Production and properties of Cu-ZrO2 nanocomposites

Abstract

In the present study, Cu–3, 6, and 9 wt.% of ZrO2 nanocomposites were prepared by an in situ reactive synthesis of copper nitrate Cu(NO3)2 and zirconium oxychloride ZrOCl2. The structure and characteristics were examined by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The results showed that the nanosized ZrO2 particles with about 45 nm was successfully formed and dispersed within the copper matrix. The effect of ZrO2 nanoparticles content on relative density, Vickers hardness, specific electrical resistivity, and coefficient of thermal expansion was evaluated. The pin-on-disc test was also performed to determine dry sliding wear behavior of specimens under different wear conditions. Hardness and specific electrical resistivity increased and density of Cu-ZrO2 nanocomposites decreased with increasing amount of ZrO2 in Cu matrix. The coefficient of thermal expansion significantly increased with increasing temperature but decreased with increasing ZrO2. The wear rate and friction coefficient of the developed surface composite was found decreasing with respect to increase in the dispersion of ZrO2. Amongst the copper surface composite, specimen with 9 wt.% of ZrO2 has shown the least wear rate with low coefficient of friction.