Patent ID: 7861403
Filing Date: 2011-01-04
Classification: C22C,H01F,Y10T

Abstract:
1. A method for manufacturing ring-shaped current transformer cores having a ratio of the core outside diameter D a to the core inside diameter D i <1.5 consisting of a soft magnetic iron-based alloy, whereby at least 50% of the volume of the alloy structure consists of fine crystalline particles having an average particle size of 100 nm or less, comprising the following steps: a) Preparing an alloy melt; b) Manufacturing an amorphous alloy strip from the alloy melt by rapid solidification technology; c) Stress-free winding of the amorphous strip to form amorphous current transformer cores; and d) Heat treating the amorphous current transformer cores in one pass to form nanocrystalline current transformer cores while extensively excluding the influence of magnetic fields.