Mechanical properties of scCu-rGO /Cu composites reinforced with Cu2O transition layer constructed by supercritical CO2 deposition

Abstract

Reduced graphene oxide (rGO) with surface-loaded Cu particles (scCu-rGO) was prepared by supercritical CO2 deposition, and Cu matrix composites with scCu-rGO as a reinforcement (scCu-rGO/Cu composites) were successfully prepared by ball milling for different times and spark plasma sintering (SPS). The scCu-rGO/Cu composites prepared with a ball milling time of 20 h exhibited high electrical conductivity (96.3 % IACS), tensile strength (240 MPa), and elongation (37 %). The outstanding properties are mainly ascribed to the uniform distribution of rGO by the ball milling process and rGO promoted by loading Cu particles onto its surface through supercritical deposition, which led to an interfacial reaction between rGO and Cu, resulting in the formation of a Cu2O transition layer with a load-transferring effect that enhanced the mechanical properties of the composites. Based on the experimental results, the strength of scCu-rGO/Cu composites is mainly enhanced by synergistic strengthening through grain refinement, Orowan looping and load transfer strengthening. This study demonstrates that the use of supercritical deposition to construct Cu2O transition layers can result in a strength-plasticity and high electrical conductivity match in scCu-rGO/Cu composites. The findings presented here offer new insights for innovative design of Cu matrix composites for advanced engineering applications by using supercritical deposition.