On Controlling Toughness of Zirconia Ceramics

Authors: Bikramjit Basu, Jef Vleugels, Dirk Dierickx, Omer Van Der Biest, Dept. of Metallurgy and Materials Engineering, K.U. Leuven

Abstract

Transformation toughened zirconia ceramics (Y-TZP) are known for their high fracture toughness upto 10MPa m1/2. However, in practice the observed toughness may vary between 3 and 10 Mpa m1/2 depending on powder source and processing route. This problem of controlling the toughness of zirconia ceramics has been investigated in this contribution by comparing behaviour of several starting powders and powder mixtures under nominally identical processing conditions and by detailed analysis of the phase assemblages obtained. The present work shows that an in-house processed powder mixture has better mechanical properties than the comercially available starting powders. The nature and parameters of the measured grain size distribution in the sintered ceramics have been characterised. These are considered as key information in the understanding of the factors which control toughness in these materials.