TWI

Alternative friction stir welding tool shoulder materials to improve welding speed and quality were evaluated. The materials, which were compared with tool steel using a tool designed for exchangeable shoulder inserts, were: nitrided tool steel, Inconel 718, Nimonic 105, zirconia, tungsten carbide (WC, 6%Co), and nickel silicide intermetallic. Welds were made using 6 mm thickness 7108.50-T79 aluminium alloy plates, using various shoulder forces, tool rotational speeds and welding speeds. The theoretical power input was calculated, and heat distributions were determined by metallographic studies of the welded joints. The materials were evaluated in terms of heat input and HAZ width.

1st International Symposium, 14-16 Jun 1999, Session 07: Process Developments 2, Paper 02