Transformations and cracks in zirconia films leading to oxidation of zircaloy

Abstract

This work was aimed to identify the root cause of breakaway oxidation of Zircaloy and the origin of Zircaloy cladding failure. Circumferential compressive stress is highly promoted by tetragonal to monoclinic phase transition. Therefore, this transformation is rather beneficial as it will increase the time to attain critical oxide thickness (at which the stress changes from compressive to tensile), and thus retards breakaway oxidation.