Synthesis of TiB2 from a carbon‐coated precursors method

Abstract

AbstractThis 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 (~0.3 to 0.8 μm), regular shape, loose agglomeration, and low level of contaminations (less than 0.5 wt% carbon and 0.6 wt% 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 (>1 μm), high level of contaminations (0.7 wt% carbon and 1.1 wt% 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 ~94.5% with the formation of platelike grains at 1800°C under a pressure of 35 MPa without additives.