Dry-sliding tribological properties of TiAl/Ti₂AlC composites

The microstructure, mechanical and dry-sliding tribological properties of TiAl-based composites with 20 and 40 vol% in situ formed Ti₂AlC, produced by hot press sintering process, are investigated. The microstructural characterization reveals that Ti₂AlC phase is in the form of spherical particles and large blocks, and the quantity of the blocks increases with Ti₂AlC content. This difference in the morphology and distribution of the Ti₂AlC phase leads to the discrepancy of the wear resistance of the composites. In contrast to the Ti-46Al-2Cr-2Nb intermetallics, the dry-sliding wear resistance of the TiAl/Ti₂AlC composites first declines slightly and then enhances with the Ti₂AlC content. Furthermore, the TiAl/40% Ti₂AlC composite shows low wear rate at higher sliding speed.