TWI

Extruded AZ31 (Mg, 3%Al, 1%Zn) alloy plates (thickness 6 mm) were joined by one-run or two-run friction stir welding (FSW) and the microstructure, mechanical properties and residual stress characteristics of the welded joints were investigated. FSW experiments were performed at a tool rotation speed of 1500 rpm and a welding speed of 500 mm/min. Residual stress measurements were conducted on the longitudinal centre line of plates. Static tensile and tensile fatigue tests were carried out on smooth tensile specimens and fatigue crack growth measurement was undertaken on mini-size compact tension specimens. FSW joint microstructure in the stir zone, TMAZ (thermomechanically affected zone) and HAZ was compared for one-run and two-run welding.

6th International Symposium, 10-13 Oct 2006, Session 7B: Fatigue II, Paper 01