Production of 2 μm-thick 6.5 % Si-Fe cold rolled sheet

Although 6.5% Si-Fe alloys have excellent magnetic properties, they have not been used in practical application because they are mechanically hard and brittle. In this study, we attempted an extremely thin 6.5% Si-Fe to realize a high-frequency, low-loss magnetic material, which is highly demanded for next-generation power electronic circuits. It was found that 6.5% Si-Fe with a thickness of 20 mu m prepared by the liquid quenching method could be rolled down to 2 mu m under certain conditions. The conditions under which the rollability was achieved were investigated in detail, such as grain structure, grain size, crystal orientation, etc. Since the eddy current loss of the 6.5% Si-Fe alloy with a thickness of 2 mu m is expected to be extremely low, this material is very promising as a next-generation magnetic material for high frequency applications.