Citation
Pastor Caño, Jose Ignacio and Martin Sanz, Antonia and Molina Aldareguía, Jon M. and Llorca Martinez, Francisco Javier and Oliete Terraz, Patricia Beatriz and Larrea, Angel and Peña Torre, José Ignacio and Orera, V.M. and Arenal, Raúl
(2013).
Superplastic deformation of directionally solidified nanofibrillar Al2O3-Y3Al5O12-ZrO2 eutectics.
"Journal of the European Ceramic Society", v. 33
(n. 13-14);
pp. 2579-2586.
ISSN 0955-2219.
https://doi.org/10.1016/j.jeurceramsoc.2013.03.033.
Abstract
Nanofibrillar Al2O3–Y3Al5O12–ZrO2 eutectic rods were manufactured by directional solidification from the melt at high growth rates in an inert atmosphere using the laser-heated floating zone method. Under conditions of cooperative growth, the ternary eutectic presented a homogeneous microstructure, formed by bundles of single-crystal c-oriented Al2O3 and Y3Al5O12 (YAG) whiskers of ≈100 nm in width with smaller Y2O3-doped ZrO2 (YSZ) whiskers between them. Owing to the anisotropic fibrillar microstructure, Al2O3–YAG–YSZ ternary eutectics present high strength and toughness at ambient temperature while they exhibit superplastic behavior at 1600 K and above. Careful examination of the deformed samples by transmission electron microscopy did not show any evidence of dislocation activity and superplastic deformation was attributed to mass-transport by diffusion within the nanometric domains. This combination of high strength and toughness at ambient temperature together with the ability to support large deformations without failure above 1600 K is unique and shows a large potential to develop new structural materials for very high temperature structural applications.