DEVELOPMENT OF REFRACTORY CERAMICS THAT CAN BE PROCESSED AT TEMPERATURES CONSIDERABLY LOWER THAN THEIR MAXIMUN USE TEMPERATURE

A study was initiated on the densification mechanisms of high alumina bodies that utilized the presintering process in their fabrication. Evidence is presented that the initial or presintering fire promotes the formation of phases that act as potent fluxes for the alumina in the final fire. A program is set up to determine the nature of the phases formed in the initial firing. An initial attempt to utilize the devitrification mechanisms for producing a high quality refractory composition is reported. A 92 alumina composition was flame sprayed resulting in a glass that contains some alumina crystals. Differential thermal analysis and X-ray analysis indicated that a devitrifiable glass was produced.