材料期刊网

Titanium diboride (TiB2) was successfully hot-pressed at 1500 degrees C using titanium aluminum carbide (Ti3AlC2) as a sintering aid. The mechanisms for the improved sinterability of TiB2 by the addition of Ti3AlC2 involve, first, the Al coming from the decomposition of Ti3AlC2 can eliminate the oxide layer on the surface of TiB2; second, the TiCx (also from the decomposition of Ti3AlC2) has a positive influence on the densification of TiB2 due to its plasticity at high temperatures. TEM observations reveal that the interface between TiB2 and TiCx is coherent and strong, free of amorphous layers and oxide phases. An optimized composition of TiB2-10 wt% Ti3AlC2 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.