Deformation-induced rotational eutectic colonies containing length-scale heterogeneity in an ultrafine eutectic Fe83Ti7Zr6B4 alloy

Abstract

Microstructural investigations of an ultrafine eutectic Fe83Ti7Zr6B4 alloy reveal that spherical eutectic colonies are composed of nanoeutectic areas which are encapsulated by submicron eutectic areas indicating length-scale heterogeneity of lamellar structure. Furthermore, formation of the wavy and discontinuous shear bands indicative of dissipation of the shear stress are possibly caused by a rotation of the eutectic colonies along the submicron eutectic areas during deformation, leading to developing typical dimples on the fracture surface. The rotation of the eutectic colonies containing the length-scale heterogeneity is proposed to be responsible for macroscopic plasticity of the ultrafine eutectic Fe83Ti7Zr6B4 alloy.