Effect of shock waves on the residual magnetic properties of armco iron

Abstract
The effect of shock waves on the residual magnetic properties of Armco iron is determined by measuring the magnetic hysteresis and the normal magnetization curves after shock deformation. The pressure range investigated is from 73 to 250 kilobars. It is observed that all structure sensitive properties change and these changes are related to the peak pressure associated with the shock wave. The data are discussed in terms of magnetic domain theory. Functional expressions are presented for both the change in coercive force and the change in the area of a hysteresis loop with pressure. It is noted that a minimum occurs in the pressure dependence of the residual magnetization near the pressure required for the α→ε phase transformation.