21 Result(s)
within
G. Dehm
Materials Science
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Article
Open AccessAutomated classification of granular bainite and polygonal ferrite by electron backscatter diffraction verified through local structural and mechanical analyses
Differentiation of granular bainite and polygonal ferrite in high-strength low-alloy (HSLA) steels possesses a significant challenge, where both nanoindentation and chemical analyses do not achieve an adequate...
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Article
Open AccessIn situ nanoindentation during electrochemical hydrogen charging: a comparison between front-side and a novel back-side charging approach
The effects of hydrogen in metals are a pressing issue causing severe economic losses due to material deterioration by hydrogen embrittlement. A crucial understanding of the interactions of hydrogen with diffe...
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Article
Maintaining strength in supersaturated copper–chromium thin films annealed at 0.5 of the melting temperature of Cu
The thermal stability of evaporated copper–chromium alloy films was studied by correlating hardness trends from nanoindentation to nanostructural–compositional changes from transmission electron microscopy. In...
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Importance of dislocation pile-ups on the mechanical properties and the Bauschinger effect in microcantilevers
Copper microcantilevers were produced by focused ion beam milling and tested in situ using a scanning electron microscope. To provide different interfaces for piling up dislocations, cantilevers were fabricate...
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Article
Influence of Film/Substrate Interface Structure on Plasticity in Metal Thin Films
In-situ transmission electron microscopy studies of metal thin films on substrates indicate that dislocation motion is influenced by the structure of the film/substrate interface. For Cu films grown on silicon...
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Article
Microplasticity phenomena in thermomechanically strained nickel thin films
Magnetron sputtered Ni thin films on both oxidised Si (100) and α-Al2O3 (0001) substrates of thickness 150–1000 nm were tested thermomechanically with a wafer curvature system, as well as in situ in a transmissio...
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Article
Open AccessFracture and Delamination of Chromium Thin Films on Polymer Substrates
New emerging technologies in the field of flexible electronic devices require that metal films adhere well and flex with polymer substrates. Common thin film materials used for these applications include coppe...
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Article
Influence of the indenter tip geometry and environment on the indentation modulus of enamel
The aim of the investigation was to study the influence of indenter tip geometry on the conventionally obtained indentation modulus of enamel by nanoindentation. Indentation tests on bovine enamel using three ...
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Article
Dislocation-induced crystal rotations in micro-compressed single crystal copper columns
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Article
Bonding at copper–alumina interfaces established by different surface treatments: a critical review
The present study summarizes the effects of processing conditions and substrate cleaning procedures on the structure, chemistry and bonding of Cu/(0001)Al2O3 interfaces as determined by advanced transmission elec...
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Article
In-situ TEM straining experiments of Al films on polyimide using a novel FIB design for specimen preparation
In-situ transmission electron microscopy (TEM) straining experiments are tedious to perform but give invaluable insight into the deformation processes of materials. With the current interest in mechanical size...
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Article
TEM investigations of the structural evolution in a pearlitic steel deformed by high-pressure torsion
A fully pearlitic steel was deformed by high-pressure torsion up to very high strains, and the changes in the microstructure were determined by analytic and conventional transmission electron microscopy. The i...
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Article
Influence of Gas Atmosphere on the Plasticity of Metal Thin Films
Stresses in thin films are routinely measured by the so-called substrate curvature technique. These experiments are usually carried out in air or under a protective gas atmosphere. In this contribution we desc...
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Article
Microstructure and Thermo-Mechanical Behavior of NiAl Coatings
In this study the thermo-mechanical behavior of a commercial Pt containing NiAl coating deposited on a Ni-base superalloy is compared with a Ni-rich NiAl coating sputter-deposited on a Si substrate. Both types...
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Article
Creep Behavior and Microstructural Stability of Ti-46Al-9Nb with Different Microstructures
In this paper the creep behavior and the microstructural stability of Ti-46Al-9Nb (in at.%) sheet material were investigated in the temperature range of 700°C to 815°C. The study involves three different types...
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Article
Internal Friction of a High-Nb Gamma-TiAl-Based Alloy with Different Microstructures
An intermetallic Ti-46Al-9Nb (at%) alloy with different microstructures (near gamma, duplex, and fully lamellar) was studied by internal friction measurements at 300 K to 1280 K using different frequency range...
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Article
Plasticity-Related Phenomena in Metallic Films on Substrates
Plastic deformation due to thermal stresses has been investigated for different metallic films deposited on Si or α-alumina substrates. We conducted post-mortem TEM and SEM investigations of samples that under...
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Article
Thermal stability of Pt nanowires manufactured by Ga+ focused ion beam (FIB)
Pt nanowires have been produced by FIB deposition of Pt thin films in a commercial Ga+ focused ion beam (FIB) system, followed by cross-sectional sputtering to form electron transparent Pt nanowires. The thermal ...
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Article
Laser cladding of Co-based hardfacing on Cu substrate
Cu substrates were subjected to laser cladding with Triballoy 66 SNF by means of a CW-CO2 laser, preceded by the deposition of an intermediate layer containing Cu-Ni-B-Si for improving the energy coupling between...
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Article
Microstructure of Ni2B Laser-Induced Surface-Alloyed α-Fe
Substrate surfaces of α-Fe were laser alloyed with a CW-CO2 laser using Ni2B powder. Single laser scans and laser scans with a 50% overlap between successive passes were carried out to obtain hard surface coating...
