Grain Refinement and Mechanical Properties of Cu-Cr-Zr Alloys with Different Nano-Sized TiCp Addition.

Dongdong Zhang,Fang Bai,Jinguo Wang,Yong Wang,Wenquan Wang

doi:10.3390/ma10080919

Abstract

The TiCp/Cu master alloy was prepared via thermal explosion reaction. Afterwards, the nano-sized TiCp/Cu master alloy was dispersed by electromagnetic stirring casting into the melting Cu–Cr–Zr alloys to fabricate the nano-sized TiCp-reinforced Cu–Cr–Zr composites. Results show that nano-sized TiCp can effectively refine the grain size of Cu–Cr–Zr alloys. The morphologies of grain in Cu–Cr–Zr composites changed from dendritic grain to equiaxed crystal because of the addition and dispersion of nano-sized TiCp. The grain size decreased from 82 to 28 μm with the nano-sized TiCp content. Compared with Cu–Cr–Zr alloys, the ultimate compressive strength (σUCS) and yield strength (σ0.2) of 4 wt% TiCp-reinforced Cu–Cr–Zr composites increased by 6.7% and 9.4%, respectively. The wear resistance of the nano-sized TiCp-reinforced Cu–Cr–Zr composites increased with the increasing nano-sized TiCp content. The wear loss of the nano-sized TiCp-reinforced Cu–Cr–Zr composites decreased with the increasing TiCp content under abrasive particles. The eletrical conductivity of Cu–Cr–Zr alloys, 2% and 4% nano-sized TiCp-reinforced Cu–Cr–Zr composites are 64.71% IACS, 56.77% IACS and 52.93% IACS, respectively.

Highlights

Cu-matrix composites and Cu alloys were widely used as functional and structural materials [1,2,3,4,5,6], such as electrodes for electrical-resistance welding, electric switches, lead frames, friction pieces, as well as a cooling medium of the magnetic channel, encapsulating material on account of their good wear resistance [7], excellent electrical and thermal conductivities [8,9], and good corrosion resistance [10,11]etc
Recent research indicates that the dispersion of ceramic particles in the copper matrix could play a role in pinning dislocation movement and improving the strength of the composites, in addition, alloying elements can enhance Cu alloy [12,13,14,15]
Zhang et al [2] revealed that the microhardness of solid soluted Cu–Cr–Zr alloys was 181.8 HV, which was much higher than that of pure copper (68 HV), with less decreasing electrical conductivity (70.8% International Annealed Copper Standard (IACS))

Summary

Introduction

Cu-matrix composites and Cu alloys were widely used as functional and structural materials [1,2,3,4,5,6], such as electrodes for electrical-resistance welding, electric switches, lead frames, friction pieces, as well as a cooling medium of the magnetic channel, encapsulating material on account of their good wear resistance [7], excellent electrical and thermal conductivities [8,9], and good corrosion resistance [10,11]etc. Recent research indicates that the dispersion of ceramic particles in the copper matrix could play a role in pinning dislocation movement and improving the strength of the composites, in addition, alloying elements can enhance Cu alloy [12,13,14,15]. TiCx –TiB2 /Cu composites by thermal explosion reaction synthesis. They found that the ultimate compressive strength increased with the ceramic content and the microhardness of the 40–60 vol %. The electrical and thermal conductivity of Cu was reduced because of the high content of ceramic particles. Zhang et al [2] revealed that the microhardness of solid soluted Cu–Cr–Zr alloys was 181.8 HV, which was much higher than that of pure copper (68 HV), with less decreasing electrical conductivity (70.8% IACS)

Methods

Results

Conclusion