Magnetic anisotropy predictions from texture measurements using a selected-depth technique

Abstract

The correlation of textures with certain physical properties has been studied extensively for crystalline materials. Texture measurements have usually been performed using composite specimens. With a single measurement, these provide a through-thickness textural average. While this may be appropriate for the prediction of properties that are controlled by bulk characteristics (core loss, elastic modulus,etc.), the composite technique may not accurately predict properties that are controlled by the near-surface material volumes. This is especially true for rolled materials, which often possess through-thickness texture gradients. One such surface-sensitive property is magnetic permeability. In this case, the single composite measurement could be replaced by several measurements performed in the rolling plane at selected depths. Using available software, the unmeasured rims of pole figures can be accurately completed for harmonic orientation distribution function (ODF) calculation. This study consists of examples where the selected-depth technique was used for permeability and for core-loss predictions for a motor lamination steel. An example is provided showing how emphasis on near-surface textures improved the permeability prediction for a specimen possessing a texture gradient.