Nitridation of the Zr–V Metal Pair and Evaluation of the Thermo-EMF of a Synthesized Ceramic Sample

Abstract

By nitriding the Zr–V pair while preserving the shape of the original metallic blanks, binary compact nitrides were synthesized. The kinetic and voltammetric dependencies of the nitriding process were determined. For the individual metals and the weld zone, interaction with nitrogen proceeds via different mechanisms. Pure metals react with nitrogen through the formation of three- and two-layered structures. Nitriding of the weld zone is accompanied by the decomposition of the Zr–V solid solution with segregation of metallic vanadium at grain boundaries as a separate phase. Simultaneously, mutual dissolution occurs between the nitrogen reaction products: nitrogen solid solutions in both metals and their nitrides of varying stoichiometry. The ceramic formation process is accompanied by diffusion of vanadium into the region of its lower concentration and the formation of the intermetallic compound Zr_0.3V_0.6N_0.1, which does not interact with nitrogen at the synthesis temperature. For gradient and ceramic structures (Zr–V)N_x in the temperature range from –195.7 to +550°C, the nature of the dependence of the thermoelectromotive force (thermo-EMF) on nitriding time was established and its magnitude was evaluated. The obtained ceramic and gradient materials can be used as ceramic thermoelectric converters.