Modeling the Anisotropic Flow Behavior of Precipitate-Hardened Al-Cu Alloys During Plane Strain Compression

摘要

In this study, the effects of plate-shaped precipitates on the mechanical properties and plastic anisotropy of Al-Cu alloys during plane strain loading were investigated. The modified aging kinetics model of Shercliff and Ashby was used to obtain the precipitate size and volume fraction after different schedules of aging treatment. An explicit term, named as weighting function was obtained based on the elastic inclusion model for the directional dependency of strengthening developed by non-shearable plate shape precipitates during plane strain compression. This orientation dependent term was used along with the precipitate features obtained from the kinetics model, and dislocation density varying during deformation, to calculate the slip system strength. Also, a Kocks-Mecking type dislocation evolution model of single phase materials was modified to assess the anisotropic influence of non-shearable precipitates on the flow behavior of age hardenable alloy. The proposed model is validated by comparing the modeling results for precipitates size, precipitates volume fraction and stress-strain curves under different aging conditions, with that of experiments. It is found that the presence of non-shearable precipitates can reduce crystallography anisotropy, in fact, the weak orientations are strengthened more by precipitates than hard orientations. The developed model can be applied to single crystals and also textured polycrystals.