Simultaneous increase in electrical conductivity and fatigue strength of Cu-Ni-Si alloy by utilizing discontinuous precipitates

Abstract

Cu-6Ni-1.5Si alloy having fully fiber-shaped discontinuous precipitates was fabricated by overaging (DP specimen), and subsequently cold-rolled down to 80% reduction in area (CR-DP specimen). The tensile and fatigue strengths of DP and CR-DP specimens were compared to those of CP specimen with nano-sized continuous precipitates by normal aging. The CR-DP specimen showed the highest tensile and fatigue strengths among the specimens tested, and comparable electrical conductivity to the DP specimen. The reason for such an excellent combination of tensile strength, fatigue strength and electrical conductivity was discussed based on the change in microstructure and surface states during stressing. (C) 2021 Elsevier B.V. All rights reserved.