Stress dependence of sound velocity in Fe-based amorphous wires

The dependence of the longitudinal sound velocity on the bias magnetic field and tensile stress in Fe_77.5Si_7.5B ₁₅ amorphous wires are presented, The measurements were made using the magnetostrictive delay line principle. The results show that changes in longitudinal sound velocity with bias magnetic field and tensile stress applied along the length of amorphous wires are strongly dependent on the thermal treatment. In the as-cast state, the change of the longitudinal sound velocity is negligible. There is a monotonic dependence of the sound velocity value on the tensile stress up to about 12 MPa. For about 16 MPa and 600 A/m tensile stress and bias magnetic field magnitude, respectively the saturation value of the longitudinal sound velocity is reached