| 摘要 |
PURPOSE:To produce a wound magnetic core having high squareness and small coercive force in a high frequency region and undergoing little change in the magnetic characteristics with the lapse of time by subjecting a thin amorphous Co alloy strip formed by very rapid cooling to strain relief annealing and by heat treating it in a magnetic field under specified conditions. CONSTITUTION:A molten Co alloy having a compsn. represented by formula I is very rapidly cooled by a single roll process to form a thin amorphous alloy strip. In order to relieve residual stress produced by the very raid cooling, the strip is coated with an interlaminar insulating film of MgO, formed into a wound magnetic core and subjected to strain relief annealing, by heating at 200-500 deg.C for about 1hr in an N2 atmosphere and rapid cooling to room temp. at >=5,000 deg.C/min cooling rate. The magnetic core is then heat treated in an AC magnetic field of 50Hz applied in the peripheral direction by heating to 150-250 deg.C which is below the Curie temp. of the core, holding for a certain time and cooling to room temp. |
