Experimental Examination of Weld Hardness Profile with Various Tool Pin Probes using Friction Stir Welding of AA 6082-T6 Aluminium Alloy

Abstract

In the present research work, an attempt was made to evaluate the weld hardness profile on the weldments along the weld traverse direction fabricated using various tool pin probes (Concave triangular threaded probe, Inner rake angle probe, Flats on edges of probe and Scroll threaded flute probe) at three different rotational speeds 1000 rpm, 1200 rpm, 1400 rpm at single weld traverse speed 25 mm/min. Hardness profiles are useful for establishing interpretation on microstructure and weld mechanical properties, micro hardness was performed in order to outline the weld hardness profile in the vicinity of weld affected areas like Nugget zone, Thermo-mechanically affected zone, Heat affected zone and Boundary zone in the weldments. From the hardness profiles it was found that higher hardness value of 106 VHN1kg (Vicker’s Hardness Number at 1kg load) was obtained with the weldment fabricated using Scroll threaded flute probe at 1400 rpm and 25 mm/min i.e 15 mm distance away from the weld centreline on the advancing side of the weldment , besides lower hardness value of 49.8VHN1kg was obtained with weldment fabricated using concave triangular threaded probe at 1200 rpm and 25 mm/min at nugget zone i.e at the centerline of the weldment.