Joining of polypropylene sheets with friction stir spot welding at CNC machine

Friction Stir Spot Welding (FSSW) that is method solid state welding is developed as alternative to Resistance Spot Welding (RSW). The first time was applied at aluminium sheet materials in 2001. FSSW method in the studies carried out to date has been applied to metals and thermoplastic polymeric materials and positive results were obtained. As a result of studies was found to be several parameters that effecting the welding strength. Welding tool geometry, tool spindle speed, plunge depth and stir time are the most effecting parameters to welding strength. In the study, Polypropylene (PP) samples that having good weldability were joined by FSSW method in order to obtain the optimum welding parameters and to determine effect of welding parameters to the welding strength. Four different tool which were manufactured with the different shoulder and stirring pin shape were investigated to effect welding strength of tool geometry. In result of the studies, a new welding section has been obtained and this welding section has been given a new name. The parts binding to an apparatus of designed specifically for lap-welding have been welded in CNC machine with using a program prepared in ISO G M code system. The effecting parameters to the welding strength were tested for different values and a large number of the welded samples were obtained. The tensile test was applied to the welded samples. As a result, the optimal welding parameters were obtained and the effecting parameters to the welding strength were presented.