Preparation, Microstructure, and Mechanical Properties of TiB 2 Using Ti 3 AlC 2 as a Sintering Aid

Titanium diboride ( TiB 2 ) was successfully hot‐pressed at 1500°C using titanium aluminum carbide ( Ti 3 AlC 2 ) as a sintering aid. The mechanisms for the improved sinterability of TiB 2 by the addition of Ti 3 AlC 2 involve, first, the Al coming from the decomposition of Ti 3 AlC 2 can eliminate the oxide layer on the surface of TiB 2 ; second, the TiC x (also from the decomposition of Ti 3 AlC 2 ) has a positive influence on the densification of TiB 2 due to its plasticity at high temperatures. TEM observations reveal that the interface between TiB 2 and TiC x is coherent and strong, free of amorphous layers and oxide phases. An optimized composition of TiB 2 ‐10 wt% Ti 3 AlC 2 was obtained with the unique combination of mechanical properties, including the elastic modulus of 567 GPa, the fracture toughness of 4.8 MPa·m 1/2 , the flexural strength of 711 MPa, and the hardness of 25 GPa.