More and more projects in defense and space
The need for rapid availability of spare parts is also found in other industries, such as oil platform operators. Here, the issues are less about the complexity of the parts and more about the ability to supply them quickly in isolated areas. Another example is the defense sector, where armed forces around the world are looking at the possibility of having mobile additive manufacturing units capable of monitoring operations and producing spare parts on-demand as close to the battlefield as possible. The space sector has been evaluating the possibility of having metal additive manufacturing onboard space missions for a number of years. Several projects are on the verge of completion, including one currently being developed in partnership with AddUp.
Metal 3D printing can demonstrate real potential, whether it’s about:
- limiting costs related to the storage of parts,
- reducing manufacturing times,
- decreasing transport times,
- or building more agile and environmentally friendly supply chains for spare parts.
The French Environment and Energy Management Agency (ADEME) published a study in 2017 encouraging all French 3D printing players to develop parts repair services.
Repairing parts with DED
All of the projects mentioned so far involve the manufacture of parts on demand. However, we can’t deal with the subject of metal additive manufacturing applied to maintenance activities without mentioning Directed Energy Deposition (DED) technology, which allows applications for the repair of existing parts.
Repair already accounts for 15% of DED technology applications and allows metal to be deposited on existing parts. The repair of worn parts by adding material is not new. For several decades, manufacturers have already been using welding robots, but they often tend to damage the parts. Thanks to DED technology, the repair of parts is becoming much more precise.
The use of a laser beam allows the creation of very thin metal beads around 1 mm wide, as opposed to several millimeters for traditional welding techniques that use electric arcs to melt the metal.
The beads are also thinner than in welding, allowing:
- Deposition of the right thickness of material,
- Reduced machining times (to bring the part back to its original dimensions),
- Less deformed parts.
The heat-affected zone, which is the area of the part that undergoes a rise in temperature, is less important with DED than with traditional welding, which limits the risk of degrading the mechanical characteristics of the parts.
Like PBF technology, DED technology no longer needs to demonstrate its ability to produce parts with very high mechanical characteristics. As proof, AddUp counts among its clients an aeronautical industrialist, one of the most demanding sectors in terms of metallurgical quality of parts, who has qualified a repair application on one of the most critical parts of all: an aircraft engine rotor. The industry was able to prove to the certification authorities that the rotor, instead of being replaced after 10,000 flight hours, could be recharged by DED and remanufactured up to four times, thus extending its life to 50,000 hours.