Hard, heavy, refractory, crystalline solid.
Hardness 1800 kg/sq mm, resistivity 30 μΩ?cm (room temperature).
Extremely resistant to chemical action except
at elevated temperature.
Golden brown crystals, soluble
in HF-HNO mixture. Crucible 3
container for melting ZrO and
similar oxides with high melting
point. Corrosion resistant to
molten metals such as Ta and
Re. Readily corroded by liquid
metals such as Nb, Mo, and Sn.
Burning occurs in pure oxygen
above 800°C. Severe oxidation in
air above 1100–1400°C.
Maximum operating
temperature of 3760°C in helium
A mixture of tantalum carbide (TaC) and graphite is a very hard material and is used to
form the cutting edge of machine tools.
Tantalum monocarbide, TaC, is a gold-colored powder produced industrially by direct reaction of carbon with either tantalum scrap or tantalum pentoxide at temperatures up to 1,900 °C (3,452 °F). It is added in small amounts (0.2–2 wt %) in the form of TaC or mixed carbides like TaNbC and WTiTaC to tungsten carbide–cobalt-based cutting tools in order to reduce grain growth. Adding 2–15 wt % TaC to cemented carbides considerably increases their thermal shock resistance and their resistance to cratering and oxidation. The tantalum–carbon phase diagram shows the existence of several subcarbides.
Cutting tools and dies, cemented carbide tools.
Flammability and Explosibility
Non flammable
Tantalum carbide and tungsten carbide combinedin a matrix of nickel, cobalt, and/or chromiumprovide an RHM formulation especiallysuited for a combination of corrosion and wearresistance. Some grades are almost as corrosionresistant as platinum. Nozzles, orifice plates,and valve components are typical uses.
