Synergistic regulation of mechanical and physical properties in SiC nanowire dispersion-strengthened copper via core–shell coating

A copper (Cu) matrix composite reinforced with discontinuous SiC nanowires (SICNWs) was developed through sintering of core–shell Cu-coated SICNW powders followed by high-pressure torsion processing. Through this process, a uniform dispersion of 1.0 vol% SICNWs within the Cu matrix was successfully achieved, and these individual nanowires are distributed across the grain boundaries (GBs) and embedded within the grain interiors, which significantly improved the interfacial bonding strength of the composite. The as-prepared composite exhibited exceptional comprehensive properties: yield strength ∼ 484 MPa, ultimate tensile strength ∼ 499 MPa, electrical conductivity ∼ 82 % IACS (International Annealed Cu Standard), and thermal conductivity ∼ 270 W/(m·K). Microstructural analysis revealed that the dispersed SICNWs effectively pinned GBs, and thus can inhibit the migration of GBs under heat treatment, significantly improving the thermal stability. This work provides a novel paradigm for designing fiber-reinforced metal matrix composites that achieve a well-balanced combination of mechanical, thermal, and electrical properties.