Micromechanical modelling of damage behaviour of Ti–6Al

Micromechanical modelling of damage behaviour of Ti–6Al–4V

Katani, S. / Madadi, F. / Atapour, M. / Ziaei Rad, S.

Highlights ► Titanium possesses many beneficial characteristics including excellent mechanical properties. ► Microstructure of titanium alloys is modelled by using Image processing technique which recognises phases based on SEM. ► FE-model enables the analysis of stress/strain localisation and the GTN damage model was employed to simulate the ductile. ► Voids formation is compared with the experimental results, followed by a fractographic analysis of the fractured surface. ► Results of simulation are similar to experimental test and it shows coalescence and growth of voids of microstructure.

Abstract The effort of this study is to develop a simulation method to predict the effect of microstructural morphology in mechanical properties and failure mechanism of Ti–6Al–4V with 55% α and 45% β. Finite element models were then created based on a clarification of a damage mechanism to control the ductile cracking with focusing on the heterogeneity in strength of microstructure. By the way, Simulation for the dimple failure of the material, using the Gurson–Tvergaard–Needleman (GTN) model, will be presented. The large number of micro-voids nucleation at lower strength side near two phase boundary associated with the localisation of stress/strain is found to control ductile cracking. Numerical simulations, which were carried out using the scanning electron micrograph, are able to predict the void initiation in the material. During fractography of the material, some evidence is observable which can validate the results obtained by the simulation. The good correlation between the numerical and experimental observations from fractographic and tensile test results shows the efficiency of the proposed models in predicting the failure mechanism of Ti–6Al–4V.