Simulation of the propagation of fissures in Zr with H in solution

We present atomistic studies of the deformation mechanisms that occur in the vertex of nano-fissures (up to 50 nm) during the fracture of Zr hcp at low temperatures, with H in diluted solution. We performed atomistic simulations of fractures in mode I on the basal plane of Zr, using a quasi-static method and semi-empirical embedded atom potentials (EAM). We analyzed the influence of H atoms placed in different positions near the fissure point on the energy involved in the fissure's propagation and the mechanisms of plasticity and phase transformations. We found that the fracture proceeds differently depending on the position and concentration of hydrogen atoms. In the absence of H macles appear and we found martensitic conversions of hcp to bcc near the fissure point. Low concentrations of H modify the aspect of the macle distributions and of the transformed zones and, in general, there is an increased ductility compared to the pure Zr