Stress and magnetic field-dependent Young's modulus in single crystal iron-gallium alloys

The variability in Young's modulus of single crystal iron-gallium (Galfenol) alloys having 16, 17.5, 19, 24.7 and 29 at% gallium is investigated using experiments and simulations. Some of these alloys showed more than 60% change in Young's modulus along the < 1 0 0 > directions on varying their magnetization and stress states compared to their modulus at magnetic saturation. A function, Delta E(sigma,H), is defined such that the variability of modulus is bound between 0% and 100%. The observations are related to the inherent magnetomechanical coupling in the material. An energy-based non-linear constitutive model is used to predict the variable modulus in Galfenol as a continuous function of stress and magneticfield. Model predictions showed good correlation with experimental results. (C) 2010 Elsevier B.V. All rights reserved.