CHARACTERISTICS OF MAGNETIC PROPERTIES OF GRAIN-ORIENTED SILICON IRON WITH HIGH PERMEABILITY

Grain-oriented silicon iron with high permeability is prepared using aluminum-nitride needles to restrain normal grain growth. The improvements in hysteresis loss of specimens with a permeability of 1920 are about 0.120 W/kg at 15 kG and 0.160 W/kg at 17 kG as compared to the commerical product with a permeability of 1820. That is the reason why the crystal orientation has a strong influence on total loss, especially at B = 17 kG. The effect of grain size on total loss is important also. The detrimental aluminum nitride and aluminum oxide are not present in the base metal after final annealing. For example, aluminum oxide is removed from the base metal and absorbed into a glass film. Glass-type coating plays a dominant role, not only for the magnetostriction, but also for total loss of these specimens with high permeability, especially in thin-gauge specimens. © 1969 The American Institute of Physics.