Enhancement of mechanical and physical properties of Cu-Ni composites by various contents of Y2O3 reinforcement

The increasing demand for materials possessing enhanced mechanical strength, high thermal conductivity, and excellent electrical properties has grown significantly. Cu-matrix composites, especially Cu- Ni, present a promising candidate to fulfill these demands. In this study, Cu-Ni composites were successfully synthesized using powder metallurgy with various additions (0-1.5 wt%) of Yttria (Y2O3)-reinforcement aiming to enhance their mechanical, thermal, and electrical properties. The microstructural investigations demonstrated a uniform distribution of Y2O3 particles and a slight increase in porosity of the Cu-Ni matrix. The Cu-Ni composites with 1.5 wt% Y2O3 showed the presence of Cu2NiZn intermetallic compounds, potentially harming their physical and mechanical properties. Y2O3-reinforcement significantly increased the hardness and led to a moderate rise in the yield and ultimate compressive strengths. The results indicated that the Cu-Ni matrix without Y2O3-reinforcement had the highest coefficient of thermal expansion, which decreased with the addition of Y2O3, potentially leading to improved thermal properties of Cu-Ni composites. This study puts an emphasis on the importance of Y2O3 particles dispersion and on the extent of porosity in enhancing the thermal and mechanical properties of Cu-Ni composites.