Joint properties and thermal behaviors of friction stir welded age hardenable 6061AI alloy

摘要

Joint properties and thermal behaviors of friction stir welded age hardenable 6061 Al alloy were evaluated. Through a series of friction stir welding at different tool rotation speed and travel speed, the sound joints of 6061 Al alloys were successfully formed under a wide range of the friction stir welding conditions. The surface bead width was observed to be gradually decreased with increasing welding speed and the hardness distribution of the welded zone showed lower value than that of the unaffected base metal, and tensile tests showed that the HAZ was the weakest region in the weld. While a numerical heat flow model for friction stir welding has been developed. A numerical simulation was executed against the friction stir welded zone using a newly developed thermo-elastic-plastic finite analysis to examine thermal behaviors. It was found that 6061 Al alloy was welded about 530℃ that is lower than the melting temperature of aluminum under numerical simulation.