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Every structural material has special properties that set it apart from other materials under certain conditions. As the requirements placed on the structures used in lightweight construction continue to increase in complexity, structural development is increasingly moving in the direction of high-performance materials and material systems.

As a cooperation partner for industry and research, the focus of the Lightweight Materials department is on the systematic, application-oriented and demand-oriented optimization and further development of such materials and material systems, including component manufacturing.

Our activities include the following:

  • Materials: Aluminum, titanium alloys, high-strength steels, property-graded metals, metal-metal composites, hybrid composites, function-integrated materials.
  • Manufacturing processes: Material-oriented additive manufacturing, alloy development, heat treatment, quenching, hardening, joining, testing

 

 

 

 

 

Lightweight materials projects

APFeL - Requirement-adapted process control for efficient laser additive manufacturing of lightweight components

The innovation potential of laser additive manufacturing is immense and yet the high costs to date prevent its widespread use. The APFeL project aims to reduce the manufacturing costs for additively manufactured metallic structures by 25 % by designing the process control in line with requirements and loads. This will make it possible to open up new economic applications in mechanical engineering, the automotive industry and aviation.

Today, metallic components are manufactured using selective laser powder bed fusion (Laser Powder Bed Fusion, PBF-LB/M) in a largely uniform manner and to a high quality level, although there are different quality requirements and the highest quality is not required in all component areas.

The APFeL project starts with the systematic recording of individual customer requirements in order to design the process chain and the individual process steps in a cost-efficient manner and to achieve the required quality level. Using simulation, component areas can be identified that allow a certain porosity and surface quality and are suitable for production with build-up rate-optimized parameters, thus increasing productivity. To this end, the process-property relationship is being investigated in order to develop process parameters that result in defined properties with a low standard deviation in a time-optimized manner. The resource efficiency of the component-specific process chain compared to conventional process chains is evaluated using a life cycle analysis.

The aim of the project is an automated, geometry- and load-dependent assignment of process parameters that takes into account the complex interactions between material, parameters, geometry and mechanical load. In this project, Leibniz-IWT is working together with Materialise GmbH, Fraunhofer IAPT, PRIME aerostructures GmbH, INPECA GmbH, 3N Kompetenzzentrum e.V.

 

This project is funded by the Lightweight Construction Technology Transfer Program of the Federal Ministry for Economic Affairs and Energy.

Collaboration: WT-LW, Materialise GmbH, Fraunhofer IAPT, PRIME aerostructures GmbH, INPECA GmbH, 3N Kompetenzzentrum e.V.
Funding: 03LB2053F

Duration: 01.07.2023 to 30.06.2026

Logo des Bundesministeriums für Wirtschaft und KlimaschutzLogo der Firma MaterialiseLogo Prime Engineering IdeasLogo des Kompetenzzentrums Niedersachsen - Netzwerk Nachwachsende Rohstoffe und Bioökonomie e.V.Logo der Firma INPECALogo des Fraunhofer Institut für Additive Produktionstechnologien

 

Contact:

M.Sc. Lisa Husemann
Phone: +49421 218 51325
E-mail: husemann(at)iwt-bremen.de

 
Figure: Components of a component-specific PBF-LB/M process chain
AURORA - Additive manufacturing of graded structures from iron-based shape memory alloys

The Leibniz Junior Research Group AURORA is conducting research on additively manufactured iron-based shape memory alloys. A novel 3D printing method is used to locally adjust the alloy composition during the process.

Shape memory alloys are metallic materials that return to their undeformed shape when heated after being plastically deformed. Combined with the novel 3D printing method, the fabrication of components with localized functionalization is enabled, opening up completely new possibilities for the design of cost-effective, innovative, lightweight and smart components. Based on this project, a methodology will be provided to investigate a large number of alloy variations with unprecedented material efficiency.

Cooperation: IWT-WT/VT

Funding: Leibniz-Gemeinschaft - „Leibniz-Junior Research Groups“

Contact:
Dr.-Ing. Anastasiya Tönjes
Tel.: 0421 218 51491
E-Mail: toenjes(at)iwt-bremen.de    

AMELA – Thermal adjustment of the microstructure, hot isostatic pressing and machining of additively manufactured metastable beta titanium alloys for aerospace applications

The overall aim of the AMELA project is to investigate metastable β-titanium alloys for the additive manufacturing of aerospace components.

These alloys can be processed with low residual stress and high ductility by laser powder bed fusion (PBF-LB/M) and the mechanical properties can be adjusted by a subsequent heat treatment (α-aging).

The microstructural changes are investigated along the process chain covering the PBF-LB/M -process, heat treatment, hot isostatic pressing and surface machining (milling) and correlated with the effects on the mechanical properties and the machinability of the material. It has already been shown that PBF-LB/M manufacturing can eliminate solution annealing and quenching of the components prior to α-aging, thus enabling a shortening of the overall process chain.

Cooperation: IWT-WT/FT, Technische Universität Chemnitz

Funding: LuFo VI-2 20E1901B

Contact:
M.Sc. Daniel Knoop
Tel: +49421 218 51435
E-Mail: dknoop(at)iwt-bremen.de

CONtrol - Contamination tolerant hypo- and hypereutectic Al-Si-alloys for additive manufacturing

In this project, the influence of Fe contamination on two Al-Si alloys will be investigated which will allow the contamination to be compensated by adjusted process conditions.

Aluminum, thanks to its outstanding mechanical and metallurgical properties, is being used in wide range of applications in several industries. Therefore, the utilization of recycled aluminum is increasing for the sake of more sustainability. In this project, the influence of Fe contamination on two Al-Si alloys will be investigated which will allow the contamination to be compensated by adjusted process conditions.

Cooperation: IWT-WT, Universität Bremen

Funding: DFG SPP2122

Contact:
M.Sc. Layla Shams Tisha
Tel.: +49 421 218 51345
E-Mail: tisha(at)iwt-bremen.de

UBRA ENABLE

The aim of the project is the ML-assisted development of an antibacterial Ti6Al4V-xCu alloy for laser powder bed fusion (LPBF) to reduce implant-associated infections.

Approximately 40,000 endoprostheses are replaced in Germany every year, with bacterial infections being the cause in about 20 % of cases. To counteract this, the aim is to develop an alloy with antibacterial properties from Ti6Al4V and the addition of copper (Cu). Cu has an antibacterial effect in that Cu ions penetrate the bacterial cell walls, while Ti6Al4V is an established implant alloy. Ti6Al4V-xCu is not commercially available, so its clinical suitability is unknown.  

For economic reasons, primary powder mixtures will be produced and alloyed in-situ for the investigations. It is planned to investigate powder mixtures with different copper contents in a range from 1 Ma.-% to 10 Ma.-%. Scientific studies show that LPBF in-situ alloying of Cu with Ti6Al4V powders already leads to inhomogeneous precipitation states and porosity between 1.4 Ma.- % and 6 Ma.- %. However, samples of high relative density and with homogeneous Cu distribution are basic requirements for a HIP treatment (hot isostatic pressing) to adjust copper-induced contact sterilisation by finely distributed Ti2Cu phases. Against this background, a machine learning (ML) method for efficient LPBF parameter and material screening will be developed. Using LPBF single layer experiments and an image analytical approach, suitable process parameters for the in-situ alloying of Ti6Al4V-xCu will be identified for the first time and the alloy properties (relative density, antibacterial activity, mechanical properties) will be determined.

This project is supported by the U Bremen Research Alliance with funding from the state of Bremen as part of the AI Center for Health Care.

Collaboration: Leibniz IWT-WT and University of Bremen Advanced Ceramics

Funding: UBRA 2022

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Contact:
M. Sc. Anna Strauch
Tel.: +49 421 218 51327
E-Mail: strauch@iwt-bremen.de

AM-MikroMod - Acquisition of temperature gradients and local cooling rates in laser additive manufactured components to describe and modify microstructural properties

The aim of the cooperation between Fraunhofer IWM and Leibniz IWT is a modification of the microstructure of laser additively manufactured Ti6Al4V components based on the locally and time-dependent induced energy.

This will be done by a detailed description of the temperature history by means of in-situ high-speed infrared measurement and derived thermal modeling of a laser additively manufactured component. The temperatures and temperature gradients measured in the molten pool, its surroundings and the entire component will be used to derive process and scan strategies for specific local thermal loads, e.g. as a function of the component height, installation space, support strategy and layer thickness. This should allow targeted grading or homogenization of the material. The local cooling rate during laser additive manufacturing is a decisive factor for the microstructural properties of Ti6Al4V in terms of grain size and formation of certain phases. From an exact recording of the local heating and cooling rates as well as their correlation with the component microstructure and the mechanical properties, generic correlations are derived by means of simple artificial neural networks.

Processing: Leibniz-IWT Lightweight Materials, Fraunhofer IWM

Funding: BMWK- AiF/IGF (22102 N)

Duration: 01.02.2022 until 31.07.2024

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

Contact:
M. Sc. Mika Altmann
Phone: +49421 218 51414
E-Mail: altmann(at)iwt-bremen.de

 

VerA distortion compensation in aluminum die casting process chains

The aim of the VerA project is to develop a method of compensating for process-induced residual stresses in aluminum die casting during production. The complete process chain from casting to heat treatment is considered.

The motivation of the project is the economical production of large-area, thin-walled die cast integral components that meet the lightweight construction requirements of the automotive industry. Currently, cost-intensive measures such as straightening operations are necessary to compensate for distortion. In the process chain under consideration, from casting to heat treatment, locally controlled quenching is used to influence distortion and internal stresses during heat treatment. Quenching is performed by adaptive spray field systems. When adapting the spray field, component-specific data from process monitoring are used so that warpage can be compensated for by optimum local cooling rates.

This project was funded by the German Federation of Industrial Research Associations (AiF).

Working on the project: IWT-Verfahrenstechnik, IWT-Leichtbauwerkstoffe, IFAM

Funding: BMWi-AiF

Duration: 01.04.2022 - 30.09.2024

Contact:
Dr.-Ing. Anastasiya Tönjes 
Tel.: +49 421 218 51491 
E-Mail: toenjes@iwt-bremen.de

M.Sc. Daniel Knoop
Tel.: +49 421 218 51435
E-Mail: dknoop@iwt-bremen.de

 

 

LegoLas - In-situ alloy variation in powder bed based laser beam melting

The aim of the DFG research project is the exact production of variably alloyed samples by means of powder bed based laser beam melting.

The production of variably alloyed samples is to be realized by an approach developed at Leibniz-IWT, consisting of a process combination of suspension pressure technology and powder bed based laser beam melting. This process, which is to be automated, should be able to produce graded structures with specific lower-alloyed and higher-alloyed regions as required. The basis of these different alloy variants is always the same starting powder within a manufacturing process. Furthermore, the research project will examine in detail the distribution of the alloying element both in the component space as a result of the gas flow and in the remelted component volume. The aim is to achieve a broad understanding of the recyclability of the starting powder used, without possible impurities of the applied alloying element influencing subsequent processes.

This project is funded by the German Research Foundation.

Processing: WT-LW, BIAS GmbH

Funding: TO 1395/1-1

Duration: 01.07.2021 - 30.06.2024

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

Contact:

Dr.-Ing. Anastasiya Tönjes
Tel.: 0421 218 51491
E-Mail: toenjes(at)iwt-bremen.de    

M.Sc. Marcel Hesselmann
Tel.: 0421 218 64549
E-Mail: hesselmann(at)iwt-bremen.de

UBRA Portal

The core of the project is the investigation and optimisation of the additive manufacturing process through automatic selection and adaptation of suitable parameter sets of the manufacturing process and the material selection through approximate and probalistic predictor functions.

Endoprosthetic implant fittings, such as hip and knee joints, contribute to a higher quality of life and represent an established procedure. The Ti6Al4V alloy is one of the materials used for this. This alloy has a high specific strength, stiffness, biocompatibility and corrosion resistance. In addition to forged or cast endoprostheses, these are now also manufactured with patient-specific geometries using laser additive manufacturing from the powder bed (Laser Powder Bed Fusion, LPBF). A certain amount of residual porosity in LPBF-produced objects is unavoidable. A distinction is made between gas porosity, bonding defects and keyhole porosity. Any type of porosity can lead to fatal failure, as it acts as a crack initiation point, especially under dynamic loading. LPBF objects are therefore subjected to hot isostatic pressing (HIP) for critical applications.

The core of the project is the investigation and optimisation of the additive manufacturing process through automatic selection and adaptation of suitable parameter sets of the manufacturing process and the material selection through approximate and probalistic predictor functions. To this end, machine-approximated prediction models will first be derived that allow the failure and service life of the components to be estimated on the basis of the process parameters and other sensory manufacturing data (forward model). With this knowledge, the inverse problem (backward model) should finally be obtained in order to be able to estimate the optimal manufacturing parameters from given result parameters of the products (properties).

This project is supported by the U Bremen Research Alliance with funding from the state of Bremen within the framework of the AI Center for Health Care.

Working on: Leibniz IWT-WT and University of Bremen

Funding: UBRA 2021

Contact:
M. Sc. Mika Altmann
Tel.: 0421-218 51414
E-Mail: altmann@iwt-bremen.de

TIRIKA - Technologies and repair processes for sustainable aviation in a circular economy

As a research partner in this joint project, Leibniz-IWT supports the goal of environmentally friendly aviation.

The research focuses on increasing the degree of lightweight construction, the use of materials for new propulsion technologies and increasing the service life of highly relevant components. In this context, research is being conducted on improving the mechanical properties of laser-additively manufactured Ti6Al4V components. Novel heat treatment processes are to be developed that exploit the mechanical potential of laser-additive manufactured components while taking into account their special microstructure.

Processing: WT-LW, joint project under the direction of Airbus Operations GmbH.

Funding: LuFo VI-2 20W2103J

Duration: 01.01.2022 until 31.03.2025

Contact:
M.Sc. Mika León Altmann
Tel: +49 421 218 51414
E-Mail: altmann(at)iwt-bremen.de

HIP⁴AM - Hot-Isostatic Pressing for Additive Manufacturing

As part of the project "Hot-Isostatic Pressing for Additive Manufacturing - HIP⁴AM", the process chain for additive manufacturing (3D printing) of high-strength metallic components was completed at Leibniz-IWT Bremen through the procurement of a hot-isostatic press.

The press allows heat treatment up to 1400°C under an isostatic gas pressure of up to 2070 bar. In combination with the integrated quenching capability, the development of combined HIP heat treatment processes is possible.

The system complements the institute's existing continuous process chain of additive manufacturing from powder to tested component and enables the investigation of the technological potential of these processes. The procurement was supported with funding from the ERDF program Bremen 2014-2020.

Bearbeitung: WT-LW, WT-WB, ECOMAT

Förderung: EFRE-Programm Bremen 2014-2020

Laufzeit: 04/2019 – 04/2021

Contact:
M.Sc. Daniel Knoop
Tel: +49-421/51435
E-Mail: dknoop@iwt-bremen.de