TIG spot weld bonding of 409 L ferritic stainless steel

Tungsten inert gas (TIG) spot weld bonding is a hybrid joining process, which combines the conventional tungsten inert gas welding with adhesive bonding to achieve a better quality joint with superior joint performance than any single technique. The present research aims to study the effect of input process parameters i.e. welding current, weld time and gas flow rate on weld penetration, bead width and tensile shear strength of the weld bonds using design of experiment (DOE) approach. Further, some selected samples were characterized by optical microscopy and hardness testing. It was observed that weld time most significantly affect the weld performance followed by welding current and gas flow rate. The tensile results showed failure of weld bond in two ways namely interfacial failure and button pull out failure.