The application of molybdenum sheets and tungsten sheets in high-temperature furnaces
Molybdenum sheets and tungsten sheets are widely used in high-temperature furnaces due to their excellent high-temperature performance and physicochemical properties. Their high melting points (the melting point of molybdenum is 2623°C and that of tungsten is 3422°C) enable them to withstand extreme high-temperature environments, making them indispensable materials in high-temperature furnaces.
In high-temperature furnaces, molybdenum sheets and tungsten sheets are mainly used in the following aspects: as high-temperature structural materials, including high-temperature resistant support parts and thermal field components; As a heating element, it achieves precise temperature control through direct resistance heating or special design. As an insulating shielding layer, it reduces heat loss and protects the furnace body; And in applications in special environments, such as protecting materials from oxidation in inert or reducing atmospheres, or providing corrosion resistance in corrosive environments. In addition, molybdenum sheets and tungsten sheets can also be combined with other materials to form coatings or gradient materials to meet different process requirements.
Specific application methods
High-temperature structural materials: The high melting points of molybdenum and tungsten sheets enable them to serve as support frames, trays or fixing devices in high-temperature furnaces, carrying heated samples and preventing them from softening and deforming due to high temperatures. In monocrystalline silicon growth furnaces, they can also be used to manufacture thermal screens, reflectors or crucible bases, optimizing the thermal field distribution by reflecting infrared radiation and enhancing heating efficiency.
Heating element: Tungsten sheets or molybdenum sheets can be processed into tungsten wires, tungsten rods, tungsten strips, molybdenum wires, molybdenum rods, and molybdenum strips, generating high temperatures through resistance heating. Tungsten wires are suitable for high-temperature furnaces in vacuum or inert atmospheres (up to over 3000°C), while molybdenum heating elements are often used in hydrogen or vacuum environments at 1600-1800°C. In high-temperature sintering furnaces, molybdenum/tungsten sheets can also be designed with a multi-zone heating structure to precisely control the temperature gradient.
Thermal insulation shielding layer: In vacuum or protective atmosphere furnaces, molybdenum sheets and tungsten sheets can be stacked to form a thermal shielding layer (similar to an "insulation blanket"), reducing heat loss and protecting the furnace body shell. Some high-temperature furnaces can also adjust the size of the hot zone through movable tungsten/molybdenum heat insulation screens to meet different process requirements.
Special environmental application: Molybdenum and tungsten are prone to oxidation at high temperatures, so they need to be used in hydrogen, argon or vacuum environments to avoid oxidation and pulverization. For instance, tungsten sheets can be used for high-temperature brazing in hydrogen furnaces or sintering of hard alloys, and molybdenum crucibles can be employed in vacuum furnaces for smelting high-purity metals such as titanium and platinum. In addition, in high-temperature environments containing carbon, sulfur or certain molten salts, tungsten and molybdenum have better corrosion resistance than ordinary metals and can be used as the inner lining of reaction vessels.
Compound application and precautions
Molybdenum sheets and tungsten sheets can further enhance their performance through combined applications. For instance, coating the surface of tungsten sheets with antioxidant materials (such as iridium or ceramics), or doping carbides (such as La₂O₃) into molybdenum matrices can extend their service life in oxidizing atmospheres. In extreme temperature difference scenarios, molybdenum and tungsten can also be combined with materials such as copper and graphite to balance thermal conductivity and heat resistance. However, when using molybdenum sheets and tungsten sheets, some issues also need to be noted. In terms of processing, tungsten is hard and brittle, and thus needs to be formed through powder metallurgy or electrical discharge machining. Molybdenum is relatively easy to process but cold working embrittlement should be avoided. In terms of economy, the cost of tungsten is significantly higher than that of molybdenum. The choice should be made by weighing the temperature requirements (for example, tungsten must be used when the temperature is above 2000°C) and the budget. In addition, molybdenum/tungsten may release trace amounts of volatile substances at high temperatures, and the risk of contamination needs to be evaluated in clean processes.
Mosten Alloy can produce molybdenum sheet, molybdenum block, molybdenum foil, molybdenum rod, molybdenum wire, molybdenum processing workpiece according to customer demand.
