Metal Additive Manufacturing Conference 2018

In the frame of ESA’s General Support Technology Programme (GSTP 6 E. 1 Clean Space Initiative), focus was set on the surface processing of metal parts made by additive manufacturing (AM). Recently, AM raised a significant interest due to the versatility of the method. Indeed, lightweight and complex shapes with integrated functions can be designed and manufactured with customizable material compositions, which are of prime importance for space and industry applications. The potential of the AM technologies is impeded by the quite rough surface finish observed on the as-manufactured material. The surface texture of the different faces of the parts varies according to their orientations, in the hollow bodies and the structures. Besides, it is known that such a finish is likely to impact the performance of the parts but the influence of the successive post-processing steps on the final properties is not well established. Therefore, a better understanding of the impact of surface characteristics on the material behaviour is needed to expand the use of AM for high performance parts. This study aims at proposing and testing various surface finishing techniques for metal (Ti6Al4V, AlSi7Mg and Invar) parts made by the AM technologies, in order to check their compatibility, evaluate their properties and derive guidelines for future applications. Focus is set on chemical, electrochemical and mechanical surface treatment methods. This paper is devoted to the results of material removal on Invar, AlSi7Mg0.6 and Ti6Al4V. Attention is also paid to the impact of the achieved surface properties on mechanical properties as well as secondary properties such as hydrogen enrichment. In a second step, results of surface functionalization on Invar and on Ti6Al4V are shown.