Microstructure and Mechanical Properties of Ce-Y-TZP Ceramic Composites for Ceramic Plunger and Ball Valve

摘要

Microstructure and mechanical properties of CeO{sub}2/Y{sub}2O{sub}3/ZrO{sub}2 ceramics were investigated using ultrafine CeO{sub}2/Y{sub}2O{sub}3/ZrO{sub}2 powder as the starting material. The structures of CeO{sub}2/Y{sub}2O{sub}3/ZrO{sub}2 containing 8～12mol% CeO{sub}2 were composed of tetragonal phases. They exhibited an extremely high bending strength (950 MPa) and fracture toughness (12MPa·m{sup}(1/2)). The structural details of CeO{sub}2/Y{sub}2O{sub}3/ZrO{sub}2 were studied by TEM, SEM and XRD. The effects of the structure on mechanical properties were discussed. Plungers and ball valves by the CeO{sub}2/Y{sub}2O{sub}3/ZrO{sub}2 ceramics have higher wear resistance and corrosion resistance than metal. Their service life is about 6 ～ 10 fold more than that of metal.