Effect of trace alloying elements on stress relaxation properties of high strength and high conductivity C19160 alloy

Abstract

The addition of Si in a Cu-Ni-P-Pb (C19160) alloy has been fabricated by atmospheric smelting to approach high strength, high conductivity, and high-stress relaxation resistance. The addition of Si inhibited the coarsening and phase transition of Ni5P4. The fine Ni5P4 particles were dispersed in the matrix, which pinned dislocations and improved the studied alloy’s strength and stress relaxation resistance. After homogenization at 900 °C for 4 h, cold rolled by 70%, aging treatment at 450 °C for 1 h, cold rolled by 60%, aging treatment at 400 °C for 45 min, cold rolled by 60%, annealing treatment at 200 °C for 1 h, the C19160-0.1Si alloy shows an ultimate tensile strength of 705 MPa, electrical conductivity of 53.8%IACS, and a stress relaxation rate of 17.8% after tested at 150 °C for 100 h. These findings have guiding significance for developing C19160 alloys with high strength, high conductivity, and high-stress relaxation resistance.