Prediction of plastic anisotropy of textured polycrystalline sheets based on a new single crystal model

摘要

In this paper, we predict the effect of texture on the anisotropy in plasticproperties of polycrystalline metallic sheets. The constituent grain behavioris modelled using the new single crystal yield criterion developed by Cazacu,Revil, and Chandola (2017). For ideal texture components, the yield stress andplastic strain ratios can be obtained analytically. For the case of stronglytextured sheets containing a spread about the ideal texture components, thepolycrystalline response is obtained numerically on the basis of the samesingle-crystal criterion. It is shown that for textures with misorientationscatter width up to 25 degrees, the numerical predictions are very close tothose obtained analytically for an ideal texture. Furthermore, irrespective ofthe number of grains in the sample, Lankford coefficients have finite valuesfor all loading orientations. Illustrative examples for sheets with texturescontaining a combination of few ideal texture components are also presented.The simulations of the predicted polycrystalline behavior based on the newdescription of the plastic behavior of the constituent grains capture theinfluence of individual texture components on the overall degree of anisotropy.The polycrystalline simulation results are also compared to analyticalestimates obtained using the closed-form formulas for the ideal componentspresent in the texture in conjunction with a simple law of mixtures. Theanalytical estimates show the same trends as the simulation results. Therefore,the trends in plastic anisotropy of the macroscopic properties can beadequately estimated analytically.