Zbigniew Pedzich

By Zbigniew Pędzich

Part of the book: Tungsten Carbide

By Zbigniew Pędzich

The usage of advanced ceramic materials in the applications endangered by intensive cavitation could limit erosion phenomena distinctly. In the presented work, cavitation erosion resistance of ceramics the most commonly used in structural applications was investigated. These materials were oxide ones: α-alumina, yttria-stabilized tetragonal zirconia, and two composites selected from alumina/zirconia system. Otherwise, the most promising non-oxide materials were examined: silicon carbide and silicon nitride. Results showed significant difference in cavitation wear mechanisms of all investigated materials. Degradation of alumina proceeded from the beginning on the relatively large surfaces, and the dominant mechanism of destruction was removing of the whole grains. Degradation of zirconia also consisted on removing of the whole grains, but this process proceeded locally, along ribbon-like paths. Cavitation wear of composites was strongly influenced by the residual stresses caused by the thermal expansion coefficient mismatch. Cavitation erosion of silicon nitride proceeded by selective degradation of glassy phase present on grain boundaries. On the contrary, silicon carbide degradation proceeded by large grain fragmentation process.

Part of the book: Cavitation