Additive manufacturing for aeronautical and space applications

According to the 2012 ASTM International definition, "Additive Manufacturing" (AM) is a process of assembling materials to make objects from a 3D model, usually layer by layer, as opposed to subtractive manufacturing methods, such as traditional machining or forming processes by molding or plastic deformation such as forging.

FA makes it possible to produce close-to-size parts by successive additions of material, without the need to build specific tooling. These techniques are now capable of producing fully dense, close-to-size metal parts in a single step.

Aerospace manufacturers are showing strong interest in various innovative FA processes, as they offer an attractive alternative to conventional processes in terms of cost and design flexibility.

In the aeronautical sector, where small runs of high value-added parts are involved, the growing interest lies in reducing lead times and obtaining a better buy-to-fly ratio, which leads to significant production cost savings.

Even if the market (machines, materials, services) for FA, or 3D printing, remains fairly modest at $18.5 billion in 2020, according to Wohlers, compared with the 115 billion euros in sales currently generated by the French mechanical engineering industry, the industrial stakes are nonetheless very high, particularly for the aerospace sector. Analysts predict that the global metal and polymer FA market will grow by 18% a year up to 2025 ( ).

In aeronautics, the first technological innovation offered by FA is the great freedom of design and the possibility of creating shapes that were previously impossible without the need for costly tooling.

FA also makes it possible to reduce assembly steps and machining passes, resulting in components that are highly competitive with those produced using traditional technologies (casting, forging, machining). Some complex parts are particularly attractive, reducing the total number of elements to be assembled by a factor of ten or more.

In addition, close-to-cut manufacturing minimizes subsequent processing steps.

FA's two main markets in the aerospace industry are the repair of worn parts and the manufacture of high-precision molds. AF has been introduced into the parts repair...