Achieving high strength and high conductivity of bulk metallic glass composites by controlled milling process

Abstract

Cu/Cu-Zr-Al metallic glass composites (C/CMGCs) are high-strength conductive materials that have been synthesized by a combination of ball milling (BM) and spark plasma sintering (SPS). This study investigated how the rotational speed of BM process before SPS consolidation affects the microstructure, mechanical properties and electrical properties of fabricated bulk C/CMGCs were investigated. Increasing the BM speed significantly enhanced the mechanical strength while maintaining a high electrical conductivity. However, when the speed exceeded 375 rpm, the high centrifugal force hindered effective impact between the balls and powder to impede further performance optimization. Using the grain boundary strengthening strategy, nanocrystalline copper was strengthened by tuning the milling parameters. The simultaneous achievement of high conductivity and superhigh strength in the C/CMGCs will prompt further explorations of functionalized bulk metallic glass composites with vast untapped potentials.