Evolution of the microstructure and oxidation resistance in co-sputtered Zr-Y-N coatings

- Significant improvement of oxidation resistance was obtained by Y addition.
- Phase stabilization of t-ZrO2 was achieved by Y addition.
- The outward diffusion of Y ions during oxidation was observed.
- GAXRD and TEM microstructural studies on the Zr-Y-N coatings.

This study investigates the influence of Y addition to the microstructure and oxidation resistance of ZrN coating. Zr-Y-N coatings with a 0-5.8 at.% Y addition were fabricated by reactive co-sputtering in an Ar-N2 atmosphere. The results indicate that solid solution-type Zr-Y-N coatings show a columnar structure with a strong (1 1 1) preferred orientation. The grain size decreases from 76 to 21 nm with an increase in the amount of Y from 0 to 5.8 at.%. The oxidation results demonstrate that the most beneficial addition of Y to improve the oxidation resistance of ZrN coating is 1.0 at.%. An excessive addition of Y produces detrimental effects. Cracking in the oxide scale and oxygen inward diffusion through the scale have been identified as the primary reasons for the loss of oxidation resistance.