Age-hardening characteristics of Cu–2.4Ni–0.6Si alloy produced by the spray forming process

Abstract

The microstructural features and heat treatment response of a spray formed Cu–2.4Ni–0.6Si (wt.%) alloy have been investigated. The alloy was aged at 450 ◦C either in the as spray formed condition or after a cold deformation of 40% reduction in original thickness. Some of the samples were subjected to a solution treatment at 900 ◦C for 1 h prior to their cold deformation to 40% of original thickness and subsequent ageing. The variation in hardness and electrical conductivity of the alloys wasmeasured as a function of ageing time. The results indicated the highest peak hardness value of approximately 250 kgfmm−2 for the alloy aged after the solution treatment and cold rolling, compared to the maximum hardness of 220 kgfmm−2 for samples aged directly in as spray formed condition. However, the electrical conductivity was observed to be a maximum of 62% IACS in samples which had only been cold rolled. This behaviour is discussed in the light of microstructural characteristics associated with different processing conditions of this alloy.