Bands of circumferential remanent magnetization obtained by sequential application of axial fields and torsion

Sequential application of adequate torsional stress, together with the axial field from a short encircling solenoid, is shown to result in a circumferential band wherein the remanent magnetization has a net circular orientation. The process allows for the creation of such bands in ferromagnetic shafts used in magnetoelastic torque transducers. Operation of the process is shown to be the result of domain orientations settling into a lowest energy distribution under the combined influences of magnetocrystalline anisotropy, stress anisotropy, and magnetostatic fields. Measurements on a sample shaft elucidate the operative parameters and demonstrate the efficacy of the process.