Influence of stress on Matteucci and search coil voltages in amorphous wires

Abstract The influence of tensile, compressive and torsional stresses on the magnetic properties of as-cast and treated high positive Fe-based and nearly zero Co-based magnetostrictive amorphous wires has been studied. The application of tensile and compressive stresses determine the decrease of the Matteucci voltage, Vm, as a result of cancelling of helical stresses, the effect being more important in the Fe-based wires. However, it increases with torsional stresses applied on preloaded samples, reaching a maxima at a certain number of turns that corresponds to the maximum alignment of vector components. Vm was found to be more sensitive and linear to the applied torsion than the induction voltage detected from the pick-up coil, Vs. This investigation also highlighted the occurrence and the stress dependence behaviour of the second harmonic component of the induced EMF voltages in amorphous wires. This extensive study was undertaken so that industrially viable sensors could be designed based on these stress-dependence effects.