Finite element analysis of stresses associated with transformations in magnesia partially stabilized zirconia

Anisotropy finite element analysis was performed to study stresses associated with the tetragonal precipitates and the tetragonal to monoclinic transformation in MgO partially stabilized zirconia. Stresses were assumed to be caused by the lattice misfits between the product phase and the parent phase. In the finite element calculations, the tetragonal and monoclinic precipitates were assumed to be lenticular in shape, and the anisotropic elastic constants of the cubic, tetragonal and monoclinic phases were considered. The purpose of this paper is to obtain some knowledge about how stresses respond when the microstructure is changed, and how stress fields affect microstructure development. The finite element results show that increasing at/ac and decreasing ct/ac can create a favorable stress field to reduce the growth rate of tetragonal precipitates during the heat treatment. Stresses associated with the single tetragonal precipitate in an infinite cubic matrix are distinctly larger than stresses associated with the homogeneously distributed tetragonal precipitates. The twin orientations within the monoclinic particle greatly affect stresses associated with the tetragonal to monoclinic transformation.