Various powder modifications for a newly developed cold spray process to aim cost efficient structural repair application in aerospace industry

The repair of aircraft components has become increasingly important in recent years, due to material shortages, supply chain issues and sustainability. However, there is still a certain lack of qualifiable mobile repair technologies in aerospace industry. Cold spray is a promising repair technology for on- aircraft damage of aluminum components, due to its unique properties. Traditionally, helium has been the process gas of choice for structural repairs, although it is significantly more expensive than nitrogen. However, key criteria for whether structural repairs by cold spray can be successfully qualified in aerospace industry are: i) the quality of the sprayed material, ii) improved adhesion to the substrate and iii) process stability.

This presentation explores Airbus' advancements in the cold spray technology using nitrogen, aiming to develop an accessible and cost-effective repair solution. A significant challenge in the community is the natural oxide layer of aluminum alloys, such as Al6061, which acts as a barrier for material bonding in cold spraying. So far, the standard cold spray process was not able to reach high enough particle velocities to overcome these barriers for aluminum alloys. Within this work, various powder modifications are investigated to compensate for the energy deficit of nitrogen. The mechanical properties of these new developments demonstrate a significant increase in deposit ductility, indicating an improved material bonding. Hence, this shows the feasibility of cost-effective, structural repairs using nitrogen propelled cold spray for aerospace industry.