deformation field with the scale about 20～30 atomic planes , is observed within the Al mat rix near the interface , however , no dislocations and other defect s are found within the area of the Al 2O 3particles near the interfaces. At the same time , the mechanism for forming the interface features is analyzed f rom the viewpoint of crystallography.