Zirconium nitride precipitation in nominally pure yttria-stabilized zirconia

Nominally pure yttria-stabilized zirconia alloys are shown to contain unexpectedly large amounts of dissolved nitrogen. Its presence in the lattice was detected through the observation of large precipitates in alloys with three different concentrations of yttria deformed in compression in argon in the temperature range 1600 degrees-1800 degrees C. Electron diffraction, EDS and PEELS analyses, and Moire imaging mere used to identify the precipitates as ZrN. The possible origin of the nitrogen, its likely effects on properties, and the role of annealing atmosphere are briefly discussed.