Product Code: ICA13_1805

Dissimilar Joining of Titanium Alloy Ti-6Al-4V to Aluminum Alloy 2024 Via Laser Welding
Authors:
Vittorio Alfieri, University of Salerno; Fisciano Italy
Fabrizia Caiazzo, University of Salerno; Fisciano Italy
Vincenzo Sergi, University of Salerno; Fisciano Italy
Presented at ICALEO 2013

Dissimilar joining of titanium to aluminum is required for several purposes in automotive and aerospace industries. Nevertheless, a number of issues arise due to their different properties, in terms of crystal micro structure, melting point, heat conductivity and coefficient of linear expansion. In addition, brittle intermetallic formation is induced at the interface, thus affecting the eventual strength of the joint. Therefore, irrespective of the welding method, the amount of intermetallics has to be reduced to acceptable limits.
Laser welding is a valid solution to be investigated as different advantages are benefited, with reduced heat affected zone as a consequence of a localized heat input; nevertheless, a shielding system has to be developed and the proper window for the welding parameters has to be found. The capability of dissimilar welding of titanium alloy Ti-6Al-4V to aluminum alloy 2024 with no need for filler metal is investigated using a Yb:YAG disk-laser source; 1 mm thick sheets are considered. The influence of the welding speed and the beam offset is discussed. The features of the welding bead are discussed with respect to overall geometry, micro structures and chemical composition. The results are eventually compared with similar attempts in the literature.