Nanocrystal formation, structure and magnetic properties of Fe-Si-B amorphous alloy after deformation

Nanocrystallization of Fe78Si13B9 metallic glass under severe plastic deformation was studied by X-ray diffraction and electron microscopy methods and by magnetic property measurements. The plastic deformation of the alloy was carried out by high pressure torsion at a pressure of 4 GPa at room temperature. Deformation was performed by unidirectional torsion and involves serial to-and-fro torsion. Severe plastic deformation of amorphous Fe78Si13B9 alloy was found to induce nanocrystallization with formation of Fe (Si) nanocrystals. The average size of the nanocrystals is 6 nm and a volume fraction of the nanocrystalline phase is more than 50% of the sample. The formation of the nanocrystalline structure leads to increase in saturation magnetization by 40% without appreciable changes of the coercivity. (c) 2013 Published by Elsevier B.V.