| Abstract |
| The oxidation characteristics with orientation of an unalloyed Zr were investigated. From the Zr crystal bar, the specimen representing a single crystal was prepared to be coarse enough to have its grain be 4×4×1 ㎣ in size. After identifying the crystallographic orientations and planes by XRD, the samples were cut out in such a way as the cutting planes could correspond to the desired crystallographic planes. Oxidation tests were carried out in water at 360℃. The oxidation rate of the (1120) prismatic plane was faster than that of the (0002) basal plane. The analysis of oxide using the synchrotron XRD revealed that the zirconia grown at the basal plane had the preferred (200) plane in mono-ZrO_2, while the zirconia at the prismatic plane grew at both the (200) and (002) planes of mono-ZrO_2. In addition, the oxide layer that had formed at the basal plane having only one preferred growth plane exhibited a high fraction of columnar oxide and a relatively wide range of protective barrier layer. These results mean that the characteristics of the preferred planes of mono-ZrO_2 play an important role on the oxidation rate of Zr single crystal. |
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| Key Words |
| Zr, Oxidation, Oxide, Basal plane, Prism plane, Synchrotron X-ray, mono-ZrO2 |
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