A feasible ultrafine grained Cu matrix composite microstructure for achieving high strength and high electrical conductivity

An ultrafine grained Cu-5vol.%Al2O3 composite with a microstructure consisting of bimodal Al2O3 particles distributing at the boundaries of ultrafine Cu grains was fabricated by a combination of high energy mechanical milling and powder compact extrusion. The material showed a high tensile yield strength of 486 MPa and high electrical conductivity of 80% of the international annealed copper standard (IACS). Analysis of the findings shows that such microstructure can be further tailored to achieve high strength and high electrical conductivity with ultrafine grained or nanocrystalline Cu matrix composites.