Characterisation of crystallisation in amorphous soft magnetic Fe74Si11B14Ni1 powders by EBSD method

Amorphous Fe74Si11B14Ni1 soft magnetic powder was produced by water atomisation. Crystallisation of amorphous powder was studied using multi-technique approach based on electron beams, including high resolution transmission electron microscopy (HRTEM) and electron backscatter diffraction (EBSD). It has been found that annealing of the amorphous Fe–Si–B powder at a temperature of 500 °C leads to the formation of α-Fe phase in the form of two, three and four-branch dendritic grains. The Fe2B boride is crystallised at temperatures of over 500 °C. In spite of the drift problem associated with EBSD, which is not yet resolved in any commercial EBSD system, the technique is very powerful and shows great promise as a high resolution characterisation method.