Naresh Ranvah is a 3rd year PhD student at Wolfson Centre of Magnetics, Cardiff School of Engineering, Cardiff University.

Materials for non-contact portable Magnetic NDE applications

There has been a recent interest in the magnetic materials that can be used to sense or produce stress. Such materials can be used for non-destructive evaluation (NDE) of buildings and other civil structures. In times of frequent aviation disasters, such NDE techniques can be at the forefront of accident prevention strategies.

Among these materials, magnetostrictive materials become a material of choice due to their non-contact application. However, initial investigation into such sensor materials was focussed on Terfenol-D which is brittle, easily corroded, expensive, and puts great demands on the power required for such a device to work.

Cobalt ferrite has emerged as a candidate material for non-contact magnetostrictive stress sensors and actuator applications. Initial investigations had proved that chemical substitution can change the properties of cobalt ferrite favourably for these applications. In the present study, we have investigated the effect of chemical substitution on magnetoelastic properties of cobalt ferrite. We have fabricated materials, which when used in sensors and actuators, would need 93% less power in comparison to materials previously available. These investigations have helped identify materials that can be used in sensor designs for a range of applications.