Molybdenum crucibles is a typical difficult-to-process metal process. Due to the high hardness, high melting point, strong brittleness, and easy oxidation of molybdenum, there are many technical challenges in the forming, welding, cutting and post-processing processes. The following is a detailed explanation of several core difficulties in the processing of molybdenum crucibles:
- The characteristics of molybdenum material itself lead to processing difficulties
High melting point (2620 ° C)
→ All high-temperature forming, welding, and heat treatment must use special equipment and have a narrow process window.
Strong cold brittleness and poor ductility (especially at low temperatures)
→ It is easy to crack and collapse. The deformation of forging or cold working is limited. It must be annealed or heated at high temperature.
High hardness and low plasticity
→ During turning and milling, the tool is easy to wear, the cutting force is large, chip breaking is difficult, and the tool material and geometric angle requirements are high.
Easy to oxidize
→ 500 ° C or above will oxidize rapidly in air and must be processed or stored in a vacuum or inert gas environment.
- Difficulties in the Molybdenum Crucible Forming Process
- Difficulty in forging
Molybdenum has a high recrystallization temperature (about 800–1000 ° C), cold forging is prone to cracking, while hot forging requires precise temperature control and high equipment requirements.
- Spin forming is difficult to control
Molybdenum plates have poor toughness and high hardness, and are prone to wrinkles or cracks during spinning, requiring skilled manual control or high-precision CNC equipment.
- Welding difficulties are prominent
Welds are prone to cracks, pores, and slag inclusions;
Heat affected zone embrittlement;
It needs to be protected by high-purity tungsten electrode + high-purity argon gas and carried out in vacuum or inert atmosphere.
- Difficulties of cutting
High requirements for cutting tools
Commonly used diamond and TiAlN coated carbide tools, ordinary tools are extremely easy to wear.
Surface quality is difficult to control
After cutting, scratches, micro-cracks and knife marks are common on the surface, which requires subsequent fine grinding or electrolytic polishing.
Large workpiece deformation and residual stress
Local overheating is easy to occur during the cutting process, resulting in stress concentration, so the annealing process must be matched.
- Difficulty in polishing the inner wall
The inner surface of molybdenum is very hard, and it is difficult for traditional machine tools to penetrate deeply;
Crucibles with complex shapes require customized special-shaped polishing heads or chemical or electrolytic polishing.
Polishing powder selection is limited and cannot contain contaminating impurities such as iron and copper.
- Low material utilization and high processing cost
Molybdenum is expensive, has high processing losses, and has a low yield rate – especially for large-sized molybdenum crucibles, where molding failure or welding defects will cause the entire part to be scrapped and cannot be repaired.
- Special customization process is more challenging
If the molybdenum crucible requires:
Complex geometric structures (such as internal threads, special-shaped grooves, thin-walled structures),
Or if used in vacuum electronics, semiconductors, or precision coating equipment, extremely high requirements are placed on processing accuracy, cleanliness, dimensional control, and airtightness, further increasing the difficulty of processing.
======================================================================
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
