Formability and strength of friction-stir-welded aluminum sheets

Friction stir welding was investigated as a viable process for joining thin aluminum sheets in order to manufacture tailored blanks. In the present study three alloys were tested: 5182-O, 5754-O, and 6022-T4. All three of these alloys are being used to fabricate stamped automotive parts. The gas tungsten arc welding process has been used to make aluminum-tailored welded blanks industrially, so results using this process were compared to FSW results. Blanks of the same gage of all three alloys were welded and then evaluated using tensile and formability testing. The 5xxx series alloys had similar tensile ductility and formability regardless of the welding process. However, the 6022-T4 sheets joined using friction stir welding had better formability than those joined using gas tungsten arc welding because friction stir welding caused less softening in the heat-affected zone.