Tantalum carbide (TaC/Ta2C) is an extremely hard (Mohs hardess 9-10) refractory ceramic material. The hardness is only exceeded by diamond. It is a heavy, brown powder usually processed by sintering, and an important cermet material.
Niobium carbide (NbC/Nb2C) is a frequent intentional product in micro-alloyed steels due to its extremely low solubility product in austenite, the lowest of all the refractory metal carbides. It has the appearance of a brown-gray metallic powder with purple luster. It is highly corrosion resistant.
Tantalum/Niobium carbide (TaNbC) is a black/brown powder that can be used to significantly improve alloy material wear resistance, oxidation resistance, corrosion resistance, high-temperature hardness, high temperature strength and other properties.