Thermal Modeling of Friction Stir Welding Tools Using Advanced Finite Element Simulation

Friction stir welding (FSW) is a solid‑state joining technique widely adopted in advanced manufacturing for producing high‑integrity metallic structures. Its rotating tool generates severe plastic deformation and solid‑state bonding, enabling welds with superior mechanical performance compared to conventional fusion welding. However, evaluating tool performance and predicting tool service life remain costly challenges due to the extensive experimental testing required. Numerical simulation, therefore, offers an attractive pathway for accelerating tool development.

This study applies finite element analysis (FEA) to model heat generation within an H13 steel FSW tool, its holder, and an integrated cooling system, as temperature evolution is essential to weld quality and tool wear. Four process configurations were examined: with and without cooling components, and two with compressed‑air cooling. Simulation results showed that active cooling significantly reduces heat transfer through the tooling assembly, indicating clear advantages for tool longevity.

Experimental validation was conducted for all four scenarios using high‑resolution thermal imaging, and the measured temperature fields closely matched the FEA predictions. These findings demonstrate numerical modeling can reliably replicate the thermal mechanisms in FSW, highlighting its value as a predictive tool for optimizing tool design and reducing reliance on resource‑intensive physical testing.

This report is the property of the National Center for Manufacturing Sciences (NCMS). Although the effort and this report is/was sponsored by the U.S. Department of War, the content of the report does not necessarily reflect the position or policy of the Government; no official endorsement should be inferred.

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