As already known, the challenge of the AM technology is not only mastering the printing process itself, it is the whole process chain, which must be treated and validated for a high-quality final part. Nevertheless, it is important to start with a maturation of the material itself. That is the reason why the aim of this work was to mature new aluminum alloys, which can be used for an AM powder bed process. The focus of new aluminum alloys is on high-strength alloys due to the loads on launcher primary and secondary structures. The first step was to define an additively end-to-end process for launcher aluminum structures. This includes not only the printing process itself, but also the following points: Powder requirements, heat treatment, hot isostatic pressing, surface treatment and non-destructive testing. Afterwards, the required temperature ranges, the surface condition and the material testing methods were identified. To investigate the full performance of the material the following properties were evaluated in most of the cases down to cryogenic temperatures: Tensile and compression strength, fatigue behavior, fracture toughness, crack growth behavior, shear strength and bearing strength. Furthermore, a reliable material data base is important for the AM process qualification independent from the part. In this connection, a verification logic for the qualification of a launcher part made of high-strength aluminum alloy was established. For that, also the design phase and the final inspection was considered.
- Perform qualification activities for an Ariane launcher structures
- Estimate the minimum qualification effort to be flight worthy on an Ariane launcher