Abstract

This paper introduces the boron/carbon thermal reduction reaction, represented by the equation 2Ta2O5+ B4C + 11 C = 2TaB2 + 2TaC + 10CO (g), as a novel reaction pathway for synthesizing TaB2₋TaC composite powders. Subsequently, the SPS technique is employed for the fabrication of TaB2-TaC composite ceramics via sintering. The article begins by elucidating the fundamental process of this reaction and constructing a phase diagram through thermodynamic calculations. The experimental results demonstrate that adjusting the synthesis temperature and the proportion of the boron source in the raw materials enables effective control over the ratio of the two phases within the composite materials, allowing the TaB2 phase content to be tailored within the range of 38.1–60 %. Moreover, elevating the synthesis temperature and increasing the proportion of the boron source effectively mitigate the C,O impurity content in the composite powders and facilitate the TaB2 step-growth process. It is noteworthy that the hardness of TaB2-TaC composite ceramics sintered at 2000°C using the optimized complex-phase powder as the precursor reaches 21.7±0.5 GPa, and the fracture toughness attains 5.2±0.2 MPa⋅m1/2.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.