Molybdenum crucibles can be used in atmosphere furnaces, but their use environment requires special attention to avoid oxidation and other possible chemical reactions. Atmosphere furnaces are usually used for applications such as high temperature processing, heat treatment, annealing, alloy melting and crystal growth. In order to ensure the stability of molybdenum crucibles in atmosphere furnaces, the following are some key factors to consider:
- Atmosphere Type
Inert gas (such as argon, helium): Molybdenum crucibles are very suitable for use in an inert atmosphere, which can effectively avoid oxidation reactions. Inert gas will not react with molybdenum and can protect the crucible surface from oxidation.
Vacuum environment: When using molybdenum crucibles, it is also a good choice if the furnace supports a vacuum environment. In a vacuum, oxygen cannot exist, so oxidation damage can be avoided.
Oxidizing atmosphere (such as air, oxygen): Molybdenum is easily oxidized in an oxidizing atmosphere to form molybdenum trioxide (MoO ₃), which can cause damage to the crucible surface. If a molybdenum crucible must be used in an oxidizing atmosphere, special care must be taken to control the temperature and atmosphere composition to avoid excessive oxidation.
- Temperature control
Molybdenum crucible has good high temperature stability, but in an oxidizing atmosphere, too high a temperature will accelerate oxidation. Therefore, controlling the furnace temperature is very important to avoid oxidation of the molybdenum crucible.
When used in an atmosphere furnace, the molybdenum crucible should be prevented from being exposed to high temperatures exceeding its temperature resistance range (about 3000°C) for a long time. If the temperature is too high, the oxidation rate will accelerate, resulting in damage to the crucible.
- Preheating and heating rate
When using molybdenum crucibles in atmosphere furnaces, especially in oxidizing atmospheres, it is recommended to heat up slowly. Rapid heating will cause excessive temperature changes on the crucible surface, increase thermal stress, and may lead to the rapid formation of cracks or oxide layers.
Preheating the molybdenum crucible is also an important step, especially when placing the crucible directly from a cryogenic environment into an atmosphere furnace. Preheating helps reduce the risk of thermal shock and oxidation.
- Maintenance and inspection
The atmosphere furnace, regularly check the surface condition of the molybdenum crucible to confirm whether there is oxidation, cracks or other damage. If an oxide layer is formed, it can be removed by hydrogen reduction or other deoxidation treatment.
Avoid direct contact with chemicals: Certain gases in the atmosphere furnace (such as chlorine, fluorine, etc.) may react with molybdenum and cause chemical corrosion. Therefore, avoid using these harmful substances when selecting the atmosphere.
- Protective measures
In high temperature operation, the use of inert gas or vacuum protective atmosphere is an effective way to ensure long-term stable operation of the molybdenum crucible.
For particularly sensitive applications, molybdenum alloys such as molybdenum -tantalum alloys can be considered. These alloys have stronger oxidation resistance than pure molybdenum.
======================================================================
Customized R&D and Production of Tungsten, Molybdenum Products
Chinatungsten Online and CTIA GROUP LTD have been working in the tungsten industry for nearly 30 years, specializing in flexible customization of tungsten and molybdenum products worldwide, which are tungsten and molybdenum design, R&D, production, and overall solution integrators with high visibility and credibility worldwide.
Chinatungsten Online and CTIA GROUP LTD provide products mainly including: tungsten oxide products, such as tungstates such as APT/WO3; tungsten powder and tungsten carbide powder; tungsten metal products such as tungsten wire, tungsten ball, tungsten bar, tungsten electrode, etc.; high-density alloy products, such as dart rods, fishing sinkers, automotive tungsten crankshaft counterweights, mobile phones, clocks and watches, tungsten alloy shielding materials for radioactive medical equipment, etc.; tungsten silver and tungsten copper products for electronic appliances. Cemented carbide products include cutting tools such as cutting, grinding, milling, drilling, planing, wear-resistant parts, nozzles, spheres, anti-skid spikes, molds, structural parts, seals, bearings, high-pressure and high-temperature resistant cavities, top hammers, and other standard and customized high-hardness, high-strength, strong acid and alkali resistant high-performance products. Molybdenum products include molybdenum oxide, molybdenum powder, molybdenum and alloy sintering materials, molybdenum crucibles, molybdenum boats, TZM, TZC, molybdenum wires, molybdenum heating belts, molybdenum spouts, molybdenum copper, molybdenum tungsten alloys, molybdenum sputtering targets, sapphire single crystal furnace components, etc.
If you are interested in related products, please contact us:
Email: sales@chinatungsten.com
Tel: +86 592 5129696 / 86 592 5129595
