Fugitive liquid phase densification of silicon nitride

摘要

Dense silicon nitride bodies are fabricated using conventional hot-pressing techniques using cerium oxide as a densification aid. The bodies are then further treated in a flowing inert atmosphere at a temperature of from 1400 DEG -1600 DEG C. for from several hours to 48 hours to remove all or substantially all of the densification aid from grain boundaries. Silicon nitride bodies so treated exhibit superior elevated temperature slow crack growth resistance and strength properties and are suitable for use as structural components in high temperature environments such as jet and internal combustion engines, rockets, atomic power generation, and the like.