A5049432631- Fatigue and fracture mechanics
- Nuclear Physics and Applications
- Microstructure and Mechanical Properties of Steels
- Microstructure and mechanical properties
- High Temperature Alloys and Creep
- X-ray Diffraction in Crystallography
- Aluminum Alloys Composites Properties
- Material Properties and Failure Mechanisms
- High-Velocity Impact and Material Behavior
- Metal Forming Simulation Techniques
- Non-Destructive Testing Techniques
- Shape Memory Alloy Transformations
- Metallurgy and Material Forming
- Aluminum Alloy Microstructure Properties
- Atomic and Subatomic Physics Research
- Hydrogen embrittlement and corrosion behaviors in metals
- Advanced Welding Techniques Analysis
- Advanced ceramic materials synthesis
- Metal and Thin Film Mechanics
- Nuclear Materials and Properties
- Radiation Detection and Scintillator Technologies
- Welding Techniques and Residual Stresses
- High-pressure geophysics and materials
- Ultrasonics and Acoustic Wave Propagation
- Magnesium Alloys: Properties and Applications
Charles University
2015-2021
Czech Technical University in Prague
2021
European Spallation Source
2020
Czech Academy of Sciences, Nuclear Physics Institute
2004-2016
Czech Academy of Sciences
2001-2012
Czech Academy of Sciences, Institute of Physics of Materials
2001-2011
Research Centre Rez
2006
Institute of Nuclear Physics
1989-1999
Nuclear Research Institute Rez (Czechia)
1994
Institute of Metallurgy
1982-1992
Abstract Persistent slip bands in fatigued copper single crystals are studied by means of transmission electron microscopy surface thin foils, both parallel and nonparallel to the surface. Comparing observations from different sections a three‐dimensional model internal structure may be constructed. Dislocations with all six possible Burgers vectors type 1/2 〈0011〉 found structure. This demonstrates microscopic action secondary systems during low stress fatigue. The macroscopic systems,...
Abstract The fact that very small notches (cavities, holes, scratches, etc.) have no effect on the fatigue limit of metallic materials is well known. This paper presents both a qualitative explanation for existence non‐damaging and quantitative derivation their critical sizes. condition notch (characterized by stress concentration factor K t root radius ρ) to be in material crack size l 0 ) ( 2 − 1)ρ≤ 4.5 . can expressed with good approximation terms threshold intensity growth plain limit....
Perhaps the most thoroughly studied feature of cyclic plasticity has been persistent slip bands (PSBs) formed in some metals during loading. The aim this paper is to delimit conditions for occurrence PSBs and discuss their role fatigue process all its stages, that hardening resulting a saturated stress–strain response, initiation microcracks propagation cracks. are zones high activity. Therefore response depends on volume fraction ratio activities within those outside PSB. plastic...
Abstract Dislocation structures in CuZn alloy single crystals were examined by means of transmission electron microscopy. The overall dislocation structure, typical for the whole volume fatigued crystals, strongly depends on degree difficulty cross slip. In with sufficiently easy slip surface extrusions and intrusions found to be related persistent band differing from that remaining volume, while very difficult no bands lying under relief found. Further, role fatigue process is discussed.
Abstract The dislocation distribution in the surface layer of cyclically deformed specimens polycrystalline copper is studied by means transmission electron microscopy thin foils, both parallel and nonparallel to surface. within near persistent slip bands found differ considerably from that inside specimens. consist zones alternately high low density. density link together at a particular depth below are assumed serve as “channels” which motion dislocations emitted Frank‐Read sources...
The dislocation structure both in the interior and surface layer of Cu. Cu–15 wt% Zn Cu–31 single crystals were studied by means transmission electron microscopy. types structures depend on stress amplitude stacking fault energy. This dependence can be expressed a simple schematic diagram. Further conditions for microcracks formation, as well meaning term fatigue damage are discussed. Die Versetzungsstruktur im Innern und auf der Oberflache Cu-, Gew% Zn- Zn-Einkristalle wurde mit...
ABSTRACT Several specific features of high‐cycle fatigue (HCF) and ultra‐high‐cycle (UHCF) are discussed both on the basis direct experimental results speculations extrapolating HCF data to UHCF regions. The following points dealt with: (i) Extent distribution cyclic plastic deformation. (ii) Sensitivity behaviour in regions start‐up procedure test preceding stress–strain history. (iii) Role persistent slip bands (PSBs) microcrack initiation (iv) Dependence notch sensitivity amplitude...