Comprehensive model of magnetization curve, hysteresis loops, and losses in any direction in grain-oriented Fe-Si

We report an investigation and theoretical assessment of the DC magnetic properties of high-permeability grain-oriented (GO) Fe-Si laminations under variously directed applied fields. We verified that normal magnetization curves, hysteresis loops, and energy losses depend on the field direction according to the sample geometry. This is explainable in terms of specific 180degrees and 90degrees domain wall processes and magnetization rotations. We present a novel phenomenological theory of the magnetization curves and hysteresis losses in GO laminations, excited along a generic direction; the theory is based on the single crystal approximation and pre-emptive knowledge of the magnetic behavior of the material along the rolling (RD) and the transverse (TD) directions. This approach is consistent with the general structure of Neel's phase theory, with the additional consideration of hysteresis and losses. Epstein and cross-stacked sheet testing methods are the two base measuring configurations; all the other testing geometries (single sheet, disk, square) are expected to display intermediate behavior. The devised model provides, through a direct procedure, thorough and accurate prediction of magnetization curves and quasi-static losses in these two basic cases. Its application to the other geometries is equally possible, with only a limited amount of supplementary information.