A5010251611- X-ray Diffraction in Crystallography
- Microstructure and mechanical properties
- Crystallization and Solubility Studies
- Microstructure and Mechanical Properties of Steels
- Hydrogen embrittlement and corrosion behaviors in metals
- Corrosion Behavior and Inhibition
- Catalytic Cross-Coupling Reactions
- Advanced materials and composites
- Metallic Glasses and Amorphous Alloys
- Aluminum Alloys Composites Properties
- Radical Photochemical Reactions
- Metal and Thin Film Mechanics
- Welding Techniques and Residual Stresses
- Electrodeposition and Electroless Coatings
- Catalytic C–H Functionalization Methods
- High Entropy Alloys Studies
- Advanced Surface Polishing Techniques
- Non-Destructive Testing Techniques
- Silicon and Solar Cell Technologies
- Magnetic properties of thin films
- Composite Material Mechanics
- Magnetic Properties of Alloys
- High-Temperature Coating Behaviors
- Sulfur-Based Synthesis Techniques
- Mechanical Behavior of Composites
Anton Paar (Switzerland)
2021-2023
Erich Schmid Institute of Materials Science
2015-2023
Austrian Academy of Sciences
2016-2023
Deutsches Elektronen-Synchrotron DESY
2011-2023
Anton Paar (Austria)
2021
Johannes Gutenberg University Mainz
2018-2020
University of Applied Sciences Mainz
2020
Karlsruhe Institute of Technology
2015-2016
Volkswagen Group (Germany)
2016
Saarland University
2015
Ultrafine-grained and heterostructured materials are currently of high interest due to their superior mechanical functional properties. Severe plastic deformation (SPD) is one the most effective methods produce such with unique microstructure-property relationships. In this review paper, after summarizing recent progress in developing various SPD for processing bulk, surface powder materials, main structural microstructural features SPD-processed explained including lattice defects, grain...
A new and powerful active anode system that can be operated in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) has been discovered. In HFIP the molybdenum forms a compact, conductive, electroactive layer of higher-valent species. This replace but stoichiometrically required MoV reagents for dehydrogenative coupling aryls. electrolytic reaction is more sustainable allows conversion broad scope activated arenes.
Synchrotron high-energy XRD measurements and ab-initio DFT calculations were employed to investigate microstructural degradation of copper upon exposure sulfide-containing anoxic groundwater simulating nuclear waste repository. After two-month exposure, the revealed heterogeneous lattice deformation in microstructure expansion near-surface regions. The show that sulfur promotes hydrogen adsorption on copper. Water causes surface reconstruction insertion into microstructure, occurring via...
Beta-Ti alloys have been intensively investigated in the last years because of their favorable low Young's moduli, biocompatibility and bio-inertness, making these interesting candidates for implant materials. Due to mechanical strength, efforts are currently devoted increasing it. A promising way improve strength is tailor microstructure using severe plastic deformation (SPD). In this investigation high pressure torsion was used refine a Ti-45wt.%Nb alloy inducing grain size ~50 nm. The...
Heusler alloy Ni2MnGa thin films have been grown pseudomorphically on a relaxed NiGa interlayer GaAs(001) by molecular-beam epitaxy. In situ reflection high-energy electron diffraction patterns, ex x-ray diffraction, and cross-sectional view transmission microscopy patterns confirm the single-crystal growth of Ni2MnGa. The grow with tetragonal structure (a=b=5.79 Å c=6.07 Å). Magnetic measurements using vibrating sample superconducting quantum interference device magnetometers reveal to an...
Abstract Es wurde ein leistungsfähiges aktives Anodensystem entwickelt, das in 1,1,1,3,3,3‐Hexafluor‐2‐propanol (HFIP) eingesetzt werden kann. Die Molybdänanode bildet HFIP eine kompakte, leitfähige und elektroaktive Schicht aus höhervalenten Molybdänspezies. Dieses System kann als Ersatz für leistungsfähige, aber stöchiometrisch notwendige Mo V ‐Reagenzien dehydrierenden Kupplungen von Arenen werden. Diese Elektrolyse ist nachhaltiger ermöglicht die Umsetzung eines breiten Spektrums...
Local strain development in the microstructure of a commercial 25Cr-7Ni super duplex stainless steel was mapped using high-energy x-ray diffraction during cathodic hydrogen charging under constant uniaxial load. The infusion resulted tensile strains austenite grains, one order magnitude larger than those ferrite. Most evolution occurred at near-surface, with compensating compressive forces developed underlying regions, up to two-times more compression occurring ferrite austenite. along...
A new citrate-based electrolyte is proposed for the electrodeposition of thick Fe-C films. The structure and properties deposits are compared to those from another previously reported in literature. Both consist a nanocrystalline single-phase with grain size 20 nm, which results hardness up 660 HV. Due its higher growth rate, promising candidate deposition However, codeposition oxygen causes embrittlement, limiting application both known electrolyte. On other hand, codeposited carbon provide...
Active anodes which are operating in highly stable protic media such as 1,1,1,3,3,3-hexafluoroisopropanol rare. Nickel forms, within this unique solvent, a non-sacrificial active anode at constant current conditions, is superior to the reported powerful molybdenum system. The reactivity for dehydrogenative coupling reactions of novel increases when electrolyte not stirred during electrolysis. Besides aryl-aryl coupling, arylation reaction benzylic nitriles was found while stirring mixture...
The deformation behavior of nearly fully pearlitic, bainitic and martensitic steels during severe plastic is summarized in this paper. Despite their significantly different yield stresses microstructures, hardening SPD similar. Due to the enormous capacity limited by strength tool materials. microstructure at obtainable limit strain are quite similar, which a nanocrystalline structure order 10 nm, dependent on strain. nanograins partially supersaturated with carbon grain boundaries...
Bulk composites using powder blends of Mn and Bi with equal atomic ratios are consolidated severely deformed by high-pressure torsion (HPT). Subsequent annealing treatments lead to the formation ferromagnetic rare-earth free hard magnetic α-MnBi phase. The initial phase is studied in-situ high-energy XRD experiments showing a beneficial influence HPT-deformation on amount α-MnBi. nucleation sites strongly increased, thus volumetric content exceeds 50 vol%. A lower HPT-pressure 2 GPa found be...
The local lattice strain evolution during electrochemical hydrogen charging and mechanical loading in 25Cr-7Ni super duplex stainless steel were measured in-situ using synchrotron high-energy x-ray diffraction. Post-mortem electron backscattered diffraction analysis showed that the austenite phase underwent plastic deformation near-surface due to hydrogen-enhanced localized plasticity, where ferrite experienced hardening. In bulk regions, was softer phase, remained stiff. Digital image...
Abstract High-energy synchrotron radiation has been demonstrated to be a powerful tool for materials characterization. The development of novel methodologies is still ongoing, driven by major technological advances regarding the available source brilliance and efficient large area detectors. Swedish Materials Science beamline at PETRA III dedicated characterization high-energy X-rays scheduled enter into user operation starting August 2019. designed in particular combination two...
A nanocrystalline CrMnFeCoNi high-entropy alloy produced using severe plastic deformation high-pressure torsion was annealed at selected temperatures and times (450 °C for 1 h 15 600 h), causing a phase decomposition into multi-phase structure. The samples were subsequently deformed again by to investigate the possibility of tailoring favorable composite architecture re-distributing, fragmenting, or partially dissolving additional intermetallic phases. While second in 450 annealing states...
Nickel/carbon nanotube (Ni/CNT) composites with varying amounts of CNTs are deformed by high‐pressure torsion (HPT) at different deformation temperatures to high strains, where no further refinement the Ni matrix microstructure is observed. Mean grain sizes increase increasing HPT temperature, while size CNT agglomerates significantly reduced. Additionally, distribution in metal becomes more homogenous. To investigate mechanical performance HPT‐deformed composites, uniaxial tensile and...
Bulk nanocrystalline materials of small and medium ferromagnetic content were produced using severe plastic deformation by high-pressure torsion at roomtemperature. Giant magnetoresistive behavior was found for as deformed materials, which further improved adjusting the microstructure with thermal treatments. The adequate range annealing temperatures assessed in-situ synchrotron diffraction measurements. Thermally treated CuCo show larger giant magnetoresistance after 1 h 300C, while CuFe...
The range of accessible microstructures from the combination severe plastic deformation (SPD) and heat treatments a low carbon steel martensite under various processing conditions is evaluated. SPD results in temperature decrease for recrystallization austenitization upon subsequent annealing. On contrary, precipitation cementite takes place at higher temperatures after SPD. Whereas, certain thermal stability observed processing, even annealing have strong impact on simultaneous which...
A convenient and straightforward approach to performing oxidative coupling reactions in flow is presented. collection of electron-rich benzene derivatives was subjected this protocol, the distinct utility molybdenum pentachloride (MoCl5) established. Using unexplored biphenyls could be obtained 21–91% isolated yield. This simple protocol opens a new chapter reagent-mediated dehydrogenative reactions, yields are compared classical approaches.
Nanocrystalline materials are well known for their beneficial mechanical and physical properties. However, it is of utmost importance to stabilize the microstructure at elevated temperatures broaden window application e.g. by pinning grain boundaries through impurities or oxides. CuCo alloys, severe plastically deformed using high-pressure torsion, were used investigate evolution oxides upon annealing. These investigations performed electron microscopy, synchrotron high-energy X-ray...