Friction Stir Welding of Titanium alloys: Process Parameters and Microstructural EvolutionThursday (07.11.2019) 11:25 - 11:45 Part of:
By Masoumeh Faraji (a) and Jonathan Martin (b)
a: Lecturer in Mechanical Engineering and Materials, Coventry University, Mechanical, Aerospace and Automotive Engineering, Coventry, UK
b: Friction Stir Welding Technical Manager, TWI Technology Centre (Yorkshire), Rotherham, UK
Friction stir welding (FSW) is a material joining process in the solid state using a rotating tool. FSW is an extremely complex thermomechanical process wherein materials experience plastic deformation at elevated temperatures, creating a weld zone consisting of a wrought microstructure instead of the solidification microstructure produced by fusion welding methods. FSW joints usually exhibit superior mechanical properties in terms of strength, toughness and fatigue when compared to fusion welds in the same material. This promising technique has attracted great interest from world-leading universities, research institutes, and manufacturing companies.
FSW of aluminium alloys has been successfully applied in various transport industries; however, FSW of high temperature alloys such as titanium has not attained the same level of commercial application as has FSW of aluminium alloys. More studies are needed to deepen understanding of the role of process parameters on the microstructure of titanium alloys during the process.
Microstructural examinations and microhardness testing were undertaken to evaluate microstructural features of Ti6Al4V plates welded under different process conditions using FSW. In addition, this work examines and discusses the role of process parameters on metal deformation and mechanisms responsible for strain-induced dissolution of non-metallic inclusions during FSW of high temperature alloys.