Nano-precipitates evolution and properties improvement mechanism of Cu–Zn–Ni–Si-X alloy strip based on multi-element microalloying and thermomechanical treatment

Abstract

In this paper, we put a variety of elements into the Cu–Ni–Si alloy for smelting and processing, and systematically characterized and tested the microstructure, precipitates and service performance during the process. We found that adding Cr, Zr, Ti, and Mg led to grain refinement and produced some twin structures. In addition, based on Ni–Si precipitates, the generation of the nano-Cr3Si phase (50 nm in size) is promoted, and their distribution in the matrix is relatively uniform. The dispersed precipitates can effectively strengthen the service performance of the copper alloy, and the strength of the alloy exceeds 500 MPa while maintaining high conductivity. The research results of this paper can provide a basis for the design and development of copper alloy strips for new energy vehicle connections.

Keywords

• Electrical connectors
• Cu–Ni–Si-X alloy
• Nano-precipitates
• Multi-element microalloying
• Electrical conductivity
• Strengthening mechanism