Modelling Hydrogen Embrittlement using Density Functional Theory: A theoretical approach to understanding environmentally assisted cracking in 7xxx series aluminium alloys

Benjamin T. Wilson, Joseph D. Robson, Christopher P. Race, P. Jarry, J.-C. Ehrström, C. Sigli, F. De Geuser, A. Deschamps, L. Salvo, G. Salloum-Abou-Jaoude
2020 MATEC Web of Conferences  
The effects of H segregation to a Σ11 symmetric tilt Al grain boundary are investigated using atomistic simulations, as part of a wider study on cracking in 7xxx series alloys. Density functional theory based simulations of uniaxial straining of grain boundaries containing 11 different concentrations of H were performed under the cohesive zone fracture mechanics framework. The theoretical strength of grain boundaries is shown to be supressed by H segregation, and the cause of this is attributed
more » ... this is attributed to the prevention of the formation of Al ligaments across grain boundaries. Segregated concentrations of relevant alloying elements (Zn, Mg, and Cu) show minimal impact on the H embrittlement process investigated, namely H enhanced decohesion (HEDE). Further modelling, of H transport and grain boundary precipitates, is required to confirm the validity of the HEDE mechanism in the case of 7xxx alloys.
doi:10.1051/matecconf/202032604006 fatcat:wr2m6saogje2pglt6xifyuhha4