Orientation of platelet reinforcements in ceramic matrix composites produced by pressure filtration

Alumina-platelet (Al2O3(PL)) reinforced Y-TZP composites were produced by pressure filtration of dispersed suspensions. The platelet texture within the consolidated compacts was evaluated by SEM and neutron diffraction to assess the effects of pressing rate, constant rate versus constant displacement filtration, and die loading on platelet orientation. A weak texture condition, termed 'eddy texturing' due to an apparent dependence on fluid flow during filtration, dominated platelet orientation. The resulting composites possessed an anisotropic fracture toughness between the compact surfaces and the bulk material. Die loading procedure and Al2O3(PL) agglomerate removal strongly influenced the density and flexural strength of the sintered composites. 9 refs