Residual stresses in alumina–zirconia laminates

• Published in: Journal of the European Ceramic Society Vol. 19; no. 13; pp. 2511 - 2517
• Main Authors: Green, David J., Cai, Peter Z., Messing, Gary L.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01-01-1999; Elsevier
• Subjects: Al 2O 3; Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Exact sciences and technology; laminates; residual stresses; Structural ceramics; Technical ceramics; thermal expansion; ZrO 2; ZrO 2; thermal expansion; laminates; Al 2O 3; residual stresses; Cerium Oxides; Densification; Stratified material; Mechanical properties; Stabilized zirconia; Experimental study; Indentation; Oxide ceramics; Composite material; Structural ceramic; Thermal properties; Thermal expansion; Sintering; Manufacturing; Alumina; Residual stress
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(99)00103-X

Significant residual stresses can arise in hybrid ceramic laminates during the densification and cooling processing cycles. The densification stresses in alumina–zirconia laminates were calculated assuming the layers to be linear viscous with data obtained by cyclic loading dilatometry. These stresses placed the zirconia layers in biaxial tension and even at 1
MPa or less, they were sufficient to cause a type of linear cavitation damage. The methodology was also applied to asymmetric laminates, successfully predicting their observed curling behaviour. Thermal expansion mismatch stresses arise during cooling, again placing the zirconia layers in residual biaxial tension and leading to the formation of transverse (channelling) cracks. The stresses were calculated using both elastic and viscoelastic formulations and were confirmed with indentation measurements. Additions of alumina to the zirconia layers were effective in reducing both sources of residual stress and allowed crack formation during processing to be avoided. Residual stresses were also shown to improve mechanical performance.