Damage and wear resistance of Al₂O₃-CNT nanocomposites fabricated by spark plasma sintering

In this study, we prepare Al₂O₃CNT (carbon nanotube) composites with different contents of CNT, 1-20 vol% into the Al ₂O₃ ceramics, for the purpose of improving damage and wear resistance. Al₂O₃CNT composites are obtained by spark plasma sintering in conditions of 1400-1600°C in vacuum and 30-80 MPa. Hardness evaluated by Vickers indentation shows that the hardness of Al ₂O₃-CNTcomposites can be enhanced when the CNTaddition is less than 5 vol%. Toughness evaluated by Vickers indentation indicates that the toughness of the composites is comparable with that of an Al₂O ₃ monolith. Hertzian indentations using a spherical indenter indicate the hard and elastic behavior of the composites by the addition of CNT. The wear rate and friction coefficients of the composites evaluated by the ball-on-disk method show that the composites represent low friction and reduced wear loss under constant contact load. The results indicate that the damage and wear resistance of Al₂O₃ ceramics can be enhanced by the addition of carbon nanotubes in optimum conditions.