Fatigue fracture of high-strength Al-Zn-Mg-Cu alloy

来源期刊：中国有色金属学报(英文版)2009年第5期

论文作者：蹇海根 姜锋 文康 蒋龙 黄宏锋 韦莉莉

文章页码：1031 - 1036

Key words：Al-Zn-Mg-Cu alloy; fatigue fracture; fatigue crack propagation

Abstract: X-ray diffractometry(XRD), optical microscopy(OM), scanning electron microscopy(SEM) were used to study the fatigue fracture of the T7451 Al-Zn-Mg-Cu alloy (470 ℃, 60 min+115 ℃, 8 h+165 ℃, 16 h). The study reveals mainly the microscopic structure of the alloy in the process of crack formation and crack growth. The fatigue fracture is characterized by three zones:fatigue crack source zone, fatigue crack propagation zone and fatigue fracture zone. The fatigue damage preferably incubates at the fractured inclusion particles at or near (about 25 μm) the specimen free surfaces, and these brittle Fe-rich intermetallic inclusion particles are (7-10) μm×(11-14) μm in size. Some features such as “feather-like”, “river and range” and boundary extrusions can be observed in the fatigue propagation zone, and in the fatigue fracture zone the surface is rough and uneven.

基金信息：the Key International Science and Technology Cooperation Program of China