Modelling of elastic interaction stresses in two-phase materials by FEM

Recently, by considering a bicrystal of α and β phases of Ti alloys with Burgers orientation relationships, it has been shown that elastic interactions play a significant role in the initiation of plastic deformation in two-phase materials. However, it is not known how far these interactions exist away from the interfaces. Further, it is not known how these interactions vary with morphology of phases (i.e. thickness, orientation and distribution). To study these effects systematically, a three-dimensional anisotropic finite element method (FEM) has been employed in this investigation. It is found that the interaction stresses decay from the interface in an exponential form in a distance of one-sixth to one-half of the plate thickness, that large hydrostatic stresses are found within alpha plates in beta matrix and that the anisotropic elastic material properties are not responsible for the anisotropic sliding experimentally observed by earlier investigators. In addition, it has been found that the magnitude of the interaction stresses varies with the morphology of phases.