Corrosion and recession behavior of zircon in water vapor environment at high temperature

A corrosion test in static state water vapor environment and a recession test in high velocity steam jet environment for zircon bulk were performed at 1300 °C. The trace of the water vapor corrosion could be recognized on the grain surfaces and at the grain boundaries for the sample after the static state corrosion test. Sand ripple like morphology was generated on the grain surfaces and etch pits with less than 0.1 μm size were formed at the grain boundaries. A porous structure was formed on the bulk surface of the sample after the steam jet test. A glassy phase enriched with silica could be recognized on the surface of the sample after the test. Cracks were induced on the bulk surface during the test. The zircon phase at the bulk surface decomposed into monoclinic zirconia phase and the fraction of silica component at the bulk surface decreased by the steam jet test. The monoclinic zirconia phase was observed to re-generate and grow on the bulk surface.