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The main reason for using lightweight metals in the automotive industry is the potential saving of natural energy resources simply by weight reduction. Magnesium, as the lightest available construction metal, offers a wide range of opportunities for use in automobiles. At present mostly cast parts are used and the use of wrought magnesium alloys is still well below the potential. [1] There are two main reasons for this: a lack of sufficient cold formability and the anisotropy of the properties of the finished sheets. [2,3] Also, the rolling process is not adequately developed and still needs a lot of improvement to produce material with the required properties.Generally, mechanical properties are affected by grain size, microstructural homogeneity, and texture. [4] In a plastic deformation process such as rolling, the process parameters cause changes in the microstructure, which determine the mechanical properties. It is important to understand the complex mechanisms of deformation, recovery, and recrystallization during plastic deformation at elevated temperatures in order to achieve process development. [5] This Communication describes two aspects of the deformation behavior of magnesium sheets. First, we give a brief mechanical characterization of a commercial magnesium with a focus on the anisotropy and the possible microstructural causes of this behavior. Second, we discuss the rolling process and its influence on the sheets. The aim is to show the influence of the parameters on the microstructure and texture and how this could affect the anisotropy in the rolled sheets.Experimental: We examined commercial rolled sheet, and specimens rolled to 3 mm thickness in our laboratory from various starting materials. Commercial AZ31B rolled sheet (with nominal composition 3 wt.-% Al, 1 wt.-% Zn, balance Mg) was provided in the stress-relieved H24 temper and 1.6 mm thick. Tensile tests at room temperature were conducted on a Zwick Z050 universal testing machine with a constant strain rate of 10 ±3 s ±1 . The commercial sheet tensile samples were 125 mm 20 mm 1.6 mm in size; samples taken from our rolled material had a cross section of 3 mm 6 mm. Owing to the limited material available, the specimen shape was freely chosen, taking the standard ISO specifications into consideration. Texture was measured by X-ray diffraction in reflection geometry on a Brukers AXS diffractometer. [6,7] Metallography was performed after picric acid etching.A laboratory mill was used for all rolling experiments. The rollers were kept at room temperature and operated at a speed of 3 m/min rolling rate. The specimens for stepwise rolling had a size of roughly 100 mm 50 mm 10 mm (l 0 b 0 h 0 ). The specimens for one-step rolling experiments had different starting dimensions in order to reach a final sheet thickness of 3 mm. All rolling was done at a specimen temperature of 400 C on withdrawal from the furnace, which was located directly next to the mill.The first part of the experimental processing consisted of stepwise rolling by reducing t...

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The plastic anisotropy was measured for a commercial AZ31 magnesium sheet and compared with results from a model calculation using a self consistent viscoplastic model. The anisotropy of plastic flow stresses can be explained by the off-basal character of the texture and the activation of the <a> prismatic slip in addition to the basal, <c+a> pyramidal slip and the > < 1 1 01 } 2 1 01 { twinning system. The strain anisotropy r ( r = ew/et ; ew, et – strains in width and thickness directions of a sheet material ), as obtained from model calculations, fits qualitatively with in-situ measured values. Results from these model calculations are compared with texture simulations and discussed in further consideration of the microstructure of the sheet material.

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