Formation of High Hardness ZnO/Cu Nanocomposite by Thermal Oxidation from Cu-Zn Alloy Strips

Abstract

Due to their superior thermal, electrical, and mechanical properties, brass and Cu-Zn alloys are widely used in a broad range of applications. In applications requiring greater durability, corrosion resistance, and wear resistance, however, the ZnO/Cu composite is preferable. Typically, ZnO/Cu composites are manufactured through powder metallurgy. In this article, brass strips are thermally oxidized in an oxygen atmosphere to produce ZnO/Cu composite strips. The optimal temperature and oxygen pressure are 600–650 °C and less than one atmosphere, respectively. The homogeneous distribution of nanoscale ZnO clusters in the Cu matrix can be attributed to the diffusion of both Zn and O in the matrix. In addition, the composite is substantially harder than brass, increasing from 70–90 HV to 200–240 HV. Therefore, thermal oxidation has been shown to be a simple and cost-effective process for producing ZnO/Cu composites with high hardness.