MICROSTRUCTURAL EVALUATION OF ZIRCONIA DISPERSED ALUMINA COMPOSITES

Abstract

An extensive scanning electron microscopy and image analysis is carried out on Alumina and Zirconia Dispersed Alumina (ZDA) ceramic composites containing controlled amounts of tetragonal, monoclinic, and cubic zirconia phases. ZDA powders are prepared through a partial chemical route and sintered at 1600°C for 2 h in air. Zirconia nanoparticles reduce alumina matrix grain size by more than six times. Intricate relationships are revealed between zirconia allotropes and different microstructural parameters such as matrix grain size and its distribution, abnormal grain growth, zirconia particle size distribution, pore size, fracture mode, interparticle distance, etc.