2008 Volume 49 Issue 2 Pages 339-344
In this paper development of novel ceramic microstructures by the fibrous monolithic process were reported. Attempts were made to tailor the microstructures of these advanced ceramics by introducing fibrous or layered morphology to incorporate multi-toughening mechanisms. Fabrication and characterization of four different kinds of microstructure, termed in this manuscript as network type, double network type, functional gradient microchanneled and functional gradient microchanneled double network type microstructure, were reported. In network and double network type microstructure developments the two phase Al2O3-(m-ZrO2) cores were embedded within network-type frames of t-ZrO2 single phase. In the double network type microstructure, an additional thicker network-type t-ZrO2 enclosure surrounded a network-type micro-assembly. Unidirectionally aligned continuously porous HAp-Al2O3-ZrO2 tri-phase ceramic composites were fabricated by the same method to incorporated functional gradient for improved functionality and depress processing defects. The microstructure had three layers of HAp/HAp-(Al2O3-(m-ZrO2))/Al2O3-(t-ZrO2) around the continuous pore with compositional gradient. In the functionally gradient micro-channeled HAp/HAp-(Al2O3-(m-ZrO2))/Al2O3-(t-ZrO2) composites, the size and distribution of micro-channels were homogeneously controlled. Detailed morphological analyses of the resulting microstructures were studied.