A Novel Precipitation‐Strengthened Conductive Copper Alloy: Cu–Hf–Si Alloy

Abstract

The Cu–1.1 wt% Hf–0.1 wt% Si alloy containing various precipitates is studied as a novel precipitation‐strengthened alloy with high strength and high electrical conductivity. The Cu–Hf–Si alloy prepared by solution, cold rolling, and aging processes exhibits a hardness of 238.92 HV, a tensile strength of 691.01 MPa, a breaking elongation of 15.09%, and an electrical conductivity of 62.34% International Annealed Copper Standard. The optimal peak aging parameter for Cu–Hf–Si alloy is 430 °C for 90 min. The precipitation of Hf and Si atoms from the Cu matrix is helpful to enhance the electrical conductivity. The precipitation of Hf can produce fibrous Guinier Preston zone and γ' precipitate, as well as spherical Cu10Hf7 phases. In addition, the coprecipitation of Si and Hf can also produce Hf3(Cu2Si)2 and HfCuSi phases. The high strength of Cu–Hf–Si alloy is mainly due to the multiprecipitates synergistic strengthening.