(東南大學(xué)材料科學(xué)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(qiáng)ZL109鋁-硅合金復(fù)合材料和基體ZL109鋁-硅合金的熱疲勞短裂紋擴(kuò)展行為，并且探討了復(fù)合材料熱疲勞裂紋的形成機(jī)制和擴(kuò)展過程。研究結(jié)果顯示，短裂紋擴(kuò)展階段，熱疲勞裂紋與增強(qiáng)體纖維有明顯的交互作用；但復(fù)合材料的熱疲勞短裂紋擴(kuò)展速率比基體合金的大。加強(qiáng)基體與纖維的界面結(jié)合，提高纖維質(zhì)量，可望提高復(fù)合材料的熱疲勞裂紋擴(kuò)展抗力。
關(guān)鍵字: 熱疲勞；裂紋擴(kuò)展；復(fù)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
