Micromechanical Response of Commercially Pure Titanium: Insights from Experiments and Crystal Plasticity Simulations

Abstract

In this current study, polycrystal modelling has been utilized to understand the anisotropic dwell fatigue behavior of Cp titanium along rolling and transverse directions. A 2D microstructure of polycrystalline Cp titanium obtained through Electron Back Scattered Diffraction (EBSD) microstructure which is used to study the heterogeneous stress distribution, slip activity, and evolution of texture during tensile and dwell fatigue deformation through experiments and crystal plasticity fast Fourier transform (CPFFT) simulations. A significant anisotropy in the strain hardening is observed when deformed along the rolling direction when compared to the transverse direction which was attributed to the difference in texture which eventually leads to high dwell fatigue life along RD when compared to TD. The grains which developed a higher amount of stress post-deformation are labelled as stress hotspots which interestingly were observed to be higher during tensile deformation when deformed along RD when compared to TD and during dwell fatigue deformation the number fraction of stress hotspots are high along TD when compared to RD. The tensile deformation stress hotspots along RD have initial orientations // ⟨1010⟩ and ⟨2110⟩ direction whereas in case of TD grains the stress hotspots have initial orientations which are closer to ⟨0001⟩ and ⟨2110⟩. The stress hotspots grains tend to reorient towards the ⟨1010⟩ direction along RD and towards ⟨0001⟩ and ⟨1010⟩ along TD during tensile deformation. The present study shows that crystallographic texture is a great tool to understand the anisotropy of dwell fatigue life of Cp titanium.