Exploring the Synthesis Parameters and Spark Plasma Sintering of Tantalum Carbide Powders Prepared by Solvothermal Synthesis

Abstract

ABSTRACTTantalum carbide is a technologically important material for use in ultra-high temperatures and corrosive environments. In this report, we describe the scalability of a low temperature solvothermal method for the preparation of this useful material. X-ray diffraction shows phase-pure powders with no change in average crystallite size or compound stoichiometry compared to synthesis in smaller batches, remaining at 25 nm and 0.94 respectively. Dynamic light scattering shows a slight decrease in particle size distribution with scale-up. Thermogravimetric analysis (TGA) in air shows a decrease in surface species on the powders, but the powders oxidize at a lower temperature when scaling the synthesis. Mass spectrometry performed alongside TGA in a helium atmosphere reveals that water is the most abundant species on the surface of the powders, but oxygen, carbon monoxide, carbon dioxide, and nitrogen are also detected. Oxygen analysis reveals that the oxygen content of the powders is high (>6%). The oxygen source and methods of decreasing oxygen content are discussed. Initial sintering trials were performed and demonstrate the need for further powder processing.