Influence of microstructural features on the yield strength of Ti–6Al–4V: a numerical study by using the crystal plasticity finite element method

In this paper, a numerical study was presented on the influence of microstructural features on the yield strength of bimodal α–β Ti–6Al–4V. Tensile tests and microscopic observations were conducted to provide experimental data of yield strength and microstructure characterization. Sets of representative volume elements were generated using characterization data collected from electron back-scattered diffraction. To investigate the sensitivity of macroscopic yield strength to the morphology of the microstructure, the geometrical parameters such as sizes of equiaxed α grains and lamellar colonies, lamellar widths, volume fractions of equiaxed α grains and Burgers orientation relationship, were studied systematically in a series of simulations. The simulations used crystal plasticity finite element framework to model the deformation behavior of the generated virtual samples under tensile loading condition. Yield strength trends as functions of investigated microstructural features were examined. Moreover, inspection of local deformation of individual equiaxed α grain and lamellar colonies provided an insight into the microstructure-properties relations.