Effect of shoulder diameter on bobbin tool friction stir welding of AA 6061-T6 alloy

Abstract

Abstract The present study investigated the effect of different shoulder diameter on the 6\u202fmm thick AA 6061-T6 aluminium alloy using bobbin tool friction stir welding (BTFSW). Three shoulder diameters as 20, 22, and 24\u202fmm were considered. The maximum temperature of 345 ℃ was observed for 24\u202fmm shoulder diameter sample. Void defect was observed in the weld nugget zone of sample welded with 20\u202fmm shoulder diameter, and defect-free joint was observed with increasing shoulder diameter. All the samples exhibited a fine, equiaxed grain structure in the weld nugget zone. The maximum tensile strength of 166.32\u202f±\u202f3.6\u202fMPa and & maximum % elongation of 15.8\u202f±\u202f1.35 was observed for sample welded with 24\u202fmm shoulder diameter.