The texture of a rolled AA3104 aluminum sheet was measured by the X-ray transmission method. The Lankford values or r values (ratio of plastic strain) and yield strengths in directions of 0, 15, 30, 45, 60, 75, and 90° to RD (rolling direction) of the sheet were tested during tensile loading at a strain of 2%. r values were predicted by the Sachs model and the reaction stress model in con- sideration of the measured texture. The simulated results indicate that r values calculated by the Sachs model are more exactly ap- proaching with the experimental values on the whole than those predicted by the reaction stress model. The deformation behavior of the AA3104 aluminum sheet reveals characteristic predicted by the Sachs model, which should be resulted from the sheet geometry different from bulk material as well as the low tensile deformation degree.
A plastic deformation model for bcc metals is proposed in consideration of reaction stresses. The shear strains and the corresponding reaction stresses induced by the activation of dislocations are calculated in the model, which will influence the following dislocation activation. The rolling texture in bcc metals is simulated up to 80% reduc-tion, while the ratio of critical resolved shear stresses be-tween the dislocations slipping on the {110} and {112} planes is chosen as 0.95. The corresponding calculation is also con-ducted with the activation of second dislocation, if the dif-ference between the orientation factor of the two dislocations with maximal orientation factors is lower than 5%. It is shown that the simulated texture is closer to that of the 80% rolled interstitial free steels than other modeling. It is be-lieved that the new model can give more attention to both of the strain and stress continuities during the plastic deforma-tion of polycrystalline metals, and therefore approaches closer to the real deformation process in bcc metals.
