Material Properties of EBM-Manufactured TI6AL4V with 50µm Layer

Arcam has developed the Electron Beam Melting (EBM) technology specifically for cost-efficient production of metal parts. They are manufactured layer-by-layer from metal powder, melted by a powerful electron beam. Each layer is melted to the exact geometry defined by the 3D CAD model. The parts are produced in vacuum at elevated temperatures, resulting in stress-relieved parts with material properties better than cast and comparable to wrought material. With its production-like environment EBM delivers full traceability from ingot to the final part, and do complies with the applicable industry standards for aerospace applications. The process is particularly attractive for titanium and its alloys. EBM is used pre-production of low pressure turbine blades in γ-TiAl since 2010.

Thinner layers in the EBM process have proven to give higher resolution on parts and lattice structures, as well as a larger process window and more geometrical freedom in the orientation of parts. Throughout the development of the EBM process the layer thickness has decreased and the process has been adjusted away from a single melt pool, to a faster and more built-up hatching. A main reason for moving towards thinner layers is an adjustment to the restricting beam width. In this last step the hatching distance is halved and the translation speed doubled. This study shows that not only does the resolution increase, but the mechanical properties also improve. It shows that the smaller and more rapidly cooled melt pool gives a significantly lower temperature gradient with resulting higher tensile strength with maintained ductility.