Week 18/2021

It's all about the combination!

Additive manufacturing is much more efficient than forging, especially for tall and thin components. Here, the socket as the basic element is forged, and the upper part is applied additively.
Additive manufacturing is much more efficient than forging, especially for tall and thin components. Here, the socket as the basic element is forged, and the upper part is applied additively.
Ribs, fittings and structural components that connect fuselage and wing – there are thousands of these parts in every aircraft. To date, they have usually been forged. The company OTTO FUCHS from North Rhine-Westphalia intends to enhance production with 3D manufacturing methods in the future. In this way, the advantages of both processes can be leveraged, lowering costs, speeding up production and reducing material consumption.

Both methods have advantages and disadvantages. Drop forging, for example, is fast and cost-effective for large quantities, but time-consuming and expensive for small production series. Compounding this, manufacturing some components with this method requires an excess of material. For example, very flat parts and narrow, tall ribs must first be forged with more thickness and the surplus then shaved off by machining. 3D printing, on the other hand, is ideal for prototypes and small batches. Thanks to greater design freedom and the associated possibility of near-net-shape forming, material consumption can be reduced by up to two thirds. The processes could ideally complement each other.

Deploying 3D printing where helpful

With this aim, in its multiyear SAMT64 project, OTTO FUCHS is researching the extent to which components can be produced using a combined process of drop forging and 3D printing. The project is funded under the Aviation Research Program V-3 (LuFo) of the Federal Ministry for Economic Affairs and Energy.  The process would also be of considerable advantage for structural components. Some components only differ in the small details, such as a right or left orientation or a small difference in size. The idea is to forge a basic element in large quantities and then additively apply the details, which can be complex or varied. In addition, different attribute profiles, fully adapted to the intended application, could be realized in one component.

Successful conclusion in sight

In an initial step starting in 2018, the project has been able to provide evidence that the combined process is technically feasible and meets the requirements of aviation. The researchers are currently determining which components the process is actually economically viable for. OTTO FUCHS is leading the project, which also involves the Fraunhofer ILT, the Access e. V. association and the chair of mechanical design engineering at BTU Cottbus.

The project will be completed by December 2021, after which the first components will be manufactured using this method, in cooperation with industry partners.