Investigation of precipitation hardening by dislocation dynamics simulations

Ghiath Monnet (1)

1 EDF R&D MMC - Matériaux et Mécanique des Composants

Dislocation Dynamics (DD) simulations are used to investigate the precipitation-induced strengthening in a Zr-1%Nb alloy. A method is proposed to carry out simulations under dynamical conditions in connection with the microstructure of the investigated alloy. First, the sensitivity study to simulation parameters, suspected to alter the simulation results, is presented. It allows setting up simulation conditions ensuring statistical representativeness. The effect of the strain rate is then investigated and analyzed in connection with the random distribution adopted to describe precipitation distribution. The strengthening induced by two different families of Nb precipitates is estimated from simulations whose simulation box is reduced to the volume of a single grain. It is shown that the so-obtained strengthening values are smaller than predictions by most known published models. The determination of the total strengthening shows that usual superposition rules do not apply. A mixture law, fitting well DD results, is proposed in this paper.

Mots clés: Physical Sciences

Ghiath Monnet. Investigation of precipitation hardening by dislocation dynamics simulations. Philosophical Magazine, 2006, 86 (36), pp.5927-5941. ⟨10.1080/14786430600860985⟩. ⟨hal-00513730⟩