We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Laminar Ceramics Utilizing the Zirconia Tetragonal-to-Monoclinic Phase Transformation to Obtain a Threshold Strength.
- Authors
Pontin, Michael G.; Rao, Masa P.; Sanchez-Herencia, Antonio J.; Lange, Fred F.
- Abstract
Ceramic laminates have been fabricated with thin layers, containing a mixture of unstabilized zirconia (MZ-ZrO[sub 2]) and alumina (Al[sub 2]O[sub 3]), sandwiched between thicker layers of alumina that contain a small fraction of Y[sub 2]O[sub 3]-stabilized tetragonal ZrO[sub 2] to inhibit grain growth. The MZ-ZrO[sub 2] undergoes a tetragonal-to-monoclinic phase transformation during cooling to produce biaxial compressive stresses in the thin layers. Cracks that extend within the thicker alumina layers can be arrested by the compressive layers to produce a threshold strength, i.e., a strength below which the probability of failure is zero. Laminates composed of Al[sub 2]O[sub 3] layers 315 ± 15 µm thick and Al[sub 2]O[sub 3]/MZ-ZrO[sub 2] layers 29 ± 3 µm thick exhibit a threshold strength of 507 ± 36 MPa, regardless of the MZZrO[sub 2] content, for volume fractions ≥0.35. These results, piezospectroscopic stress measurements, and microstructural observations suggest that microcracking produced during the transformation reduces the magnitude of the compressive stresses achieved, which in turn limits the magnitude of the threshold strength.
- Subjects
CERAMIC materials; ZIRCONIUM oxide; ALUMINUM oxide
- Publication
Journal of the American Ceramic Society, 2002, Vol 85, Issue 12, p3041
- ISSN
0002-7820
- Publication type
Article
- DOI
10.1111/j.1151-2916.2002.tb00576.x