(东南大学材料科学与工程系，南京 210096)
摘 要: 在室温至280℃间热循环条件下，研究了体积百分含量18%的氧化铝短纤维增强ZL109铝-硅合金复合材料和基体ZL109铝-硅合金的热疲劳短裂纹扩展行为，并且探讨了复合材料热疲劳裂纹的形成机制和扩展过程。研究结果显示，短裂纹扩展阶段，热疲劳裂纹与增强体纤维有明显的交互作用；但复合材料的热疲劳短裂纹扩展速率比基体合金的大。加强基体与纤维的界面结合，提高纤维质量，可望提高复合材料的热疲劳裂纹扩展抗力。
关键字: 热疲劳；裂纹扩展；复合材料；基体合金
（Department of Materials Science and Engineering, Southeast University, Nanjing 210096, P.R.China）
Abstract:Thermal fatigue crack propagation behavior of alumina short fibre(Vf=18%) reinforced aluminum silicon alloy composite and aluminum silicon matrix alloy have been investigated under thermal cycling condition between room temperature and 280 ℃, the initiation of thermal fatigue crack have been discussed. The results show that in the range of short crack, the fibres play an important role in thermal fatigue cracking, but the crack propagation rate of composites is much larger than that of the matrix alloy. Also, strengthening fibre/matrix interface and improving fibre quality are considered to improve resistance to thermal fatigue crack of composites.
Key words: thermal fatigue; crack propagation; composites; matrix alloy
