Use and application of tungsten and molybdenum
At present, the world refractory research has developed from the traditional "high purity, super fine, uniform" to "nano, composite design and integrated manufacturing". Through these advanced technologies, refractory tungsten alloy materials can not only retain its high melting point, corrosion resistance and other excellent properties, but also greatly improve its comprehensive mechanical properties. At present, the research and application of refractory metal lags far behind that of other metal materials. Therefore, it is the focus of current research to further optimize and perfect the processing technology of various tungsten alloy materials according to the requirements of different application fields through technical transformation.
Due to its high density, high strength, low thermal expansion coefficient, corrosion resistance and good machinability, tungsten alloy has been widely used in aviation/aerospace, military equipment, electronics, chemical industry and many other fields.
Its main uses include :(1) carbides for cutting, welding and spraying, such as tungsten carbide. (2) A large number of filament and cathode for electron tubes in the electronics industry, heating elements for high temperature resistance furnaces, such as impact-resistant tungsten wire and composite rare-earth tungsten electrode. (3) armor-piercing bullets, lining plates, etc. It's used in the heat field, even the military.
Improving the plasticity of tungsten and tungsten alloy materials, reducing their plastic-brittle transition temperature, and further improving their high temperature thermal strength have been the focus of research in the field of tungsten alloys. Therefore, the main contents of tungsten research and development are the plastic-brittle transition behavior, high temperature strength characteristics, welding and composite, and manufacturing process optimization. Technologies developed around these include purification, refinement, toughening, and recombination.
Molybdenum is the leading application in the iron and steel industry, accounting for about 80% of the total molybdenum consumption, followed by chemical industry, accounting for about 10%. Molybdenum is also used in electrical and electronic technology, medicine and agriculture, accounting for about 10% of total consumption.
Molybdenum is used as the matrix to add other elements (such as titanium, zirconium, hafnium, tungsten and rare earth elements) to form non-ferrous alloy. These alloy elements not only play the role of solid solution strengthening and maintaining low temperature plasticity of molybdenum alloy, but also can form a stable and dispersed carbide phase to improve the strength and recrystallization temperature of the alloy. Molybdenum based alloy has good strength, mechanical stability, high ductility and is used in high heating components, extrusion abrasives, glass melting furnace electrodes, jet coating, metal working tools, spacecraft parts and so on.
