Surface composite on Cu substrate with SiO2 reinforcement fabricated by severe plastic deformation: Microstructure, mechanical and tribological properties

In this study, the mechanical and tribological properties of copper/SiO2 composites fabricated by the friction stir processing (FSP) were investigated. Micro-hardness measurements and tensile testing as well as atomic force and scanning electron microscopy were utilized to characterize the fabricated composites. The results showed that increase in the number of FSP passes leads to significant improvement in the mechanical properties. The microhardness and tensile strength of the sample fabricated by four passes of FSP improve by about 149% and 70% with respect to the base metal, respectively. In contrast, ductility dramatically degrades as more FSP pass are applied. The investigations into the wear behavior of fabricated samples showed that the weight loss and friction coefficient remarkably decrease in the composites. It was also observed that the wear rate in the fabricated samples decrease with increase in the number of FSP passes. (C) 2019 Elsevier B.V. All rights reserved.