Investigation of Deformation Using Squid Magnetometry

Abstract

Most of the effort in the area of ferromagnetism has been directed towards improving magnetic properties of materials. For example, residual stress (strain) and defects are studied for their influence on magnetization, in order to produce magnetically hard materials etc., as opposed to studying the influence of magnetic properties of materials on their mechanical behavior or as a means of investigating micro-mechanical behavior. A few exceptions are studies of macro-mechanical behavior under very high magnetic fields [1], the “delta E” [2] and Barkhausen effect [3–5]. These are directed towards understanding mechanical behavior but usually use intrusive means, by perturbing the material with a magnetic field to produce measurable changes. A great deal of interest has been shown in the Barkhausen effect by the NDE community. Although this is a nondestructive technique, it is still somewhat intrusive.