Abstract
The electrical insulating effects of interlayer coating in thin tape wound magnetic cores have been investigated for grain-oriented 50 Permalloy and Supermalloy, treated with different coatings of MgO type ceramics, e.g., MgO, MgCO3 and Mg(OH)2, by a cataphoresis method.
Among the various coatings, Mg(OH)2 coatings result in superior qualities in both uniformity and adhesiveness, such that the coatings maintain the interlayer insulation satisfactorily even after annealing in H2 atmosphere at a high temperature such as 1473 K and hinder secondary recrystallization in the cubic texture. The tape wound magnetic cores of grain-oriented 50 Permalloy subjected to the interlayer insulation by Mg(OH)2 coatings to the thickness of about 2 μm exhibit excellent rectangular hysteresis loop characteristics with low coercivity, and those of Supermalloy are high in effective permeability and low in core loss at a high frequency field.
