ANNEALING MAGNETIC ELEMENTS FOR STABLE MECHANICAL PROPERTIES

摘要

A control element for a magnetomechanical EAS marker is formed by annealing an amorphous metalloid (20) so as to be at least partially crystallized while remaining substantially flat. Preferably a two-stage process is applie d to induce semi-hard magnetic characteristics in an amorphous metallic material (20) that is magnetically soft as cast. In a first stage (26), the material is annealed for at least one hour at a temperature below a crystallization temperature of the material. This produces a reduction in volume of the material. The second stage (30) is carried out at a temperature above the crystallization temperature for a time sufficient to crystallize the bul k of the material and give it semi-hard magnetic properties. The two-stage annealing process prevents deformation of the material which has resulted from conventional crystallization processes.