张道乾,陈小红,周洪雷,刘平,任钰鹏

• 1:上海理工大学材料与化学学院

摘要(Abstract)：

为了研究预时效后微变形对7050铝合金疲劳性能的影响，首先对预时效后的试样进行微变形，随后对变形后的试样进行120℃时效10 h的处理。使用光学显微镜、扫描电镜和疲劳试验机等分析了7050铝合金在不同时效状态下的微观组织和疲劳性能。结果表明：7050铝合金在不同热处理状态下微观断口形貌具有很大的差异性。退火再回归时效(RRA)处理的试样在应力幅为250 MPa和400 MPa下的裂纹扩展区形貌为羽毛形状结构，瞬断区形貌为微孔聚集型断裂。预时效后微变形处理的试样在应力幅为250 MPa下的瞬断区形貌为准解理断裂，在400 MPa下瞬断区为微孔聚集型断裂和准解理断裂的混合形貌。预时效有助于细小GP区的产生，微变形处理使得位错产生，GP区和位错的协同作用导致更均匀的变形，能够降低应力集中从而提高7050铝合金的疲劳性能，在应力幅为250 MPa时其疲劳周期N_f=5448685周。

关键词(KeyWords)： 7050铝合金;疲劳;断口;疲劳寿命

Abstract:

Keywords:

基金项目(Foundation): 上海高性能医疗器械材料工程技术研究中心资助项目(20DZ2255500)

作者(Author): 张道乾,陈小红,周洪雷,刘平,任钰鹏

DOI: 10.13289/j.issn.1009-6264.2022-0080

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