Main applications of molybdenum and molybdenum alloys
Molybdenum and molybdenum alloys have become important materials for power electronic equipment manufacturing, metallurgical industry, processing industry, aerospace and national defense industry because of their good thermal conductivity, electrical conductivity, low expansion coefficient, high temperature strength, low vapor pressure and wear resistance.
Molybdenum is widely used in electronic and power equipment manufacturing industry because of its excellent conductivity and high temperature performance, especially the close thermal expansion coefficient of glass. These include filament, lighting and vacuum tube components, gate and anode support materials in vacuum tubes, expansion materials for integrated circuit components, and buffers for power supply and heat dissipation of equipment. In addition to pure molybdenum, molybdenum-rhenium alloy can be used as the structural material of electron tubes and special bulbs. Tungsten-molybdenum alloy has been widely used in the field of quartz glass for LED lighting and LED luminescent electrode.
In the metallurgical industry, the molybdenum consumed by the iron and steel industry accounts for 70%~80% of the total consumption of molybdenum products, and many important steels contain molybdenum, whose content is generally 0.1%~10%. The addition of molybdenum as alloying element in steel can not only improve the high temperature strength and toughness of steel, but also significantly improve the corrosion resistance of steel in acid and alkali solution and liquid metal, improve the wear resistance of steel, improve the hardenability, weldability and heat resistance. Molybdenum can be used alone or in combination with other alloying elements because it can form good carbides and does not oxidize during iron and steel smelting.
In vacuum furnaces and electric furnaces with protective atmosphere, molybdenum and molybdenum alloy products are widely used in heating element, heat insulation screen, fixed parts, chassis, guide rail and boat. Large-size molybdenum crucible is widely used in surface coating industry, single crystal production industry, diamond and cubic BN production because of its high corrosion resistance and high temperature resistance. With the rapid development of die industry, the EDM technology has been widely used, molybdenum wire is an ideal electrode wire for wireline EDM machine tool, which can cut all kinds of steel and hard alloy and process the parts with extremely complex shape, and its stable discharge machining can effectively improve the precision of die.
Molybdenum alloys are very important in aerospace and military industries because of their excellent heat resistance and high temperature mechanical properties. Molybdenum copper alloy can be used as air rudder and high temperature connector of missile. The high sound velocity and high density of molybdenum make it a kind of shell that can break armor bravely. Molybdenum alloy heat resistance and high strength, aircraft and other aircraft engine flame nozzle, combustion chamber, spacecraft nose cone, satellite and spacecraft skin, ship wing, guide plate and coating materials and other special equipment components. Molybdenum has low thermal expansion coefficient and good thermal conductivity, and its size can remain stable under the intense action of solar radiation. Therefore, it can be made into artificial satellite antenna, which can not only maintain its complete parabolic shape, but also lighter than graphite composite antenna.
In the nuclear industry, because the thermal neutron capture section is small, and has high strength and good resistance to liquid metal corrosion, molybdenum is used in the nuclear fusion reactor as the protective plate of the armoured element of the converter, molybdenum boat is also widely used in the nuclear fuel processing boat in the nuclear industry. At the same time, ferromolybdenum is also used for thermionic energy converter envelope materials, heaters and reflectors in space reactors. Molybdenum and TZM alloys can be used as spring material of liquid alkali metal working medium, fuel cladding element and release element of gas cooled reactor.
