Microstructural characterization of Ce-TZP/Al₂O₃ after degradation in water

ABSTRACT

In this study, the long-term resistance of Ce-TZP/Al₂O₃ specimens to hydrothermal treatment is evaluated in terms of their microstructure. Treatment of the specimens is carried out in an autoclave with water at 134°C for up to 360 h. The biaxial strength and Weibull modulus of the specimens remains unchanged after 120 h of hydrothermal treatment, and their pseudo-plasticity is preserved. However, after 360 h of hydrothermal treatment the biaxial strength decreases by 12% and the Weibull modulus is also decreased. The transformation surface layer is observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The thickness of the transformation layer can be estimated only through TEM analysis, revealing minimal microcrack formation at the surface layer. For comparison, several Y-TZP specimens are also prepared. After 24 h of hydrothermal treatment, the monoclinic phase content in the Y-TZP specimen reached 60%, resulting in a 40% decrease in strength. This strength decrease can be attributed to microcrack formation in the surface layer.

KEYWORDS:

• Zirconia
• degradation resistance
• phase transformation
• microstructure

Acknowledgments

This study was supported by National Science and Technology Council (NSTC 112-2923-E-002-005, MOST 111-2221-E-002-158), and Chang Gung Memorial Hospital at Linkou (CMRPG3L0751, CMRPG3L0752). The technique help on SEM from Ms. Yu-Wen Chen is appreciated.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the Chang Gung Memorial Hospital, Linkou [CMRPG3L0751, CMRPG3L0752]; National Science and Technology Council [NSTC 112-2923-E-002-005, MOST 111-2221-E-002-158].