Heat Treatment of Metals ›› 2024, Vol. 49 ›› Issue (9): 58-63.DOI: 10.13251/j.issn.0254-6051.2024.09.010

• MATERIALS RESEARCH • Previous Articles     Next Articles

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

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

CLC Number: