Microstructure and Properties of SnO2‐rGO Reinforced Copper Matrix Composites Fabricated by Molecular‐Level Mixing Method and Spark Plasma Sintering

Abstract

Herein, the SnO2‐rGO compound powders are synthesized by reducing the graphene oxide with the SnCl2+HCl solution, and the SnO2‐rGO reinforced Cu matrix composites with uniform microstructure are successfully fabricated via molecular‐level mixing method along with spark plasma sintering. The hardness of the Cu matrix composite increases progressively with more incorporation of SnO2‐rGO content. At 0.1 wt% SnO2‐rGO, the yield strength and tensile strength of the Cu matrix composite are 305 and 350 MPa, which are, respectively, increased by 56% and 43% as compared to pure Cu. When the SnO2‐rGO content is beyond 0.2 wt%, the fractograph of the SnO2‐rGO/Cu bulk composite presents obvious tear ridges, and the fracture mode changes from ductile fracture to brittle fracture. With the introduction of SnO2 nanoparticles, the (Cu, Sn) solid solution formed at the interface between rGO and Cu matrix promotes the interface bonding. The strengthening mechanism of the SnO2‐rGO/Cu bulk composite can be ascribed to the dominant load transfer, supplemented by grain refinement and thermal mismatch effect.