Before shields are suitable for use, they must be heat treated. This process increases the magnetic shielding properties of our alloys and the process yields the best possible product. Magnetic Shields only recommend using pure dry hydrogen atmosphere furnaces in order to achieve the best magnetic properties, and our facility has seven fully controlled furnaces, capable of heat treating a range of sizes of component.
Contact our Technical Sales Team for assistance.
In order to produce shields with the highest possible magnetic permeability we have developed distinct heat treatment cycles for each shielding material, which are performed after all manufacturing processes have been completed.
All of our furnaces are equipped with the latest NADCAP approved, computer controlled chart recorders enabling us to deliver a high quality product with complete traceability of the heat treatment process. This provides compliance to 21 CFR Part 11 Electronic Records and Signatures requirements, and an Audit Trail option which also gives complete traceability of configuration and operator actions without the stringent Electronic Signatures controls. All audit trail information is integrated into the process data files. Our advanced heat treatment furnaces enable us to offer a first class sub contract heat treatment service for Nickel Iron, Cobalt Iron, Stainless Steel and Pure Iron materials.
All heat treatment cycles consist of three basic steps. The first is a gradual temperature increase. The second is an extended hold of high temperature (typically 2hrs to 4hrs at 850°C to 1150°C) during which impurities from the metal are ejected and the magnetically permeable microscopic structure is formed. Finally, the temperature is reduced under tight control during which the microscopic structure becomes fixed and the permeability increase is locked in. The entire heat treatment process takes around 24hrs for MuMetal® may exceed 36hrs for our cyrogenic alloy, CRYOPHY®.
If a shield receives any bumps or knocks, or you are just generally concerned about the performance of your shield we are happy to take a look, perform any necessary tests and potentially re-heat treat shields where required, to ensure that our products have the longest lifetime possible.
For a quote we ask you contact us with the following information;
- Material type
- Heat treatment specification
- Any special handling requirements