Atomic models of the structure of niobium silicides in Nb–Si in situ composites

Abstract

The results of the investigation of the phase and quantitative composition of reinforcing phases of the Nb–Nb₅Si₃in situ eutectic composite during high-gradient directional crystallization are reported. The crystal structures of the hexagonal γ and tetragonal α modifications of Nb₅Si₃ silicide are comparatively characterized. Possible structural positions for the stabilizing atoms in the structure of hexagonal silicide are proposed. The dependence of the creep deformation resistance on the silicide structure is discussed.