Vacuum furnace
Encyclopedia : V : VA : VAC : Vacuum furnace
Vacuum furnaces are used to obtain very high temperatures with little contamination of the metals being treated.
Heat can be transmitted three different ways.
1. Convection (Heat from the surrounding air or gas)
2. Conduction (Heat transferring along a sold item such as a rod or plate)
3. Radiation (Heat from a energy source, the sun for example)
The vacuum furnace removes one of the three ways that heat can be transferred, that being convection. Within a vacuum chamber and with the proper layers of hi-temp insulation temperatures can be maintained within the hot zone area exceeding 2400Deg F. The temperature will drop dramatically within a very short distance due to layers of insulation but more so to the lack of convection transfer. Hi-Temp treating of metals within an atmosphere environment will cause a rapid oxidization presses to occur. This metallurgical event is not desired and must be avoided. Vacuum furnace will usually employ an inert gas (Argon) to quickly cool the treated metal back to non metallurgical levels (below 400Deg F) after the desired process under heat has occurred. This inert gas can be pressurized to 2 times atmosphere or more then circulated thru the hot zone area to pickup heat. The gas then is passed thru a heat exchanger to remove heat. This process is repeated until the desired temperature is reached.
Some of the benefits of using a Hi-Temp vacuum furnace include:
1. Temperature uniformity can me maintained at the 2000-2800Deg F range
2. Contamination of parts due to carbon, oxygen and other gases.
3. Very high temperatures can be achieved and controlled within a small area.
4. Quick cooling (quench) of parts within hot zone.
5. Computer controlled process that assures metallurgical repeatability.
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.