a set of zirconia pellets was subjected to surface toughening by the inclusion of alumina particles into the zirconia matrix before firing. the alumina particles were formed in the matrix by an infiltration process. non-destructive tests were carried out to measure the density profile, the alumina distribution and the residual strains in the matrix. the density profile was measured by computed tomography, the inclusion distribution and residual strains by neutron diffraction. the density profile showed higher densities along the walls and at the ends of the pellets. this is consistent with the single-ended pressing procedure used as part of the fabrication process for the compression and axial tension. tangential compression tends to improve the surface toughness. residual strains, found in the cores of both infiltrated and control pellets, were attributed to the initial single-ended axial pressing of the zirconia powder that formed the matrix. (atomindex citation 21:049188)