Neutron Imaging of distribution of hydrogen in electrochemically charged high entropy alloys

Abstract
Hydrogen is heralded as the key fuel for a ‘net zero’ future. The production, containment, and transportation of hydrogen is crucial for achieving the potential it offers. The ramifications of hydrogen interacting with metals and causing degradation have been a subject of intense research since the late 19th century. Among these topics, Hydrogen Embrittlement (HE) stands out as a widely studied and discussed phenomenon. HE is marked by the deterioration of mechanical properties, specifically the strength and ductility of the material, ultimately culminating in the brittle failure of structural components. In situations where hydrogen is present and can cause damage to materials a notable contender that has gained significant attention in withstanding HE is high entropy alloys (HEA). To fully understand the mechanism of hydrogen embrittlement in HEA and to improve the materials resistance towards HE, it is required to have a deeper understanding of the ingress of hydrogen into the metals, the transport of hydrogen, the interaction of hydrogen with defects in the crystal lattice. A thermal dependent hydrogen diffusion study proposed here uses a neutron radiographic technique to visualize diffusible hydrogen in electrochemically charged Al(0.1)HEA, and quantify the concentration and diffusivity of hydrogen in these alloys.