Strengthening of Al-Cu alloys by Guinier-Preston zones: Predictions from atomistic simulations

A scale bridging strategy based in molecular statics and molecular dynamics simulations in combination with transition state theory has been developed to determine the flow stress of Al-Cu alloy containing Guinier-Preston zones. The athermal contribution to the flow stress was determined from the Taylor model, while the thermal contribution was obtained from the obstacle strength and the free energy barrier. These two magnitudes were obtained by means of molecular statics and molecular dynamics simulations of the interaction of edge dislocations with Guinier-Preston zones in two different orientations. The predictions of the model were compared with experimental data and were in reasonable agreement, showing the potential of atomistic simulations in combination with transition state theory to predict the flow stress of metallic alloys strengthened with precipitates. (C) 2019 Elsevier Ltd. All rights reserved.