Materials Science Forum Vols. 704-705

Abstract: With the demands of environmental protection and energy conservation, increasing resources and improving environment, TWB (Tailor Weld Blank) as one of green re-manufacturing technologies will be a guiding orientation in industry. In this study, microstructure of welded joint、tensile test、fracture surface、cupping test of the TWB were carried out. Results show that the microstructure of weld is acicular ferrite and plate pearlite. The microstructure of HAZ beside SAPH440 is pearlite and grain ferrite, and the microstructure of HAZ beside DP600 is numbly pearlite and plate ferrite. The results of tensile test show that the shape of the materials after drawing is not easy to be rebounded, plastic deformation of the blanks is excellent, and the SEM of fracture morphology shows that the fracture is ductile and cleavage when the weld line parallels tensile axis. When the weld perpendicular to tensile axial, the deformation of the TWB is uneven, the plastic deformation is poor and the fracture is typical ductile rupture. The research results of the cupping test suggest that the bulging formability of the TWB is worse than that of base materials, and the bigger proportion of the thin blank in the TWB, the better bulging formability of the TWB. Introduction

Abstract: In this study TIG welding of Tailor welded Galvanized Sheets and their formability of stretch forming have been carried out. It has been found that the microstructure of weld region is ferrites and pearlites, and the microstructure of heat-affected zone (HAZ) is blocky pearlites and ferrites. Stretch tests suggested that when the weld line parallels the tensile axis, σs , σb and the σs/σb is higher than that of the weld line perpendicular to the tensile axis. When the weld line parallels the tensile axis, the elongation of the specimen and n are lower than that of the specimen with the weld line perpendicular to the tensile axis. When the weld line perpendicular to the tensile axis, the fracture surface is basically the same as that of the base metal, when the weld line parallels the tensile axis, the fracture surface is dimples and cleavages.

Abstract: Tensile properties of 6061 aluminum alloy sheet were investigated by means of electric universal test machine, scanning electron microscopy ( SEM) etc．and compared with those parameters of 6010 aluminum alloy; By using machine performance parameters of 6061 aluminum alloy ,finite element software eta/DYNAFORM of Sheet Forming made the numerical simulation of Erichsen tester process of 6061 aluminum alloy sheet ,and the result of numerical simulation compared with actual Erichsen tester. The press forming performance of 6061 alloy sheet have been analyzed．The results show that compared with 6010 aluminum alloy, proof strength σ_s and tensile strength σ_b of 6061 aluminum alloy sheet exhibits worse,but even percentage elongation δ of 6061 alloy sheet exhibits similar; The value IE of numerical simulation exhibits similar with actual value IE. So 6061 aluminum alloy sheet have formability in a certain extent and apply in some fields of automobile instead of 6010 aluminum alloy.