【摘要】 利用透射电镜拉伸台技术对Ａｌ２Ｏ３基复合材料的动态断裂行为进行原位观 察。实验结果显示，Ａｌ２Ｏ３短纤维增强Ａｌ－１２Ｓｉ复合材料在断裂行为的细节上与其它Ａｌ基 复合材料有所不同，它除在基体中可萌生微裂纹并扩展外．纤维／基体界面也是重要的裂纹源 及扩展路径，同时还发现裂纹在纤维薄弱处形核、扩展引起纤维断裂。导致这一结果的原因 可能在于，一是纤维／基体界面结合较弱，增加了界面开裂的几率，二是该复合材料纤维平均 长度大于其临界纤维长度，外加载荷可有效地从基体通过纤维／基体界面传递到纤维上来，当 纤维存在结构缺陷时会引起纤维的破坏。更多还原

【Abstract】 The fracture behavior of AlO3/Al -12Si alloy matrix composite is in - situ investigated. The results show that Al₂O₃ short fibre/Al - 12Si matrix composites differ from other Al alloy matrix composites. In Al₂O₃ - 12Si alloy matrix composites, not only matrix but also the fibre/matrix interface is the nucleation site and propagation route of cracks, and it is also found microcracks are nucleated and propagated in the weak of the fibre. It is analysed that the combining strength of the fibre/matrix interface is weak, on the other hand, the average length of the fibre in the compositers is longer that its critical fibre length, so the external load is handed down from the matrix through the fibre/matrix interface to the fibre, when the fibre having structure faults, it may be destroyed.更多还原