| Based on the consideration of environmental protection and energy conservation, lowering the auto body weight becomes the basic development goals of automotive industry. Nowadays the main methods of light weighting of automotive are the adoption of new materials and forming methods. As aluminum alloy sheets with small density, high strength, corrosion resistance, etc., which meet the specific requirements of lightweight of automobile, it has become the main alternative to steel materials in the technology of lightweight of automobile. And TWB (Tailor Weld Blank) technology can optimize the structure of the workpieces and reduce material consumption, so the TWB technology plays an important role in lightweight of automobile, it has been widely used in automotive industry.In this paper the tensile properties of TWB for SGCC galvanized sheet with same thickness jointed were researched. The tensile tests were carried out with different locations of weld lines in the specimens. Compared with the tensile properties of original materials, the influence of weld line location on formability of the TWB was studied. The research results were shown that when the weld line was paralleled to tensile axis, the deformation of the TWB was uneven, the plastic deformation was poor. Compared with its of original materials, elongation after fracture was poorer. when the weld line was perpendicular to tensile axial, the forming process of the TWB was stable, the shape of materials after drawing was not easy to be rebounded, the plastic deformation of the blank was very good.By the fracture surface scanning test, the research results were shown that the fracture surface was the same as those of welding materials SGCC, but the directions of dimples were different, when the weld line was perpendicular to tensile axial. the fracture was ductile fracture and cleavage fracture, when the weld line was paralleled to tensile axial.The cupping tests were carried out to test the bulging formability of the TWB, which compared with base material, eventually the phenomenon of weld movement during the cup test was discussed. The research results were shown that cupping test value (IE) of the TWB was smaller than that of the base materials, material deformation on both sides of the weld line was same, the weld line didn't move, the weld line didn't deform and was still straight line, the weld line had apparent effect as the rebar.In this paper tensile properties and forming properties of 6061 aluminum alloy sheet were investigated. The research results were shown that 6061 aluminum alloy had certain forming capability. When this sheet was subjected to non-uniform biaxial stress in unilateral stretching, this sheet easily occurred stress concentration and brittle rupture, but when this sheet was subjected to biaxial stress and spread even in cup drawing, it appeared excellent formability. When 6061 aluminum alloy is to be processed, it should be avoided to appear bidirectional non-uniform stress. Because 6061 aluminum alloy appeared fluctuation load in strain hardening stage of stretching, it easily brought on tracery that come on surface as a result of slip band, it would damage product appearance. So when 6061 aluminum alloy were made on automotive panel, fluctuation of load must be augmented to avoid.Grain size gradually decreased along with deformation increase in the process of plastic deformation of aluminum alloy sheet, accordingly microhardness will be increased as a result of dislocation multiplication.The key technologies of finite element simulation of 6061 aluminum alloy were used to analyze sheet stress, plastic strain, thick variety analyzed, and the wrinkling and cracking prone areas. Therefore, the effective reference can be provided for the forming process of 6xxx based Alloy auto panel.
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