Fundamentals of hydrogen in structural metals at the atomic scale
H is an element that plays an important role in the production and efficient usage of energy as it significantly influences the way we produce and consume energy: In high-strength materials, the usability and service life is limited by H induced failure. These materials are key in transport systems, wind power and H storage. Despite the enormous economic significance, little is known fundamentally about the underlying damage mechanisms, which are inherently playing out on the atomic scale.

The PI’s team will use atom probe tomography, an atomic scale 3D microscopy method to systematically analyse the location and pathways of H in the microstructure and shed light on damage mechanisms in Fe and Ni based materials. This will include vacancies/clusters (0D), dislocations (1D), interfaces (2D) and second phased (3D). The approach will be combined with micro-mechanics to investigate the involvement of H in fracture behaviour. We will measure the amount of H at dislocations required for enhanced plasticity, in the plastic wake of a crack and at the crack tip. In production materials, we will determine the amount of H at identified traps after processing as well as penetration pathways into the material. Finally, we will clarify the contribution of H to a important problem for wind power generation: white-etching cracks.

These experiments are now made possible in a commercial atom probe by using 2H (D) charging combined with cryo specimen transfers to avoid H loss. In the project, the team will go a step further and build an atom probe with ultra-low H background to enable the direct detection of 1H, enabling analysis without tracers.

The resulting knowledge will greatly enhance our knowledge on the fundamentals of H in metals at the atomic scale. This will lead to increased predictability of failures, the rational design of H resistant high strength materials and protection measures and with it great cost savings especially in renewable energy generation and electromobility.