Nitridation of Zirconia

ZrO 2 can be nitrided partially by nitrogen at temperatures >1400°C. It is possible to describe all the synthesized phases with the general formula ZrO 2‐2χ N 4χ/3 (system ZrO 2 ‐Zr 3 N 4 ). Parameters–such as nitridation time, temperature, nitrogen pressure, and particle size–have a strong effect on the amount of incorporated nitrogen. Variation of these parameters allows the synthesis of Zr‐O‐N ceramics within a wide range of possible compositions. ZrO 2‐2χ cN4 χ/3 phases synthesized by reaction of ZrO 2 with nitrogen show ordered anion vacancies (β‐type structures). β‐type phases are non‐transformable under mechanical stress at ambient temperature. Nitrogen‐containing ZrO 2 shows very poor oxidation resistance. At temperatures >600°C, stability is found only in the presence of an oxygen getter.