Dissimilar titanium and titanium aluminide joints manufactured by laser beam welding and laser additive manufacturing

Abstract

Motivated by the increasing demands for lightweight constructions, the aim is to obtain crack-free dissimilar Ti- and γ-TiAl-Ti-alloy joints by focusing on laser beam welding as the joining method. This was successfully achieved by preheating and the crack formation could be correlated to the microstructure-phase evolution. Through tensile tests the influence of the dissimilar interface on the fracture position and tensile properties could be revealed. Extending the thesis, the gained knowledge regarding the microstructure-phase evolution at the interface could be successfully transferred to the laser metal dep-ositions. Besides, the limited transferability concerning the crack formation was demonstrated. Hence, the fundamentals for crack-free γ-TiAl-Ti-alloy joints and depositions were established.