On the effect of strain on the coercive force of some Fe-Ni alloys under tensile stress

The behavior of the coercive force of two Fe-Ni alloys with 51 and 72 percent Ni as a function of plastic strain was studied, both with a static tensile stress applied and released. It was found that the coercive force depends on the interaction between dislocations and 180° domain walls when the tensile stress was applied, and therefore increases linearly with the square root of the strain. When the tensile stress was released, however, the coercive force showed an anomalous behavior: it increased rapidly at the beginning of the plastic deformation up to maximum, then decreased or remained constant.