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

Abstract

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 180 and 90 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 Néel'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.

Scaling-based prediction of magnetic anisotropy in grain-oriented steels

“…It should be noted that the angular dependence of magnetic induction for H = 100 A/m has a different trajectory compared to the other dependencies -the worst direction of magnetic properties is for φ = 90°. Similar results were reported in [21][22][23][24][25]. This effect may result from the change of the magnetization mechanism for magnetic field strength of about 200 A/m.…”

Anisotropy and magnetization process in soft magnets: Principles, experiments, applications

“…processes and rotations separately occur at low and high fields,respectively. Despite the apparent complexity of the associated phenomena,it can be shown,again within the framework of the magnetic phase theory,that the dependence of magnetization curve and hysteresis energy loss upon the measuring configuration is predictable [8]. Fig.…”

Magnetic properties of Fe–Co-based bulk metallic glasses

“…As an example, at a frequency of 50 Hz, the cylinder having x = 0.4 has P/f ≈15 mJ/kg, while the corresponding composition casted as ribbon is ≈3.6 mJ/kg at f = 50 Hz. These values have to be compared with the ones measured at the same frequency in systems as the Fe-based METGLAS 2605 SC characterised by a P/f lower than 2 mJ/kg, measured in open samples at a peak induction of 0.7 T [16], and in grain oriented Fe-Si laminations (thickness 0.35 mm) measured in an Epstein closed circuit at 0.7 T having P/f ≈7 mJ/kg [17,18].…”