5 Werkstofftechnik
Filtern
Dokumenttyp
- Vortrag (374)
- Posterpräsentation (101)
- Zeitschriftenartikel (55)
- Beitrag zu einem Tagungsband (54)
- Forschungsdatensatz (27)
- Buchkapitel (6)
- Dissertation (4)
- Beitrag zu einem Sammelband (2)
- Sonstiges (2)
- Video (1)
Sprache
- Englisch (628) (entfernen)
Referierte Publikation
- nein (628) (entfernen)
Schlagworte
- Additive Manufacturing (51)
- Corrosion (44)
- Additive manufacturing (40)
- Ontology (33)
- Microstructure (29)
- Glass (28)
- Creep (23)
- Fatigue (20)
- Transmission electron microscopy (17)
- Crack growth (16)
Organisationseinheit der BAM
- 5 Werkstofftechnik (628)
- 5.1 Mikrostruktur Design und Degradation (174)
- 5.2 Metallische Hochtemperaturwerkstoffe (162)
- 5.4 Multimateriale Fertigungsprozesse (121)
- 5.6 Glas (90)
- 5.3 Polymere Verbundwerkstoffe (64)
- 5.5 Materialmodellierung (61)
- 8 Zerstörungsfreie Prüfung (55)
- 7 Bauwerkssicherheit (52)
- 9 Komponentensicherheit (47)
- 8.5 Röntgenbildgebung (42)
- 6 Materialchemie (40)
- 5.0 Abteilungsleitung und andere (34)
- 7.6 Korrosion und Korrosionsschutz (33)
- 9.4 Integrität von Schweißverbindungen (19)
- 6.3 Strukturanalytik (18)
- 6.1 Oberflächen- und Dünnschichtanalyse (16)
- 9.6 Additive Fertigung metallischer Komponenten (16)
- 1 Analytische Chemie; Referenzmaterialien (14)
- 3 Gefahrgutumschließungen; Energiespeicher (12)
- 4 Material und Umwelt (12)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (11)
- 9.0 Abteilungsleitung und andere (10)
- 9.3 Schweißtechnische Fertigungsverfahren (7)
- 1.2 Biophotonik (6)
- 3.1 Sicherheit von Gefahrgutverpackungen und Batterien (6)
- 4.2 Material-Mikrobiom Wechselwirkungen (6)
- 6.5 Synthese und Streuverfahren nanostrukturierter Materialien (5)
- 8.0 Abteilungsleitung und andere (5)
- 1.6 Anorganische Referenzmaterialien (4)
- 4.1 Biologische Materialschädigung und Referenzorganismen (4)
- 6.0 Abteilungsleitung und andere (4)
- 6.6 Physik und chemische Analytik der Polymere (4)
- 7.4 Baustofftechnologie (4)
- 8.3 Thermografische Verfahren (4)
- 8.4 Akustische und elektromagnetische Verfahren (4)
- 9.2 Versuchsanlagen und Prüftechnik (4)
- 6.4 Materialinformatik (3)
- 8.6 Faseroptische Sensorik (3)
- 1.4 Prozessanalytik (2)
- 2 Prozess- und Anlagensicherheit (2)
- 2.1 Sicherheit von Energieträgern (2)
- 3.0 Abteilungsleitung und andere (2)
- 3.4 Sicherheit von Lagerbehältern (2)
- 3.5 Sicherheit von Gasspeichern (2)
- 4.3 Schadstofftransfer und Umwelttechnologien (2)
- 4.4 Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung (2)
- 6.7 Materialsynthese und Design (2)
- 7.0 Abteilungsleitung und andere (2)
- 7.7 Modellierung und Simulation (2)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (2)
- 1.0 Abteilungsleitung und andere (1)
- 1.8 Umweltanalytik (1)
- 1.9 Chemische und optische Sensorik (1)
- 3.6 Elektrochemische Energiematerialien (1)
- 6.2 Material- und Oberflächentechnologien (1)
- 9.5 Tribologie und Verschleißschutz (1)
- VP Vizepräsident (1)
- VP.1 eScience (1)
Gypsum (CaSO4∙2H2O), bassanite (CaSO4∙0.5H2O), and anhydrite (CaSO4) are essential evaporite minerals for the evolution of hyper-arid surface environments on Earth and Mars (Voigt et al. 2019; Vaniman et al. 2018). The formation mechanism of especially anhydrite has been a matter of scientific debate for more than a century (van’t Hoff et al. 1903). To date, there exists no model that can reliably predict anhydrite formation at earth’s surface conditions. While thermodynamics favor its formation, it is hardly achieved on laboratory time scales at conditions fitting either the Atacama Desert on Earth, or the surface of Mars (Wehmann et al. 2023). In light of most recent developments (e.g. Stawski et al. 2016), that advocate for a complex, non-classical nucleation mechanism for all calcium sulphates, we present an analysis of natural samples from the Atacama Desert to identify key features that promote the nucleation and growth of anhydrite under planetary surface conditions. Our analyses reveal at least three distinct anhydrite facies, with differing mineralogy and micro- to nano-structures. The facies are (1) aeolian deposits with sub-μm grain sizes, (2) (sub-)surface nodules that formed from aeolian deposits and (3) selenites with secondary anhydrite rims. Possible mechanisms of their formation will be discussed.
Several studies have shown that the electron beam (e-beam) can be used to create nanomaterials from microparticles in situ in a TEM. However, attempts to produce gold nanoparticles (NPs) on silicon oxide substrate remained to be accomplished. Here, we show that the production of gold NPs is possible by using the e-beam in a SEM, under a set of parameters. To understand the physical mechanisms leading to the gold NPs, the mechanisms of e-beam induced charging as well as e-beam induced heating of the MPs were discussed. Several hints point to heating as the driving mechanism.
Several studies have shown that the electron beam (e-beam) can be used to create nanomaterials from microparticles in situ in a TEM. However, attempts to produce gold nanoparticles (NPs) on silicon oxide substrate remained to be accomplished. Here, we show that the production of gold NPs is possible by using the e-beam in a SEM, under a set of parameters. The NPs produced present a size gradient along the radial direction. A parameter study shows that the microparticles may: 1) flicker away without producing NPs, 2) fragment to form NPs and/or 3) react with the silicon oxide substrate, depending on the applied current. A hypothesis regarding the driving physical phenomena that lead the microparticles to fragment into NPs is discussed. Fabrication of gold NPs in the SEM provides a more cost-effective option as compared to the established method in the TEM.
With this presentation, the push-out technique is explained. The focus of the experimental work is on the characterization of the fiber-matrix interface of short fiber reinforced composites. The reinforcing component was glass fibers and the matrix polymer was PA6.6 and PPA.
It is demonstrated for the first time that the push-out technique ca be applied on injection molded short fiber PMC and is sensitive to the mechanical interface properties. Further studies are planned on the influence of multiple processing, the temperature and humidity.
Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific.
In this presentation, an approach how to maintain a comprehensive and intuitive MSE-centric terminology composing a mid-level ontology–the PMD core ontology (PMDco)–via MSE community-based curation procedures is shown.
The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications.
Gypsum (CaSO4∙2H2O) and anhydrite (CaSO4) are among the dominant evaporite minerals in the Atacama Desert [1]. They are distributed ubiquitously, and play a key role in local landscape evolution.
The formation mechanism of especially anhydrite has been a matter of scientific debate for more than a century [2]. To date, there exists no model that can reliably predict anhydrite formation at earth’s surface conditions. While thermodynamics favor its formation [3], it is hardly achieved on laboratory time scales at conditions fitting the Atacama Desert. Long induction times for nucleation have recently been modeled by Ossorio et al. [4]. However, anhydrite can be readily found in the Atacama Desert. Recently, the mineral was synthesized in flow-through reactors as a byproduct of K-jarosite dissolution at high water activity (aw=0.98) and room temperature [5], even-though the thermodynamic stability field begins only under a value of ~0.8. Additionally, recent studies investigated the nano-structure of various calcium-sulfates, which advocate for highly non-classical crystallization behavior [6]. The specific roles of particulates, ionic or organic reagents working as catalysts for the non-classical crystallization pathway remain to be determined.
Here, we present recent results from flow-through experiments as well as analyses of anhydrite samples from the Atacama Desert. Flow-through experiments were performed to systematically explore the domains of flow rate, composition, ionic-strengths and starting materials. Neither primary, nor secondary anhydrite was produced in any of these experiments. Analyses on Atacama samples reveal the existence of at least three distinct anhydrite facies, with differing mineralogy and micro- to nano-structures. The facies are (1) aeolian deposits with sub-µm grain sizes, (2) (sub-)surface nodules that formed from aeolian deposits and (3) selenites with secondary anhydrite rims. Possible mechanisms of their formation will be discussed.
While a lage amount of research on high entropy alloys is oriented towards mechanical properties and the microstructural improvement it is also necessary to keep an eye on the environment that potential application materials will be submitted to. The Co-Cr-Fe-Ni based high entropy family has shown great potential over the years of high entropy research and some candidate alloys are chosen for an insight into their corrosion behaviour. Several atmospheres are studied, i.e. O2, H2O, SO2 and a mix thereof in argon as well as synthetic air. Just as for classic alloys, the chromium is the most important element in terms of protection agains further corrosion. The addition of manganese, as in case of the “Cantor alloy” CrMnFeCoNi, overpasses Cr when it comes to oxygen affinity and thus counteracts the layer formation of Cr2O3. Even without Mn, a temperature chosen too high will also affect the formation of the chromium oxide layer and spall it off, annulling its protective potential. We can also observe how trace elements influence the layer formation. These effects and their mechanisms will be discussed for the alloys CrFeNi, CoCrNi, CrMnFeCoNi and variations of Al10Co25Cr8Fe15Ni36Ti6 using a combination of electron microscopy, thermodynamic calculations and x-ray diffraction.
The multi-phase approach has proven to widen the application properties of high entropy alloys. After a decade of testing different alloys in the Al-Co-Cr-Cu-Fe-Ni-Ti family the Al10Co25Cr8Fe15Ni36Ti6 was found to be a solid base for more fine-tuned microstructural optimization. Following the example of superalloys, the Al10Co25Cr8Fe15Ni36Ti6 alloy aims for a γ/γ' microstructures in order to guarantee a good microstructural stability at high temperatures. The shape and volume fraction of the γ' particles is known to influence the mechanical properties of superalloys, and they do so in the high entropy family as well [1]. Shape, misfit and creep properties of several modified versions of the Al10Co25Cr8Fe15Ni36Ti6 alloy are compared and discussed in this talk.
The BAMline at the synchrotron X-ray source BESSY II (Berlin, Germany) is supporting researchers especially in materials science. As a non-destructive characterization method, synchrotron X-ray imaging, especially tomography with hard X-Rays, plays an important role in structural 3D characterization. The imaging capabilities allow for in-situ and operando experiments. In this presentation the equipment, data handling pipeline as well as various examples from material science are presented.