TWI

Friction stir welding (FSW) was employed to join various aerospace aluminium alloys, the welded joints were characterised with respect to microstructure, mechanical properties and corrosion resistance, and the effects of post-weld artificial ageing (PWAA) were investigated. The grades tested were 7075 (Al, 1-5.1%Zn, 0.8-2.1%Mg, 0.38-1.2%Cu), 7055 (Al, 0.8-7.6%Zn, 0.5-1.8%Mg, 0.6-2%Cu), 7249 extrusions (Al, 0.7-7.5%Zn, 0.4-2%Mg, 0.6-1.3%Cu) and 7136 extrusions (Al, 1-8.4%Zn, 0.7-1.8%Mg, 0.6-1.9%Cu). An experimental programme was conducted to study the effect of PWAA on microstructure stabilisation, tensile properties (ultimate tensile strength and joint efficiency), electrical conductivity profiles, Vickers microhardness, and corrosion resistance as determined by exfoliation corrosion tests.

6th International Symposium, 10-13 Oct 2006, Session 11B: Aerospace III, Paper 01