Synthesis and characterization of Niobium Carbide (NbC) Nano-powder

Abstract

Transition metal carbides are in demand for their unique properties resembling with metal and ceramic constituents. These carbides have high hardness, high melting temperature, and high-temperature strength. They have been used as hard constituents in metal matrix composites for high temperature applications and as coatings on cutting tools. Among these carbides, niobium carbide is a very important and promising example for industrial applications. Therefore in the present study niobium carbide (NbC) nanoparticles were synthesized through a reduction-carburization route by using niobium pentoxide and acetone (C3H6O) or charcoal as Nb and C sources along with metallic Mg as the reductant at 600 °C, 700 °C and 800 °C in an autoclave. The asprepared NbC nanopowders were characterized and studied by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy at room temperature. The thermal stability of synthesized powder was investigated by differential thermal analysis and differential scanning calorimetry. The XRD results indicate that optimum reaction condition for the formation of nanocrystalline NbC was 600 °C for 2h carburization at high pressure with acetone and 800 °C for 10h with charcoal. The NbC nanoparticles produced from the present route typically have an average size around 90 nm (acetone) and 17 nm (charcoal) having core-shell structure. The influencing factors of the synthesis of the NbC nano powder have been discussed in present work.