Effect of process parameters on the mechanical behavior of additively manufactured and FSW joined PLA wood sheets

Friction stir welding (FSW), a solid-state joining method, is an innovative technique widely employed in the welding of thermoplastics, with broad application areas such as the automotive and aerospace industries. Due to its inherent advantages, including ease of processing, biodegradability, and printability, polylactic acid (PLA) and its derivatives are notably the most commonly used polymers in 3D printing. The limited print area of 3D printers necessitates post-production joining processes. In this study, the weldability of plates obtained using PLA Wood filament through the FSW is evaluated. For this purpose, different pin geometries (triangle, square, and screw), feed rates (20, 40, and 60 mm/min), and tool rotation speeds (1250, 1750, and 2250 rpm) are employed. Visual inspections are conducted to determine the effects of process parameters on weld quality and to identify defects in the weld region. Temperature values are measured to investigate the influence of heat generated during the FSW process. Furthermore, after determining the highest weld strengths achieved for each pin geometry, the weldability of PLA Wood material with PLA-CF and PLA Plus materials is investigated using these parameters. The results indicate that the highest weld quality for joining PLA Wood plates is achieved using the square pin geometry, 20 mm/min feed rate, and 1750 rpm with an efficiency of 74.5%. When welding PLA Wood with PLA-CF and PLA Plus, high weld strengths are obtained using the same process parameters (square pin, 20 mm/min, and 1750 rpm).Highlights center dot Friction stir welding process of 3D printed PLA Wood material.center dot Friction stir welding process of dissimilar materials pairs.center dot Effect of welding parameters on weld strength and hardness.center dot Identifying the fracture surface images occurring in parts after friction stir welding.center dot Examination of temperature generation during friction stir welding.