Sintering, Welding and Stamping: In-depth Analysis of Process Boundaries and Application Logic of Three Types of Molybdenum Crucibles
Molybdenum Crucible is the core of the core thermal field in high-temperature industries such as semiconductor crystal growth, quartz smelting and rare earth refining. However, in the face of the three types of molybdenum crucibles of "sintering, welding, and stamping" in different shapes on the market, buyers often face the problem of model selection. The difference in process not only determines the cost, but also directly affects the service life and yield of the crucible at extremes above 2000 °C. This article will deeply disassemble the physical background, comparison of advantages and disadvantages, and application scenarios of these three types of processes for you.
1. Sintered molybdenum crucible (Sintered): the "Magic Cudgel" of large thermal fields
The sintering process is to use powder metallurgy technology to sinter molybdenum powder at high temperature after isostatic pressing.
Production process: molybdenum powder → isostatic pressing molding → intermediate frequency induction sintering → fine machining.
Core Advantages: Dimensional Breakthrough: It is the only reliable way to manufacture crucibles with super-large specifications (diameter 400mm-800mm).
Thermal stability: The wall thickness is usually thick (10mm-30mm), and the heat capacity is large, which can effectively buffer thermal field fluctuations.
Main disadvantages: The density (about 9.4-9.8 g/cm ³) is slightly lower than that of forgings, and it is not suitable for making ultra-thin-walled containers.
Application fields: Sapphire crystal growth furnace (HEM method), quartz glass continuous melting furnace, rare earth metal melting.
2. Welded molybdenum crucible: the balance between cost performance and flexibility
The welding process is to roll the molybdenum plate round, then use vacuum electron beam welding or argon arc welding to seal the bottom and weld the seam.
Production process: molybdenum plate → rolling/bending → bottom and seam welding → weld flaw detection and vacuum annealing.
Core advantages: Cost advantage: Compared with large-sized sintered parts, because they are mainly processed with plates, the material utilization rate is high, and the price is more competitive.
Flexibility: Suitable for manufacturing large diameter, thin wall (3mm-8mm) cylindrical containers.
Major drawbacks: Welds are its "Achilles' heel." In the thermal cycle, the weld is prone to crack or leakage due to stress concentration.
Application fields: general vacuum heat treatment in laboratory, sintering of rare earth permanent magnet materials, non-corrosive molten salt bearing.
3. Stamping/spinning molybdenum crucible: the ultimate pursuit of microscopic density
The stamping or spinning process uses mechanical force to directly deform molybdenum sheets into cups, and is usually suitable for small and medium-sized products.
Production process: molybdenum plate → high temperature heating → stamping molding/strong spinning → edge trimming and polishing.
Core advantages: extremely high density: after plate rolling and subsequent deformation, the density can be close to the theoretical value (10.22 g/cm ³), and the anti-permeability is the strongest.
Thin-walled lightweight: It can manufacture lightweight crucibles with a wall thickness of only 1mm-3mm, and the thermal response is extremely fast.
Main disadvantages: High mold cost, and limited by the ductility of the plate, it is difficult to manufacture ultra-deep and ultra-large models.
Application fields: LED evaporation source, coating industry, sintering of electronic tube parts, trace element analysis in laboratory.
II. Decision Guide for Core Selection
|
Characteristic Indices |
Sintered |
Welded |
Pressed/Spun |
|
Maximum Diameter |
800mm |
600mm |
250mm |
|
WT uniformity |
excellent(thick wall) |
general (slightly different at weld) |
excellent (thin wall) |
|
Density |
95% |
98% (sheet) |
Sim 99% |
|
Heat Impact Resistance |
Excellent |
Medium (weld risk) |
Excellent |
|
Unit Cost |
Higher (more material) |
lower |
medium (depending on mold) |
In the context of high-temperature manufacturing in 2026, the logic of model selection is changing. "Instead of pursuing omnipotence, it is better to pursue matching."
If your process is long-term, large-volume crystal growth, please choose sintered molybdenum crucible without hesitation, its deep wall thickness is the guarantee of yield;
If it is fast-in, fast-out, high-frequency sample evaporation, the extremely fast thermal response and density of the stamping/spinning crucible will save you a lot of power and time costs.
Monica
Position:Sales Manager
WhatsApp: +86 182 9270 2722
E-mail: Cr-Re@titanmsgp.com
