Dislocation dynamics simulations were used to investigate precipitation-induced strengthening in a Zr-1%Nb alloy. A method was proposed to carry out simulations under dynamic conditions in connection with the microstructure of the investigated alloy. Firstly, a sensitivity study of simulation parameters, suspected of altering simulation results, was presented. It permitted the setting-up of simulation conditions which ensured statistical meaningfulness. The effect of the strain rate was then investigated and analyzed in connection with the random distribution adopted to describe precipitation distribution. The strengthening induced by 2 different families of Nb precipitates was estimated from simulations whose simulation box was reduced to the volume of a single grain. It was shown that the obtained strengthening values were smaller than those predicted by most published models. Determination of total strengthening showed that usual superposition rules did not apply. A mixture law, which fitted the dislocation dynamics results well, was proposed.

Investigation of Precipitation Hardening by Dislocation Dynamics Simulations. G.Monnet: Philosophical Magazine, 2006, 86[36], 5927-41