Magnetostriction of Nickel under Applied Stress

Abstract

Magnetostriction curves of nickel are measured under various levels of applied stress. Several techniques using magnetic properties have been developed for the nondestructive stress measurement in ferromagnetic materials. We have already revealed that the maximum value and the knee point value of the magnetostriction curves can be used for the nondestructive stress evaluation in steel and Invar alloy, respectively. The minimum value of the magnetostriction normal to the magnetization direction was also proved to be useful. Accurate measurement of magnetic field was not required in measuring such characteristic values. In this study, in order to examine the possibility of stress measurement using magnetostriction, we measure the stress dependence of the magnetostriction of nickel in both directions parallel and normal to the magnetic field. The results can be explained considering the domain realignment by the stress. It is found that the saturation values in these magnetostriction curves can be applied to the nondestructive stress evaluation.