Preparation of Niobium Carbide-Based High-Temperature Ceramics by Direct Niobium Carburization

Stoichiometric niobium carbide (NbC) samples with a tailored shape have been synthesized by direct carburization of rolled metallic niobium in an atmosphere of an argon + ethylene gas mixture. Ceramics have been produced by reacting niobium metal with ethylene gas, through absorption of the carbon released on the niobium surface as a result of ethylene decomposition. Complete carburization has been shown to be accompanied by the formation of an anisotropic inner cavity, reflecting the initial shape of the sample, which is characteristic of ceramics produced using the oxidation-assisted engineering approach. We have studied the substructure, superconducting properties, and mechanical properties of NbC synthesized via high-temperature carburization of niobium foil.