Converting forgings or weldments to castings is a matter of great satisfaction for foundries and diecasters, but those conversions go the other way too. And lately, forgings, weldments, milled parts, and castings are being converted into additive manufactured parts. That does not happen quickly, but rather as a result of long research and development programs.
Over the past decade Airbus has been comparing critical parts (castings, and others) with AM alternatives, to reduce weight or improve precision, or to achieve other objectives. For some critical titanium parts, wire-based additive manufacturing has emerged as a preferred approach for the OEM.
Faster production at reduced costs are the main advantages of wire-based additive manufacturing technologies in commercial aerospace supply programs. The aerospace industry has become one of the principle manufacturing sectors producing metal parts by AM (or, 3D printing), and the economic impact of that industry means the OEM and Tier suppliers have no difficulty gaining research assistance for their conversion plans. The Regis project, funded by the German Federal Ministry of Economic Affairs and Energy, has allowed Airbus to pursue additive manufacturing applications with various companies.
Gefertec was selected for the project due to its invention of the 3DMP® process for producing larger parts, quickly and cost-effectively, in titanium. The method is based on electric arc welding techniques, using the welding wire as the source material for CAD-derived, layered production of three-dimensional shapes. The near-net-shaped part is formed welding layer by welding layer.
Wire-based technology offers advantages compared to other additive manufacturing methods too, especially compared to powder-bed AM. Sintering metal powders is frequently more time consuming than wire-based 3DP, among other costs and liabilities in the process.
In particular, the Regis project intends to overcome the geometric-scale restrictions of other 3DP process, all of which impose dimensional limits on the metal parts to be produced. The project is focused on wire-based AM methods with high production rates (up to 650 cm3/h), in combination with joining technology to manufacture critical structural components. The program directors predict the productions costs will be reduced by 50%, compared to standard manufacturing.
Airbus and its research partners use a Gefertec arc403 3D printer, which has a working space of half a cubic meter but manufactures even larger parts at high speed. Immediately after 3D printing the part can be finished by conventional milling.
“Airbus considers wire-based high-performance additive manufacturing methods, like Gefertec’s 3DMP-technology, to provide enormous cost and resource saving potentials in manufacturing of structural components in the aerospace industry,” according to Dr. Jens Telgkamp, who heads the Additive Layer Manufacturing Research & Technology team for Airbus Operations GmbH. “Together with our Regis team partners we aim to develop methods for additive manufacturing of larger parts along the entire process chain.”
In its first stage, the project focused of developing wire-based AM with titanium materials. Medium-sized titanium parts offer the largest potential savings, as the amount of the high-value raw material that is ground or milled away in the finishing process can be up to 90% for more conventionally manufactured parts.
In the second phase, the Regis partners will concentrate on aluminium materials, which it’s expected will lead to adopting new construction methods of aircraft parts. If successful, that will mean that design conversion is also material conversion. And that probably will not be the end of the process.
The Regis research program will conclude in 2021, at which time the new manufacturing method is expected to be qualified for aerospace parts production.