3D mapping of dislocation structures upon tensile deformation in (111)-oriented single-crystal nickel exposed to hydrogen environment

Understanding the hydrogen embrittlement (HE) in advanced structural metals is essential for future infrastructures in hydrogen-based energy industries. HE has been long recognized in metals, but it is still not fully understood because H is related to multiple embrittlement phenomena, e.g., from the activation of plastic flow (i.e., dislocation-H interaction) to crack propagation. The change in dislocation behaviors under H influence alters the deformation behavior of metals. Therefore, a systematic characterization of the formation and evolution of dislocation patterns exposed to H environment plays a salient role in understanding HE mechanisms. Thus, this experiment aims to investigate the 3D dislocation structures in single-crystal nickel upon tensile deformation exposed to H environment. Here, we propose to employ ex-situ synchrotron dark-field X-ray microscopy to quantitatively map the strain field of dislocations and to reveal the evolution of the dislocation patterns in 3D.