Effect of pre and post welding heat treatment in SiC-fortified dissimilar AA6061-AA2024 FSW butt joint

The present study focuses on the effect of pre and post welding heat treatments on microstructural and mechanical properties of SiC included Friction Stir Welded joints in AA6061 and AA2024 aluminium alloys. The annealing of base metals as a pre welding heat treatment leads to more uniform distribution of SiC particles in the weld nugget. The post welding artificial aging heat treatment results in joint strength near AA6061-T6 base metal strength. Besides, the pre annealing and post aging heat treatment result in tensile strength and toughness of 92 and 96% of AA6061-T6 tensile strength and toughness, respectively. The micro SiC reinforcement in the weld nugget results in at least 14% higher weld strength than joints post weld heat treatment and without SiC particles additive. The abnormal grain growth in the weld nugget after post welding heat treatment has negligible effect on joint strength.