Microstructure Tribological Characterization of Copper Metal Matrix Reinforced with Cerium Oxide

Abstract

Copper has extensive applications in manufacturing of electronic products for power generation and transmission because it has high thermal and electrical conductivity. Copper has high malleable property as well so widely used in the automotive and industrial sectors. In addition, the copper requires additives to improve its performance. Experimental research has been conducted to study the composite metal powder copper-cerium oxide’s tribological behavior in the present work. Using powder metallurgy process, copper composites reinforced with CeO2 particles are prepared. In this research, using a die and punch assembly with a UTM, four cylindrical preforms (CeO2 0.0, 0.2, 0.6, and 1 wt%) were prepared. These preforms were sintered at 900, 950, and 1000 °C in an electric muffle furnace and subsequently cooled. A pin-on-disk tester, the tribological characteristics of copper, and composites were studied. Under dry ambient conditions, the pins were slid against an EN-32 steel disk. Mechanical properties (hardness and wear) were investigated. XRD pattern and SEM were also examined in order to identify the element distribution and microcracks. SEM analysis shows that cerium oxide particles are uniformly distributed into the copper powder matrix. The wear analysis confirmed a too high wear loss for Cu with 0.2% CeO2 at 900 °C. However, the addition of 1% CeO2 particles appeared to significantly improve copper’s sliding wear resistance. CeO2 enhances hardness and density as well. Results show that with an increase in CeO2% content and sintering temperature, the density and hardness increase, and the wear relies heavily on CeO2% as it decreases with an increase in the content and temperature of CeO2%.