【摘要】 采用挤压铸造成功制得界面结合良好的“Saffil”（TM）δ－Al2O3短纤维增强Al－12Si－Cu复合材料。用扫描电镜对材料的室温拉伸断口和原位动态拉伸过程的观察及分析结果表明：纤维断裂和界面脱粘共同导致材料失效。主裂纹在材料中萌生后，在裂纹尖端区形成明锐的应力集中，造成裂纹前沿与拉伸方向呈小角度（0°＜θ＜45°）排列的纤维正断，而呈大角度（45°＜θ＜90°）排列的纤维则基本沿界面脱开形成微裂纹，成为主裂纹发展的路径。基体中无剪切屈服现象出现。更多还原

【Abstract】 Saffil"(TM) δ-Al2O3 short fibre reinforced Al-12Si-Cu alloy matrix composite with perfectly interfacial bonding is manufactured by squeeze-casting method. Using Scanning Electric Microscope,the tensile fracture surface at room temperature and in situ dynamic tensile process of the composite are observed and analyzed. The results show that fibre’s fracture and interfacial debonding result in failure of the material. The stress concentration appears obviously in the crack tip zone when the main crack is initiated in the material. The fibres which make a small angle (0°<θ<45°) with tensile direction break normally, but the fibres which make a large angle (45°<θ<90°) with tensile direction debond along fibre/matrix interfaces to form microcracks. The main crack propagates along them until the material fractures. There is no shear yield in the matrix.更多还原