Microstructural Evolution and Mechanical Property of Cu–Cr–Zr–ZrB2 Composites Subjected to Cryorolling and Aging Treatment

Abstract

A new strategy has been developed to combine the nanotwins and dual‐scale particles into copper matrix composites and the comprehensive properties of Cu–1Cr–0.3Zr–1ZrB2 exhibit excellently with the addition of intermediate aging and cryorolling. The effects of different deformation processes on the evolution of microstructure, room temperature, and elevated‐temperature mechanical properties are investigated. The result demonstrates that the number of nanoscale Cr precipitates increases obviously after intermediate aging. The nanosized Cr precipitates impede the movement of grain boundaries and dislocations, resulting in the refinement of deformation bands and the dislocation tangle. The combined effect of intermediate aging and cryorolling also improves the formation of nanotwins, which plays an important role in enhancing the tensile strength of composites. The tensile strength, elongation, and conductivities of the composites subjected to two‐step cryorolling reach 653 MPa, 8.02%, and 79.51% IACS, respectively, showing an optimum comprehensive property. In addition, the stable nanotwins and the uniform distribution of dual‐scale particles inhibit the recrystallization process at elevated temperatures, contributing to improving the mechanical behavior at elevated temperatures and heat‐resistant performance of composites.