Effects of Ordering Transformation and Grain Size on the Magnetic Properties of Fe-Co Alloy

Abstract

It is well known that when Fe-Co alloying undergoes ordering transformation, exellent softmagnetic properties could be obtained and there are many reports that the magnetic properties of the materials are changed with variation of grain size. In this study, nanostructured (NS) Fe-50at%Co powders were fabricated by mechanical alloying. The mean grain size of the milled powders was about 10nm. The NS Fe-Co powders were heat-treated to reduce the internal strain introduced during the milling process and investigate the effect of ordering transformation and grain size on the magnetic properties of Fe-Co alloy. XRD analysis was performed on the powders milled and heat-treated for different time durations. The magnetic properties were evaluated by VSM (vibrating sample magnetometer). With the heat-treatment, the corecivity decreased fairly and the causes for this decrease were suggested as the relaxation of the internal strain and ordering transformation.