STWIN, or Advanced, Non-destructive Technologies to Improve Steel Stir Welding Process Through Artificial Intelligence and Smart Digital Twin, is a project funded by the Research Fund for Coal and Steel that started in July 2023 and will run until June 2026.

STWIN will develop a new friction stir welding (FSW) method capable of creating complex 3D structures for a variety of steel grades and thicknesses.

In parallel, the project will explore the specific advantages of the friction stir welding process in combination with real-time quality control, with a view to achieving zero-defects manufacturing. To this end, the integration of artificial intelligent and smart digital twin solutions will be enhanced.

STWIN’s technology will be demonstrated by 3 innovative use cases containing: (1) complex 3D joint assemblies; (2) dissimilar material joints and (3) dissimilar thicknesses joints.


  1. Optimised process parameters for FSW of 3D joints in high strength steels and for dissimilar joints (steel-aluminium and sheets with dissimilar thicknesses).
  2. Demonstration of the techno-economic advantages of the new production method using demonstrators.
  3. Weld quality prediction by AI models, obtained by correlating real-time measurement data during welding with physical weld defects.
  4. Validation of applicability of real-time quality monitoring in real workshop circumstances, using pilot test-ups of the demonstrators.