Effect Of Warm Rolling Processing On Microstructure And Texture Evolution Of 7050 Aluminum Alloy Cast Rolling Plate

Ultra high strength 7050 aluminum alloy is a kind of structural material with high temperature strength and good comprehensive mechanical properties, which belongs to the Al-Zn-Mg-Cu system in the deformed aluminum alloy. It is widely used in aerospace, transportation, automobile manufacturing and other fields. Twin-roll casting(TRC) is a near-net-shape process which combines rapid solidification with hot rolling by one-step method to produce thin strips directly from molten metal. Rolling is a plastic deformation process, not only can refine the grain, but also improve the casting rolling plate defects, and rolling process with less investment, quick effect, energy saving and other characteristics, it widely used in plate, deformation processing alloy. Rolling has great potential for improving the quality of strip casting, and also has great significance in the field of aluminum alloy strip processing. The Rolling technology with the superiority may solve the molding problems of ultra-high strength aluminum alloy sheets, produce sheets with uniform chemical composition.In this paper, the 7050 aluminum alloy cast rolling plate strip were produced by Horizontal two roll mill machine under reasonable parameters, specifications for 1mm×200mm. The structure and microsturcture evolution were investigated by means of optical microscope(OM), scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), hardness test and tensile mechanical properties test at room temperature. and other experimental methods, the structure and microstructure evolution of 7050 aluminum alloy and heat treated 7050 aluminum alloy were studied. The results show that the deformation rate is 15%, and most of the grains still remain in the cast rolling state. When the deformation amount is over 75%, the cast rolling state is completely disappeared. Under the same deformation, With the increase of rolling temperature, the grain deformation is uniform, and the rheological property of the material is better than that of 370 and ℃400℃. With the increase of rolling temperature, the tensile strength is gradually increasing While the yield strength and elongation are increased and then decreased. The mechanical properties of the sheets prepared at 450℃ were the best, the tensile strength was 310.2MPa, and the elongation was 3.77%. In the 75% deformation of the plate, there are 450℃ main deformation of the(r-cube{001}<110>) and [112]<110>, and the cube texture(r-cube{001}<110>) is always very strong. After the heat treatment, the microstructure of the tissue was changed to the recrystallization process. The grain size was changed into uniform and fine grain, and many second phase particles were produced at the grain boundary and grain boundary, and most of them were distributed at the grain boundaries. 450℃ rolling sample after heat treatment the yield ratio of the minimum, The ductility and plasticity of the plate is also good.