- pore analysis
- Grain size determination
- Microstructure and phase analysis
- Degree of purity
Important note:
As part of restructuring measures, the services provided by the Metallic Materials and Structures department will be assigned to the areas of Metallographic Analysis and Mechanical Properties from 2026 onwards. The portfolio of services and contact persons will remain unchanged.
Metallographic and materialographic analysis is a central field of work in materials science for the qualitative and quantitative description of microstructures.
In the field of research and development, for materials science consulting and quality assurance or for damage analysis, the light and electron microscopic microstructure evaluation is an essential component for the assessment of the material properties. Among other things, microscopic observation enables conclusions to be drawn about the manufacturing process and helps to clarify cases of damage. Furthermore, the results of a metallographic analysis form the basis for innovative material developments through the understanding between microstructure and material properties.
The available methods of materialographic analysis are also fully applicable in industrial contract investigations, both for quality control and for identifying product defects and their causes as part of a damage analysis as required.
The Metallographic Analysis Department carries out materialographic investigations for internal projects at Leibniz-IWT, MPA (Bremen) and the University of Bremen, as well as for external orders from industry and commerce.
Contract investigations and service
Our department offers industrial companies, experts and insurance companies targeted assistance in the characterization of metallic and composite materials and their damage analysis. Our services include:
- Damage analysis and development of remedial measures
- Preparation of damage reports
- Comprehensive metallographic characterization in accordance with current standards
- Scanning electron microscopic fracture surface analyses
- Characterization of microstructures and structural components
- Detection of defined phases or phase fractions
- Expert reports for insurance companies, courts, companies and private individuals
- Damage analysis of metallic components and machines in accordance with VDI 3822 (e.g. gearboxes, bearings, motors, pipelines, fittings, etc.)
- Advice on materials science, heat treatment, etc.
- Determination of classic properties of metallic materials (e.g. material tests on steel, aluminum, copper, titanium, magnesium)
- Hardness testing according to Rockwell, Vickers, Brinell (DIN EN ISO 6506-1, 6507-1, 6508-1), among others
- Determination of component properties according to customer specifications
- Metallographic analysis (e.g. macrosection, microsection, grain size determination, etc.)
- Scanning electron microscope analysis including EDX analysis (e.g. fracture surface analysis (fractography), analysis of corrosion products, etc.)
- Element distribution using electron beam microprobe, EBSD (electron backscatter diffraction)
- Spectral analysis to determine the chemical composition using OES, GDOS
Contact us to find out more and realize your projects together with us.
Digital image analysis
- Pore analysis
- Grain size determination (according to ASTM and DIN)
- Determination of microstructure and phase fractions
- Determination of purity (according to DIN)
Hardness testing
Hardness test according to Vickers
- Hardness values in the micro, small and macro load range from 0.05 to 30 kp
- Recording of hardness curves
- Hardness determination on individual microstructural components
- Testing of heat treatment conditions
Electron microscopy
REM
- Qualitative / semi-quantitative phase analysis (EDX)
- Size determination of particles, layers etc.
- Investigation of surface structures
- Fracture surface analysis
- 3D surface measurement
EBSD
- Qualitative determination of phase fractions
- Analysis of local textures
- Location of precipitates
- Analysis of grain boundaries
- Location / intensity of deformations
Microprobe
- Quantitative / qualitative determination of elemental contents (WDX and EDX)
- WDX - analysis of light elements like C, N, O
- Element distributions in the measuring range
Xe-Plasma-FIB-REM
- STEM - Investigations
- Fabrication of TEM lamellae
- Nanostructuring
- Target preparation
- 3D characterisation (EBSD / SEM / EDX)
Projects of Metallographic Analysis
Development of a High-Speed Process for Laser Powder Directed Energy Deposition for Coating Formable Superheater Tubes (MICO)
Collaborative project with the Bremen-based project partners innojoin GmbH, BIAS – Bremer Institut für angewandte Strahltechnik GmbH, and the Leibniz Institute for Materials Engineering – IWT
Extreme temperatures and corrosion place high demands on superheater tubes in waste incineration plants. Laser Powder Directed Energy Deposition (LP-DED) can be used to apply thin nickel-based coatings that are environmentally friendly and highly durable. To ensure the economic viability of the process, the tubes must be completely clad first and subsequently formed. This requires ensuring that the Inconel layer can be formed without cracking. In the previous project “DED Tubes”, two key factors were identified as obstacles: the alloy composition of the Inconel powder, particularly the niobium content, and the undefined thermal management of the LP-DED process. Both aspects are addressed in the current MICO project.
The coating of superheater tubes made of the heat-resistant structural steel 16Mo3 with the nickel-based alloy Inconel 625, the commercial designation, for use in waste-to-energy plants is an established process. It is typically carried out using conventional welding processes such as plasma transferred arc welding or CMT welding, Cold Metal Transfer. Due to its low heat input and the resulting reduced dilution with the base material, Laser Powder Directed Energy Deposition offers advantages in terms of corrosion resistance. In addition, LP-DED enables a reduction in coating thickness compared with conventional processes, accompanied by a reduction in the use of Inconel powder by more than one tonne per superheater. This saves costs and raw materials. Nevertheless, the process has not yet been successfully implemented for this application, since economic viability can only be achieved through the combination of a laser-deposited thin coating and maximum tube formability. Only in this way can complex additional work for joining with conventionally clad tubes be avoided and an economically viable solution ensured. The reproducible crack-free formability of tubes in the coated state is therefore the technical challenge addressed by this project.The cause of the unreliable formability of the tubes coated by innojoin lies in hot cracks, particularly liquation and solidification cracks, which form in the Inconel layer during LP-DED and open up completely during forming. The causes of hot crack formation are, on the one hand, related to process control, particularly thermal management, which leads to uncontrolled dilution between the Inconel powder and the 16Mo3 tube. On the other hand, the chemical composition of the Inconel 625 powder alloy appears to play a decisive role, since alloying elements such as niobium are known to promote hot cracking.
The objective is therefore to develop a process window for Laser Powder Directed Energy Deposition that enables a thin Inconel coating to be applied to superheater tubes while simultaneously ensuring crack-free deformation. To this end, both the alloy composition of the Inconel powder and in-situ thermal management of the LP-DED process will be systematically analysed, developed and optimised.In addition to the conventional alloying elements, the addition of nanoparticles will also be investigated as a means of optimising the powder properties and the resulting coating. The aim is to prevent solidification cracks and achieve a fine solidification microstructure with good formability. The material and process understanding developed in the project will enable subsequent transfer to other material combinations, allowing further applications to be implemented or optimised.
For example, the required corrosion protection of components used in ammonia electrolysis as an intermediate step in hydrogen production is one potential field of application. This could potentially allow laser-deposited steel components to replace chromium-containing stainless steel.
 a) |  d) |
 b) |  e) |
 c) |  f) |
Microstructure of the 16Mo3 tube clad with Inconel 625; on the left, metallographic images etched with HNO₃+HCl+CH₃COOH: a) starting powder In625Nb4, b) Cladding layer with TiC additive, c) Close-up from b); right: OIM maps from EBSD measurement c) Inverse pole figure (fcc, bcc) with confidence index, e) Fe distribution, f) Nb distribution.
Processing: Innojoin GmbH, BIAS GmbH, Leibniz Institut für Werkstofforientierte Technologien - IWT
Funding: 65002594
Duration: 01.10.2025 bis 30.09.2026
Funding body: FEI-Programm zur Förderung der Forschung, Entwicklung und Innovation. Ein Programm des Bremer Aufbaubank BAB
Contact: Dr.- Ing. Kerstin Hantzsche
Tel.: +49 421 218 51430
E-Mail: hantzsche@iwt-bremen.de
Development of a High-Speed Process for Laser Powder Deposition Welding for Coating Formable Superheater Tubes (DED Tubes)
Collaborative project with the Bremen project partners innojoin GmbH and BIAS – Bremer Institut für angewandte Strahltechnik GmbH
Extreme temperatures and corrosion place high demands on superheater tubes in waste incineration plants. Laser powder deposition welding (LPD) enables the application of thin nickel coatings that are cost-effective, environmentally friendly, and high-strength. To achieve this, it is necessary to develop a high-speed process for laser powder deposition welding and to optimize preheating in such a way that crack formation during tube forming is avoided while simultaneously achieving maximum service life.
Laser coating has established itself as an innovative technology for improved corrosion protection of numerous components. This includes laser coating of superheater tubes for waste-to-energy plants.
Coating is performed by many companies using conventional welding processes. In contrast, laser powder deposition welding (LPD) offers both economic and ecological advantages (e.g., lower coating thickness with the same or improved corrosion protection), enabling a significant reduction in environmental impact and improved efficiency in energy generation.
However, the combination of a thin coating and the requirement for unrestricted formability presents a technical challenge. Unacceptable crack formation repeatedly occurs during the forming of coated superheater tubes.
The aim of the project is to gain a fundamental understanding of the cause(s) of crack formation during forming after laser powder deposition welding. Building on this, a new process control strategy is to be developed that will enable, for the first time, process-reliable production of thin coating thicknesses on superheater tubes while simultaneously allowing crack-free forming of the coated tubes.
Microstructure and crack formation in a formed sample (electrolytically etched)
Processing: Innojoin GmbH, BIAS GmbH, Leibniz-Institute for Materials Engineering - IWT
Funding: 65002594
Duration: 16.09.2024 bis 14.09.2025
Funding body:
FEI-Programm zur Förderung der Forschung, Entwicklung und Innovation. Ein Programm des Bremer Aufbaubank BAB
Contact: Dr.- Ing. Kerstin Hantzsche
Tel.: +49 421 218 51430
E-mail: hantzsche@iwt-bremen.de
Iron-steam process for the transport and storage of hydrogen (Me2H2)
Hydrogen is essential for industrial decarbonization, but the large quantities required cannot be met solely by domestic renewable energy. Therefore, environmentally friendly methods for large-scale hydrogen transport and storage are crucial. The iron-steam process offers a promising solution by enabling the cyclic production of hydrogen, heat and electricity through metal oxidation and reduction reactions.
At the point of consumption, metals are oxidized with steam to produce hydrogen, while the resulting oxide can be returned to regions with abundant renewable energy for reduction. The scientific and technical goal of this collaborative project is to further develop the iron-steam technology for largescale applications, with the development of a suitable process technology seen as a core task. To address the problem of decreasing reactivity of the iron carrier in the classical iron-steam process, iron alloys with varying Mn contents (3, 5, 10, and 20 wt%) were tested, and the alloy containing 10 wt% Mn was identified as the optimum material system under the current experimental conditions, which include temperatures of 800 °C, 700 °C, and 600 °C.
Cooperation: Universität Duisburg-Essen, Institut für Technologien der Metalle (ITM), Lehrstuhl für Metallurgie der Eisen- und Stahlerzeugung, Technische Universität Clausthal, Institut für Metallurgie (IMET), Metallurgische Prozesstechnik, thyssenkrupp Steel Europe AG, SMS group GmbH
Funding: BMBF 03SF0658C (Me2H2)
Contact:
M.Sc. Carolina Souza Santiago
Tel.:+49 421 218 64511
E-Mail: c.santiago@iwt.uni-bremen.de