Tensile shear strength and dynamic mechanical analysis of 6063 aluminium alloy and 304 stainless steel by spot welding

Abstract

Mechanical properties of dissimilar metal of spot welding were tested and analyzed based on the variation in welding currents and welding times. From visual observation, the largest weld nugget recorded was 7.43 mm at 5 kA, meanwhile the smallest was 6.4 mm at 3 kA. It was found that weld nugget size increase with the increment of weld current and extension of weld time. Based on tensile result, the largest weld nugget size of 7.43 mm produced the highest tensile strength, 31.99 N/mm2 mean while the smallest weld nugget 6.4 mm produced 29.40 N/mm2. The results show that weld nugget size affect the tensile shear strength, and with the increment of weld current and extension of welding time, tensile shear strength increase. Dynamic mechanical properties defined the storage modulus, loss modulus and damping capacity of dissimilar metal spot welded. It was found that at 10 Hz frequency between 70°C to 350°C, with heating rate of 10°C/minute, the storage modulus increase with increment in weld current and the extension of weld time to 8 s. Meanwhile the loss modulus decrease with the increased of weld current and weld time. Same pattern happen to damping capacity, the value dropped with the increases of welding current and welding time.