Effect of nanoscale defects on inelastic processes in aged alloys

The high strain rate deformation of an aged alloy with a high concentration of Guinier-Preston zones is theoretically analyzed. The analysis was carried out within the framework of the theory of dynamic interaction of defects. An analytical expression for the dependence of the dynamic yield strength on the concentration of impurity atoms has been obtained. The reasons of the different influence of Guinier-Preston zones on inelastic processes at different strain rates are analyzed. It is shown that under high strain rate deformation, nanosized defects affect the nature of the dependence of the dynamic yield stress on the concentration of impurity atoms. This dependence becomes nonmonotonic and has a minimum and a maximum. The maximum corresponds to the transition from the dominant influence of the collective interaction of dislocations on the spectral gap to the dominance of the influence of the collective interaction of impurity atoms. The minimum corresponds to the transition from dominance of dislocation drag by Guinier-Preston zones to dominance of drag by impurity atoms. Numerical estimates of the contribution of the Guinier-Preston zones to the yield strength are made. It is shown that at a high concentration of Guinier-Preston zones, this contribution is very significant. Numerical estimates are made of the concentration of impurity atoms, at which the concentration dependence has a maximum and a minimum.