TWI

Friction stir welding (FSW) experiments were undertaken on commercially pure Ti and Ti-6%Al-4%V plates (thickness 6 mm) by incorporating nickel foil markers of varying thicknesses to reduce forging load, enhance surface finish, eliminate void formation and increase travel speed. FSW was performed on an MTS ISTIR PDS system using a lanthanated tungsten tool with a tapered probe and narrow shoulder. The nickel foil was placed halfway down the butt joint in the direction of travel. The influence of nickel as a fast diffuser was examined by X-ray computed microtomography as well as microstructural analysis using optical microscopy, SEM and electron backscattering diffraction. Mechanical properties were characterised by Vickers microhardness measurements and microtensile testing in the weld and transition zones. The localised effects of nickel foil resulting in enhanced weld consolidation are discussed.

9th International Symposium, 15-17 May 2012, Session 11B: High Temperature FSW II, Paper 01