Hydrogen embrittlement of additively manufactured metallic materials

In the quest to achieve net zero emissions, there is a push for using hydrogen as a fuel in mobility and power generation applications. However, when hydrogen interacts with structural metallic components used in these applications, there is a risk of hydrogen-induced embrittlement in them. Additive manufacturing (AM) is an alternate manufacturing method for designing structural metallic components, which offers avenues for tailoring of microstructural features and formation of non-equilibrium phases that have a profound effect on their mechanical properties. Consequently, the interaction of hydrogen with AM fabricated alloys is expected to have a different effect on their structural integrity. This paper presents a comprehensive review of the physical processes and the fundamental scientific principles that govern the metallurgical structure and properties of alloys produced through different AM methods. It then discusses the detection of hydrogen and mechanisms of hydrogen embrittlement in different metallic alloys. Finally, the latest research on hydrogen embrittlement of additively manufactured metals and alloys is summarized.