航空学报 > 1994, Vol. 15 Issue (11): 1362-1369

3.5%NaCl溶液和取向对铝合金2124T851疲劳裂纹扩展特性的影响

刘绍伦1, 王淑芝1, 欧阳辉1, 岳俊文2   

  1. 1. 北京航空材料研究所25室,北京,100095;2. 成都飞机公司,成都,610041
  • 收稿日期:1992-09-07 修回日期:1993-11-17 出版日期:1994-11-25 发布日期:1994-11-25

INFLUENCEOFSEAWATER, STRESS RATIO AND FREQUENCY ONFATIGUE CRACK GROWTH BEHAVIOR IN ALLOY 2124T851

Liu Shaolun1, Wang Shuzhi1, Ouyang Hui1, Yue Junwen2   

  1. 1. Beijing Institute of Aeronautical Materials, Beijing,l00095;2. Chengdu Design Bureaus for Aircraft,Chengdu,6l0041
  • Received:1992-09-07 Revised:1993-11-17 Online:1994-11-25 Published:1994-11-25

摘要: 针对某型号飞机结构损伤容限设计的要求,对高强铝合金2124T851进行了不同环境与取向对疲劳裂纹扩展特性影响的试验研究。结果表明,3.5%NaCl溶液中的Cl加速了2124T851铝合金的疲劳裂纹扩展速率da/dN。断口电镜分析表明,分布密度较大的第二相质点使横向的da/dN高于纵向的da/dN。有效应力强度因子可以满意地表征不同取向及不同环境中的da/dN。裂纹面上的腐蚀产物较薄,对裂纹闭合的影响可以忽略不计,1~10Hz范围内的试验频率对3.5%NaCl溶液中的da/dN几乎没有什么影响。

关键词: 铝合金, 腐蚀, 疲劳寿命, 裂纹扩展, 裂纹闭合

Abstract: The corrosion fatigue crack growth properties in aluminum alloy 2l24T85l in both L一Tand T-L orientations were studied,primarily,in 3.5%NaCl solution and at frequencies of l and l0 Hz with stress ratios of 0.5,0.06 and-1.The results show that the fatigue crack growth rate (FCGR) in 3.5%NaCl solution is higher than that in air. FCGR in TL orientation is slight-y higher than that in L一Torientation,FCGR for all test conditions are well correlated with Keff derived from equation based on crack closure theory proposed by Schijive. This implies that crack closure role is negligible by Auger spectroscopy because of the thinner corrosion prod-uct on the crack surface. Little effect of a test frequency between l Hz and l0 Hz on FCGR was observerved a possible explanation is offered.

Key words: aluminium alloys. corrosion, fatigue life, crack propagation, crack closure

中图分类号: