Formation during Nitriding of Vanadium Disilicide

Abstract

The evolution of microstructural and phase transitions during nitriding of mechanically pre-activated vanadium disilicide powder is investigated by X-ray diffraction, chemical analysis, and transmission electron microscopy. It is established that, in the initial stage of nitriding (1000–1100 °С), the phase formation proceeds with the dispersion of near-to-surface zones of VSi₂ particles and formation of vanadium nitride of composition V₂N and silicon nitride of α-modification. With increase in the nitriding temperature, the phase formation occurs with the delamination of particles and formation of vanadium nitride with the predominant composition VN and silicon nitride of α- and β-modifications. The nitriding of the mechanically activated vanadium disilicide powder at 1400 °С enables synthesizing high-dispersion composite powder of the system “silicon nitride–vanadium nitride” in a single process. The synthesized powder is formed as loose aggregates consisting of 50 nm particles.