You might have decided to increase the life of your equipment by putting magnetic shields around them, but one thing you should know that prior to use the shields, they are required to be heat treated. When the alloys are heat treated, properties of magnetic shielding enhance and a good quality resultant product is obtained. In protecting the magnetic shield, usage of furnaces which have dry hydrogen atmosphere are recommended.
To make the magnetic shield effective and highly permeable, the alloys should be heat-treated so that the strength of the magnetic shield be maximized. The process of heat treatment helps to purify the alloys and optimize the performance of magnetic shield. This process is performed through a hydrogen furnace and many companies who offer these services have in-house heat-treating plants. With this kind of heat furnace the customers are guaranteed best quality and high level of permeability of all the magnetic shields produced by them. When the magnetic shields are large, vacuum heat treatment yields the similar results.
Hydrogen Heat Treatment Process
While heat treating the magnetic shields, the inner temperature of the retort should exceed 1150C (2100F) and the shields should be held stable for 1-4 hrs. The time depends upon the type of application. Basically, the alloy used for magnetic shielding is in crystalline form. At such high temperature, these crystals turn into molten state and then reorder themselves into larger piece of crystals. This reorder of the alloys into larger segments make the magnetic shields more effective.
During this process of enlargement of grains (alloy in small crystalline form), the hydrogen flows through the retort and attracts any hydrogen-oxygen or hydrogen-carbon molecules which flows out with the exhausted hydrogen gas and thus the hydrogen moves out of the retort.
This process can be understood simply as purification of magnetic shield materials by separating out the grains. The grains with bigger size are considered as pockets in which magnetic flux is absorbed. If the size of the pocket is big, more of magnetic flux can be absorbed in it.
Some Other Considerations
You should look for the companies which heat treat the magnetic shields without compromising the structural integrity of the shield. When the sales team of a good company will work with you, the outcome will be a precise magnetic shield as per the requirement. It should be noted that when the material will come out from the furnace, it will be considerably softer and the extreme heat will make the material little twisted.
The most important thing to note is that heat-treating of the fabrication of any kind of magnetic shield should be the final and last process. Moreover, all the magnetic shields should be properly and carefully handled. If any additional impact or work is introduced, the Magnetic Shield abilities of the material will be degraded.
So, these are some of the properties of hydrogen heat treatment which make the magnetic shielding more influential. Heat treatment of magnetic shields ensure complete protection.