The interaction of H with planar defects (free surfaces, stacking faults) in α-Zr–H solid solutions was studied by using ab initio calculations which were based upon density functional theory. It was found that a high level of H greatly lowered the surface excess energies, but had little effect upon critical cleavage stresses; contrary to the usual models that correlated these quantities. The H significantly reduced the stacking fault excess energies; thus tending to enhance planar slip and hinder cross-slip. This was in agreement with the predictions of the H-enhanced localized plasticity model.

Atomic-Scale ab initio Study of the Zr–H System - II. Interaction of H with Plane Defects and Mechanical Properties. C.Domain, R.Besson, A.Legris: Acta Materialia, 2004, 52[6], 1495-502