Mechanical properties up to 1900 K of Al2O3/Er3Al5O12/ZrO2 eutectic ceramics grown by the laser floating zone method

Directionally solidified Al2O3–Er3Al5O12–ZrO2 eutectic rods were processed using the laser floating zone method at growth rates of 25, 350and 750 mm/h to obtain microstructures with different domain size. The mechanical properties were investigated as a function of the processing rate. The hardness, 15.6 GPa, and the fracture toughness, 4 MPa m1/2, obtained from Vickers indentation at room temperature were practically independent of the size of the eutectic phases. However, the flexural strength increased as the domain size decreased, reaching outstanding strength values close to 3 GPa in the samples grown at 750 mm/h. A high retention of the flexural strength was observed up to 1500 K in the materials processed at 25 and 350 mm/h, while superplastic behaviour was observed at 1700 K in the eutectic rods solidified at the highest rate of 750 mm/

Mechanical properties up to 1900 K of Al2O3/Er3Al5O12/ZrO2 eutectic ceramics grown by the laser floating zone method

Directionally Solidified Eutectics: Selected Papers from DSEC IV.Directionally solidified Al2O3-Er3Al5O12-ZrO2 eutectic rods were processed using the laser floating zone method at growth rates of 25, 350 and 750mm/h to obtain microstructures with different domain size. The mechanical properties were investigated as a function of the processing rate. The hardness, ~15.6GPa, and the fracture toughness, ~4MPam1/2, obtained from Vickers indentation at room temperature were practically independent of the size of the eutectic phases. However, the flexural strength increased as the domain size decreased, reaching outstanding strength values close to 3GPa in the samples grown at 750mm/h. A high retention of the flexural strength was observed up to 1500K in the materials processed at 25 and 350mm/h, while superplastic behaviour was observed at 1700K in the eutectic rods solidified at the highest rate of 750mm/h. © 2013 Elsevier Ltd.This study was funded by the Ministry of Science and Innovation under project MAT 2009-13979. M.C. Mesa would like to thank the Gobierno de Aragón for a grant. Authors acknowledge the use of Servicio de Microscopia Electrónica (Servicios de Apoyo a la Investigación), Universidad de Zaragoza.Peer Reviewe