Sintering and mechanical properties of titanium diboride with aluminum nitride as a sintering aid

Titanium diboride (TiB2) was hot-pressed at 1800 °C with aluminum nitride (AlN) as a sintering aid. The presence AlN had a strong influence on the sinterability and mechanical properties of the TiB2. When a small amount (⩽5 wt.%) of AlN was added to the TiB2 the titania (TiO2) present on the surface of the TiB2 powder was eliminated by a reaction with AlN to form TiN and Al2O3. The elimination of TiO2 markedly improved the sinterability and consequently the mechanical properties of TiB2. However, when too much AlN was added (⩾10 wt.%), the sinterability and the mechanical properties decreased, apparently due to the remaining unreacted AlN.