Zirconium oxide film formation on zircaloy by water corrosion

The objective of this work is to study the morphological, micro-chemical an d micro-mechanical characteristics of the thick zirconium oxide layer forme d on a zircaloy-4 clad after a standard water corrosion test (ASTM G2-67). The oxidized samples were analyzed by Raman and Auger spectroscopy, SEM-EDS , XRD and the mechanical properties of the oxide film were evaluated using the Vickers microindentation method. The results reveal the formation of a textured oxide layer constituted of m-ZrO2 crystals oriented primarily in t he direction perpendicular to the (002) crystallographic plane. In addition , a not previously reported thin zirconium carbide film on the top surface of the oxide layer was detected by SEM-EDS, XRD and Auger spectroscopy. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. ALI rights reserved.