The melting process of tantalum alloy in industrial production is similar to that of pure metal, but the specific process is different. The powder is first made into alloy billets, and then ingots or castings are obtained by sintering or casting at high temperature. However, the fusion casting method is mostly used, and the fusion casting method is mainly electron beam melting and electric arc furnace melting.
Tantalum has good plasticity and is easy to be processed. A variety of industrial profiles (tubes, rods, wires, strips) can be produced by conventional processing techniques (extrusion, forging, rolling and stretching). Both tantalum and tantalum alloy smelting ingots have coarse grain structure, which must be crushed by extrusion or hot forging (initial processing) before it can be processed into materials. Pure tantalum can be forged at room temperature. During the process of opening the tantalum alloy at a temperature of 10012,000, the surface of tantalum alloy is oxidized to form loose oxide, which can penetrate into the alloy substrate to form a hard permeable layer, and cracks will appear during processing. Therefore, the metal surface should be protected from oxidation during the whole process. At present, the protection of tantalum blank includes salt bath heating, coating, coating, inert gas protection, etc.
Extrusion process can produce different specifications of metal tubes, rods, profiles; Tantalum ingotscan be directly forged into rolled slab. Glass coating can be used as lubricant; Tantalum alloy plate rolling, usually two or four high rolling mill, pass deformation of 10%-15%, when rolling 2.5mm sheet, the total deformation of 70%~80% rolling 2.5mm sheet, using kerosene or palm oil as lubricant.
