Papers by Keyword: Texture Components

Abstract: In the present research, the texture variation during cold rolling of cladded 3003 type aluminium sheets was examined by means of X-ray diffraction. The aluminum sheets were formed in a series of 14 rolling steps, after which texture examinations were performed on both cladded and base material sides of the sheets. After certain rolling steps, the texture was also examined by removing layers from the sheets by electropolishing to reveal the texture distribution along depth. The texture was characterised through the calculation of volume fractions of the main rolled texture components. Local drawbacks were found in the texture versus thickness reduction function. The texture was found to be higher in the middle of the sheets than at the surface.

Abstract: The paper describes an experimental verification of a previously proposed formula establishing the relationship between the crystallographic parameters of a rolled sheet and the anisotropy index in a hot-rolled aluminum alloy. The main texture components were identified in the hot-rolled 3104 alloy using the X-ray structure analysis. The crystallographic parameters and anisotropy indices were then calculated both for the entire workpiece and for each individual texture component. The earing level of the hot-rolled workpiece was determined using the process of cylindrical cup drawing. Cup formation was also simulated using the finite element software package PAM STAMP. The earing data obtained through t simulation were compared with experimental results. For the validation of the calculations the hot-rolled workpiece anisotropy indices were also experimentally determined.

Abstract: Aluminum sheets used for beverage cans show a significant anisotropic plastic material behavior in sheet metal forming operations. In a deep drawing process of cups this anisotropy leads to a non-uniform height, i.e., an earing profile. The prediction of this earing profiles is important for the optimization of the forming process. In most cases the earing behavior cannot be predicted precisely based on phenomenological material models. In the presented work a micromechanical, texture-based model is used to simulate the first two steps (cupping and redrawing) of a can forming process. The predictions of the earing profile after each step are compared to experimental data. The mechanical modeling is done with a large strain elastic visco-plastic crystal plasticity material model with Norton type flow rule for each crystal. The response of the polycrystal is approximated by a Taylor type homogenization scheme. The simulations are carried out in the framework of the finite element method. The shape of the earing profile from the finite element simulation is compared to experimental profiles.

Abstract: Starting from simple geometric considerations concerning directions and orientations, intelligent strategies for pole figure measurements were developed for the area detector. The amount and quality of texture information contained in measured or available data sets can be directly controlled. The texture approximation is done by the component method. The method does not have any restrictions concerning the grids of sample directions in the pole figures. An almost constant information depth can be obtained at a low angle of incidence of the primary beam for the study of thin surface layers.