Abstract:Cu-Cr-Zr alloy is widely used in communication electronics, rail transit, aerospace and other fields, and improving its strength and conductive properties is a research focus in recent years. In this research, Cu-1Cr-0.1Zr and Cu-1Cr-0.1Zr-0.069La alloy ingots were designed and prepared, and treated by solution-warm rolling-cold rolling-preaging-cold rolling-aging processes. The macrostructure and microstructure of two alloys were analyzed by optical microscope, scanning electron microscope and transmission electron microscope. The hardness and conductivity of the alloys were measured by microhardness tester and eddy-current metal conductivity meter. The results show that after 400 ℃ warm rolling, a small amount of nanoscale Cr phase with fcc structure is precipitated from the alloy matrix. The primary Cr phases are distributed in spherical and rod-like forms at grain boundaries and within grains, and rare earth La is wrapped around the outer layer of Cr phase to form a core-shell structure, which inhibits the growth of Cr phase. After 83% cold rolling+400 ℃×2 h aging treatment, Cu-1Cr-0.1Zr-0.069La alloy reaches the peak hardness of 199.8 HV and the conductivity of 66.5%IACS, which is an increase in peak hardness of 20 HV and a decrease in conductivity of 3.5%IACS compared to Cu-1Cr-0.1Zr alloy. After further 44% cold rolling, Cu-1Cr-0.1Zr-0.069La alloy reaches the peak hardness of 212.9 HV, tensile strength of 640 MPa and the conductivity of 74.4%IACS after aging at 400 ℃ for 4 h. The peak hardness of Cu-1Cr-0.1Zr-0.069La alloy is 17.2 HV higher than that of Cu-1Cr-0.1Zr alloy, and the conductivity is decreased by 4.7%IACS.