Advances in friction stir welding of Ti6Al4V alloy complex geometries: T-butt joint with complete penetration

In this work, the friction stir weldability of Ti6Al4V T-joints has been investigated. Its aims are: (i) to study the influence of tool and welding parameters on weld quality, (ii) to assess the joints’ mechanical strength to foresee future applications, and (iii) to characterize Co-based FSW tools’ wear by following the wear during the tests. Welds’ defectivity is studied by cross-section macrographies analysis. Independently from welding parameters and tools, internal voids are avoided, and a suitable weldability window is identified. Microstructure observations have corroborated temperatures below the β -transus point even in the nugget zone, guaranteeing joints’ maximum mechanical strengths at 96