Rev.Adv.Mater.Sci. (RAMS)
No 1, Vol. 25, 2010, pages 52-57

STRUCTURE AND PROPERTIES OF NANOCRYSTALLINE ALLOYS PREPARED BY HIGH PRESSURE TORSION

A. Aronin, G. Abrosimova, D. Matveev and . Rybchenko

Abstract

Formation of nanocrystalline structure in amorphous Fe--Si alloy under severe plastic deformation was studied by X-ray diffraction and transmission electron microscopy. Severe plastic deformation of the alloy has been carried out by high pressure torsion method with a pressure of 4 GPa. The severe plastic deformation was found to lead to an appearance of Fe(Si) nanocrystals in the amorphous matrix. The nanocrystal size is independent of the deformation level and they formed by diffusion mechanism of crystallization. When the deformation degree increases, the volume fraction of the nanocrystalline phase also increases. The average size of the nanocrystals formed at severe plastic deformation was found to depend on the deformation temperature. The nanocrystalline phase formation may lead to increase saturation magnetization.

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