Friction welding: An effective joining process for hybrid additive manufacturing.

• Linear Friction Welding (LFW) demonstrated for hybrid additive manufactured (AM) parts. • Microstructure evolution compared between conventional and AM parts. • Temperature history predicted by finite element models correlated well with the microstructure changes. • The effects of process parameters on metallurgical evolution have been explained. Hybrid additive manufacturing combining bulk components from traditional manufacturing route can overcome the size limitation in typical metal additive process. Investigating the joining process of bulk and additive components is crucial in hybrid processes. In the present work, a comprehensive study, including both experiments and simulations, has been carried out to describe the linear friction welding of electron beam melted Ti6Al4V. Three different welding configuration have been considered: conventional-conventional, EBMelted to EBMelted and the dissimilar conventional-EBMelted. Successive weld joints were achieved in all the three configurations. The mechanical behavior and the phase transformation in the weld region is highly influenced by the base material microstructure. The thermo mechanical behaviour during the friction welding is simulated using finite element method. The temperature history is predicted with very good accuracy in all the three configurations. The experimental data along with the simulation results are used to further explain and understand the phenomena occurring during the welding. [ABSTRACT FROM AUTHOR]