Niobium and niobium alloys can maintain high strength and good processing performance at high temperature. Can be made into thin plates and parts with complex shapes. Therefore, it can be used as the preferred thermal protection and structural materials on some ultra-high sonic aircraft, space vehicles, satellites, missiles and supersonic low-altitude rockets. The radiation-cooling nozzle extension of Apollo 11's lunar module descent engine is made of C-103 (Nb-10Hf-1Ti) niobium alloy and is coated with highly radiation-resistant alumina. The R-4D reaction control engine combustion chamber is machined with C103 and Scb291 (Nb-10W-10Ta) Niobium alloy. FS-82 (Nb-33Ta-0.75Zr) Niobium alloy has been used for the leading edge and lapel of Dynasrcar TF devices. With the development of the aviation industry, the flight height (≥ 30,000 m) and speed (≥ Mach 3) have been improved. Therefore, the turbine inlet temperature of the engine needs to be raised to 1200℃ or higher. Therefore, it is necessary to look for new materials. Niobium alloys and other refractory metals are expected to be used as turbine blades and structural materials for turbine engines. For example, Nb-33Ta-0.75Zr、Nb-10Ti-Mo、Nb-0.75Zr and Nb-10Ti alloys have been tested on supersonic aircraft. But because of the complexity and high cost of coating, the interest in making leaf material with niobium alloy is greatly reduced.
The superconducting transition temperature of niobium is high, and niobium compounds and alloys can be used to make superconducting materials (such as Nb35-Ti65, Nb3Sn, etc.). The thermionic emission of niobium is good. The getter and the low pressure rectifier for the vacuum tube can be manufactured. Niobium is used in cold tubes (a hundred of which can fit into a thimble), as well as replacing electron tubes and transistors, greatly reducing the size of the equipment and improving the computer and radar.
Niobium and niobium alloys have their unique applications in chemical industry, medicine and other industries.
Tantalum has high melting point, low vapor pressure, low coefficient of expansion, good processing performance, compact oxide film and excellent dielectric properties. Therefore, tantalum's main use is to make electrolytic capacitors. Tantalum capacitors are characterized by large capacitance, good reliability, wide operating temperature range, shockproof, long service life and small volume. Tantalum capacitors are more than five times larger than other capacitors of the same size. Tantalum is also a good material for high power vacuum tube parts. The anode, grid and cathode can be made. Tantalum has good resistance to chemical corrosion under 50℃ and is stable in strong acids. This is due to the formation of a Ta2O5 film with a thickness of less than 0.5 micron on the surface. This film has a strong bond with the matrix and only dissolves in hydrofluoric acid, hydrochloric acid and concentrated alkali at high temperature.
