Fabrication and evaluation of tribological properties of Al₂O₃ coated Ag reinforced copper matrix nanocomposite by mechanical alloying

Abstract

This study aims to detect the positive effects of alumina coating by silver on the mechanical and tribological characteristics such as hardness and wear resistance of Al2O3 reinforced copper matrix nanocomposites. 2.5, 5, 7.5, and 10% wt. of alumina particles reinforced coated silver copper matrix nanocomposites were fabricated using the PM method. A scanning electron microscopy (SEM) was used to investigate the morphology of powders and microstructure of the nanocomposite samples. The density and hardness of samples were measured by the Archimede’s method and Vickers microhardness method, respectively. Abrasive wear test of samples was measured using pin on disk. The results showed that coated alumina were homogenous distributed in the copper matrix. The densification of samples decreased but the hardness of samples increased with increasing Al2O3 content due to hard structure of Al2O3 ceramic particles. The highest microhardness was measured as 175 HV for copper matrix nanocomposites fabricated by using 10%wt of Al2O3 content. 70 HV was obtained for the copper matrix. Abrasive wear rate reduces by increasing the coated alumina percent and increase via increasing the normal load. In addition, the friction coefficient of the developed surface was found to decreasing with respect to increase coated alumina percent and increasing normal load.