A5019645839- Aluminum Alloys Composites Properties
- Aluminum Alloy Microstructure Properties
- Magnesium Alloys: Properties and Applications
- Hydrogen Storage and Materials
- Microstructure and mechanical properties
- Muon and positron interactions and applications
- Metal and Thin Film Mechanics
- Copper Interconnects and Reliability
- Intermetallics and Advanced Alloy Properties
- Advanced Chemical Physics Studies
- Thermodynamic and Structural Properties of Metals and Alloys
- Material Properties and Applications
- MXene and MAX Phase Materials
- Quasicrystal Structures and Properties
- Plasma Diagnostics and Applications
- ZnO doping and properties
- Metallurgy and Material Forming
- Fusion materials and technologies
- Ammonia Synthesis and Nitrogen Reduction
- High Temperature Alloys and Creep
- Nuclear Materials and Properties
- Hydrogen embrittlement and corrosion behaviors in metals
- Economic and Business Development Strategies
- Sustainable Agricultural Systems Analysis
- Boron and Carbon Nanomaterials Research
Charles University
2014-2023
Czech Academy of Sciences, Institute of Plasma Physics
2022
Precipitation stages in the hot-deformed Al-5.28wt.%Zn-3.21wt.%Mg-1.48wt.%Cu-0.24wt.%Si-0.24wt.%Mn-0.14wt.%Fe(−0.23wt.%Sc-0.19wt.%Zr) alloys were investigated. Positron annihilation spectroscopy was employed for a study of vacancy assisted clustering solutes on atomic scale, type and concentration open volume misfit defects local chemical surroundings defects. Microhardness testing, thermal analysis microstructure observations also used. The contain eutectic grain boundary phases: T-phase...
Various defect studies of hydrothermally grown (0001) oriented ZnO crystals electrochemically doped with hydrogen are presented. The content in the is determined by nuclear reaction analysis and it found that already 0.3at.% H exists chemically bound form virgin crystals. A single positron lifetime 182ps detected attributed to saturated trapping at Zn vacancies surrounded atoms. It demonstrated a very high amount (up ∼30at.%) can be introduced into electrochemical doping. More than half this...
Abstract The effect of Sc and Zr addition on microstructure hardness development in a commercial as-cast solution-treated (530 °C/45 min) AA6082 alloy was studied. electrical resistivity decrease increase the temperature range 180 – 300 °C are caused by precipitation β′′ and/or β′ needles Mg Si system. Precipitation morphology changes Al Mn Fe system phases AA6082-ScZr alloys influence significantly, but have negligible hardness. initial containing is higher mainly due to presence 3 (Sc, Zr)...
Response to isochronal annealing up 440 °C of squeeze cast Mg–Y–Zn alloy and the same prepared by powder metallurgy (PM) extruded at 280 was studied resistivity microhardness measurement, differential scanning calorimetry (DSC) microstructure investigation. Electrical measured 77 K room temperature after each step. DSC measurement performed various heating rates. Transmission electron microscopy optical revealed ribbons long-period ordered structure (LPSO) 18R planar defects within grain...
A detailed characterization of phase transformations in the heat-treated commercial 7075 aluminum alloys without/with low Sc–Zr addition was carried out. Mechanical and electrical properties, thermal corrosion behavior were compared to microstructure development. The eutectic consists four parts: MgZn2 phase, Al2CuMg (S-phase), Al2Zn3Mg3 (T-phase), primary λ-Al(Mn,Fe,Si) phase. Strengthening during non-isothermal (isochronal) annealing is caused by a combination formation GP zones, η’-phase,...
Microstructure, thermal, electrical and mechanical properties of the hot-extruded hotrolled AlMnScZr alloys were studied.The resistometry microhardness together with differential scanning calorimetry measurements compared microstructure development observed by transmission electron microscopy, X-ray diffraction, backscatter diffraction.Fine subgrain or grain structure developed fine coherent Al3(Sc,Zr) particles precipitated during hot deformation subsequent cooling.The distinct resistivity...
Abstract The effect of Mn addition on the microstructure, thermal and mechanical properties in as-cast cold-rolled Al–Sc–Zr alloys was studied. Electrical resistometry, differential scanning calorimetry microhardness measurements were used. Transmission electron microscopy, backscatter diffraction X-ray specimens quenched from temperatures pronounced changes resistivity helped to identify microstructural processes responsible for changes. distinct increase observed after annealing above...
Precipitation reactions of the Al-Zn-Mg(-Mn,Fe)-based alloys with/without Sc,Zr-addition were studied by microhardness and resistivity measurements, differential scanning calorimetry.Microstructure observation proved Zn,Mg-containing eutectic phase at grain boundaries.Positron spectroscopy confirmed presence Guinier-Preston (GP) zones in initial state.The changes curves as well heat flow are mainly caused formation and/or dissolution precipitation particles from Al-Zn-Mg system.Formation...
Abstract Substantial natural aging occurring on the time scale of less than 1 month was observed in solution‐treated Mg–Gd and Mg–Tb alloys. Solution treatment at 500 530 °C for alloys, respectively, leads to dissolution Gd or Tb Mg matrix. By quenching alloys room temperature a supersaturated solid solution formed. During subsequent ambient hardness quenched increases, most probably, due agglomeration dissolved atoms into small clusters. Positron lifetime spectroscopy combined with...
Solute clustering and precipitation processes in hot-extruded Al–Mn–Sc–Zr alloy were studied. Positron annihilation studies combined with electrical resistometry, microhardness testing microstructural characterization. Extrusion introduced dislocations which arranged into a cell structure. Sc solutes segregated at dislocations. Moreover, fine coherent Al3(Sc,Zr) particles precipitated during extrusion subsequent cooling. During the isochronal annealing agglomerated forming Sc-rich...