Synthesis of Y2O3 and graphite-added copper-based hybrid composites by powder metallurgy: Mechanical properties and tribological behavior

In the presented study, Y2O3 and graphite-reinforced Cu matrix hybrid composite materials were prepared using the powder metallurgy method. The aim is to compare the microstructure, density, hardness, and wear behavior of composites with different yttria contents (5, 10, and 15 wt%) and graphite (2 wt%) reinforcements. An increase in the Y2O3 ratio, along with the addition of graphite, resulted in an observed increase in the hardness values of the composites. Additionally, it was observed that Y2O3 and graphite are homogeneously distributed in the copper matrix in the SEM-EDX spectra. Upon examining the microstructures of the composites, it was determined that with the increase in yttrium oxide content, partially yttrium oxide agglomerations formed in some regions. The addition of Y2O3 resulted in a copper sample that is 1.34 times harder than pure copper. Addition of Y2O3 -graphite, samples with 3.301?22.3 % higher wear resistance were obtained.