Microstructure and properties of a nanocrystalline Cu-Al-NbC composite with high strength and good conductivity

A combination of high tensile strength of 900 MPa and a good electrical conductivity of 50% International Annealed Copper Standard (IACS) was achieved in a nanocrystalline Cu-0.1 wt%Al (grain size: 96 nm) matrix composite reinforced with 6.4 vol% NbC nanoparticles (6.5 nm). The composite was produced by combining high energy mechanical milling (HEMM), sintering and powder compact extrusion. The composite was highly thermally stable that a higher electrical conductivity of 57% IACS was achieved, while maintaining a high tensile strength of 722 MPa and good ductility after annealing at 1000 °C for 5 h.