Local Stress and its Effects on Metastable Tetragonal Phase in ZrO2 Film on Zr Alloys

Abstract

An in-depth understanding of the phase stability in ZrO₂ film is very important for improving the corrosion resistance of zirconium alloys. ZrO₂ film formed on the zirconium alloys was characterized by grazing incidence X-ray diffraction. It is shown that there exist the regions of stress concentration in ZrO₂ film. In addition to the macroscopic compressive stress and the grain size, the local stress also plays important role in the transformation from the tetragonal to the monoclinic phase. The correlation of the macroscopic compressive stress, the grain size and the local stress was analyzed qualitatively from a thermodynamic viewpoint.