Characterization of grain boundary sliding in a fine-grained alumina–zirconia ceramic composite by atomic force microscopy

Grain boundary sliding has been investigated on the three kinds of interface during the superplastic deformation of a fine-grained alumina–zirconia ceramic composite by atomic force microscopy. The changes in surface topography on both sides of the same boundaries have been characterized throughout specimen deformation. In the experimented deformation conditions (1325°C, 60 MPa) the three kinds of interface exhibit similar sliding mobilities, within 20%, and in average grain boundary sliding contributes to more than 80% of the total strain. The stress redistribution, associated to the difference in phase ductility, has been estimated. The results are in agreement with the values that can be calculated by an isostrain model or a three phase model.