| The microstructure and mechanical properties of a High-Speed Friction Stir Welded aluminum alloys obtained using rotating and non-rotating shoulder tool were investigated. An optical microscope was used to characterize the microstructure of the weld. In rotating shoulder tool welds four different regions/zones were present: the nugget, thermo mechanically affected zone, the heat affected zone and the unaffected parent material. In non-rotating shoulder tool welds five different regions/zones were present: the nugget, thermo mechanically affected zone, the heat affected zone, the unaffected parent material and the induced stir zone. High Speed-Friction Stir Welding (HS-FSW) causes dynamic recrystallization in the weld resulting in smaller and equiaxed grains as compared to the larger elongated grains of the base material. The defects in the weld zone were reduced/eliminated in non-rotating shoulder tool welds compared to rotating shoulder tool welds. Mechanical properties were characterized using tensile tests and hardness measurements. (Abstract shortened by UMI.)... |
