High-strength and high-conductivity nanograined copper fabricated by partial homogenization and asymmetric rolling

Abstract

In this study, microstructure, mechanical properties, and electrical conductivity of copper matrix composite fabricated by partial homogenization and asymmetric cold rolling investigated. The microstructure of the copper matrix composite investigated by optical microscopy (OM) as well as scanning electron microscopy (SEM) equipped by energy dispersive spectroscopy (EDS). The copper matrix composites with uniformly dispersed copper oxide particles, free of porosity, and appropriate interfacial adhesion between particles and matrix successfully fabricated via partial homogenization followed by asymmetric cold rolling. By 90% and 96% rolling, numerous nanograins observed in the copper matrix due to the occurrence of discontinuous dynamic recrystallization (DDRX) and particle stimulated nucleation (PSN) mechanisms. The produced composites had excellent mechanical properties due to the well-dispersed copper oxide particles in the copper matrix, strain hardening, and grain refinement. The 96% asymmetric cold rolling resulted in the hardness of 91.3 HB, yield strength of 413.9 MPa, and electrical conductivity of 84.10% IACS, which is an excellent combination for modern applications in electrical engineering. Finally, all fracture surfaces exhibited numerous dimples, indicating ductile failure mode. With increasing the deformation, the number, diameter, and depth of dimples and the height of the torn edge decreased.