Improving flexural strength of Ti₂C-Ti cermet by hot compressive deformation: Microstructure evolution and fracture behaviors

In order to improve the microstructure and mechanical properties, the hot compressive deformation with 50% height reduction at 1100·C was conducted on a Ti₂C-Ti cermet. The results showed that the lamellar Ti precipitates in Ti₂C grains were transformed to bimodal size distribution, which was approximately 290 nm and 5.8 μm in diameter, respectively, after the hot deformation. The bimodal Ti precipitates suppressed {011} cleavage surfaces of Ti₂C during flexural fracture, which resulted in an 18.5% increment of strength. This phenomenon can be attributed to the bimodal Ti precipitates that decreased the average crack driving force due to their gentle variation in elastic modulus compared with the monolithic lamellar Ti precipitates. The present work can guide further deformation and mechanical property improvement of Ti₂C cermets.