Effect of Notch on Tensile Properties and Fatigue Properties of 7A85 Aluminum Alloy
ZHANG Zhuodong1, ZHAO Junwen1,*, FAN Jun2, ZHANG Haicheng3, GAO Jiewei4, HAN Ruipeng1
1 School of Material Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China 2 CRRC Changchun Rail Car Company Limited, Changchun 130000, China 3 China National Erzhong Group Deyang Wanhang Die Forging Company Limited, Deyang 618000, Sichuan, China 4 School of Mechanical and Electrical Engineering, University of Electronic Science and Technology, Chengdu 611731, China
Abstract: Annular notches with a depth of 0.1 mm and 0.2 mm were prefabricated on the surface of smooth specimens, and the effects of different notch sizes on the tensile and fatigue properties of 7A85 aluminum alloy were investigated, the fatigue fracture mechanism of 7A85 aluminum alloy was also analyzed. The results show that with the increase in notch depth from 0 mm to 0.2 mm, the ultimate tensile strength, elongation and fatigue strength of the specimens decrease by 6%, 47.5% and 44.4%, respectively. The notch of the specimens has a much greater effect on the elongation than tensile strength, which is linearly related to fatigue strength. The fatigue notch factor increases with the increase of notch sizes and fatigue cycles. The fatigue crack sources of 7A85 aluminum alloy are usually iron-rich second-phase particles, and the stress concentration at the bottom of the annular notch promotes the initiation of multiple fatigue crack sources. Furthermore, the effective bearing area of the specimen is rapidly reduced by the simultaneous propagation of multiple cracks, leading to a sharp decrease in fatigue life.
通讯作者:
*赵君文,西南交通大学材料科学与工程学院副教授,硕士研究生导师。2009年于华中科技大学材料加工工程专业获得工学博士学位,同年到西南交通大学材料学院工作至今。目前主要从事轨道交通关键材料、先进铸锻技术、相变储能材料等方面的研究工作。在Materials Science and Enginee-ring A、Journal of Materials Processing Technology、《金属学报》等国内外核心学术刊物上发表论文100余篇。swjtuzjw@swjtu.edu.cn
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2023, Vol. 37 
