Effects of Ag content and the annealing process on the microstructure and properties of Cu–7Mn–Ag–0.2Ce–0.2Zr resistor alloys

Abstract

Designing alloys with a low resistance over a wide temperature range, specifically a low temperature coefficient of resistance (TCR), remains a great challenge from a material application perspective. In this study, the effects of Ag content and the annealing process on the microstructure, resistivity, TCR, hardness, and electrochemical corrosion properties of a Cu–7Mn–Ag–0.2Ce–0.2Zr resistance alloys were investigated. The results indicate that adding Ag to the Cu–Mn alloy can improve the solid solubility and change the lattice constant, resulting in a lower resistivity, TCR and better corrosion resistance. The hardness of the alloy increases because Ag segregates and is dispersed in the matrix to form a second phase during the annealing process. The Cu–7Mn–0.5Ag–0.2Ce–0.2Zr alloy performs the best, with a resistivity of 24.1 μΩ·cm and a TCR of 76 × 10−6/°C at 300 °C for 1 h. The alloy had low resistivity and TCR over a wide temperature range, and it also had high stability as well as long-term performance.