High-strength nanostructured copper alloys via mechanical consolidation of pure copper and Fe-Si-B glassy powers

Abstract

High-strength nanostructured copper alloys were fabricated through the mechanical consolidation of pure copper and Fe-Si-B glassy powders using a two-step high-pressure torsion (HPT) process. Structural characterization by transmission electron microscopy and electron backscatter diffraction revealed that, after overall 20 HPT revolutions, 1 wt% Fe₇₈Si₉B₁₃ glassy powders can be fully decomposed and homogeneously supersaturated into the copper matrix. The resulting Cu-1 wt.% FeSiB alloy exhibited a compositionally uniform nanostructure with an average grain size of 63.3 nm and a high proportion of low-angle grain boundaries (54.2 %), achieving an ultimate tensile strength of 1246 MPa. In contrast, the addition of 5 wt% Fe₇₈Si₉B₁₃ glassy powder under the identical HPT conditions resulted in a crystal-glass composite structure with an ultimate tensile strength of 895.8 MPa. This work advances a hybrid method that integrates bottom-up particle bonding with top-down grain refinement to fabricate high-performance alloys.