Fraunhofer Institute for Mechanics of Materials IWMWe develop capillary suspensions (CapS) with custom-designed porosities and strengths tailored to specific requirements. This enables us to create pore and materials gradients as well as complex geometries that optimize mass transport and increase the efficiency of energy conversion.
Crystal Structure and Phase Analyses
We correlate mechanical, electrical, magnetic, and other functional properties with the crystal and microstructure, and explain changes in properties during operation or as a result of high-temperature use, deformation, and corrosion. To do this, we use X-ray, synchrotron, or neutron radiation to provide information about the structure of polycrystalline components. In the laboratory, we can also simulate conditions that occur during the actual operation of the materials and components.
Our R&D Services
Depending on the measurement method, different sample sizes and penetration depths can be measured:
- Analysis and evaluation of the manufacturing and stress-induced structure and phase composition of materials.
- Qualitative or quantitative analysis of the crystal and microstructure.
- Elucidation of structure-property relationships.
- Determination, simulation, and evaluation of stresses, strains, and texture in components.
- Analysis of degradation mechanisms in materials in contact with hydrogen.
Conventional laboratory X-ray equipment allows access to surface areas with penetration depths of a few micrometers (1–100 µm). By scanning the samples, mapping with structural analysis can be performed. However, with the aid of high-energy radiation, bulk information such as dislocation densities or complete phase analyses can also be obtained in the laboratory using transmission geometry.
With mobile X-ray systems, examinations can be conducted on-site or in hard-to-reach locations. This makes it possible to measure residual stresses in threads or grooves, as well as at joints. Additionally, these measurements can be performed on-site on very large components or installations.
Synchrotron radiation typically has a higher energy and is therefore suitable for providing information from within the material in transmission geometry. Furthermore, entire components can be examined under real operating conditions. Even complex sample environments such as load frames, electric or magnetic fields, as well as thermal, chemical, or mechanical stresses can be applied or simulated.
With neutron radiation, even larger samples or components can be measured in transmission to obtain similar information. Furthermore, neutrons are sensitive to magnetic structure. This allows for investigations that are not accessible with X-rays. Other limitations, such as the examination of coarse-grained materials, can also be overcome in this way. With the help of suitable experimental setups, depth profiles or mappings can be performed within a large material or component.
In situ and operando experiments with different stimuli
In the laboratory, conditions can be created that mimic those encountered during the actual operation of the material or component. These in situ or operando experiments can be conducted using temperature, electric fields, magnetic fields, mechanical loads, and many other external stimuli. This makes it possible, for example, to explain the effects of fluctuating process or operating conditions on structure and properties, or to understand the mechanisms of functionality in order to improve the properties of materials and components.
Was sind Auslöser für Kristallstruktur- und Phasenanalysen?
- Auffälligkeiten in der Produktion, im Testbetrieb oder im Einsatz (z.B. Festigkeitsminderungen, Rissbildung, Korrosion, Oberflächendefekte).
- Eigenschaftsveränderungen im Betrieb durch externe Einflüsse (thermisch, mechanisch, chemisch, elektrisch, magnetisch oder gekoppelt).
- Einsatz neuer Werkstoffe (Herstellbarkeit, Korrosion, Langzeitstabilität, Festigkeit, Maßhaltigkeit, strukturelle oder funktionale Eigenschaften).
- Optimierung der Mikrostruktur hinsichtlich Fremdphasen, Inhomogenitäten, Ausscheidungen, Segregationen
- Absicherung der Einhaltung von Normen oder Spezifikationen bei Werkstoffen und Bauteilen.
- Funktionscharakterisierung unter realen Betriebsbedingungen (Transportmechanismen, elektrische oder magnetische Felder, mechanische Beanspruchung).
- Bedarf an Inputdaten für Modellierungen oder Werkstoffsimulationen.