腐蚀预损伤与盐水环境对铝合金细节疲劳性能的影响

摘要

The effects of pre-corrosion damage and saline environment on the detail fatigue property of 7XXX aluminum alloy were investigated by SEM analysis and fatigue tests.Influence mechanism of pre-corrosion damage and saline environment on the initiation and propagation of fatigue crack was also discussed.The results show that pre-corrosion damage and saline environment had significant effects on the detail fatigue property of 7XXX aluminum alloy.The detail fatigue rating cutoff value for uncorroded sample tested in lab air was chosen as a benchmark, the detail fatigue rating cutoff value retention rates for 48 h pre-corroded sample in lab air, uncorroded sample in saline environment and 48 h pre-corroded sample in saline environment were 97%, 73% and 67%, respectively.%采用扫描电镜分析和疲劳试验等方法,研究了腐蚀预损伤和盐水环境对7XXX铝合金细节疲劳性能的影响,并探讨了对疲劳裂纹萌生和扩展的影响机理.结果表明:腐蚀预损伤和盐水环境对7XXX铝合金细节疲劳性能的影响较为显著;以未腐蚀试样在实验室空气环境下的细节疲劳额定强度截止值为基准,预腐蚀48 h试样在实验室空气环境下的细节疲劳额定强度截止值的保持率为97%,未腐蚀试样和预腐蚀48 h试样在盐水环境下的细节疲劳额定强度截止值的保持率分别为73%和67%.