Tantalum is the most corrosion resistant metal in common use today. Tantalum is not a noble metal, but it is comparable to them in terms of chemical resistance. When exposed to air, tantalum forms a very dense oxide layer (Ta2O5) which protects the base material from aggression. This oxide layer therefore makes tantalum corrosion-resistant.
Tantalum‘s corrosion resistance in sulfuric acid and hydrochloric acid is excellent. It is inert to almost all organic and inorganic chemicals. Its corrosion resistance is similar to that of glass, as both are not working for use in hydrofluoric acid and strong hot alkali surroundings. Tantalum will not be corroded by nitric acid in concentrations up to 98% and temperatures up to at least 100°C, it has verified itself to be totally inert in many corrosion applications. Some heat ex-changer establishments have been in consistent use for more than 40 years in multi-item look into situations without even a gasket change because of erosion.
Tantalum’s resistance to corrosion by many materials is exemplified. Tantalum is also resistant to a series of metal melts such as Ag, Bi, Cd, Cs, Cu, Ga, Hg, K, Li, Mg, Na and Pb, provided that these melts have a low oxygen content. However, the material is affected by Al, Fe, Be, Ni and Co.