Friction and Wear Behavior of Al2O3–YSZ–CNT Based Nanocomposites Prepared by Spark Plasma Sintering

The design of advanced self-lubricating ceramic nanocomposites is crucial for applications that demand high wear resistance and reduced friction under severe operating conditions. In this study, Al2O3, yttria-stabilized zirconia (YSZ), carbon nanotube (CNT) nanocomposites were fabricated via spark plasma sintering (SPS) to investigate their structural, microstructural, and tribological performance. The incorporation of CNTs and YSZ into the Al2O3 matrix resulted in dense, well-bonded composites with a uniform distribution of reinforcements. Wear tests performed under different loads revealed that the hybrid nanocomposites exhibit a significant reduction in wear rate and coefficient of friction compared with monolithic Al2O3. The enhanced wear resistance was attributed to the synergistic effects of YSZ-induced toughening, the lubricating role of CNTs, and the formation of protective tribofilms during sliding. Among the compositions, the optimized sample demonstrated the lowest wear loss at both 10 and 15 N loads, confirming its suitability for demanding tribological environments. Overall, this work highlights the effectiveness of combining Al2O3, YSZ, and CNTs in achieving multifunctional nanocomposites with promising potential for high-performance wear-critical applications.