The effect of strain on the magnetization process
Residual stress in magnetic materials is linked to deformations at the cell and grain level as a result of composition, fabrication processes, thermo-mechanical treatment, aging or the history of the material. The dependence of magnetic properties on stress is well established and has been demonstrated by a number of experimental techniques at the macroscopic level, such as major and minor hysteresis loops, permeability and magnetic Barkhausen noise measurements, as well as at the grain or atomic level, such as EBSD or XRD measurements. The present work aspires to contribute to the discussion on the relationship between macroscopic measurements and microstructure on the way towards establishing a methodology that will allow the quantitative assessment of the effect of strain on magnetic properties in the plastic deformation regime. In particular, we study the effect of strain on the magnetization process as a result of a varying anisotropy profile at the grain level [1]. Results on micromagnetic calculations of hysteresis loops for various configurations of magnetic anisotropy are shown and discussed against experimental loops on a series of strained electrical steel samples as well as magnetic Barkhausen noise measurements on the same samples.