Analysis of Microstructure and Mechanical Properties of Bi-Modal Nanoparticle-Reinforced Cu-Matrix

Bi-modal particles are used as reinforcements for Cu-matrix. Nano TiC and/or Al2O3 were mechanically mixed with Cu particles for 24 h. The Cu-TiC/Al2O3 composites were successfully produced using spark plasma sintering (SPS). To investigate the effect of TiC and Al2O3 nanoparticles on the microstructure and mechanical properties of Cu-TiC/Al2O3 nanocomposites, they were added, whether individually or combined, to the copper (Cu) matrix at 3, 6, and 9 wt.%. The results showed that titanium carbide was homogeneously distributed in the copper matrix, whereas alumina nanoparticles showed some agglomeration at Cu grain boundaries. The crystallite size exhibited a clear reduction as a reaction to the increase of the reinforcement ratio. Furthermore, increasing the TiC and Al2O3 nanoparticle content in the Cu-TiC/Al2O3 composites reduced the relative density from 95% for Cu-1.5 wt.% TiC and 1.5 wt.% Al2O3 to 89% for Cu-4.5 wt.% TiC and 4.5 wt.% Al2O3. Cu-9 wt.% TiC achieved a maximum compressive strength of 851.99 N/mm2. Hardness values increased with increasing ceramic content.