Nitrogen‐Containing Tetragonal Zirconia

Abstract

The present paper gives evidence for the replacement of oxygen by nitrogen when partially stabilized tetragonal zirconia is reacted with nitrogen above 1400°C to give a tetragonal product but in the t ′ (nontransformable) form. No transformation toughening is therefore expected from this nitrogencontaining tetragonal phase. These results may explain why less‐effective toughening is obtained in nitrogen‐containing ceramic‐based composites than in equivalent zirconia‐alumina and other oxide‐based systems.