Surface uplift and wear implications of zirconia toughened ceramics

Zirconia ceramics have shown promising wear properties in a number of applications. However, in certain load configurations the wear performance is very poor. The reason for this is believed to be subsurface phase transformation. The surface uplift due to transformation of a circular inclusion in a half-plane and of a spherical inclusion in a half-space is analyzed. The general uniform transformation strain has significant effects on the surface topography and has ramifications for the rolling/sliding wear characteristics of the surface. The two-dimensional approximation overestimates the surface uplift by up to three times compared with the more realistic three-dimensional model. The results indicate that the occurrence of transformation strains, and in particular shear transformation strain, in the near surface area will affect the surface topography considerably.