Metal Additive Manufacturing Conference 2018

It is commonly known that the additive manufacturing (AM) technology provides various advantages, such as the production of highly complex (bionic) structures that cannot be realized conventionally, the unused raw material can be recycled and no specific tools are needed. On the economical side, also the lead time saving must be taken into account. Within this project, the surface roughness of Laser Beam Melting (LBM) and Electron Beam Melting (EBM) produced parts was measured. For the LBM process, AlSi10Mg, SS316L and Ti64 powder on an EOS M280 machine and for the EBM process only Ti64 powder on an ARCAM Q20 machine have been used. In general, the “as built” – surface roughness of AM parts is rather high compared to conventional milled parts and due to the powder bed process, semi-molten particles are always attached on the side surface. In this project, various (abrasive or coating) surface treatment technologies like shot peening, (electro-)chemical polishing or anodization were applied and analyzed in order to make a proposal for the most promising surface finishing scenarios, consisting of different treatments. But not only lowering the surface roughness is important; other issues like geometry of the sample, surface quality in terms of particles and cracks or similar roughness on top and side surface have to be considered in space applications. To determine the impact of the chosen surface finishing scenarios, SEM images of the surfaces have been taken and mechanical properties like tensile strength or fatigue of “as built”- and surface treated parts were measured and compared. Furthermore, also the stress corrosion cracking behavior of the additive manufactured parts was analyzed.