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

• Published in: Journal of the European Ceramic Society 2005, Vol.25 (10), p.1805-1812
• Main Authors: Herrmann, Mathias, Seipel, Björn, Schilm, Jochen, Nickel, Klaus G., Michael, Grit, Krell, Andreas
• Format: Article
• Language: English
• Subjects: Al 2O 3; Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Cermets, ceramic and refractory composites; Chemical industry and chemicals; Corrosion; Cross-disciplinary physics: materials science; rheology; Defects; Exact sciences and technology; Materials science; Mechanical properties; Miscellaneous; Other materials; Physics; Specific materials; Technical ceramics; ZrO 2
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2004.12.009

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 °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 Al 2O 3 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.