Tantalum (Tantalum) is a metal element, the element symbol is Ta, the atomic number is 73, the density is 16.68g/cm³, the melting point is 2980℃, is second only to tungsten, rhenium the third most difficult metal to melt. Pure tantalum has a bluish color, excellent ductility, and can be rolled into very thin (less than 0.01 mm) plates without intermediate annealing in the cold state. The corrosion resistance of tantalum is the same as that of glass, and at medium temperature (about 150 ° C) only fluorine, hydrofluoric acid, sulfur trioxide (including fuming sulfuric acid), strong alkali and some molten salts have an effect on tantalum. Tantalum metal is stable in air at room temperature, and when heated above 500 ° C, oxidation is accelerated to produce Ta205. Tantalum has a series of excellent properties such as high melting point, low steam pressure, good cold working performance, high chemical stability, strong resistance to liquid metal corrosion, and large dielectric constant of surface oxide film, and has important applications in high-tech fields such as electronics, metallurgy, steel, chemical industry, cemented carbide, atomic energy, superconducting technology, automotive electronics, aerospace, medical health and scientific research. At present, the main application of tantalum is tantalum capacitor.