Effects of Hf addition on the microstructure and properties of Cu-Sn-P alloy

• Published in: Journal of materials research and technology 2024-11, Vol.33, p.2981-2988
• Main Authors: Wei, Biao, Yang, Haoren, Wang, Chen, Zhou, Jianhui, Xiao, Lei, Ma, Tianyu, Wang, Bingshu
• Format: Article
• Language: English
• Subjects: Cu-Sn-P; Electrical conductivity; Hf element; Mechanical properties; Microstructure
• ISSN: 2238-7854
• DOI: 10.1016/j.jmrt.2024.10.033

In this paper, the effects of Hf addition on the mechanical properties, electrical conductivity and microstructure of Cu-Sn-P alloy were investigated. The results show that the Hf addition can enhance the mechanical properties and electrical conductivity of Cu-Sn-P alloy. The alloy with 0.05 wt% Hf exhibits the best comprehensive performance with yield strength of 625 MPa, tensile strength of 661 MPa and electrical conductivity of 16.8 %IACS. Compared with the Cu-Sn-P alloy without Hf addition, the yield strength and tensile strength are increased by 8.4% and 7.8%, and the electrical conductivity is increased by 24.4%. The increase in the strength of Hf-added alloy can be attributed to the synergistic effect of multiple strengthening mechanisms, including fine grain strengthening, twin strengthening, dislocation strengthening, precipitation strengthening and Σ3n (n = 1, 2, 3) grain boundary strengthening. Moreover, the Hf-P precipitates can be observed in the Hf-added alloy. According to the amount of Hf addition, these precipitates can manifest as the fine HfP2 phase and the coarse HfP phase. The formation of Hf-P precipitates contributes to the precipitation strengthening and the purification of Cu matrix, thus contributing to the improvement of strength and conductivity.