Joining of polyamide 6 material by friction stir spot welding

In the experimental study, the friction stir spot welding (FSSW) was applied for joining Polyamide 6 (PA 6) material. The friction stir spot welding method is a derivative of the friction stir welding (FSW) process, which is a new process that recently has received considerable attention from the automotive and other industries. The FSSW process consists of three phases of plunging, stirring and retraction with the FSSW tool similar to the FSW tool. Studies by various researchers have shown quite the effect of tool geometry, tool rotation speed, tool penetration and dwell time on tensile failure load of the joint for this method. In the experimental study, 2 tool geometries and 1 clamping apparatus suitable for welding are designed and manufactured. 4 mm thick Polyamide 6 sheets were done lap joints with FSSW. Tensile tests were applied to the welding samples. Depending on the polymer material and parameters used, the maximum tensile force value obtained is 2864,63 N. This value is equivalent to 86,59% of the base material. The optimum combination of parameters that maximises joint tensile failure load was identified. In addition, fracture surfaces, rupture zones and cross sections were examined by optical microscope.