Microstructure and Properties of Spark Plasma Sintered Carbon Nanotube Reinforced Aluminum Matrix Composites

In this paper, spark plasma sintering (SPS) of multi-walled carbon nanotube (CNT) reinforced aluminum matrix composites is reported. Ball milling of the Al-CNT mixture with polyacrylic acid (PAA) dispersion agent followed by SPS resulted in uniform dispersion of CNTs in dense composite compacts. Significant improvement in microhardness, nanohardness, and compressive yield strength was observed with 2wt% CNT reinforcement in aluminum matrix composites. The Al-CNT composites further exhibited improved wear resistance and lower friction coefficient due to strengthening and self-lubricating effects of CNTs.