Wetting and corrosion of yttria stabilized zirconia by molten slags

We present first results of a study dealing with the corrosion of yttria stabilized zirconia ceramics by molten slags. Good wetting of a typical metallurgical slag as a pre-requisite for an effective chemical interaction of melt and zirconia was found. Both the dissolution of Zirconia and the leaching of the stabilizing agent into the molten slag are observed corrosion mechanisms. The latter induces a phase transformation from tetragonal or cubic zirconia into the monoclinic modification. The transformation with its increase in volume by app. 5% induces cracks. Those act to give new pathways for the corrosive media, accelerating corrosion. Crucibles from Y-PSZ have been used as samples in experiments with various slags. We also demonstrate the use of cathodoluminescence microscopy as a powerful mapping tool for zirconia phase differentiation which was verified by Raman and XRD measurements.