(東南大學材料科學與工程系，南京 210096)
摘 要: 在室溫至280℃間熱循環(huán)條件下，研究了體積百分含量18%的氧化鋁短纖維增強ZL109鋁-硅合金復合材料和基體ZL109鋁-硅合金的熱疲勞短裂紋擴展行為，并且探討了復合材料熱疲勞裂紋的形成機制和擴展過程。研究結果顯示，短裂紋擴展階段，熱疲勞裂紋與增強體纖維有明顯的交互作用；但復合材料的熱疲勞短裂紋擴展速率比基體合金的大。加強基體與纖維的界面結合，提高纖維質(zhì)量，可望提高復合材料的熱疲勞裂紋擴展抗力。
關鍵字: 熱疲勞；裂紋擴展；復合材料；基體合金
（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
