INFILTRATION KINETICS STUDY AND PROCESSING OF LAYERED GRADED Al2O3-ZrO2 COMPOSITE

Abstract

INFILTRATION KINETICS STUDY AND PROCESSING OF LAYERED GRADED Al₂O₃-ZrO₂ COMPOSITE. Layered graded Al₂O₃-ZrO₂ composite was successfully synthesised through infiltration of porous Al₂O₃ preform with a solution containing ZrOC_l2.8H₂O. The infiltration rate of liquid into porous Al₂O₃ preformhad also been investigated. It was found that the infiltration rate equation proposed by Washburn is most suitable for describing the effects of preform sintering temperature, viscosity and multiple infiltrations on the infiltration behaviour, whereas the influence of applied pressure is consistent with the model proposed by Darcy, where the applied pressure enhances the infiltration rate behaviour. Depth profilling of layered graded Al₂O₃-ZrO₂ composite was characterised by x-ray diffraction, the result shows that the concentration of ZrO₂ decreased with depth, while that of Al₂O₃ increased with depth.