Additive Manufacturing at French Space Agency with Industry Partnership

As an introduction, the role of CNES (Centre National d’Etudes Spatiales, the French Space Agency) in France is defined as well as its involvement in the European context. The first part details the organization of research and technology activities dedicated to additive manufacturing (AM) for liquid-propellant rocket engines and its associated objectives, which are conducted together with SNECMA of SAFRAN group. This work is orchestrated around two axes, one dealing with design aspects, realization, justifications which are as much as possible transverse to the second one, which covers the applications of this technology. Our strategy aims at developing additive manufacturing mainly to reduce costs and manufacturing cycles. It results in some actions that will be developed in a second part. Among them, we find the characterization of materials, the related processes to improve surface finishing and to address issues related of anisotropy and porosity. Controllability aspects, deformation (by simulation), design rules (taking account residual stresses) are also presented. Next, examples of parts made by additive manufacturing for launchers are presented. To ensure these innovative technologies lead to significant benefits (both from cost and mass savings point of view, and from manufacturing flexibility and production cycle), key challenges must be overcome. These are presented in a dedicated part. Such challenges are related mainly to the design (design rules and tools), manufacturing (size machine, standardization of powders, new materials, simulation tools) and qualification (qualification methods, process optimization, range acceptable defects, surface treatment and normative framework).