硅酸铝短纤维/铝合金复合材料的断口分析

利用SEM观察了硅酸铝短纤维/铝合金复合材料的拉伸断口,发现陶瓷增强相主要有三种破坏形式;当纤维沿拉伸方向的有效长径比超过临界值时纤维以断裂破坏为主;(近似)垂直于拉伸载荷的纤维因承受横向拉伸导致界面或纤维开裂而发生脱附;机械损伤及不均匀热收缩在陶瓷颗粒内产生的应力导致大颗粒发生开裂.纤维断裂能有效提高复合材料的强度;纤维脱附及颗粒开裂对材料的强度没有贡献.

Fracture Analysis of Alunina-Silica Short Fiber/Aluminium Alloy Composites

The tensile fracture of alumina silica short fibers/aluminium alloy composites has been surveyed by SEM, and it is found that ceramic reinforcers are broken in three ways. The fibers are chiefly broken as the ratio of effective long to radius along the tensile direction surpasses the critical value, The fibers (approximate) perpendicular to tensile load are separated away from matrix because the horizontal pull bearing by fibers leads to boundary or fibers oneselfs split open. Uneven thermal contract produces larger stress in the ceramic grains and leads to the large grains break. Material strength is heightened as the fibers are broken. It is no contribution for material strength that fibers are separated away from matrix of grains ate broken.