Apart from few exceptions metallic softmagnetic alloys and parts need to undergo a heat treatment to obtain “good” and reliable magnetic properties.
The softmagnetic properties of ferromagnetic metals are influenced by several different coupling and interaction-mechanisms (exchange interaction, crystal anisotropy, magnetostriction etc.) which can directly or indirectly be influenced by a thermal annealing. Conversely the magnetic properties can be reduced by mechanical stresses and in particular plastic deformations. Very high-permeable alloys like MUMETALL® are especially sensitive.
For most alloys It is recommended to conduct the magnetic annealing under alloy-specific temperatures under dry hydrogen atmosphere. Alloy-specific temperature bandwidths are a first hint, but also shape of the parts, size and mechanical strain is a determining factor for the exact annealing conditions.
Magnetic annealing should be done after the last step of mechanical treatment. Any further mechanical or thermal impact after the annealing reduces the magnetic parameters, sometimes considerably.
We offer magnetic annealing in stationary hydrogen furnaces and will provide you with your most striking and cost-effective annealing option.
Annealing under hydrogen up to 1150 °C
Treatment matched to the specific alloy
Consideration of application-specific requirements