Surface treatment methods for mitigation of hydrothermal ageing of zirconia

Chong Wei (1, 2) , Laurent Gremillard (2)

1 NPU - Northwestern Polytechnical University [Xi'an]
2 MATEIS - Matériaux, ingénierie et science [Villeurbanne]

Hydrothermal ageing of zirconia ceramics (tetragonal-to monoclinic phase transformation in the presence of humidity) is highly sensitive to the surface characteristics. Thus chemical modifications of the surfaces over a few microns may be a good way to mitigate ageing without affecting bulk mechanical properties. Here, the efficiency of different post-sintering thermal treatments in powder beds of different compositions to prevent or slow down hydrothermal ageing of 3Y-TZP is tested. The microstructure, ageing kinetics at different temperatures and mechanical properties of the treated samples are then evaluated. Treatments with 12Ce-TZP proved to be the most efficient to limit ageing at 134°C while keeping good mechanical properties. However, this is accompanied by a decrease of the activation energy of ageing, thus by an acceleration of ageing at lower temperature. These results also show that the activation energy of ageing is material-dependant, thus should be ascertained for every developed zirconia-based ceramic.

Mots clés: Zirconia; hydrothermal ageing; surface treatments

Domaines: Matériaux

Chong Wei, Laurent Gremillard. Surface treatment methods for mitigation of hydrothermal ageing of zirconia. Journal of the European Ceramic Society, 2019, 39 (14), pp.4322-4329. ⟨10.1016/j.jeurceramsoc.2019.06.013⟩. ⟨hal-02156270⟩