Characteristics of the oxides and suboxides on Zr-1.0Nb-0.01Cu isothermally oxidised in steam at 650–1200 ℃

The texture of monoclinic ZrO2, grain morphology and crystal structure of suboxides ZrO and Zr3O, and orientation relationships near the ZrO2/α-Zr(O) interface of Zr-1.0 Nb-0.01Cu isothermally oxidised in steam at 650–1200 ℃ were investigated. The findings show that the morphology and distribution of the suboxide phase ZrO vary significantly with temperature, and both ZrO and Zr3O grains have hexagonal structures. The number density of orientation relationships of different phases near the interface decreases as the oxidation temperature increases. The characteristics of the oxides and suboxides can provide some insights into the understanding of the high-temperature oxidation and cooling processes.