Microstructure and mechanical properties of a Cu-1.28Cr-0.24P alloy with high electrical conductivity and tensile strength

Abstract

Cu–Cr system alloys usually show high strength (400–600 MPa) but limited electrical conductivity (∼80% IACS). In this work, a Cu-1.28Cr-0.24P (wt.%) alloy with high electrical conductivity (∼90% IACS) was fabricated by atmospheric melting. After homogenization, hot rolling, solid solution treatment, cold rolling, and aging treatment, the Cu-1.28Cr-0.24P alloy possessed an ultimate tensile strength of 390 MPa, yield strength of 350 MPa, and electrical conductivity of 89.4% IACS. Then continue a secondary cold rolling (50%) and aging treatment (400 °C, 2 h). The ultimate tensile strength, yield strength, and electrical conductivity were 380 MPa, 340 MPa, and 91.2% IACS, respectively. After aging treatment, submicron Cr3P and nano-scale Cr particles appeared in the Cu matrix, and Cr particles were the primary strengthening particles. The designed alloy achieved high electrical conductivity and considerable strength, which would become a new family member of high-electrical-conductivity copper alloys.