Siyu Huang
PhD Student - University of Sydney
Project Title: Uncovering the Distribution of Hydrogen in Zirconium Alloys (supervisors: Prof. Julie Cairney, Dr Ingrid McCarroll, Dr Patrick Burr)
Degradation of zirconium alloys in the nuclear industry occurs as a result of hydrogen ingress. However, despite decades of research towards understanding how hydrogen interacts with zirconium alloys, there is still limited atomic-scale information about hydrogen interaction with microstructural features. The objective of Siyu Huang’s project is to discover how the hydrogen is distributed in the material before it forms hydrides, with specific reference to grain boundaries, dislocations and second phase particles (SPPs).
Previous work by Jones et al. showed evidence of deuterium co-location with Zr(Fe,Cr)2 SPPs, and highlighted that even state-of-the-art nano-SIMS lacks the spatial resolution to determine whether deuterium lies inside or around the SPPs, due to the high mobility of hydrogen isotopes. Here we will investigate hydrogen distribution in different Zr alloys using advanced microscopy, including state-of-the-art cryo atom probe tomography (cryo-APT) and tailored deuterium-charging protocols.
The outcome of the project will be a better scientific understanding of the hydrogen distribution in zirconium alloys, providing insight into the hydrogen distribution and migration within the Zr matrix. Such findings will help build a mechanistic understanding of hydrogen pick-up, hydrogen embrittlement and delayed hydride cracking of Zr alloys, and inform the design of future Zr alloys.