The following projects are currently being worked on as part of our research focus "Additive Manufacturing":
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
InnoHatch - Innovative Hatching Strategies for the Reduction of Support Structures in Powder Bed Based Laser Beam Melting
The goal of the InnoHatch project is the strong reduction of the necessary support structures in powder bed based laser beam melting by developing a reliable simulation based method for the automatic component specific adaptation of the hatching strategies.
An important part of the additive process chain is the generation of support structures. Depending on the component, these can account for up to 30% of the total component volume. The support structures to be removed in post-processing account for up to 15% of the total costs. For this reason, InnoHatch has set itself the goal of drastically reducing the number of support structures.
Intelligent component-specific planning of the hatching strategies (position and sequence of the laser paths) based on simulations should make the majority of the support points superfluous. In this way, it will be possible to dispense with at least 50% of the support structures, thereby increasing productivity by up to 15%. On the one hand, components can be built up faster by up to 80% due to the reduction in material consumption for the support structures, and on the other hand, the amount of post-processing required is reduced by up to 50%.
This project was funded by the European Regional Development Fund (ERDF).
Processing: WT-LW, AMSIS GmbH
Funding: EFRE_FUE0638B
Duration: 01.09.2020 - 01.06.2022
This project is part of the research focus "Additive Manufacturing" at IWT Bremen.
Contact:
M.Sc. Lisa Husemann
Tel.: +49421 218 51325
E-Mail: husemann(at)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.Eng. Selina Müller
Tel: +49 421 218 51334
E-Mail: s.mueller(at)iwt-bremen.de
LuFo V-3 cooperative research project „Development of additive manufactured integral structure parts”
Subproject: Mechanical machining of CMT-welded parts
This subproject focuses on the mechanical machining related effects on the size and shape changes as well as material properties of CMT deposition welded parts for aerospace applications. The cold metal transfer process is still a welding process with high thermal impact, despite the term “cold”. As a consequence thermal stresses can cause significant part distortion during machining or distortion requires large tolerances. Since CMT structures have a comparably rough surface structure eventually all-side machining is required. The aim of this project is to determine suitable machining parameters on one hand and to master the distortion behavior of CMT-welded parts made e.g. of TiAl6V4 in combination with the influence of the machining process on the other. The size and shape deviations as well as residual stress distributions of CMT / plate hybrid structures serve as input properties for a simulation-based analysis of the impact of the machining process.
Editing: FT
Funding: BMBF LuFo V3
Contact:
Dr.-Ing. Rüdiger Rentsch
Telefon. +49421 218 51191
E-Mail: rentsch@lfm.uni-bremen.de
BMWi AIF ZIM project „Development of additive manufactured Aluminum bearings with hard-particle reinforced raceway”
In this collaborative research project the aim is to utilize the laser metal deposition (LMD) process to generate large Aluminum roller bearings and/or bearing houses directly rather than following standard casting process routes.
To manufacture bearing house blanks flexibly in-house it could help to reduce significantly lead-times for single part or small batch production of lightweight, large-size bearings. By additionally reinforcing the Aluminum surface using hard spherical fused tungsten carbide particles (SFTC) the printed surfaces could directly be used as roller raceways and thereby further increasing lightweight capability. The BIAS GmbH, the IBO GmbH and the Leibniz-IWT are collaborating on developing this additive manufacturing technology. The Leibniz-IWT machines the blanks to size and will analyze those with particles regarding their tribological interaction with bearing rollers. It is expected that distortion engineering is required when scaling up the LMD to larger bearings and adding the reinforcement.
Editing: FT, BIAS GmbH, IBO GmbH
Funding: BMWi AIF ZIM
Contact:
Dr.-Ing. Rüdiger Rentsch
Telefon. +49421 218 51191
E-Mail: rentsch@lfm.uni-bremen.de
RobustAM - Robust and efficient processes for laser additive manufacturing
The objective of the project is to reduce the variability of quality-relevant product parameters (e.g. porosity) in laser additive manufacturing of metallic components.
Using the example of a Ti6Al4V component, it is to be demonstrated that the component service life can be significantly improved compared to the state of the art through appropriate understanding of the interactions and further development of the individual process steps, as well as improved process monitoring. In this way, the required testing effort should be reduced in the medium term and ideally only carried out selectively. Therefore, the data quality from the processes, a deeper understanding of the cross-process step interactions and the effects of defects on the component lifetime will be investigated.
This project was funded by the European Regional Development Fund (ERDF).
Editing: WT-LW, AKON Robotics, AMSIS GmbH, BIAS GmbH, Materialise GmbH, Testia GmbH
Associated partner: Airbus Operations GmbH
Funding: EFRE-LURAFO3001C
Duration: 15.04.2020 until 30.06.2022
Contact:
Dr.-Ing. Christian Werner
Telefon: +49421 218 51354
E-Mail: werner@iwt-bremen.de
SupStruct3D - Phenomenological Model Calibration for the Automatic Generation of Optimised Support Structures for Laser Additive Manufacturing
The aim of the joint project is to develop a tool that enables these support structures to be generated fully automatically and optimised for each construction process in order to reduce process time, material and post-processing effort.
This is because components that are laser-additively produced from metal powder usually have to be stabilised during the construction job by so-called support structures.
For this purpose, a test specimen development is first necessary, which ensures that the specimens always fail in the area of the support structure (not in the overhang to the clamping area of the tensile testing machine) and are tested in a non-preloaded state. The subsequent mechanical characterisation of varying support structure is incorporated into an extended material model. With the help of a few printed calibration samples, the support optimisation module can then make it possible to generate the optimal support structure without lengthy tests.
This project was funded by the European Regional Development Fund (ERDF).
Editing: IWT-WT-LW
Funding: EFRE-FUE0616B
Cooperation partner: Additive Works GmbH
Contact:
M.Sc. Lena Heemann
Tel.: +49421 218 51414
E-Mail: heemann@iwt-bremen.de
N-alloyed, stainless steels for additive manufacturing using L-PBF (AddFeN II)
The goal of the renewal proposal is to give a deeper understanding of the microstructure formation mechanisms and the associated properties of nitrogen-alloyed austenitic stainless steels and duplex steels processed by L-PBF.
The powder production, L-PBF processing of the powders, post processing as well as characterization of the resulting microstructures and the mechanical and chemical properties are carried out. In particular, the interactions between single powder particles during flowing of the powder are used to interpret the global powder properties and are correlated to the powder production and conditioning parameters. The solidification sequences of the nitrogen-alloyed stainless steels depending on their chromium and nickel equivalents are of special interest considering the process specific thermal conditions during L-PBF.
Editing: IWT-VT, IWT-WT, RUB, TU Dortmund University
Funding: DFG UH 77/12-2
Contact:
Dr. Chengsong Cui
Tel.: +49421 218 51404
E-Mail: cscui@iwt-bremen.de
Laser beam melting of amorphous metal powders - LaSaM
The LaSaM project intends to broaden the production of bulk metallic glasses (BMGs) by laser beam melting (LPBF) and expand their economic applicability.
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
Pegasus - Development of a pressure gas atomization process for a cost and material efficient production of aluminum alloy powder for additive manufacturing
Within the project “Pegasus” a novel pressure-gas-atomization process (PGA) will be developed to significantly increase the cost and material efficiency in the production and processing of aluminum powders.
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
GenMat3D – Generation of tailored material properties by selective laser beam melting for launcher structures
The overall aim of the GenMat3D project is the development of a new type of process control for laser powder bed fusion (LPBF), which enables the production of components with material properties tailored to the specific requirements.
Such a process control could be used in integrally printed large bionic structures in the aerospace industry. By applying local gradation, adapted to the requirements, the aim is to decrease production times while optimizing the weight of the components at the same time. To make this possible, correlations between the process parameters and the resulting component properties must be determined. Especially on the microscale there is no sufficient knowledge about the influence of component temperature and geometry on the material properties.
This project was funded by the European Regional Development Fund (ERDF).
Editing: WT-LW, Ariane Group GmbH, Materialise GmbH, Reiner Seefried GmbH
Funding: EFRE_LURAFO2002A
Duration: 01.04.2019 - 31.03.2022
Contact:
M.Sc. Daniel Knoop
Tel.: +49421 218 51435
E-Mail: dknoop@iwt-bremen.de
PORE-Ti - Machining optimized printing of Ti6Al4V components for composite parts with CFRP
The aim of this project is the production and machining of titanium-CFRP composite components whose titanium component is produced by selective laser melting.
The aim is to investigate whether the machining properties of the titanium-CFRP composite component can be positively influenced by introducing pores into the titanium. The focus is also on the potential for optimising the geometry of drilling and milling tools.
Additively manufactured components are usually produced close to the final contour. However, it is not always possible to do without machining, especially if the printed component is further processed into a composite component with a fibre composite material. This places special demands on the production process and tools, especially when combining titanium and CFRP.
Titanium is considered to be a difficult material to machine, with significantly higher forces acting on the cutting edge than is the case with CFRP. Therefore, tools for machining titanium are provided with a defined cutting edge rounding to prevent cutting edge chipping. With CFRP, however, this rounding leads to increased delamination or reamed bore walls. This poses a continuing challenge for the machining of titanium CFRP composites.
This project was funded by the European Regional Development Fund (ERDF).
Editing: IWT-WT/ IWT-FT/Isemann
Funding: EFRE_LURAFO
Contact:
Dipl.-Ing. Annika Repenning
Tel.: +49421 218 51492
E-Mail: repenning@iwt-bremen.de
ProAM - From powder to component
Establishment of a continuous process chain for the additive manufacturing of highly stressed metallic components
As part of the "ProAM" project, a complete process chain for the additive manufacturing of high-strength metallic components is being set up at the IWT (see Figure 1). The aim is to cover the entire spectrum from powder production to manufacturing and quality assurance. This closed process chain represents a unique selling point of the IWT, also in national and international comparison. The cross-process chain consideration of the production of highly stressed metallic components has been a central element of the IWT's research strategy for many years. This is now transferred to the process chain of additive manufacturing. As an advantage, the broad infrastructure and expertise already available at the IWT is accessible.
Structural analysis with xenon plasma FIB-REM
To expand the analysis, a focused ion beam/scanning electron microscope (FIB-REM) was procured, which enables a high-resolution, three-dimensional material and structure analysis down to local residual stresses (Figure 2).
Hybrid production using cold gas spraying and 5-axis milling
To expand the manufacturing possibilities, a hybrid manufacturing cell was set up with funds from the ProAM project. This consists of a spray booth for the additive application of metal powder by means of cold gas spraying and a 5-axis milling machine. Using a common workpiece interface (hydraulic clamping system), components can be processed sequentially and iteratively both additively and subtractively with the help of this system (Figure 3).
Contact:
Dr.-Ing. Andree Irretier
Phone: +49421 53708 12
E-mail: irretier@mpa-bremen.de
Dr.-Ing. Kerstin Hantzsche
Phone: +49421 218 51430
E-mail: hantzsche@iwt-bremen.de
Dr.-Ing. Lars Schönemann
Phone: +49 421 218-51142
E-mail: schoenemann@iwt.uni-bremen.de
"From Powder to Component - ProAM" was funded by the European Union with the following objective: "Strengthening a specialised, company-oriented innovation system" and is thus part of the ERDF Programme Bremen 2014-2020.
Duration: January 2018 until the end of 2021
More information: www.efre-bremen.de
