TWI

The friction stir welding (FSW) process was determined for stiffener to skin lap joints of different aluminium alloys (similar 2024 T3, similar 2139 T3 and T8, dissimilar PA 765 T79 extrusion on 2139 T8 skin) and FSW procedures with retractable pin tools (RPT) were developed for run-out control, eliminating the end hole. A method for extension and retraction of the pin along a tapered stringer foot was considered. The FSW/RPT procedures were established on small coupons and validated on larger structural panels with welded stringer and frame to skin. Test coupons with integrated run-in and run-out were welded. Results obtained with respect to microstructural zones, hardness distributions, tensile, static and fatigue tests, and damage tolerance are discussed.

6th International Symposium, 10-13 Oct 2006, Session 6A: Aerospace II, Paper 01