Processtng and Mechanical Properties of Silicon Nitride Formed by Robocasting Aqueous Slurries

Abstract

Robocasting is a new fieeform fabrication technique for dense ceramics. It uses robotics to control deposition of ceramic slurries through an orifice. The optimization of concentrated aqueous Si3N4 slurry properties to achieve high green density robocast bodies and subsequent high sintered densities was investigated. The effects of pH, electrolyte, additives and solids loading on the dispersion and rheological properties of Si3N4 slurries were determined. The mechanical behavior of sintered robocast bars was determined and compared to conventionally produced silicon nitride ceramics.