Mineralogical and microstructural changes in fused cast Ti-stabilized alumina-zirconia eutectic ceramics at elevated temperatures

Author(s)
Annalena Erlacher, Adrian Villalba Weinberg, Christian Leopold Lengauer, Andreas Börger
Abstract

Ti-stabilized alumina-zirconia eutectic ceramics produced by

fusion-casting are characterized to investigate microstructural

mechanisms at elevated temperatures and to explain the self-sharpening

effect. Scanning electron microscopy (SEM) images show fine-grained

lamellar eutectic microstructures with well-defined domains. After

thermal annealing at 800 °C, distinct cracks formed along the domain

boundaries. Thermal analyses and powder X-ray diffraction (pXRD), using

Rietveld evaluation, confirmed that the cracks are triggered by the

phase transformation from meta-stable tetragonal to monoclinic ZrO2,

causing a volume increase of up to 13.4 %. This indicates a decrease in

the stabilizing effect of Ti in the meta-stable tetragonal ZrO2

starting from 669 °C, and subsequently triggering the phase

transformation. Additionally, structural analysis of pXRD data reveals

internal stresses within the crystal lattice, showing expansion of

tetragonal ZrO2 along the c-axis and distortions in the basal plane in both tetragonal and monoclinic ZrO2.

Organisation(s)
Department of Mineralogy and Crystallography
External organisation(s)
Imerys Technology Center Austria
Journal
Open Ceramics
Volume
22
Pages
1-8
No. of pages
8
ISSN
2666-5395
DOI
https://doi.org/10.1016/j.oceram.2025.100798
Publication date
06-2025
Peer reviewed
Yes
Austrian Fields of Science 2012
105116 Mineralogy, 105113 Crystallography
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/019f3d1e-d7c8-4f67-a493-6e1fa46cb010