In concrete terms, new aluminum alloys for LAM shall be developed, which meet the automotive-specific requirements for strength, crash, part quality, etc. Finally, the process chain of highly functional vehicle structures shall be validated.

The IWT is responsible for the development of tailor-made aluminum materials for LAM production. An alloying concept was developed which uses the fast cooling rates in the LAM process to provide a competitive alternative to widely used materials. The suitability of the material was demonstrated using structural and chassis components for automotive applications.

Editing: WT-LW, VT-SK, EDAG Engineering GmbH, Concept Laser GmbH, Mercedes-Benz AG, ECKA Granules Germany GmbH, Fraunhofer Institute for Industrial Mathematics ITWM, Fraunhofer Research Institution for Additive Production Technologies IAPT, MAGMA Gießereitechnologie GmbH

Funding: BMBF ProMat_3D 03XP0101G

Duration: 02/2017 - 01/2020

Contact:

M.Sc. Daniel Knoop / Farhad Mostaghimi
Tel.: +49421 218 51435
E-Mail: dknoop@iwt-bremen.de

The complete process chain from powder production to the tested component is considered, with the project being divided into the following sub-steps:

•     Alloy development according to the component requirements
•     Development of a powder atomization system as well as powder production and characterization
•     Process development of the laser beam melting process for high-strength Al alloys
•     Heat treatment strategies for components made of high-strength Al alloys
•     Tests of the manufactured components

The heat treatment investigations focus on the influence of the treatment on the mechanical properties of the components and the control of distortion.

Editing: WT-LW, IWT-VT

Funding: ZIM 16KN021235

This project is part of the research focus "Additive Manufacturing" at IWT Bremen.

Contact:
Dr.-Ing. Anastasiya Tönjes
Telefon: +49421 218 51491
E-Mail: toenjes@iwt-bremen.de

By N2 flushing of metal melts and subsequent rapid solidification by means of gas atomisation, powders with a high N2 content of up to 0.2 wt. % can be produced. The synthesised powders are subsequently additively manufactured into cm-scale samples, formed and heat-treated. The influence of the individual process steps on the strengthening mechanisms and microstructure formation are the aim of the investigation. Using the example of a CoCrFeNi alloy, a positive influence of particle reinforcement on the micromechanics of the metallic powders produced and samples manufactured by L-PBF (laser-powder-bed-fusion) could be demonstrated. Furthermore, powders whose processability was not given in the L-PBF application process were improved by means of nanoscale additives of the type so that an optimal flowability was achieved. This powder conditioning step enables the use of the fine fraction < 20 µm in the L-PBF process and leads to an enormous yield increase of approx. 20 %. Flow-improving effect of nanoparticulate coatings on metal powders for additive manufacturing using the example of the dynamic angle of repose for CoCrFeNi powders.

Editing: VT SPK

Partner: MPI Iron Research, Düsseldorf

Funding: German Research Foundation in the Priority Programme 2006 "Alloys with Complex Composition - High Entropy Alloys (CCA-HEA); funding code: UH77/11-1

Contact:
M.Sc. Eric Gärtner
Phone: +49421 218 64502
E-mail: e.gaertner@iwt.uni-bremen.de

The potentially narrower particle size distribution of powders produced by PGA increases material efficiency and could thus create both ecological and economic advantages compared to conventional technology. In order to evaluate these effects, the produced aluminum alloys will be investigated with respect to their suitability for additive manufacturing. The focus is mainly on the characterization and processing of temperature sensitive powder alloys.

Editing: IWT-VT / WT

Funding: BMWI-AiF/ZIM

Contact:
M.Sc. Marcel Hesselmann
Tel.: 0421 218-64549
E-Mail: hesselmann@iwt-bremen.de

The greatest challenge is to avoid crystallization along the entire process chain from powder production to use in LPBF to maintain the superior properties of BMGs. The main goal is to produce amorphous components made of CuTi-based alloys by LPBF and to gain knowledge about the oxygen intake and cooling behaviour taking place during the process, as they could lead to crystallization. This will allow extending the narrow process windows for defect-free processing and the adaptation of the technology to new product geometries. The project is a cooperation with the University of Saarland and the University of Duisburg-Essen.

Editing: IWT-VT

Funding IGF No.: 21227 N

Contact:
M.Sc. Erika Soares Barreto
Tel.: +49421 218 51404
E-Mail: sbarreto@iwt.uni-bremen.de

To this end, the blast furnace slags are to be sprayed particularly finely while still in a molten state using an innovative spraying technique in order to avoid the time-consuming grinding process and to use the advantages of the ideally round grain shape of the blast furnace slag balls in modern and environmentally friendly concretes.
The high viscosity of blast furnace slags leads to undesirable fibres during atomisation. This is to be counteracted, among other things, by increasing the atomiser gas temperature in order to increase the yield of desired round particles.
On the one hand, this eliminates the need for granulating, drying and very energy-intensive grinding of the blast furnace slags to produce granulated blast furnace slags. On the other hand, the expected ideally round particle shape of the sprayed blast furnace slags means that concretes with a lower cement demand can be expected than when using classic cements containing blast furnace slag. Both savings potentials lead to the expectation of a considerable reduction of previously occurring CO2 emissions in the entire production chain of structural concrete.

Working on the project: IWT-WT-MPA-Bauwesen / IWT-VT

Funding: AUF programme for the promotion of applied environmental research with funds from the ERDF and the State of Bremen, funding code: AUF0014B

This project is funded by the European Regional Development Fund (ERDF).

Cooperation partner: HS Bremen, Institute for Building Materials Technology

Kontakt:
Prof. Dr.-Ing. Udo Fritsching
Telefon: +49 (0)421 218-51230
Email: ufri@iwt.uni-bremen.de

M.Sc. Maike Peters
Telefon: +49421 53708 71
E-Mail:peters@mpa-bremen.de

The stiff and light TiB₂ particles in the Fe-based metal matrix composite (MMC) induces higher stiffness / density ratio, which enables a weight saving of up to 10 – 20% depending on the component. However, the conventional liquid-metallurgical casting process results in severe embrittlement due to very large (several µm diameter) and sharp-edged particles. Through the rapid solidification process this negative effect can be significantly reduced. For example, through spray forming process a factor of approx. 100 (nano-scale particles) have been achieved. The finely divided precipitations lead to a substantial improvement in the mechanical properties. The tensile strength increases by approx. 60%, with the elongation at break only decreasing insignificantly. In addition, the modulus of elasticity decreases slightly. In this project a process chain will be developed with ideal parameters for industrial use, for example in drive components.

Editing: IWT-VT, MPIE

Funding: Projekt IGF 21460