Microstructural investigation of Zirconium alloys subjected to oxygen ions irradiations

Abstract

In this study, samples of zircaloy-2 were irradiated with oxygen ion beam (O⁵⁺ ions with 116 MeV energy) to fluence varying from 10¹³ to 10¹⁵ ion/cm². The irradiated samples were observed under a transmission electron microscope to identify the irradiation-induced defects and phase transformations. Microstructural investigations on these samples showed the presence of interstitial defects and ZrO₂ precipitates in the α (hcp) matrix. The alignment of defects appeared to facilitate the formation of the ZrO₂ phase in the irradiated samples. Orientation relationship between the oxide and the matrix phase was determined and a possible mechanism for the formation of the ZrO₂ phase based on the entrapment of the oxygen ions has been proposed.

Keywords:

• metals
• TEM
• radiation