Use
Tantalum filaments were used in incandescent lamp bulbs before tungsten replaced them. At temperatures below 150°C, tantalum is attacked only by hydrofluoric acid, fluoride ion in acidic solutions, and free sulfur trioxide. It also is attacked, but slowly, by alkalies. Tantalum and its alloys, therefore, are used to build reactors, vessels, and cruicibles for preparing and carrying out reactions involving many reactive intermediates. The metal and its alloys are used to construct furnace parts, electrolytic capacitors, aircraft and missile parts, chemical process equipment, and nuclear reactors. Being nonreactive to body fluids and a nonirritant to body tissues, tantalum is used in making surgical appliances. Plate and sheet tantalum are applied in bone repair, foil and wire for nerve repair, and plate, gauge, and sheet for repair of abdominal muscle. Tantalum oxide is used to produce optical glasses of high refractive index. The oxide film on the metal makes it a rectifier for converting alternating current to direct current.