Magndreifing

Magndreifing, or magnetic annealing, is a heat-treatment process used to tailor the magnetic properties of ferromagnetic materials by combining thermal treatment with the application of a magnetic field. The goal is to modify the material’s internal structure and magnetic domain configuration to achieve a desired magnetic anisotropy and performance characteristics.

The basic procedure involves heating the material to a temperature at which atomic mobility allows domain reorientation, while applying a controlled magnetic field in a chosen direction. After the exposure, the material is cooled under the influence of the field or with the field removed, so that the preferred orientation of magnetic domains becomes locked in. The exact temperatures, field strength, and cooling rate depend on the material and the target properties.

Magndreifing is used to enhance attributes such as magnetic permeability, coercivity, and the squareness of the hysteresis loop. It can also relieve internal stresses developed during prior processing and promote directional grain growth or alignment. The technique is employed in the manufacture of certain permanent magnets, soft magnetic materials for transformers and motors, and magnetic sensor components, where controlled anisotropy improves performance.

Material considerations include alloy composition, grain size, and existing microstructure, all of which influence how readily domains reorient and how stable the induced anisotropy remains under operating conditions. Equipment typically involves a furnace or heat-treatment chamber coupled with a source of a magnetic field, such as electromagnets, and precise temperature and field controls.

See also: annealing, heat treatment, magnetic anisotropy, coercivity.