Effect of particle size and sintering additive on densification and mechanical properties of titanium diboride (TIB2) ceramic

Abstract

This research paper investigates the impact of particle size on the densification and mechanical properties of TiB2 ceramics. The study compares the behavior of as-received TiB2 powder with a particle size of 6.5 ± 3.5 μm to ball-milled TiB2 powder with a particle size of 1.1 ± 0.6 μm. The addition of a B4C sintering additive was employed to enhance densification. The results reveal that full densification was not achieved with the as-received powder, even with the addition of the B4C sintering additive. However, the ball-milled powder demonstrated complete densification. The microstructure analysis of the fully dense TiB2 ceramic showed a core-shell type structure with the shell composed of (Ti, W)B2 and the core composed of TiB2, as observed through compositional analysis. However, electron backscattered diffraction analysis did not differentiate between the core and shell regions. Furthermore, the fully dense TiB2 ceramic exhibited exceptional mechanical properties. It demonstrated a high hardness value of 30 GPa, and a fracture toughness of 5.7 MPa m1/2.