Magnetic hardening mechanism in low-cobalt Fe-Cr-Co alloys

The torque curves, rotational hysteresis energy, rotational hysteresis integral, and magnetic domain structure of low-cobalt Fe_26.6Cr_12.2Co (in wt.%) alloys at the different stages of heat treatment have been studied in order to clarify the mechanism of magnetic hardening of this alloy. The results are compared with the theoretical values obtained from the Shtrikman-Treves theory. An analysis of the torque curves shows that the first stages of heat treatment are capable of inducing anisotropic properties in the Fe-Cr-Co alloy. Study of the rotational hysteresis energy provides evidence that changes in the magnetization of the Fe-Cr-Co alloy occur principally by the curling mechanism. The domain structure of the Fe-Cr-Co alloy after solution treatment is typically one with Bloch domain walls; however, after thermomagnetic treatment interaction domains are created. These domains form domain walls parallel to each other on the axial plane and labyrinth-like on the basal plane