Production and properties of Cu-ZrO 2 nanocomposites

In the present study, Cu–3, 6, and 9 wt.% of ZrO 2 nanocomposites were prepared by an in situ reactive synthesis of copper nitrate Cu(NO 3 ) 2 and zirconium oxychloride ZrOCl 2 . 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 ZrO 2 particles with about 45 nm was successfully formed and dispersed within the copper matrix. The effect of ZrO 2 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-ZrO 2 nanocomposites decreased with increasing amount of ZrO 2 in Cu matrix. The coefficient of thermal expansion significantly increased with increasing temperature but decreased with increasing ZrO 2 . The wear rate and friction coefficient of the developed surface composite was found decreasing with respect to increase in the dispersion of ZrO 2 . Amongst the copper surface composite, specimen with 9 wt.% of ZrO 2 has shown the least wear rate with low coefficient of friction.