Modeling of solute hydrogen effect on various planar fault energies

Abstract The strength, plasticity and ductility-brittleness transition of metals are often governed by various planar fault energies. Due to interactions between the solute hydrogen (H) and the planar faults, the planar fault energies are heavily affected in the H-charged metals. An accurate quantitative description of the H-affected planar fault energies is essential for us to understand correctly the H-induced plasticity mechanism in metals. In this paper, a reliable atomistic modeling method is s2uggested to calculate quantitatively the effect of solute H on four frequently-used fault energies. The computed results show that solute H can increase the unstable stacking fault energy but decrease the other three, and the fault energies are linearly related to the equilibrium hydrogen concentration up to 0.020. In addition, the generalized stacking fault energy curves of the H-charged Ni in the and directions are also computed to construct the γ -surfaces. Finally, the influence of pre-stress on the unstable and stable stacking fault energies is discussed in detail. These quantitative results are helpful to understand the dislocation/twin-dominated plastic mechanisms in the H-charged metals and to develop the H-affected discrete dislocation dynamic (DDD) and crystal plasticity (CP) algorithms.