Tribological Behavior of Novel Ti₃SiC₂ (Natural Nanolaminates)-Reinforced Epoxy Composites during Dry Sliding

Abstract

In this article, we report for the first time the synthesis and characterization of Ti₃SiC₂–epoxy (MAXPOL) composites. Three novel composites were designed by adding 20.7, 30.6, and 71.6 vol% Ti₃SiC₂ particulates to an epoxy matrix. The microstructure evaluation by scanning electron microscopy (SEM) showed that the Ti₃SiC₂ particles are well dispersed in the epoxy matrix. The addition of Ti₃SiC₂ enhanced the ultimate yield strength (UYS) and hardness of all of the composites compared to epoxy. Tribological studies were performed by a tab-on-disc method against Inconel 718 and alumina substrates. In both cases, the mean friction coefficient (µ_mean) decreased as the concentration of Ti₃SiC₂ in the epoxy matrix was increased. The concomitant wear rates (WRs) also decreased steadily and then increased slightly after reaching a concentration of ~32.6 vol% Ti₃SiC₂. The tribological studies proved conclusively that the addition of Ti₃SiC₂ in the epoxy matrix imparts self-lubricity to the composites. The tribofilms formed on different tribosurfaces were also characterized by detailed SEM investigations.

KEY WORDS:

• Ti₃SiC₂
• MAXPOL
• Solid Lubricants
• Self-Lubricating Composites
• Self-Lubrication

FUNDING

S.G. acknowledges the University of North Dakota startup funding for support. The authors thank Kanthal Inc. for supplying the Ti₃SiC₂ powders. The NDSU Electron Microscopy Center core facility is also acknowledged for the microscopy. This material is also based on work supported by the National Science Foundation under Grant Nos. 0619098 and 1229417. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.