Innovative Design and Simulation of Friction Stir Welding

Friction stir welding has been extensively studied and widely used in various industries, including shipbuilding industry for producing deck, hull, and submarine, and aerospace industry for producing wing and fuselage. Furthermore, expansion of this revolutionary joining technology to the other applications, including railroad and automobile industries, are currently been studied. In most of the studies regarding friction stir welding, a 2°-3° tilt angle was always used to avoid welding defects. But welding with this tilt angle will result in the need of using specialized and complicated machines or mechanical arms. This will greatly increase the production cost. Furthermore, when the joint contour is non-linear, the welding procedure and the machine-tool design will become very extremely complex. In this study, a novel eccentric friction stir pin will be designed in order to eliminate the need of the tilt angle during welding of 4.8-mm thick AA6061-T6 plates. The design parameters include: eccentricity, tapering, and screw design. Welds free of defects will be expected to be successfully produced using a specially designed pin with eccentric, tapered and screwed design characteristics. Marker Insert Technique (MIT) will be used in this study to simulate plastic flow in welding zone. The results of feasibility study indicate that the eccentricity and screwed design are critical in eliminating welding defects because they have significant influence on the plastic flow of the softened metal during welding.

Project ID:PB10107-1724
External Project ID:NSC101-2221-E182-025