Method for the manufacture of a ferromagnetic amorphous metal tape and such a ferromagnetic amorphous metal tape

摘要

The invention relates to a method for the manufacture of a ferro magnetic amorphous metal tape having, at least on one side, an insulating silicon dioxide layer with favourable adhesive properties. In a way common in the art an amorphous metal tape is manufactured from an amorphous metal alloy comprising between 8 and 20 at. % of silicon. At least part of the surface of the metal tape is etched using an etching fluid thereby forming an insulating layer of silicon dioxide. The etching fluid comprises a solution of iron(III)-chloride in water.;The insulating layer, which preferably has a thickness of 0.05 µm to 1 µm, suppresses the development of eddy currents when the said amorphous metal tape is used, for example, in transformer cores.