Abstract
Zirconium (Zr) alloys, such as Zircaloy-4 (Zy-4), are widely used for cladding in nuclear applications. Zy-4 consists of an α-Zr matrix and various second phase particles (SPPs). These precipitates play a crucial role in determining the overall alloy performance, so understanding their composition is essential for the development of these advanced nuclear materials. We have studied two SPPs in this alloy, Zr(Fe,Cr)2 and Zr2(Si,Fe), using site-specific focused ion-beam lift-out and atom probe tomography, and measured the composition and distribution of alloying elements at the precipitate/matrix interface. Residual Cu and B segregated to the interfaces of both precipitates and the matrix while Sn only segregated to the interface in the Zr2(Fe,Si) precipitate. Hydrogen segregation was observed at the interface of Zr(Fe,Cr)2 and the matrix.