Hydrothermal corrosion of zirconia--toughened alumina (ZTA) at 200 deg C

To investigate the corrosion behaviour of zirconia--toughened alumina (ZTA) under hydrothermal corrosion, a commercial material was compared with materials of similar composition, but fabricated using different processing methods and pure alumina. The specimens were corroded at a temperature of 200...

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Bibliographic Details
Published in:Journal of the European Ceramic Society 2005-01, Vol.25 (10), p.1805-1812
Main Authors: Herrmann, M, Seipel, B, Schilm, J, Nickel, K G, Michael, G, Krell, A
Format: Article
Language:English
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Summary:To investigate the corrosion behaviour of zirconia--toughened alumina (ZTA) under hydrothermal corrosion, a commercial material was compared with materials of similar composition, but fabricated using different processing methods and pure alumina. The specimens were corroded at a temperature of 200 deg C in deionised water. Generally, linear corrosion kinetics were found. Pure alumina shows the lowest mass loss and the smallest rate constants. The reduction of the four--point bending strength does not correlate with the mass loss. The main parameter for the degradation is the cubic /tetragonal to monoclinic transformation of zirconia. Investigation of the corrosion of polished surfaces reveals spallation of Al2O3 grains or groups of grains surrounded by zirconia as the main mechanism. A decrease in the size of zirconia grains helps to reduce the strength degradation.
ISSN:0955-2219