金属热处理 ›› 2024, Vol. 49 ›› Issue (9): 58-63.DOI: 10.13251/j.issn.0254-6051.2024.09.010

• 材料研究 • 上一篇    下一篇

微合金化调控7075铝合金的微观组织与力学性能

陈子健1, 林业佳1, 李传强1, 邓仁昡2, 董勇1, 章争荣1   

  1. 1.广东工业大学 材料与能源学院, 广东 广州 510006;
    2.东风日产乘用车公司, 广东 广州 510800
  • 收稿日期:2024-03-18 修回日期:2024-07-23 出版日期:2024-09-25 发布日期:2024-10-29
  • 通讯作者: 李传强,副教授,博士,E-mail: chuanqiang.li@gdut.edu.cn
  • 作者简介:陈子健(2001—),男,硕士研究生,主要研究方向为轻合金的组织性能调控,E-mail: 2511226791@qq.com。
  • 基金资助:
    广东省自然科学基金面上项目(2023A1515012299);广东省自然科学基金青年提升项目(2024A1515030065);广州市基础与应用基础研究-科技精英“领航”项目(2024A04J6299);广州市科协青年科技人才托举工程项目(QT2024-12);大学生创新创业训练计划(xj2023118450625)

Regulating microstructure and mechanical properties of 7075 aluminum alloy via microalloying

Chen Zijian1, Lin Yejia1, Li Chuanqiang1, Deng Renxuan2, Dong Yong1, Zhang Zhengrong1   

  1. 1. School of Materials and Energy, Guangdong University of Technology, Guangzhou Guangdong 510006, China;
    2. Dongfeng Motor Corporation Passenger Vehicle Company, Guangzhou Guangdong 510800, China
  • Received:2024-03-18 Revised:2024-07-23 Online:2024-09-25 Published:2024-10-29

摘要: 采用同步添加微量Ni、RE(La和Ce)和Mg合金元素,对试验合金的微观组织、相组成、拉伸性能和硬度进行对比研究,以调控7075铝合金的微观组织和力学性能。结果表明:经Ni-RE-Mg微合金化处理后,铸态7075铝合金第二相种类没有发生变化,但其含量有所提高,同时晶粒尺寸得到一定细化;合金的拉伸性能也得到一定提高,当Ni-RE-Mg质量分数为0.2%时,铸态合金的抗拉强度最大,为338 MPa。经固溶时效处理后,总体上合金化元素含量越高,合金中析出的第二相越多,时效硬化现象越明显,当Ni-RE-Mg质量分数为1.0%,经固溶和6 h时效处理后,合金硬度达到最大值155.2 HV0.5。

关键词: 7075铝合金, 稀土元素, 微合金化, 微观组织, 力学性能

Abstract: Microstructure, phase composition, tensile properties and hardness of a series of modified 7075 aluminum alloys were comparatively studied by co-adding trace elements of Ni, RE (La and Ce) and Mg, so as to regulate the microstructure and mechanical properties of the 7075 aluminum alloy. The results show that after Ni-RE-Mg microalloying, the type of second phases in as-cast 7075 aluminum alloy does not change, but their content increases, and also the grain size is refined to some extent. In addition, the tensile property of as-cast 7075 alloy is improved via Ni-RE-Mg microalloying, and the maximum tensile strength of the as-cast alloy is 338 MPa when the mass fraction of Ni-RE-Mg is 0.2%. After solution treatment and aging, the precipitated phases in the alloy increase and the age-hardening phenomenon is more obvious with the increase of microalloying element content. When the Ni-RE-Mg mass fraction is 1.0%, the maximum hardness of the 7075 alloy after solution treatment and aging (6 h) reaches 155 HV0.5.

Key words: 7075 aluminum alloy, rare earth element, microalloying, microstructure, mechanical properties

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