Enhanced electrical, mechanical and tribological properties of Cu-Cr-Zr alloys by continuous extrusion forming and subsequent aging treatment. (30th May 2022)

• Record Type: Journal Article
• Authors: Shen, Zhe; Lin, Zhongze; Shi, Peijian; Zhu, Jiale; Zheng, Tianxiang; Ding, Biao; Guo, Yifeng; Zhong, Yunbo
• Is Part Of: Journal of materials science & technology. Volume 110(2022)
• Page Start: 187
• Page End: 197
• Publication Date: 2022-05-30
• Subjects: Cu-Cr-Zr alloy -- Continuous extrusion -- Electrical conductivity -- Mechanical properties -- Tribological properties; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2021.10.012
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: A high performance Cu-1Cr-0.1Zr alloy was obtained by continuous extrusion forming and subsequent aging treatment. The strengthening contributions of the grain refinement, dislocation and precipitation were quantitatively calculated. The wear behavior was studied by examining the evolution of wear surface morphology and subsurface microstructure. The microhardness (H), H/Er ratio and H 3 /Er 2 ratio were considered to gage the wear resistance of Cu-Cr-Zr alloy. Abstract: As a promising material for the new generation of high-speed railway contact wires, the comprehensive optimization of the electrical conductivity, strength, hardness and wear resistance of the Cu-Cr-Zr alloy has received extensive attention. In this paper, a high-performance Cu-1Cr-0.1Zr alloy with an ultimate tensile strength of 599.1 MPa, a uniform elongation of 8.6%, a microhardness of 195.7 HV0.2 and an electrical conductivity of 80.07%IACS was achieved by the continuous extrusion forming (CEF) and subsequent peak-aging treatment. The grain refinement strengthening, dislocation strengthening and precipitation strengthening are identified to be responsible for the excellent electrical and mechanical properties of Cu-Cr-Zr alloy. The wear behavior of Cu-Cr-Zr alloy was investigated by examining the evolution of worn surface morphology and subsurface microstructure. The microhardness ( H ) and reduced elastic modulus ( E r ) of the subsurface below the worn surface measured by nanoindentation were calculated to gage the tribological performance of Cu-Cr-Zr alloy. Results show that the continuously extruded and subsequently peak-aged specimen has the best wear resistance, which indicates that the tribological properties of Cu-Cr-Zr alloy strongly depend on its strength and hardness. It can be concluded that the CEF and subsequent aging treatment process provides a new and high-efficiency procedure for the continuous preparation of Cu-Cr-Zr alloys.