Experimental and Numerical Evaluation of L-PBF Printed Tool for Friction Stir Welding

In Friction Stir Welding (FSW) tool geometry plays a critical role in governing heat generation, material flow, and microstructural evolution within the weld. In this study, the feasibility and performance of FSW tools manufactured by Laser Powder Bed Fusion (L-PBF) are experimentally and numerically investigated. A non-conventional FSW tool produced in AISI 316L by L-PBF was designed and compared with a conventional machined steel tool in the welding of AA6082-T6 sheets performed using already optimized process parameters. This was followed by tensile testing and macro- and micro-hardness measurements, and a punctual microstructural analysis. In addition, a 3D thermo-mechanical finite element model was employed to forecast and analyze the temperature distribution, the effective strain and the overall material flow. The results show that the tool manufactured using L-PBF enables FSW joints to achieve mechanical properties and welding efficiency similar to those of the standard tool. Finite Elements Model (FEM) model, in good agreement with experimental results, show that the geometry of the additive tool promotes greater plastic deformation and lower peak temperatures, confirming both the validity of the model and the suitability of L-PBF for the advanced design of FSW tools.