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

Abstract

This study investigated the synthesis mechanism of tantalum boride (TaB₂) powder via the boron/carbothermal reduction method, based on thermodynamic calculations and experimental results. The insufficient presence of the intermediate product B₂O₃ leads to the emergence of TaC and Ta₃B₄, while in the presence of a sufficient boron source in the reaction system, the primary products formed include TaB₂, TaC, and B₂O₃, with TaC subsequently reacting with B₂O₃ and carbon to yield TaB₂. TaB₂ powder was successfully synthesized at 1500°C with the addition of an excess of 20 wt% B₄C. 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.