High-Speed Deformation of Pinless FSWed Thin Sheets in AA6082 Alloy

Abstract

The high-speed deformation behavior of friction stir-welded thin sheets in AA6082-T6 aluminum alloy, under biaxial balanced stretching, was investigated by means of a hemispherical punch test carried out using direct tension-compression Split Hopkinson Bar. The friction stir welding process was performed on thin sheet blanks using a pinless tool; the rotational and welding speeds were kept constant during process. The dynamic tests were carried out, with a punch speed of 4500 mm/s, at different punch stroke values until failure of the friction stir welded sample. It was seen that failure occurs along the welding line at a dome height about 11% higher than that at the onset of necking. Fractographic analysis shows that deformation is localized in the fracture zone. The results were compared with those obtained on friction stir welded blanks deformed under quasi-static condition in order to evaluate the influence of the loading rate on the weld deformation and fracture mechanisms. It was shown that joints deformed under dynamic loading condition are characterized by a dome height at the onset of necking significantly higher than the one measured under quasi-static condition.

Influence of Initial Structural Dimensions of Plates on Welding Distortion

“…Zhou Z [14] et al studied the welding deformation characteristics of coplanar double lap-joints by using the thermoelastic-plastic finite element method, and analyzed the influence of welding direction on welding deformation and the mechanism of welding deformation of coplanar double lap-joint. Forcellese A [15] et al studied the high-speed deformation behavior of AA6082-T6 aluminum alloy friction stir welded sheet under biaxial balanced tension, and discussed the influence of loading rate on the deformation and fracture mechanism of the weld. Zhou, Hong [16,17] et al combined the thermoelastic-plastic finite element method with the inherent deformation finite element method, accurately predicted the out-of-plane buckling behavior of typical marine plate girder welded structure with ortho-cross reinforcement, and studied the influence of welding sequence on the outward welding deformation.…”