High-temperature deformation of Al₂O₃/Y-TZP particulate composites

Jue Wang ^a, Eric M. Taleff ^a,b, Desiderio Kovar ^a,b,*

^a Materials Science and Engineering Program, The University of Texas at Austin, Austin, TX 78712, USA
^b Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA

Received 10 January 2003; received in revised form 20 March 2003; accepted 21 March 2003

Abstract
Al₂O₃/Y-TZP particulate composites with compositions of between 20 and 80 vol.% Y-TZP were produced by tape casting, lamination, and sintering. The processing methods employed resulted in fine grain sizes with only small variations between the composites produced. The resulting particulate composites were tested in compression at a temperature of 1350°C over strain rates from 10^-5 to 3.16 x 10^-4 s. Microstructural changes during testing were minor. Stress exponents were measured to the range from approximately two to three, which are consistent with published data on similar materials from tensile experiments. Models of composite creep behavior are compared to the experimental data over the full range of compositions studied. A constrained isostrain model is found to provide better predictive capabilities than either an unconstrained model, an isostress model, or a rheological model.  Furthermore,the constrained isostrain model provides the most reasonable predictions for creep rates of 100% Al and 100% Y-TZP materials.

2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.