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How does a vacuum furnace roughing pump work?
The roughing pump is the component that primes the other pumps in series on the vacuum line, evacuating the system until a pressure level is reached at which a booster pump (known as a lobe-type roots pump) can be activated, followed by other types of diffusion, turbo molecular, cryogenic, ionic andRead more
The roughing pump is the component that primes the other pumps in series on the vacuum line, evacuating the system until a pressure level is reached at which a booster pump (known as a lobe-type roots pump) can be activated, followed by other types of diffusion, turbo molecular, cryogenic, ionic and other pumps that can be used when the pressure is reached.
Depending on the flow rate, the pumping system is proportioned in relation to system volume, pumping cycle speed, load degassing and contamination produced by the load (vapors, dust, binders, etc.) in the pump itself. It is for this reason that mechanical strength and wear influence the choice of pump type.
I highly recommend you to read an intersting article (splitted in two parts) about this topic:
Roughing pump in high-vacuum furnaces for beginners [1/2]
Roughing pump in high-vacuum furnaces for beginners [2/2]
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]
What is AMS2570 pyrometry?
AMS 2750 (Aerospace Material Specifications) is an aerospace international specification which covers the pyrometric requirements for plants used for the heat treatment of metallic materials. Specifically, it covers temperature sensors, instrumentation, plant equipment, correction factors and offsetRead more
AMS 2750 (Aerospace Material Specifications) is an aerospace international specification which covers the pyrometric requirements for plants used for the heat treatment of metallic materials. Specifically, it covers temperature sensors, instrumentation, plant equipment, correction factors and offsets of instruments, system accuracy testing and temperature uniformity testing. These are necessary to ensure heat treatment of parts or raw materials in accordance with applicable specifications.
The AMS 2750 is now in revision F, was revision E from July 2012.
If you want more info on the new revision, take a look at these two articles:
See lessAMS 2750: what’s new in revision F
AMS 2750F: what’s the comparative SAT