Data on microhardness and structural analysis of friction stir spot welded lap joints of AA5083-H116

Friction stir spot welding (FSSW) was established to compete reasonably with the reverting, bolting, adhesive bonding as well as resistance spot welding (RSW) which have been used in the past for lap joining in automobile, aerospace, marine, railways, defence and shipbuilding industries. The use of these ancient and conventional joining techniques had led to increasing material cost, installation labour, and additional weight in the aircraft, shipbuilding, and other areas of applications. All these are disadvantages that can be overcome using FSSW. This research work carried out friction stir spot welding on 5058-H116 aluminium alloy by employing rotational speed in the step of 300 rpm ranges from 600 rpm to 1200 rpm with a no travel speed. It was noted that the dwell times were in the step of 5 s varying from 5 s to 15 s while the tool plunge rate was maintained at 30 mm/min. In this dataset, a cylindrical tapered rotating H13 Hot-working steel tool was used with a probe length of 5 mm and probe diameter of 6 mm, it has a shoulder diameter of 18 mm. The tool penetration depth (plunge) was maintained at 0.2 mm and the tool tilt angle at 2°. Structural integrity was carried out using Rigaku ultima IV multifunctional X-ray diffractometer (XRD) with a scan voltage of 40 kV and scan current of 30 mA. This was used to determine crystallite sizes, peak intensity, d-spacing, full width at half maximum intensity (FWHM) of the diffraction peak. TH713 digital microhardness equipment with diamond indenter was used for microhardness data acquisition following ASTM E92–82 standard test. The average Vickers hardness data values at different zones of the spot-welds were captured and presented.