Fabrication and Characterization of Mullite Reinforced CeO2 Added ZrO2 Ceramics

In this study, mullite (3Al2O3.2SiO2) and 10 mol % ceria added zirconia (10 mol % CeO2 - 90 mol % ZrO2) ceramic powders were synthesized by conventional ceramic production processing route. The mixtures were prepared by mechanical alloying method in acetone environment with zirconia ball mill. Mullite and ceria added zirconia ceramic powders were synthesized in air at 1600 oC for 3 h and 1300 oC for 2 h, respectively. Then, the ceramic phases formed were made ready to form ceramic - ceramic composites by crushing, grinding and sieving processes. Then 0 and 10% by weight mullite added ceria doped zirconia mixtures were prepared by powder metallurgy method. The prepared mixtures were wet milled with zirconia ball mill for 24 h and sieved. After drying, the powders were compacted by uniaxial pressing at 200 MPa. The green compacts were sintered at 1500-1600 oC for 1-5 h in air conditions using a heating rate of 5 oC min-1 in a high temperature furnace. Then, microstructure (SEM), phase analysis (XRD), mechanical (hardness, 3-point bending and wear) and physical properties (% shrinkage, water absorption, porosity and density) tests were performed on the ceramic composites. In this study, whether there is a phase change in the ZrO2 - CeO2 mixture at high sintering temperatures and the effect of mullite additive on the properties of this mixture was investigated.