Effect of Humidity on Fracture Mechanism of Age-hardened Al Alloys under Ultrasonic Loading
Effect of humidity on the propagation mechanism of a fatigue crack in age-hardened Al alloy 2017-T4 was investigated under ultrasonic loading in relative humidity of 25% and 85%,respectively.Plain specimen of both extruded and drawn Al alloys were tested.In the extruded alloy,fatigue cracks that propagated macroscopically in tensile mode in low humidity changed to extend in shear mode to failure,comparing to that fatigue cracks always grew in shear mode in high humidity.On the other hand,in the drawn alloy,fatigue cracks propagated in tensile mode to final fracture in low humidity,and in a combined mode of tensile and shear in high humidity.In the both alloys,the growth of cracks shorter than a specific length,e.g.~1 mm,which is stress level dependent,was accelerated in high humidity,but it was not or little influenced by humidity beyond that specific length.The difference in fatigue crack propagation behavior between the two alloys and the effect of humidity on the fracture mechanism were discussed based on fractographic and crystallographic analyses.
Fatigue Ultrasonic loading Age-hardened Al alloy Humidity Texture
Norio Kawagoishi Kohji Kariya Hironori Matsusako Yuzo Nakamura Xishu Wang Qingyuan Wang
Department of Mechanical System Engineering,Daiichi Institute of Technology,Kirishima 899-4395,Japan All Nippon Airways Co.,Tokyo 105-7133,Japan Department of Mechanical Engineering,Kagoshima University,Kagoshima 890-0065,Japan Department of Engineering Mechanics,Tsinghua University,Beijing 100084,China Department of Civil Engineering & Mechanics,Sichuan University,Chengdu 610065,China
国际会议
北京
英文
1-8
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）