Strain-Induced Refinement and Extension of Solubility in Cu-1Cr-0.1Zr (wt.%) Alloy Subjected to Surface Mechanical Attrition Treatment

Cu-1Cr-0.1Zr (wt.%) alloy has been subjected to surface mechanical attrition treatment (SMAT). The strain-induced microstructure evolution, including the grain refinement and extension of the solubility between copper and chromium particles, was examined using transmission electron microscopy and scanning electron microscopy. The results indicated that the presence of dispersed chromium particles in copper facilitated the refinement of coarse-grained copper, as the copper–chromium interface is an effective nucleation site for dislocations and provides barriers to dislocation motion. In addition, a clear furrow structure and cold-welding structure with a long-range intermixing area were observed, suggesting that a process that combines abrasion, fracture, and cold welding plays an important role in the formation of a supersaturated solid solution. Finally, the results demonstrate that SMAT can effectively strengthen Cu-1Cr-0.1Zr (wt.%) alloy without drastically reducing its electrical conductivity, obtaining excellent performance in the top ~ 300-μm layer with tensile strength of 524 MPa and electrical conductivity of 75.8% IACS.