Fabrication, Properties, and HIP Treatment of (Y, Ce)-TZP Ceramics Obtained from Fine Powders Prepared by a Hydrolysis Technique

Abstract

Fine powders with compositions 4mol% YO1.5-4mol% CeO2-ZrO2 (4Y, 4Ce), 2.5mol% YO1.5-4mol% CeO2-ZrO2, and 2.5mol% YO1.5-5.5mol%CeO2-ZrO2 were prepared by hydrolysis of ZrOCl2 solution. Using thus obtained powders, yttria- and ceria-doped tetragonal zirconia ceramics ((Y, Ce)-TZP) were fabricated by a normal sintering and a hot isostatic pressing (post-sin-tering hot isostatic pressing) and their bending strength, microstructure, and tetragonal-to-monoclinic phase transformation during low-temperature aging were studied. Mean values of the bending strength of (Y, Ce)-TZP fabricated by a normal sintering at 1500°C for 2h were 840MPa for (4Y, 4Ce)-TZP, 860MPa for (2.5Y, 5.5Ce)-TZP and 1000MPa for (2.5Y, 4Ce)-TZP. The grain size of (Y, Ce)-TZP was larger than that of 3Y-TZP. (4Y, 4Ce)-TZP and (2.5Y, 5.5Ce)-TZP showed improved thermal stability as compared with 3Y-TZP. The bending strength of (4Y, 4Ce)-TZP increased from 840MPa to 1100MPa by post-sintering HIP at 1500°C and 147MPa for 0.5h.