Enhancement of strength and electrical conductivity for hypo-eutectic Cu-12Ag alloy

• Published in: Journal of alloys and compounds 2023-01, Vol.931, p.167506, Article 167506
• Main Authors: Choi, Eun-Ae, Lee, Sang Jin, Ahn, Jee Hyuk, Choe, Seunghoe, Lee, Kyu Hwan, Lim, Sung Hwan, Choi, Yoon Suk, Han, Seung Zeon
• Format: Article
• Language: English
• Subjects: Aging (natural); Cold rolling; Copper; Copper base alloys; Cu-Ag alloy; Dispersion hardening; Electrical conductivity; Electrical resistivity; Eutectic alloys; Eutectic temperature; Hypo-eutectic alloy; Precipitation hardening; Silver; Tensile strength; Thermomechanical treatment
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.167506

A thermo-mechanical treatment was designed for a hypo-eutectic Cu-12Ag alloy in order to enhance its tensile strength, as high as 1189 MPa, at the relatively minimal cost of the electrical conductivity, as good as 71.9%IACS, the combination of strength and conductivity being far superior to other Cu-Ag alloys ever reported in the literature. To understand detailed mechanisms, a Cu-7Ag alloy and a Cu-12Ag alloy, which is beyond the maximum solubility (8 wt%) of Ag in Cu, were chosen for comparison and homogenized at 777 °C for an hour followed by aging at 400 ℃. The peak-aged alloys were then cold-rolled with a 99% reduction. Cu-7Ag showed higher hardness than that of Cu-12Ag at peak aging. However, Cu-12Ag showed higher strength and conductivity than those of Cu-7Ag after cold rolling. The elongated dispersed Ag phases in Cu-12Ag attributed extra strengthening, while keeping a minimal reduction of the conductivity after cold rolling. •The Cu-Ag alloy strengthened by the precipitates and eutectic phase.•Dispersed Ag phase help improving strength and conductivity with precipitates together.•Excellent combination of 1189 MPa / 71.9%IACS was achieved in Cu-12Ag alloy.