Molecular Dynamics Simulation and Experimental Proof of Hydrogen-enhanced Dislocation Emission in Nickel

A quasi three dimensions molecular dynamic method was used to simulate the effect of hydrogen on dislocation emission and crack propagation in nickel. In situ observation in a transmission electron microscope (TEM) was used to confirm the simulation results. The simulation result indicated that hydrogen solubilized in nickel decreased the critical stress intensity for the dislocation emission, , hydrogen enhanced dislocation emission. In situ observation in TEM showed that hydrogen enhanced dislocation emission and motion before the initiation of hydrogen-induced crack.