|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals and Materials 2021
||APT Composition Profiling for Accurate Evaluation of Diffusion Coefficients in the Zr-Ta Binary System
||Yaqiao Wu, Megha Dubey, Shujuan Wang, Chuangye Wang, Ji-Cheng Zhao
|On-Site Speaker (Planned)
The diffusion coefficients of the Zr–Ta binary system are valuable information for the design and lifetime prediction of accident-tolerant fuel (ATF). The extremely steep concentration gradients on the Ta-rich side of the Zr/Ta diffusion couple require high spatial resolution composition profiling beyond the capabilities of electron probe microanalysis (EPMA). A novel approach is demonstrated to employ atom probe tomography (APT) to obtain near-atomic resolution composition profiles cross the steep gradient locations from stacked needle samples extracted using focused ion beam (FIB). The combined quantitative results of the APT data from the steep gradient region with the EPMA data from the shallow gradient region enable accurate evaluation of the diffusion coefficients across the entire composition range of the Zr-Ta binary system for the first time. Such an approach also enables evaluation of extremely low diffusion coefficients (< 10-18 m2/s) without resorting to the laborious isotope experiments.