Positioning-controlled friction welding of a 6061 aluminum alloy

In conventional friction welding, it is difficult to match phases at the particular position of a rotation side and a fixed side, because the rotating spindle does not exactly control the stopping position. Development of positioning control friction welding solves such difficulties as stopping at the specified position during braking. This positioning control friction welding was achieved by installing a servomotor positioning system. The positioning control was examined for the friction welding of aluminum alloy 6061. The positioning control was satisfactorily performed with sufficient accuracy. Severe metal flow was observed in the vicinity of weld interface during positioning control. In tensile tests, the fracture occurred at the softened zone. The positioning control did not influence the tensile strength of welded joints. The width of softened zone decreased with increases in brake timing and pressure. The joint welded under an optimum condition showed the maximum joint efficiency of 83.5 percent.