On the Mechanism of Domain Refinement due to Scratching

As well known, defined scratching of soft magnetic materials results in domain refinements and thus in reduction of anomalous eddy current losses. However, the present paper shows that scratching a grain oriented HI-B sheet causes a stress configuration corresponding to slight bending which would lead to domain widening. Moreover, it is demonstrated that regions of domain refinement due to scratches of restricted length are clearly demarcated by the scratch endings. These experiments indicate that changed stress configurations are nonrelevant for resulting refinements which, rather, are due to stray field generation. Effects are discussed by a theoretical model resulting in refinements especially of wide domains which is in agreement with presented experimental data.