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.