Numerical simulations of void growth in aluminum alloy AA5083 during elevated temperature deformation

Finite element computations are used to simulate void growth during elevated temperature deformation of polycrystalline aluminum alloy AA5083. The model accounts rigorously for the coupling between dislocation creep, grain boundary diffusion and grain boundary sliding; and considers a realistic 2D grain structure. The simulations are used to predict the influence of loading conditions, material properties and microstructure on void growth rates. The predictions are shown to be in good agreement with experimental observations of cavitation in aluminum. In addition, the simulations show that the rate of void growth is strongly sensitive to the detailed grain structure near the void. Consequently, the void growth rates in a realistic microstructure differ substantially from the predictions of models that idealize the grain structure as a periodic array.