Interaction of SiC with Al2O3−(t + m)ZrO2(Y2O3) Oxide Composition.

We employed contact alloying in the range 1000–1860°С to study the reaction specifics between SiC and Al₂O₃−(t + m)ZrO₂(Y₂O₃) oxide composition. Real-time experiments with photographic recording of the changing size and shape of the Al₂O₃−(t + m)ZrO₂(Y₂O₃) sample on a SiC ceramic substrate showed that Al₂O₃−(t + m)ZrO₂(Y₂O₃) compositions react with the silicon carbide substrate in the range 1720–1860°С to melt and penetrate into (impregnate) the substrate. X-ray powder diffraction patterns were measured for samples taken from the contact area of the oxide composition with SiC directly on the substrate and in a chipped-off <1-mm-deep near-surface layer. ZrС, Al₂Y₄O₉, and Al_3.21Si_0.47 were formed in the contact area via redox reactions involving oxide melt, in addition to 6H-SiC, Si and Al₂O₃, t-ZrO₂ phases, which are the initial components of the substrate and oxide composition, respectively. [ABSTRACT FROM AUTHOR]