Comparative molecular dynamics study of fcc-Al hydrogen embrittlement

Abstract

A c c e p t e d M a n u s c r i p t • Bulk distributed hydrogen facilitates brittle intergranular fracture.• Vacancy distributed hydrogen facilitates void assisted locally plastic fracture.• Hydrogen containing systems yield reduced failure strains and tensile toughness.• Finite temperature and strain rate effects attributed to structural relaxation.• Hydrogen diffusivity depends on microstructure change during plastic deformation. AbstractHydrogen embrittlement studies using reactive molecular dynamics have been conducted for Al metal nanoslabs with oxidized surfaces. These have provided evidence for possible grain boundary decohesion and void formation related range of hydrogen embrittlement mechanisms at different loading conditions with different initial defect configurations. Particularly, the effect of initial vacancy concentration on hydrogen diffusivity and localization, as well as on the amount of plasticity and grain formation is estimated. The results indicate significant reduction in diffusivity due to vacancy concentration, as well as hydrogen embrittlement effect through increase in dislocation emission and increase in dislocation slip propagation rate.

Crack‐induced intergranular corrosion behavior of aerial aluminum alloy subjected to severe plastic deformation

“…Simultaneously, with the concentration of hydrogen ion increasing, hydrogen generates and enters into the crack tips, and then decreases the bonding strength of metal atoms, and eventually accelerates the propagation of SCC. [46] Hydrogen embrittlement is referenced many times as a cause of SCC, [47][48][49] and its effect can be influenced by the size of grain boundary precipitates, as the larger grain boundary precipitates contain a larger number of irreversible trapping sites that trap hydrogen, reducing the amount of hydrogen in solution. This prediction is in agreement with observation made by Michler et al [50] 5 | CONCLUSIONS In this study, to investigate intergranular corrosion behavior of cracked aerial aluminum alloy subjected to ECSEE, the observation for microstructure and induced-crack of the ECSEE extruded alloy was carried out.…”

Analysis of Hydrogen Embrittlement on Aluminum Alloys for Vehicle-Mounted Hydrogen Storage Tanks: A Review

“…The HE of aluminum alloy has become an important factor restricting its application and development [34]. Since the 1980s, the problem of HE has been a concern and studied by many scholars, based on which many theories have been proposed [35] to explain HE, such as the hydrogen-enhanced decohesion mechanism (HEDE) and the hydrogenenhanced local plasticity model (HELP).…”

Molecular Dynamics Simulation of Reinforcing Steel Corrosion when Subjected to Both Chloride Attack and Mechanical Loading

“…Molecular dynamics (MD) simulation is a powerful tool that provides the real-time evolution of molecular structures and has been applied in many fields [14]; examples include the hydrogen embrittlement of metal [15], the performance of corrosion inhibitors used in concrete [16,17], the transport properties of water in cement [18], and the moisture susceptibility of asphalt [19]. In MD simulation, atoms and molecules are allowed to interact for a period of time by approximations of known physics in order to explore the physicochemical properties of structures.…”