| Popis: |
Experiments have been carried out to freeze the friction stir welding (FSW) process by stopping the tool and immediately quenching the work piece in an Al-2195 alloy welded under typical conditions. This has allowed the grain structure development to be directly observed, as fresh material encounters the deformation field surrounding the rotating pin, by sectioning through the frozen weld keyhole with the tool in place. The mechanisms involved in forming the thermo-mechanically affected zone (TMAZ) and nugget structures are discussed as well as the influence of static annealing in the wake of the thermal field trailing the welding tool. |
