Outstanding strength and conductivity of metallic glass composites with multiscale configuration

Cu-based composites with multiscale configuration for electrical contact applications are fabricated via a ball milling (BM)-spark plasma sintering (SPS)-aging process. Synergistic strengthening of the Cu alloy matrix by micro-scale metallic glass particles and nanoscale intracrystalline precipitation phases is realized. The annealing technique achieves the decomposition of solute atoms in the Cu alloy, ensuring the excellent electrical properties of the matrix conductive network. The composite with multiscale configuration achieves an outstanding combination of ultimate compressive strength of (1114 ± 15) MPa and electrical conductivity of 33.0% ± 1.1% International Annealed Copper Standard (IACS) after annealing at 400 °C for 10.0 h. Investigation of the strengthening and conductivity mechanisms suggests that the precipitation of the Cr-rich phase within the matrix crystals is a critical contributor to the concerted enhancement of strength and conductivity. In addition, the positive role of nanocrystals precipitated at the edges of metallic glass particles on the interfacial bonding of composites is addressed. Graphical abstract