Synthesis mechanism and characterization of tantalum boride powder prepared by boron/carbothermal reduction

Abstract This study investigated the synthesis mechanism of tantalum boride (TaB 2 ) powder via the boron/carbothermal reduction method, based on thermodynamic calculations and experimental results. The insufficient presence of the intermediate product B 2 O 3 leads to the emergence of TaC and Ta 3 B 4 , while in the presence of a sufficient boron source in the reaction system, the primary products formed include TaB 2 , TaC, and B 2 O 3 , with TaC subsequently reacting with B 2 O 3 and carbon to yield TaB 2 . TaB 2 powder was successfully synthesized at 1500°C with the addition of an excess of 20 wt% B 4 C. The particle size of the powder was approximately 298 nm, and the oxygen content and carbon content in the powder were 0.6 and 0.1 wt.%, respectively.