Indentation Damage and Residual Stress Field in Alumina-Y2O3-Stabilized Zirconia Composites

• Published in: Journal of the American Ceramic Society Vol. 92; no. 1; pp. 152 - 160
• Main Authors: Baudín, Carmen, Gurauskis, Jonas, Sánchez-Herencia, Antonio Javier, Orera, Victor M.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.01.2009
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1551-2916.2008.02813.x

Fracture features, residual stresses, and zirconia transformation are studied in indentation strength specimens of alumina‐Y2O3‐stabilized zirconia (3% mol of Y2O3, 3YTZP) ceramics in order to analyze the extension of the indentation damage in the bulk of the specimens. Two compositions, 5 vol% 3YTZP (A5) and 40 vol% 3YTZP (A40), have been prepared by stacking tape‐casted tapes and sintering. After indentation with loads ranging from 50 to 300 N, samples were fractured in four‐point bending and the fracture surfaces were characterized by scanning electron microscopy. Raman and piezospectroscopic techniques were used to determine the monoclinic zirconia fraction and the residual stresses through the fracture surfaces. In the A5 composition, the indentation damage morphology was clearly half‐penny, whereas the A40 composition presented Palmqvist crack formation. Zirconia transformation was only observed in the plastically deformed zones underneath the imprints whereas there were significant residual compressive stresses outside the plastic zones due to the indentation damage. The intensity of this residual compressive field was dependent on the level of zirconia transformation due to indentation damage because zirconia transformation induced tensile stress fields superimposed on the compressive stresses.