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VacuumFurnaces.com is a Q&A community where vacuum furnace product and service suppliers connect with commercial and captive heat treaters to share their practical skills and know-how and to establish valuable relationships around niche topics of expertise with vacuum furnace end-users in operations, production, training, maintenance, marketing, sales, and engineering.
Why must the cryogenic medium used to cool the cold trap between the gas manifold and the mechanical pump be liquid nitrogen?
Liquid nitrogen cold traps prevent products arising during the equipment operation from passing from the chamber into the pump where they could either contaminate the pump or cause the breakdown of the pump fluid. In either case, severe loss of efficiency and poor vacuum levels result. In the examplRead more
Liquid nitrogen cold traps prevent products arising during the equipment operation from passing from the chamber into the pump where they could either contaminate the pump or cause the breakdown of the pump fluid. In either case, severe loss of efficiency and poor vacuum levels result. In the example shown the diffusion pump was only capable of reaching 4 x 10-3 Torr rather than the typical 1 x 10-5 Torr range achieved with a clean pump. In addition, these types of cold traps prevent backstreaming of the pump.
SOURCE: Cold Traps / VAC AERO International Inc.
See lessWhat are some common vacuum furnace pumping system failures and their solutions?
For the many vacuum furnaces in use around the world, the vacuum pumping system is a critical component. To get the best value from the vacuum furnace system and to extend its useful life, the regular and careful maintenance of the various vacuum pumps is of utmost importance.Β Here are two resourceRead more
For the many vacuum furnaces in use around the world, the vacuum pumping system is a critical component. To get the best value from the vacuum furnace system and to extend its useful life, the regular and careful maintenance of the various vacuum pumps is of utmost importance.Β
Here are two resources that delve deeply into this question, courtesy of Solar Atmospheres and Bill Jone.
This PDF published by Solar Atmospheres Inc. and a Youtube Video presented by the legendary founder of Solar Atmospheres, Bill Jones
SOURCE: Solar Atmospheres Inc. https://solaratm.com/
See lessWhat are acceptable helium leak rates?
The leak-up rate you should be looking for depends primarily on the type of base metals you are trying to braze. As mentioned at the beginning of this article, any air leak into the furnace represents an influx of oxygen into the furnace. Metals vary considerably in their tolerance of oxygen, with nRead more
The leak-up rate you should be looking for depends primarily on the type of base metals you are trying to braze. As mentioned at the beginning of this article, any air leak into the furnace represents an influx of oxygen into the furnace. Metals vary considerably in their tolerance of oxygen, with nickel and gold being examples of metals that have a large tolerance for the presence of oxygen. That is, they will not oxidize to the point that there is any negative effect on brazing.
However, other metals, such as chromium, or base metals which contain titanium and/or aluminum in their chemistry, will be highly sensitive to the presence of any oxygen in the furnace. Thus, may I suggest the following as a guideline for vacuum-furnace brazing:
Tolerable Vacuum Furnace Leak-up Rates:
SOURCE: Kay & Assoc. Brazing Consultants
See lessWhat is an AMS2750 calibration survey?
Our blog post takes a short look at the AMS2750E standard, with a special focus on the requirements set for calibration, calibration accuracy, and test/calibration equipment. The AMS2750E is predominantly designed for heat treatment in the aerospace industry. Heat treatment is an essential process fRead more
Our blog post takes a short look at the AMS2750E standard, with a special focus on the requirements set for calibration, calibration accuracy, and test/calibration equipment. The AMS2750E is predominantly designed for heat treatment in the aerospace industry. Heat treatment is an essential process for many critical parts of an airplane, so it is understandable that there are tight regulations and audit processes set. While the results and success of some other industrial processes can be relatively easily measured after the process, this is not the case in a heat treatment process. Therefore, very tight control and documentation of the heat treatment process are essential to ensure the quality of the end products.>>>READ MORE
Source: Beamex Blog for Calibration Professionals
See lessHOW CAN I CELANΔ°NG CONTAMΔ°NATΔ°ON OF VACUUM FURNACES?
"When operating vacuum furnaces, situations may arise in which the hot zone and/or cold walls may become contaminated (Fig. Nos. 1 β 2). This can occur from a variety of sources: air leaks, outgassing from residues left on the parts as a result of the manufacturing or cleaning processes, vaporizatioRead more
“When operating vacuum furnaces, situations may arise in which the hot zone and/or cold walls may become contaminated (Fig. Nos. 1 β 2). This can occur from a variety of sources: air leaks, outgassing from residues left on the parts as a result of the manufacturing or cleaning processes, vaporization of sensitive materials (e.g., chromium-bearing materials), process-induced contaminations such as carbon in the form of soot or tar, fluxes from brazing pastes, excess braze alloy as well as many other sources. Often times the work being processed is also affected (Fig. 3). The question becomes, how do we attempt to clean up our contaminated vacuum furnaces? >>>Read More
Source: VAC AERO International
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