Variation of power losses with stresses in amorphous sheets for power applications

The behavior of power losses in amorphous magnetic sheets excited at a frequency of 50 Hz for various stresses is investigated. Strip specimens cut off from iron based amorphous alloy sheets, Metglas 2605S2 (composition Fe78B13Si9), are used in three different conditions: as-received and annealed with and without magnetic fields. Power losses are measured on a single strip of samples using the B sensing and the H sensing coil. Applied stresses are the tension and compression parallel to the magnetizing direction, the compression to the surface and side of the strip specimen, and the bending. The result shows that application of any stresses yields increase of power losses in specimens except the application of tension. Since increments of power losses are found to be classified to hysteresis components of losses by loss separations, the degradation of dc magnetic properties occurs in specimens. This is probably caused from local wavy bendings of sheets under stresses. Power losses in laminated strips, therefore, are observed to become lager than those in the single strip.