SEDL / STP / STP551-EB / STP32133S

Characterization of Zircaloy Oxidation Films

Urquhart, AW
Metallurgists, Research and Development Center, General Electric Co., Schenectady, N. Y.

Vermilyea, DA
Metallurgists, Research and Development Center, General Electric Co., Schenectady, N. Y.

Pages: 15    Published: Jan 1974

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Abstract

Capillary condensation measurements of the pore size distribution, transmission electron microscopy using ion micromilling to thin the oxide, and a–c impedance measurements in aqueous electrolytes have been used to obtain information on the porosity and grain structure of post-transition oxide films grown in oxygen at 600°C on Zircaloy-2. The results indicate that the films contain important amounts of very fine porosity which is interconnected to the exterior surface. The impedance measurements suggest the presence of a nonporous sublayer near the oxide-metal interface. The oxide has a fine columnar grain structure at some distance from the metal and an extremely fine structure or substructure near the oxide-metal interface.