Abstract: Tetragonal Zirconia Polycrystals (TZP) with different mechanical properties were obtained by adding certain glass additives with different thermal expansion into
Y-TZP powders and sintered at low temperature. Boundary residual stress was calculated qualitatively by set up thin grain boundary model. The influences of additives’
thermal expansion coefficient on samples’ boundary residual stress and mechanical properties were investigated. The experiment results show that for additives with
low thermal expansion coefficient, because they result in compressive boundary residual stress, samples with relative high fracture toughness can be obtained.

Key words: Y-TZP, additives, thermal expansion coefficient, boundary residual stress, low- temperature sintering