The Dislocation Model of Zirconia-Toughened Ceramics

In order to understand the mechanism of toughening in zirconia-toughened ceramics , this paper tries to set up a dislocation model of zirconia transformation -toughened ceramics . On the basis of this model the crack extension force and the fracture toughness are calculated . This paper also compares the contributions to toughness due to the transformation particles ahead of the crack as compared with that at side of the crack . From the point of view of dislocation the size effect of zirconia trasformation is explained . Results of analysis point to the conclusion that plastic deformation due to transformation may contribute to toughness .