MICROSTRUCTURE OF COMPOSITES [CE-TZP] - [AL2O3] MODIFIED BY Yb +3 AND Ca +2

Scanning electron microscope and atomic force microscope were used to study the microstructure of the modified nanocomposites produced from Ceria-stabilized ZrO2/Al2O3 ([Ce-TZP]-[Al2O3]) nano-powder blend with/without Ca+2- and Yb+3- modifiers. The presence of Me+2- and Me+3- ions determines the various processes of the phase formation of metastable tetragonal zirconia and thus affects the changes in the composition and size of the grains. The data on the qualitative phase composition, the crystallization degree of the powder and crystal lattice parameters of tetragonal ZrO2 solid solutions were obtained. The microstructure of all composites designates two types of the grains: one corresponds to alpha-Al2O3- phase with habit close to hexagonal one and ZrO2 grains with a soft smooth shape. It was found that the composite modified by Ca+2 contains also elongated prismatic grains. The composition analysis of these grains, given by energy dispersive spectrometry, detects the presence of elements Al, Ca and Ce in amounts close to the compound of CaCeAl3O7.