Multiscale Deformation of Commercial Titanium and Ti一6Al-4V Alloy Subjected to Electron Beam Surface Treatment

Abstract

The paper studies the effect of electron beam irradiation on the surface morphology, microstructure, and phase transformations in the surface layers of commercial titanium and titanium alloy Ti-6Nl-4V. It has been found that the plastic deformation of the modified surface layers under uniaxial tension of the studied specimens occurs at several scale levels. The main plastic deformation mechanism of the modified surface layers is shear induced by the maximum tangential stresses. The dislocation deformation mechanisms effectively accommodate the material rotation caused by the displacement of one part of the crystal relative to the other. Noncrystallographic shear banding in the surface layer with a nonequilibrium martensitic structure is associated with plastic lattice distortion and with reversible structural phase transformations.