Effect of Co on microstructure and properties of Cu-Cr alloy

doi:10.13251/j.issn.0254-6051.2022.10.015

Abstract

Abstract: Microstructure and properties of Cu-Cr-Co alloys after cold rolling with deformation of 80% and aging at 450 ℃ were studied and compared with Cr-Cr alloy. The results show that when aging at 450 ℃ for 4 h, the properties of Cu-0.66Cr-0.05Co and Cu-0.62Cr-0.22Co alloy reach the peak, and the tensile strength, hardness and conductivity are 376 MPa and 410 MPa, 143.7 HV0.5 and 138.4 HV0.5, 84.1%IACS and 66.2%IACS, respectively. The precipitates of the peak-aged Cu-Cr-Co alloy have a body centered cubic (bcc) structure with a Nishiyama-Wassermann orientation to the matrix, and the Co content has little effect on the grain morphology of Cu-Cr-Co alloy. Compared with Cu-Cr alloy, the addition of Co prolongs the aging time of the alloy, increases the hardness, improves the softening resistance, but decreases the tensile strength and conductivity. As Cu and Co have a certain degree of solution above 422 ℃, some of the Co gradually dissolves into the matrix during aging, forming solid solution, and is not distributed in the periphery of the precipitation phase as predicted, reducing the comprehensive properties of the alloy.

Key words: Cu-Cr-Co alloy, thermomechanical treatment, properties, microstructure

CLC Number:

TG146.1

Gong Qinghua, Liu Jian, Chen Huiming, Xie Weibin, Wang Hang, Yang Bin. Effect of Co on microstructure and properties of Cu-Cr alloy[J]. Heat Treatment of Metals, 2022, 47(10): 94-98.

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