Plastic strain localization in surface-hardened titanium polycrystals

Abstract

Abstract In this paper, features of plastic strain localization in commercial purity titanium surface-hardened by ultrasonic impact treatment (UIT) are numerically investigated. Three- dimensional polycrystalline structures inherent in unhardened and UIT surface-hardened titanium specimens are generated by a step-by-step packing method. For taking into account the deformation mechanisms at the micro- and mesoscales, constitutive equations describing a nonlinear behavior of individual grains are constructed using crystal plasticity theory. Quasi-static boundary value problems are solved in a dynamic statement using ABAQUS\Explicit finite-element package to simulate uniaxial tension of the model polycrystalline specimens. Based on the calculation results, conclusions are drawn on the effect of the UIT surface- hardened layer on the plastic strain localization and deformation-induced surface roughening in model polycrystals.