Monophasic Nanostructured Powders of Niobium, Tantalum, and Hafnium Carbonitrides Synthesized by a Mechanically Induced Self‐Propagating Reaction

Abstract

Niobium, tantalum, and hafnium carbonitride nanopowders were obtained by high‐energy ball milling of elemental metal and graphite in a nitrogen atmosphere. By adjusting milling parameters, a mechanically induced self‐propagating reaction was observed during the formation of carbonitride phases. The stoichiometry of transition metal carbonitrides was controlled by fixing the starting metal‐to‐carbon molar ratio. Ignition of the reactant mixture was determined by the combined effect of nitrogen and carbon, gas, and solid reagents, respectively. The composition and lattice parameters were determined by X‐ray diffraction measurements. Microstructural characterization showed a nanophase structure with a homogeneous chemical composition.