Microstructures and mechanical properties of non-thinning and penetrating friction stir welded 2219-T6 aluminum alloy

The aim of this paper is to offer a novel friction stir welding technique achieve non-thinning and lack kissing bond welds with excellent mechanical properties. In the conventional (CFSW) process, certain size spindle tilting angle shoulder plunge depth were applied in order obtain high-quality welds. However, what was reason for thinning phenomenon weld thus weakening bearing capacity? reduction likely cause tool not being able reach root, thus, it engendered or absence complete penetration. present study, large Archimedes spiral groove designed microstructures properties joints obtained by penetrating (NTPFSW) (PFSW) had been analyzed detail. Compared PFSW, NTPFSW narrow shoulder-affected zone. thickness joint 0.1 mm thicker than that BM 0.22 PFSW joint. zones (SZ) both composed fine equiaxed grains. grains upper part larger size, number precipitates (θ’ phase) less. completely eliminated phenomenon, tensile 365 Mpa, which 2% higher PFSW.