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

TL;DR

This paper introduces a new single crystal model to predict how texture influences plastic anisotropy in polycrystalline metallic sheets, combining analytical and numerical methods for accurate predictions.

Contribution

The paper develops a novel single crystal yield criterion and demonstrates its effectiveness in predicting polycrystalline anisotropy analytically and numerically.

Findings

Predictions closely match for textures with up to 25-degree misorientation.

Lankford coefficients remain finite across all loading orientations.

Analytical estimates capture the trends in anisotropy effectively.

Abstract

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