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Innovative repairing technique via Additive Manufacturing
1 : Thales Alenia Space
2 : WAAM3D
3 : WAAM3D
* : Corresponding author
Space infrastructures are made of many sub-systems and components, which sometimes may be scraped due to the presence of defects, cracks and general damages, mostly caused by a not perfect parts handling and storage. Generally, the issue is localized in a reduced and superficial area not affecting the whole part integrity. Despite this, the damaged component cannot be used because these damages can propagate during the application and lead to final failure during system's life. As a result, each damaged part shall be rejected involving a huge waste of money and an increase of the final product's lead-time.
In this regard, specific technological processes are able to repair damaged parts or sub-system. There are several methods to repair metal parts, which are based on different approaches.
In this kind of applications, Additive Manufacturing (AM) technologies are particularly promising. In fact, compared with more traditional welding based methods, the AM generally enables better control of spatial resolution and deposition path and therefore substantially improves the precision in repairing of complex components.
Among these innovative technologies, one of the most promising for these applications is the WAAM (Wire Arc Additive Manufacturing). This AM technology is able to both create and repair medium-to-large components. WAAM can be used to repair holes, cracks, segregation, inclusions, surface marks and notches, which are common defects in space components. The repairing procedure consists of three main steps: the removal of defects by machining, the deposition of a suitable metal material to fill the groove and its finishing by machining.
By using this innovative process some parts or samples will be repaired and the material used as a filler (e.g. wire) should be the same alloy as the base material. Then, the assessment at mechanical and morphological level of the repaired samples will be performed, validating the process.
