Effect of Ti on the microstructure and properties of Cu–Cr alloy

Abstract

Cu–Cr–Ti alloy was successfully prepared by vacuum melting, solution treatment at 960 °C for 1 h, 80 % cold rolling and aging at 500 °C for 1 h. The effect of Ti content on the microstructure was characterized by Scanning electron microscope (SEM) and Transmission electron microscope (TEM). Their tensile strength, electrical conductivity, thermal stability, wear resistance and arc erosion resistance were also measured. The results showed that Ti can form the Ti0.77S phase with S, which can prevent the occurrence of sulfur embrittlement. And Ti can segregate around the Cr precipitates, hindering their growth. Therefore, the tensile strength, hardness, high temperature softening resistance, wear resistance and arc erosion resistance improved with the increase of Ti content. But the electrical conductivity decreased sharply since Ti was mainly solidly dissolved in the matrix. What's more, the electrical conductivity decreased sharply and other properties did not improve when the content increased from 0.066 wt% to 0.098 wt%, that is, the comprehensive performance was the best when the Ti content was 0.066 wt%. The tensile strength was 551 MPa, electrical conductivity was 78.3%IACS and the friction coefficient was 0.33. This work provides effective ideas for preparing copper alloys with desired properties.

Keywords

• Cu-Cr-Ti alloy
• Microstructure
• Properties
• Precipitation behavior