The ANDDURO (ANalysis of Defects and DURability Optimisation) project, started in 2016 by the IRT Saint Exupéry brought together a consortium of 21 members*, including research centers, academic laboratories, SMEs, and large industrial groups, to build a significant database of information relative to several aspects of metal additive manufacturing.
With a very large panel of industry operators, including powder manufacturers, parts manufacturers, partners specialized in the post-processing of parts and industrial end-users, the ANDDURO project team, in collaboration with academic partner laboratories, has now built a base of knowledge and robust methodologies covering many topics, including, but not limited to additive manufacturing materials, parts and processes characterization.
One of the goals of the project was to remove barriers shared by many players in the aerospace sector, with a project budget of €17.2 million – financed at 27% by the private sector and 73% by the public sector (50% by the PIA and 23% by the Occitanie Region). It took 59 months to complete.
The industrial partners (which included Airbus, Lisi, Oerlikon and other companies heavily invested in AM) were motivated by obstacles such as a lack of knowledge about mechanical behavior, in-service performance, and aging of the materials used in additively manufactured products. As well as the effects of the defects generated during manufacturing, a fine characterization of the specific microstructures developed during manufacturing, and the response of the latter to heat treatments and surface treatments.
The ANDDURO project focused on the study of 3 main alloys used in the aerospace industry: an aluminum-based alloy, the AS7G06 alloy, a titanium-based alloy, the TA6V alloy, and a nickel-based superalloy, the 718 alloys, with the main objective of supporting the qualification processes of materials and processes of additive manufacturing on powder bed electron beam melting (aka EBM or EB-PBF) and laser melting (aka SLM, LBM or L-PBF).
Thus, the links between the conditions of elaboration (machine, parameters, thermal post-treatments, etc) and the quality of the material elaborated were in the center of the activities of the project, as well as the characterization of the typical defects of the processes used, their impacts on the mechanical properties, the identification of the means and conditions of control necessary to their detection, or the evaluation of the stability of these materials in contexts representative of life conditions in service.
Opportunities and challenges
The involvement of 15 major industrial members of the aerospace sector, as well as the support of the Occitanie Region, associated with the significant financial leverage provided by the PIA, offered the ANDDURO team unprecedented opportunities, such as:
The access to numerous resources, including 13 industrial additive manufacturing machines, the implementation of differentiating platforms within IRT Saint Exupéry (manufacturing, post-processing, controls and characterizations), the implementation of exhaustive and robust research programs, the implementation of long-term isothermal aging tests (up to 10,000 hours – nearly 14 months), and the identification and exploration of future developments for metal additive manufacturing.
The ANDDURO team faced challenges such as the development of work plans allowing a rise in the maturity of each industrial member despite unequal initial knowledge, ensuring knowledge and control of all manufacturing steps to identify sources of variability, minimize uncertainties, and, thus, allowing manufacturers to consider metal additive manufacturing on powder bed as a reliable manufacturing process, and keeping coherence in the activities carried out, without ignoring the opportunities which could arise in terms of available alloys.
Characterization: Metallographic preparation methods, methods of characterization of microstructures resulting from additive manufacturing by powder bed, powder characterization methods, methods of non-destructive testing, including x-ray microtomography and thermal analysis methods.
Materials: Establishing the impact of process parameters, the development of thermal and thermomechanical treatments, identifying and quantifying the evolution of microstructures and mechanical properties of alloys transformed by additive manufacturing during long-term thermal aging, and establishing methodologies for the creation of controlled defects.
Processes: Control of the digital chain associated with the manufacture of trays, handling and managing powders, and the implementation of an experimental bench for better control of the manufacturing process on powder bed with laser beam fusion.
All the results obtained from the research project, structured in a database of more than 5,500 specimens spread over more than 100 different manufacturing platforms, associated with complete traceability of the raw material to the specimen/final part and its associated mechanical characteristics, will allow the members of the ANDDURO project to define sizing criteria according to the targeted applications.
To disseminate the results of the research project to as many people as possible – and therefore to allow everyone to better understand the capabilities and challenges offered by metal additive manufacturing on powder bed – the ANDDURO team has selected 11 of the 46 deliverables to make them available to the general public.
Links to the 11 deliverables can be found below:
Airbus Group (Airbus Operations, Airbus Defence & Space), Altran Technology (current Capgemini Engineering), Daher, Element Materials Technology, Fusia, IRT Saint Exupéry, Latécoère, Lauak, Liebherr, Lisi Aerospace Additive Manufacturing, Mecaprotec Industries, Oerlikon AM, Safran, Satys Surface Treatment, Stelia Aerospace