Abstract：In order to accurately describe and predict the plastic deformation of V5Cr5Ti alloy, a microstructure evolution-based constitutive model was established. Miniaturized specimens of V5Cr5Ti alloy are used to carry out a series of uniaxial tensile tests by pulling up to different strain levels. Microstructural evolution analyses are then performed in order to capture the physical mechanisms and dominating its plastic deformation. It is found that the evolutions of dislocation density and second phase are the main factors affecting plastic deformation behavior of V5Cr5Ti alloy. Based on these observations, the equations of dislocation density evolution and that of flow stress which involves non-thermal stress, thermal activation stress and dispersive phase strengthening stress are developed, using microstructure evolution information. The new model is then numerically implemented using finite element method through an implicit stress update algorithm. The validity and prediction accuracy of the model are finally checked and verified by comparing to the experimental results and that of other conventional constitutive models.
2020, Vol. 41 
