Strain-induced metal-hydrogen interactions across the first transition series -- An \textit{ab initio} study of hydrogen embrittlement

The attractive interaction between hydrogen and distorted regions of the host matrix underlies all the currently discussed mechanisms of hydrogen-induced embrittlement of metals, such as hydrogen enhanced local plasticity (HELP), hydrogen enhanced decohesion (HEDE) and stress-induced hydride formation. In this study we investigate these interactions systematically by determining heat of solutions, H-H binding energies within the metal matrix, as well as phase diagrams as a function of the lattice strain and the H chemical potential across the first transition series (3d elements) using Density Functional Theory (DFT) calculations. The results will be interpreted in terms of the likely embrittlement mechanisms of these metals.