Tantalum carbide

Overview
Tantalum carbide (TaC) is an extremely hard refractory ceramic material, commercially used in tool bits for cutting tools. The hardness even exceeds that of diamond. It is a heavy, brown powder usually processed by sintering, and an important cermet material. It is sometimes used as a fine-crystalline additive to tungsten carbide alloys. Tantalum carbide has the distinction of being the stoichiometric binary compound with the highest known melting point, at 4150 K (3880°C). The substoichiometric compound TaC0.89 has a higher melting point, near 4270 K (4000°C).

When used as a mould coating, it produces a low friction surface.

Tantalum carbide-graphite composite material, developed in Los Alamos National Laboratory, is one of the hardest materials ever synthesized.

Dusts from grinding can be flammable.

Substances to avoid are: flammable gases (dust may form explosive mixtures with gases)