Effects of Y2O3 and ZrO2 on the Densification of Si3N4‐Zr(Y)O2 Composites

Abstract

The effects of ZrO2 and Y2O3 on the densification of hotpressed Si3N4‐Zr(Y)O2 composites have been studied. High density could not be obtained by the addition of pure or 3‐mol%‐Y2O3‐doped ZrO2 in this composite; however, nearly full density (>97%) could be obtained in Si3N4 using 6‐ and 8‐mol%‐Y2O3‐doped ZrO2. It is concluded that Y2O3 diffusing out from the added Zr(Y)O2 promoted the densification and that ZrO2 also had some role in the formation of an oxynitride glass.