Inert atmosphere furnaces are devices purpose-built for heat-treating applications that need inert atmosphere protection. This protection means that the work is not subject to oxidation. This article will explain in more detail what an inert atmosphere furnace is and how it is used.
What is an Inert Atmosphere
Inert means chemically inactive, so inert atmospheres are those in which chemical processes can take place without the risk of reactive gas contamination. Inert atmospheres are made of purified argon and nitrogen gases, due to their high natural abundance.
Why Would a Process Require an Inert Atmosphere Furnace
Many heat treatment processes such as sintering, bright annealing, and carbonitriding need atmospheres that are highly controlled to result in a successful process. Such processes are used to manufacture parts for the automotive, aerospace, and petrochemical industries amongst others. Inert atmospheres may include helium, nitrogen, argon, hydrogen, and endothermic mixtures.
The Importance of Furnace Atmospheres
The atmosphere of a heat treatment process can be extremely important. The atmosphere can act as a carrier of key elements in the process or it may work to safeguard the heated element from the impacts of exposure to air whilst at increased temperatures.
The atmosphere is chemically reactive with the surface and this can lead to enhanced surface characteristics, supporting processes such as hardening. It can also protect the surface of the part from chemically reacting with potentially damaging elements inside the atmosphere.
The lack of a controlled protective atmosphere can sometimes lead to chemical reactions on the surface of a part, negatively impacting its quality and performance and resulting in rejected parts. This decreases profits over time as well as wastes employee time and could result in danger to users if not picked up in the supply chain.
Where to Buy Inert Atmosphere Furnaces
There are a plethora of suppliers of vertical and horizontal tube furnaces, but very few suppliers of bottom load, top hat, and front load furnaces that are specifically designed for processing in inert atmospheres.
To do so, the furnaces need to be sealed including the thermocouple ports, door access, and element ports. Gas inlets will allow purging in any furnace to operate in other atmospheres, inert atmosphere furnaces must displace the room air with desired gas mixtures.
Deltech inert atmosphere furnaces are known as ‘atmosphere envelopes’. They are available in front load, bottom load, and top hat configurations. They can be customized to meet any size specification the application requires and they operate at pressures of as much as .022 atmosphere. They also have the option for vacuum-assisted evacuation meaning the room air can displace before backfilling with desired gases.