Internal stress and strain energy yielded by gamma -> epsilon martensitic transformation in a polycrystalline ferrous alloy

The stress distribution and strain energy have been calculated for two shap es of inclusions, i.e., an oblate spheroid and a hexagonal plate bearing id entical uniform transformation strains associated with gamma(fcc) --> epsil on(hcp) martensitic transformation in a high Mn ferrous alloy. The stress d istribution within the inclusion is constant for the spheroid but shows a m aximum near the interface and decreases gradually with a distance from the interface for the hexagonal plate. The stress concentration behavior at the tip of the inclusion is different from each other for these two shapes. Th e influences of the plate thickness on the stress distribution and strain e nergy are computed and the results suggest that the hexagonal plate is more realistic in order to discuss the improvement of shape memory effect by al loying or training treatment.