The effect of micro-swinging on joint formation in linear friction welding

Abstract

A 3D Eulerian numerical model was developed to investigate the effect of micro-swing on joint formation during workpiece oscillation in linear friction welding (LFW). The temperature field and axial shortening history for different amplitudes of micro-swing have been studied. Results show that the amplitude of micro-swing influences flash morphology and axial shortening. The micro-swing contributes to the extrusion of viscoplastic metal and the formation of flash during the LFW process. Flash volume and axial shortening increase as the amplitude of micro-swing becomes larger. When the amplitude of micro-swing is more than a critical value, a sudden change of axial shortening (different from the period of the oscillation cycle) would occur at certain welding time, which change would also have a periodic nature. Although different amplitudes of micro-swing affect joint morphology, the inner temperature field and the highest temperature of joints remain constant. The high temperature region inside the joints remains about the same, when the amplitude of micro-swing is constant. This indicates that the heat generated through plastic deformation could maintain the welding process, and so that the welding process would enter the equilibrium phase.

Keywords

• Linear Friction Welding
• Micro-swing
• Axial shortening
• Numerical simulation