Effect of heat treatment on the electrical and mechanical properties of a Cu–Ni–Si cast alloy

Abstract

Abstract The electrical and mechanical properties of a Cu–2.50Ni–0.50Si–0.45Cr–0.25Co–0.25Zr (wt%) cast alloy were investigated. The alloy produced as billet material by arc melting technique was solution annealed at 900 °C for 2 h, quenched in water, and aged at 350–500 °C for 2–192 h. The electrical conductivity of the heat-treated alloy was measured using an Eddy current apparatus, and the mechanical properties were determined using hardness measurements and compression tests applied between room temperature and 600 °C. Microstructural characterization of the cast and aged alloys was carried using light optical and scanning electron microscopy to characterize the precipitated phases within the Cu solid solution matrix. It is found that (i) very fine δ-Ni2Si precipitates in the matrix of cast alloy aged at 400 °C for 72 h give an optimal combination of hardness and conductivity and (ii) the aged alloy has a higher yield strength than the cast one at all temperatures investigated.