Niobium (Nb), tantalum (Ta) of refractory rare metal, steel gray, have more than major (Nb and Ta 8.6 to 16.6), high melting point (niobium 2467 ℃, tantalum 2980 ℃), high boiling point (niobium 4740 ℃, tantalum 5370 ℃), high strength, resist fatigue, resistance to deformation, corrosion and heat conductivity, superconductivity, unipolar conductive and absorption gas excellent features. Nb and ta in the periodic table of belong to people, nature are very similar, they in nature of the communist party of China was born in together, occurrence in nb and ta acid salts in minerals. Chemists in the early s and it was from niobium iron ore (Ke iron ore)-tantalite series found in mineral nb and ta the two elements.

In 1801 the British chemist ha strange (C.H atchett) on the analysis of ore found a new element, named for Columbium (Ke), the ore is called Columbite (Ke ore, iron ore, which is now called Ke nb iron ore). In 1844 the German chemist, rothie (H.R ose) claimed that he found a kind of "new" element, because of its nature and tantalum (tantalum) similar, in nature and tantalum symbiosis, tantalum is according to the Greek myth Tantalus characters (TanDaLuoSi) named, hence press Tantalus daughter Niobe name named Niobium (Niobium). Set in 1866 Ke and niobium is the same elements, so for a long time, the same element appeared two kinds of different names, and used in the United States Ke, the element symbols as Cb; In Europe, was in niobium, element symbols as Nb until 1951, the year the international pure powder applied chemistry and chemical association (IUPAC) decided to name the unity of niobium (niobium), but some countries will continue to use Columbium (Ke), as in some American chemical related books also see Cb (Ke).

Tantalum is by Swedish chemist love g berger (A.G.E keberg) found in 1802. He is from Finn kimi "(Kimito) place to produce of a kind of ore in analysis out a new metal, according to Greek mythology Tantalus hero (TanDaLuoSi) name for tantalum (ta), because the new metal has the characteristics of hero, can fight the variety of acid erosion.

Nb and ta has corrosion resistance, cold forming good performance and oxidation film performance advantages, there are many important applications. Niobium has refined grain steel ability, widely used in steel industry, electronic industry, aviation, atomic energy, ocean exploitation and other fields, mainly used as alloy steel additive, superconducting materials, high temperature alloys, oxide single crystal, ceramic capacitor, etc. Tantalum in acid in electrolyte to form stable anode oxidation film, made by the electrolytic capacitor tantalum, with large capacity, small volume and good reliability and other advantages, system the most important tantalum capacitor is USES, at the end of 70 s, the amount of total amount of tantalum two-thirds. Use made of tantalum corrosion equipment used in the production of acid, bromine, ammonia and other chemicals. Metal tantalum can make aircraft engine combustion chamber of structural materials, etc. Tantalum tungsten, tantalum tungsten Ha, tantalum Ha alloys as the rockets and missiles and jet engines of heat and high strength materials control and adjust the equipment parts, etc. Tantalum easy process molding, in high temperature and vacuum furnace as support accessories, heat shielding, a heater, and heat sink, etc. Tantalum also for orthopaedic surgery and materials. Tantalum carbide used in the manufacture of hard alloy. Tantalum of boron carbide, silicides and nitrides and its alloys as atomic energy industry in heat release components and the liquid metal bag set of materials. Oxidation tantalum used to make advanced optical glass and catalyst.