Additive Manufacturing of Gamma Titanium Aluminide Parts

Electron Beam Melting (EBM) has become an established manufacturing technology for fully dense metal parts with excellent material properties. The parts are built in a vacuum chamber by additive consolidation of thin layers of metal powder. EBM opens up new degrees of freedom in design of complex 3D geometries, e.g. fine network structures, internal cavities and channels. With its production like environment it delivers full traceability from ingot to the final part and do comply with the industrial driven standards for both medical and aerospace applications. The process is particularly attractive for:
i)                    reactive metals, e.g. titanium alloys, which are safely processed without risk of contamination
ii)                  expensive materials, because the powder waste is negligible
iii)                materials which are difficult to fabricate or shape into full density with conventional methods, e.g. hard or brittle materials.
The EBM technology will be described in detail, with focus on mechanical and chemical properties at elevated temperatures for heat treated gamma titanium aluminide. This intermetallic compound has a strong potential for aerospace applications due to its low density and high strength at high temperatures, but its use has previously been hampered by the available fabrication methods.