INVESTIGATION OF FRICTION STIR SPOT WELDING PARAMETERS ON SHEAR FORCE AND MICROHARDNESS OF AA 6061 AND PURE COPPER JOINTS

Friction stir spot welding (FSSW) is widely utilized in this study for the purpose of joining dissimilar metals, specifically AA6061-T6 Aluminium Alloy and pure Copper. The parameters governing the welding process encompass tool speed, plunge depth, and dwell time. The study further delineates certain mechanical properties derived from the tensile-shear experiments of the AA6061-pure copper joints. Six welded specimens are performed at each process condition. Scanning electron microscopy (SEM) was used for the microstructure analysis. Energy Dispersive X-ray Spectroscopy (EDX) was used to analyze the elemental composition and distribution within the welded specimens. The maximum tensile shear force of 4.18 kN is achieved at 2000 rpm, 0.2 mm depth, and 20 seconds. Conversely, the minimum tensile shear force of 2.01 kN is obtained at 2200 rpm, 0.1 mm depth, and 15 seconds. The highest Microhardness value of the Stirred Zone (SZ) is 122.78 HV at 2200 rpm, 0.2 mm depth, and 15 seconds. In contrast, the lowest Microhardness value of 54.1 HV is recorded at 2000 rpm, 0.2 mm depth, and 15 seconds. The tensile shear force increases from 2.46 kN (conventional FSSW) to 2.64 kN (Stitch FSSW at 2 mm distance traveled) and 2.68 kN (Stitch FSSW at 4 mm distance traveled).