Influence of the pin shape of the tool during friction stir welding on the process output parameters

In this paper, computer simulation of the friction stir welding (FSW) of AlMg6Mn0.6 aluminum alloy sheet blanks by means of the DEFORM-3D software package is carried out to select the optimum pin geometry based on the calculation of the displacement and speed of displacement of the material points. Pins in the shape of a cylinder and a truncated cone with the cone angles of α =10, 20, and 30° were considered. The friction coefficient of 0.5 was assumed. Instrumental steel AISI-D2 was chosen as the material for the tool. To reduce the computation time and avoid the instability of solution, the model of welded blanks was built as a single body of 3 mm thickness and 40 and 30 mm length and width, respectively. The behavior of the AlMg6Mn0.6 alloy was described using the Johnson-Cook model. The FSW process was simulated at the tool moving speed v = 2 mm / s, rotation frequency ω =1000 rpm and axial force P = 25 kN. The initial temperature of the workpiece and the tool was 20°C. When welding the blanks, the conditions of heat exchange with the environment were set. The simulation results solution have shown that the flow of the material of the workpiece depends on the shape of the pin and is different over the thickness of the workpiece. The material in the lower area of the workpiece is practically not subjected to mixing for all values of the cone angle of the pin, in contrast to the middle and upper areas of the workpiece, where the material is noticeably mixed. Of all the tips considered, the most preferred for the FSW is a pin in the form of a truncated cone with the cone angle of 10°, since it provides good mixing in the plane of the workpiece, the maximum displacement of the material towards the root of the weld, and also allows one to get the most symmetrical seam.

Microstructure and mechanical properties of a welded joint obtained by friction stir welding of thin copper and aluminum plates

V.N. Danilenko, L.U. Kiekkujina, A.S. Selivanov, Y.V. Logachev, V.V. Atroshenko, R.R. Mulyukov

1. The present work was accomplished according to the state assignment of IMSP RAS. - The present work was accomplished according to the state assignment of IMSP RAS.