TWI

In order to develop a method for microjoining by friction stir welding (FSW), micro-FSW trials were conducted on Mg alloy AZ31 (2.97%Al, 0.83%Zn) thin sheets (0.4 mm thickness), and the welding performance was assessed. The micro-FSW system incorporated a vertical milling machine, a high-speed spindle motor, a dynamometer, an array of thermocouples, and a CCD (charge coupled device) camera. An improved version was equipped with a motor support frame, facilitating a variable tilt angle. Results are presented from micro-FSW tests at three different tilt angles (0, 1.5 and 3.0 degrees) including: joint efficiencies as a function of revolutionary pitch for tool steel or tungsten carbide tools (transverse tensile tests); hardness distribution versus distance from weld centre; and temperature profiles in the backing plate.

5th International Symposium, 14-16 Sep 2004, Session 4B: Process Developments, Paper 03