Sintering factors for a dry-milled silicon nitride-yttria-alumina composition

Of the paths leading to strong and tough silicon nitride (Si{sub 3}N{sub 4}) ceramics, those beginning with Si{sub 3}N{sub 4} powders have the advantage of short sintering times and potential for high purity. Problems with this route have been with the limited availability of quality powders that would permit reproducible fabrication at a reasonable cost. In this paper, the authors describe their work tailoring a pressureless sintering cycle to a high-cation-purity commercial powder. This work is intended to form a base line for testing low-carbon powders under development.