820774 MANUELA: Additive Manufacturing using Metal Pilot Line

• Forschungsstelle: METAS
• Projektnummer: F-5111.30106

Schlüsselwörter (Englisch)

Metal Additive Manufacturing, Powder Bed Fusion, design for AM, in-line control, quality monitoring, machine learning, post AM processing, material qualification for AM, automation, standardization

Kurzbeschreibung (Englisch)

Metal additive manufacturing (AM) allows, by enabling use of advanced design, production of high added value components, at levels that cannot be reached with conventional manufacturing technique.

Still, the AM-based manufacturing sequence implies large amounts of critical steps – design for AM, AM fabrication, post processing, etc. – compared to conventional production sequences. Presently, the key competencies related to these steps are either not fully implemented at industrial level (process quality monitoring) or dispersed geographically with poor connection between different steps.

Relying on two major AM technologies (LPBF: Laser Powder Bed Fusion and EBM Electron Beam Melting), MANUELA aims at deploying an open-access pilot line facility, covering the whole production sequence, to show full potential of metal AM for industrial AM production.

This is a joint research project co-funded by the European Unions's Horizon 2020 research and innovation programme. METAS is one of the project partners in the project.

Projektziele (Englisch)

At first, careful instrumentation and adaptation of LPBF & EBM machines will allow increased process reliability and speed.
Secondly, the pilot line – including the adapted processes – will be deployed. The hardware layer will integrate novel process quality control monitoring and automated post-AM handling and processing. The line will be fed by design/optimization and AM process simulation workshops. Those workshops will collect continuous feedback from the physical parts of the pilot lines, to increase process reliability and robustness.

MANUELA relies on a consortium composed of industrial end user’s, suppliers, (material/powder, AM hardware, quality monitoring system, software, automation and post-AM treatment) as well as top research institutes in powderbed metal-AM, covering full range of AM technology chain for pilot line deployment. The deployed pilot line will be validated for use cases, covering wide span of applications including automotive, aerospace, energy and medical. To insure sustainability of the deployed line and its open access at project end, a dedicated exploitation plan will be established.

Abstract (Englisch)

Powder quality and its effect on AM test parts printed with an e-beam system was investigated by FAU Erlangen, and different test objects with different dimensions were analyzed for the optimal AM geometry.

Several test cylinders with varying laser power and writing speed were analyzed and the formation mechanisms of the pores were determined. Sputtering (including deposits of e.g. oxide particles) was characterized in collaboration with Chalmers. 30 samples of the alloys IN718 and Hastelloy were examined for structural defects. Deep sphericity (< 0.5) is an indication of non-fused layers (lack-of-fusion defects). Both samples were manufactured with the same parameters, but were in different positions in the build volume and were therefore exposed to different degrees of spatter (redeposited, oxidized powder particles). This defect mechanism has not yet been sufficiently investigated in the literature. The Chalmers AM system was equipped with in situ optical tomography (OT) to capture images during part fabrication. In the collaboration with POLITO, the focus was on the additive manufacturing quality (shape and porosity) of various titanium alloys on a defined test piece with holes (Ti64ELI, Ti6246). 

With a digital twin where the porosity distribution of the sample was reproduced, it was determined, for example, that the evaluation method used systematically underestimates the equivalent pore radii, which is why pores below the detection limit were found. AM test samples with different surface treatments were produced and measured by us to validate the optical coordinate measuring machine, which is used in the post-processing pipeline at RISE. Various analyses were carried out on the basis of the measured data: dimensional characteristics, porosity and surface quality. The "Space" use case (RUAG Space - slip ring), a slip ring made of copper, was manufactured in the meantime, characterized at CSEM and then scanned at Metas CT. The CAD-supported surface finding delivered good results for the space use.

Umsetzung und Anwendungen (Englisch)

At the beginning of the project, the METAS-CT had just been set up and its geometry had not yet been characterized down to the finest detail. Thanks to the project, Metas was able to experiment with "real" problems on "real" parts. The automation of the METAS-CT procedures was improved as a result.

Metas has also focused particularly on the pore analysis measurements of AM powder. Traceability is absolutely trivial here. However, we can now confirm such results through simulations. 

Although the METAS-CT can show its full value when measuring small parts (4mm x 4mm x 4mm), the project partners were also enthusiastic about the results with larger parts, thanks to which AM parameters of the partner plants could be characterized. Metas also had the opportunity to study parts with strong absorption and its "beam hardening" artifacts, which led to the idea for a correction.

Through this project, METAS has gained a lot of know-how as well as improvements and confidence in its METAS-CT. 

Publikationen / Ergebnisse (Englisch)

"High-resolution X-ray computed tomography for additive manufacturing: Towards traceable porosity defect measurements using digital twins", B. A. Bircher, S. Wyss, D. Gage, A. Küng, C. Körner and F. Meli, euspen SIG Advancing Precision in Additive Manufacturing, St. Gallen, Switzerland 2021

"In-situ detection of stochastic spatter-driven lack of fusion: application of 2 optical tomography and validation via ex-situ X-ray computed tomography" ,C. Schwerz, B. A. Bircher, A. Küng and L. Nyborg, Additive Manufacturing, Vol.?, p.?, submitted 2023.01.19,

"Investigating critical design features in LPBF-produced parts: a comparison between different titanium alloys" A. Carrozzo, B. A. Bircher, et al, submitted to Metals and Materials International 2023-01.

"Beam hardening correction based on image noise", S. Burkhard and A. Küng, submitted to 7th Dimensional X-ray Computed Tomography Conference, 26th-27th June 2023, Bath.

 

" Mechanical properties of Hastelloy X affected by spatter redeposition", C. Schwerz, J. Moverare, B. A. Bircher, A Küng and L. Nyborg, submitted to Metals and Materials International 2023-05.