Influence of Tool Pin Profile on Mechanical Properties and Microstructure of Friction Stir Welded Aluminium AA7075 Alloy

Abstract

The present investigation describes the effect of different tool pin profiles on microstructure and mechanical properties of friction stir welded aluminium AA-7075 alloy. The tool pin profiles namely taper cylindrical threaded (TT), cylindrical (CT), square (SQ), triangular (TR), pentagonal (PT), hexagonal (HX) with constant shoulder diameter have been selected to make joints. The friction stir welding was done at constant tool rotational speed and traverse speed. From this study, it is noted that the weld joints prepared using taper cylindrical threaded pin profile exhibited good mechanical properties when compared to other pin profiles. It is due to more surface contact of tool pin and production of equiaxed fine grain structure in the weld region.