Tantalum alloy is an alloy based on tantalum with other elements. The anodic oxide film of tantalum is stable, corrosion-resistant and excellent dielectric property, which is suitable for making electrolytic capacitors. Tantalum has strong resistance to chemical corrosion, so it can be used as corrosion resistant material in chemical industry and medicine。In 1958, Ta-10W alloy was put into production. In 1960s, tantalum alloy was used in aerospace industry as high temperature structural material. Tantalum and tantalum alloy products are plate, strip, foil, bar, wire, shaped parts and sintered products.
Pure tantalum has good plasticity, low deformation resistance and low work hardening rate. All kinds of profiles and special-shaped parts can be made by plastic processing. Pure tantalum can be rolled into sheet, strip, foil, tube and bar at room temperature, and the processing rate can reach more than 90%.Because of its high strength and poor plasticity, tantalum alloy must be bloomed above 1200 ℃, and the processing technology is the same as that of pure tantalum.In order to ensure good stamping and spinning properties of the products, cross rolling should be used. The processing rate should be kept about 80% before cross rolling. Tantalum plate can be made into cup, cap, tube, cone and nozzle by spinning and deep drawing.
Cutting and heat treatment of tantalum alloy
Tantalum and tantalum alloy are easy to wear and bond tools. High speed steel tools should be used and cooled with organic solvents such as carbon tetrachloride. Silicon carbide grinding wheel is suitable for grinding, because alumina grinding wheel is easy to crack the grinding surface.
There are mainly annealing and solution aging treatment. In order to prevent air pollution, the heat treatment of tantalum alloy must be carried out in vacuum of 10-4 torr or high purity inert gas, and sometimes even wrapped with tantalum foil.
Application of tantalum alloy
Vacuum consumable arc and electron beam melting are common methods to produce tantalum and its alloy ingots. The electron beam melting process is mainly used for the purification of tantalum. The consumable arc melting process can produce ingots with large diameter and more uniform alloy composition. The electrode of consumable arc melting can be made of sintered bar or electron beam melting ingot. The ingot grain obtained by melting method is coarse, and it is often necessary to break the as cast grain to improve the plasticity. In order to further purify tantalum or prepare single crystal, electron beam zone melting method can be used.
Tantalum can be used to make various malleable alloys with high melting point. These alloys can be used as materials for superhard metal processing tools, as well as in the manufacture of Superalloys for jet engines, chemical experimental equipment, nuclear reactors and missiles. Tantalum has high ductility and can be drawn into filaments.
