Preparation and Some Properties of Tantalum Carbide

Abstract

Small tantalum carbide objects may be made by heating the objects made from tantalum in dilute hydrocarbon atmospheres at temperatures >2000°K. Carburization proceeds quite rapidly above 2300°K by diffusion of carbon initially deposited on the surface into the metal, principally along grain boundaries, to form a thin layer of Ta₂C which is quickly converted to the TaC. The latter has a tensile strength of 21–25 kg/mm², a work function φ=3.17 ev, an emissivity of 0.40–0.46 between 2400° and 3500°K, rising with increasing temperature, and a resistivity ρ=102+0.0178 T (°K) ohm cm between 1400° and 3500°K.