Fabrication of Mo-20Cu sheets via liquid sintering, cold rolling and heat treatment

Abstract

Mo-Cu alloys are widely utilized in heat sink materials, electronic packaging, and related fields due to their excellent electrical and thermal conductivity and low coefficient of thermal expansion. However, poor interfacial bonding significantly compromises their plastic deformability, thereby adversely affecting the processability during manufacturing operations. In this work, 0.5-mm-thick Mo-20 wt%Cu (MC20) composites with 80 % deformation were fabricated through high-temperature liquid-phase sintering followed by cold rolling and subsequent heat treatment, using self-synthesized ultrafine Mo powder and commercial Cu powder as raw materials. The changes in microstructure and properties of MC20 composites were investigated under various conditions. The Mo particles exhibited two distinct deformation behaviors at the Mo-Mo interfaces and Mo-Cu interfaces. The synergistic deformation behavior and failure mechanisms of the dual-phase material in the MC20 composite were revealed. Cold mechanical deformation induced a transition in the fracture mechanism of the MC20 composite from ductile to brittle. After annealing at 400 °C, the MC20 composite achieved an ultimate tensile strength of 1042 MPa.