Heat Treatment of Metals ›› 2023, Vol. 48 ›› Issue (7): 49-53.DOI: 10.13251/j.issn.0254-6051.2023.07.009

• MATERIALS RESEARCH • Previous Articles     Next Articles

Effect of trace Ni element addition on precipitation behavior and properties of Cu-Cr alloy

Wu Fan1,2, Gong Qinghua2, Xie Weibin1,3, Wu Yu4, Chen Huiming1,2, Wang Hang2   

  1. 1. Advanced Copper Industry Institute, Jiangxi University of Science and Technology, Yingtan Jiangxi 335000, China;
    2. Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou Jiangxi 341000, China;
    3. National Rare Earth Functional Materials Innovation Center, Ganzhou Jiangxi 341000, China;
    4. Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang Jiangxi 330096, China
  • Received:2022-12-28 Revised:2023-05-16 Online:2023-07-25 Published:2023-09-04

Abstract: Cu-Cr and Cu-Cr-Ni alloys were prepared by vacuum melting in argon atmosphere, followed by solid solution at 950 ℃ for 1 h and aging at 450 ℃. The properties and microstructure of the two alloys were analyzed and characterized by means of Vickers hardness tester, DC digital resistance tester, metallographic microscope and transmission electron microscope (TEM). The results show that the hardness of the Cu-Cr-Ni alloy reaches the peak value of 124.6 HV0.5 after aging at 450 ℃ for 8 h, and the conductivity is 83.2%IACS, while the hardness of the Cu-Cr alloy reaches the peak value of 116.7 HV0.5 after aging at 450 ℃ for 1 h, which indicates that the addition of Ni increases the hardness of the Cu-Cr alloy and maintains a high conductivity. At the beginning of aging (1 h), bcc-Cr phase is observed in the Cu-Cr-Ni alloy, which indicates that the addition of Ni accelerates the precipitation rate of precipitates, and promotes the transformation of precipitates from fcc-Cr structure to bcc-Cr structure. In addition, the Cr precipitates of the Cu-Cr-Ni alloy still maintain a semi-coherent relationship with the matrix after aging for 12 h.

Key words: Cu-Cr-Ni alloy, precipitates, hardness, electrical conductivity

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