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Two thousand degrees?
Our tungsten and molybdenum crucibles can stand it.

Pressed-sintered tungsten crucibles

During sapphire production, Al2O3 - the compound that is to become the future single crystal - is melted in molybdenum and tungsten crucibles. It is in the Kyropoulos process that our pressed-sintered crucibles show their strengths to best effect. They are repeatedly heated to more than 2 000 °C (3632 °F) and then cooled down again. This process, which would cause fissures and distortions in other materials, is not a problem for PLANSEE products.  



With our many years of experience in the field of powder metallurgy, we produce crucibles of a particularly high density and purity. By correctly filling the mold used for the crucible and carefully controlling the temperature distribution during sintering, we achieve uniform wall and base thicknesses - an important prerequisite in achieving the high level of creep resistance that characterizes our crucibles. 


Save production costs! With our ultra-smooth tungsten crucibles.

Wolframtiegel mit besonders glatter Oberfläche If the surface of the crucible is too rough, the sapphire cannot be released or can only be partially released from the wall of the crucible, which results in cracks and faults in the crystal. Not only that: The crucible itself is also damaged in the process and has to be reworked or replaced earlier than planned.







Our pressed-sintered crucibles made of tungsten have a surface roughness of less than 0.8 µm. The sapphire can be extracted from the crucible without difficulty and without damaging the surface of the crucible. For the sapphire producers, this results in less complex and expensive reworking of the surface of the crucible. The cycles run smoothly and deliver high-quality ingots. And there's another advantage: The smooth surface is less susceptible to corrosion caused by the aggressive melted sapphire. This increases the service life of the reusable tungsten crucibles.


Do you use molybdenum melting crucibles? We are glad to deliver these crucibles with ultra-smooth surface too. Talk to us!

A single source for all your needs.

We handle every stage in the manufacture of our products in-house. From the raw materials through to the finished product: including the development of new materials. In this way, we can guarantee that you benefit from the very best quality.


Raw material Reduction  Metal powder Mixing Pressing Sintering Forming Heat treatment Machining-Joining-Coating Quality assurance

Raw material










Sure and certain.

    Ever since 1921, our customers have been able to rely on Plansee as an independent private company. Like us, they place great importance on reliability and continuity – especially when it comes to raw materials procurement. With Global Tungsten & Powders (GTP) and a holding in Molibdenos y Metales (Molymet), the Plansee-Group covers all the stages involved in the processing of tungsten and molybdenum – from powder manufacture through the subsequent powder metallurgy processes and on to the production of semifinished products and customer-specific components.

And we have something else for you:
Products for high-temperature processes.

Products for high-temperature processes

Whether for annealing and soldering processes, coating systems, MIM furnaces, sintering furnaces, HIP processes or for growing single crystals: Whenever things get hot, we're here for you with our molybdenum, tungsten, tantalum and niobium.


Find out more about our intrepid products for your systems: Rotary tubes, heating elements, HIP cylinders, charge racks, formed crucibles, hot zonesannealing and sintering boats, shielding panels and any number of spare parts for your high-temperature process.


Is your product not yet on the list? That's not a problem. We'll be happy to find a tailor-made solution for you.

Sapphire growth is the first step during the production of LED chips. Get to know some more of  PLANSEE's products for LED production.

Are you feeling the heat? Just contact us.

Do you need heat-resistant components for your high-temperature process? Then we are just the people you need. Choose your country and get to know us better. We're looking forward to your call.

Crucibles with ultra-
smooth surface

Heike Larcher, application group manager single crystal growing, talks about smooth sapphire growth.

Just call us.




Furnace parts 

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