Niobium crucible and processing parts

Niobium is an off-white metal with a melting point of 2468°C, a boiling point of 4742°C, and a density of 8.57 g/cm3. Niobium is stable in the air at room temperature, and is not completely oxidized when it is red hot in oxygen. It can directly combine with sulfur, nitrogen, and carbon at high temperatures, and can form alloys with titanium, zirconium, hafnium, and tungsten. It does not interact with inorganic acids or alkalis, nor is it soluble in aqua regia, but it is soluble in hydrofluoric acid.