MOLYBDENUM CRUCIBLE
Molybdenum crucible
Mo ≥99.95% | Density ≥10.2 g/cm³ | Diameter, depth and wall thickness to furnace
WeiBeam · Electrode solutions for high-temperature melting
Molybdenum crucibles are high-temperature vessels used in sapphire crystal growth, vacuum sintering, high-temperature melting and evaporation coating. With a melting point of about 2623 °C, molybdenum serves long-term in vacuum or inert atmospheres, making it suitable for holding high-temperature melts and raw materials. Service life depends on wall-thickness design, structural density and charging practice. A thin wall may lack load capacity and thermal-shock resistance; a thick wall adds weight and thermal inertia and demands more from the heating system. For the same outside diameter, the right wall thickness differs between furnaces and charging methods.
Molybdenum oxidizes in hot air, so crucibles should be used under vacuum, reducing or inert atmosphere and not left exposed to air for long periods. We customize diameter, depth, wall thickness and rim design to the furnace and supply alongside discs and electrodes, with material certificates and dimensional records.
In high-temperature melting and thermal-field systems this part is often used alongside electrodes elsewhere in the line. We recommend selecting them together against furnace structure, assembly method and working temperature to reduce thermal-expansion mismatch between different materials.
FEATURES
Molybdenum crucible — key features
Core characteristics for furnace conditions and operating requirements.
High-temperature capability
Melting point about 2623 °C for vacuum, reducing or inert high-temperature melting and crystal growth.
Melt-erosion resistance
A dense structure reduces melt penetration and localized erosion for longer service.
Designed wall thickness
Wall thickness and rim design set by furnace, charge weight and heating rate.
Furnace-specific build
Diameter, depth, wall thickness, flanges and flow guides machined to drawing.
SPECIFICATIONS
Specification data
This product is accepted to the relevant material standard or a mutual technical agreement, with key dimensions, density and material inspected batch by batch. Special sizes can be machined to drawing.
| Parameter | Specification |
|---|---|
| Application | Sapphire / crystal growth, vacuum sintering, high-temperature melting, evaporation coating |
| Material | Pure molybdenum (Mo1); MoLa / TZM on request |
| Molybdenum content | ≥99.95% |
| Density | ≥10.2 g/cm³ |
| Melting point | ≈2623 °C |
| Atmosphere | Vacuum / reducing / inert (avoid oxidizing conditions at temperature) |
| Size | Diameter, depth and wall thickness custom to furnace drawing |
| Reference standard | Accepted to technical agreement and drawing (material, dimensions, density) |
| Surface / machining | Turned, ground, alkali cleaned; drilling and grooving available |
| Delivery documents | Material certificate, dimensional records (on request) |
Material and physical properties
| Parameter | Typical value / note |
|---|---|
| Available grades | Mo1 (pure Mo) / MoLa (lanthanum-doped) / TZM (Ti-Zr-Mo) / Mo-Zr ODS |
| Molybdenum content | ≥99.95% (higher purity by technical agreement) |
| Density | ≥10.2 g/cm³ (varies slightly by grade and condition) |
| Melting point | ≈2620–2623 °C |
| Resistivity (20 °C) | ≈0.053 µΩ·m |
| Conductivity | ≥30% IACS |
| Thermal expansion | ≈5.25×10⁻⁶/°C |
| Elastic modulus | ≈315 GPa |
| Hardness | ≥85 HRB (by grade and condition) |
| Standards | Accepted to the relevant material standard or a mutual technical agreement |
| Factory inspection | Spectral composition, density, metallography, ultrasonic inspection, dimensions and appearance |
| Delivery documents | Mill certificate with full batch traceability |
Typical values for pure molybdenum. MoLa, TZM and special sizes follow the mutual technical agreement and the test report supplied with each batch.
FAQ
Common questions
Selection, customization and quotation questions.
Can a molybdenum crucible be used in air?
Not recommended. Molybdenum starts to oxidize noticeably in air at about 600 °C, and an oxidizing atmosphere at temperature will steadily thin the wall. Use under vacuum, reducing or inert atmosphere and control the atmosphere during heating and cooling.
How is wall thickness determined?
It depends on furnace type, charge weight, heating and cooling rates and thermal-shock requirements. Too thin lacks load capacity; too thick adds thermal inertia. Provide the furnace, charging method and target service life so we can confirm together.
Can crucibles and discs be purchased together?
Yes. Both are high-temperature molybdenum parts and can be produced and inspected as one batch to keep material and batch consistency; sizes and lead times are confirmed per project.
CUSTOM
Selection and quotation
Share your furnace structure and process conditions. Our engineers will help select the right electrode and you can request a standard-size sample. We support export customers worldwide with remote technical coordination.