Modelling cube texture effects on formability of FCC metal sheets

J.W. SIGNORELLI; M.A. BERTINETTI; P.A. TURNER; R.E. BOLMARO

Pittsburgh, Pennsylvania

Congreso; The 15th International Conference on the Textures of Materials; 2008

Cube texture component is inevitably present in FCC sheet metal. Such preferred orientation leads to anisotropic properties which affect the sheet formability. In this research, the effect of the cube texture on forming-limit strains is studied using a rate-dependent viscoplastic law in conjunction with the Marciniak-Kuczynski approach. Generalized Taylor-type polycrystal simulations predict higher formability for the cube texture component than that for a random texture in biaxial stretching paths. This unexpected behavior is not observed when a self-consistent homogeneization scheme is employed. The forming limit diagram and yield locus are determined for several spreading of grain orientations around the ideal {100}<001> component. The spreading respect to the ideal orientation is taken according to a Gauss distribution or assuming a uniform distribution with a standard deviation or cut-off angle from 0° to 15° respectively. The trend of the predicted limit strains shows that the main differences in the forming limit strains have a correlation with the sharpness of the yield locus near equibiaxial stretching path, and also with the texture evolution and subsequent selected slip systems predicted by each model.