Synthesis of TiB2 from a carbon-coated precursors method

This article deals with the synthesis of TiB2 from carbon-coated TiO2 precursors with the addition of B4C. The carbon-coated precursors method alters the reaction process, compared with the conventional mixing of reactants, to produce high-quality TiB2 powders. The produced powders have a single phase, a submicron particle size (similar to 0.3 to 0.8m), regular shape, loose agglomeration, and low level of contaminations (less than 0.5wt% carbon and 0.6wt% oxygen). The formation mechanism proposed is based on experimental results and thermodynamic evaluations. For comparison, the powders obtained from the mixture of reactants show higher agglomeration, a large particle size (>1m), high level of contaminations (0.7wt% carbon and 1.1wt% oxygen), and difficulty to control the reaction process (formation of TiBO3 and Ti2O3 as the intermediate phases). The synthesized powders from the precursors method can be hot pressed to a relative density of similar to 94.5% with the formation of platelike grains at 1800 degrees C under a pressure of 35MPa without additives.