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Why use partial pressure in a vacuum furnace?
Partial pressure is typically used to raise the pressure in the furnace above the vapor pressure of the material being heated, thus minimizing the out-gassing of certain constituents of the material
Partial pressure is typically used to raise the pressure in the furnace above the vapor pressure of the material being heated, thus minimizing the out-gassing of certain constituents of the material
See lessCFC, Graphite, or Moly, which is the best choice for vacuum ovens?
Thanks for the information. My direct question was related to fixturing, not hot zones for htre furnace.
Thanks for the information. My direct question was related to fixturing, not hot zones for htre furnace.
See lessCFC, Graphite, or Moly, which is the best choice for vacuum ovens?
Hot zones are the hearth of every vacuum furnace. When purchasing a new furnace, you might face with the Hamletic doubt about hot zones: graphite-based or all-metal design hot zone? That’s the question! The graphite wafer is an excellent material. It allows operation at very high temperatures (up toRead more
Hot zones are the hearth of every vacuum furnace. When purchasing a new furnace, you might face with the Hamletic doubt about hot zones: graphite-based or all-metal design hot zone? That’s the question!
The graphite wafer is an excellent material. It allows operation at very high temperatures (up to 3000°C based on the vacuum level), has low density, reduced weight and modest thermal capacity. It creates the ideal black body conditions (emissivity about 1) inside the heating chamber for obtaining high uniformity.
All-metal hot zones are used in high demand industries where sensitive materials are processed, such as aerospace, electronics and medical. There are heat treatments that require a particularly clean environment or extreme vacuum levels. There may be different reasons: in some cases the chamber’s graphite could interfere with the process, resulting in unwanted carburation of the pieces treated. In other cases, the load could be particularly sensitive to the presence of residues in the oxygen or hydrogen atmosphere (which could lead to embrittlement of the pieces), and so graphite wafer degassing during the cycle could be damaging. In these circumstances, the user should opt for all-metal heating chambers (shields and resistor).
If you want more information on this topic and a detailed analysis of the differences, take a look at the following 2 articles:
See lessVacuum furnace hot zone: graphite vs all-metal design [1/2]
Vacuum furnace hot zone: graphite vs all-metal design [2/2]
Why use partial pressure in a vacuum furnace?
Partial pressure can be used to assist in removing impurities and heat distribution during the heating process.
Partial pressure can be used to assist in removing impurities and heat distribution during the heating process.
See lessWhere is it required to do hydrogen bakeout?
Hydrogen bakeout is commonly used for materials or processes when hydrogen induced cracking is a concern. Heating the material to a temperature high enough and long enough to allow the trapped hydrogen to escape from the areas where it is trapped in the material. This is a common process for post weRead more
Hydrogen bakeout is commonly used for materials or processes when hydrogen induced cracking is a concern. Heating the material to a temperature high enough and long enough to allow the trapped hydrogen to escape from the areas where it is trapped in the material.
This is a common process for post welding of chrome moly steels that do not use low hydrogen welding processes or electrodes and heavy weldments.
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