Stress-Sensory Properties of Amorphous Co-Alloy Wires with Negative Magnetostriction under Elastic Deformation

The effect of the wire diameter and tensile and torsion loads on the remagnetization ability and the stress sensitivity of amorphous Co-alloy wires is investigated. It is shown that amorphous wires have a high magnetic softness to the applied external field in a wide range of diameters of 20–300 μm. The amplitude of the electromagnetic signal of electromotive force (EMF) increases with increasing wire diameter. It is established that amorphous wires with diameter in the range of 50–140 μm are sensitive to applied elastic tensile stresses. Increase in stresses to 300 MPa is accompanied by a fourfold decrease in the amplitude of the EMF signal. These wires are also sensitive to torsion stresses in a weakly and strongly stretched state. The first stage is accompanied by an intense increase in the amplitude of the EMF signal to values near to the amplitude of the original unloaded wire. At the second stage, the amplitude value achieved is preserved. It is established that an optimum interval of recording torsion stresses is determined by the wire diameter and values of applied tensile load. It is concluded that amorphous wires in a wide range of diameters can be used as highly sensitive noncontact sensors of field and tensile and torsion load detectors.