scholarly journals Microstructure Evolution and Texture Development in a Cu-8.5%AT. AL Material Subjected to Hydrostatic Extrusion

2016 ◽  
Vol 61 (2) ◽  
pp. 933-936 ◽  
Author(s):  
D. Jakubowska ◽  
J. Zdunek ◽  
M. Kulczyk ◽  
J. Mizera ◽  
K. J. Kurzydłowski
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
Transmission Electron Microscope ◽  
Texture Evolution ◽  
True Strain ◽  
Nanocrystalline Structure ◽  
Transmission Electron ◽  
The Stability ◽  
Xrd Method

AbstractThe aim of the present paper was to investigate microstructure and texture evolution of two single crystals and polycrystal of Cu-8.5%at.Al material. All of mentioned samples were deformed by HE to achieve true strain ε = 1.17. For microstructure analyzes observations by transmission electron microscope (STEM) were done. Crystalline size for samples after SPD were determine using XRD method. The global texture measurements were done using Bruker D8 Discover diffractometer equipped in Cr radiation. Microstructure investigations revealed nanocrystalline structure in single crystals with initial orientations <110> and <100> and polycrystalline Cu-8.5%at.Al material after SPD. The global texture measurements have shown the stability of initial orientation of <100> Cu-8.5%at.Al single crystal after HE, whereas the same SPD process strongly brakes up the orientation <110> Cu-8.5%at. Al single crystal.

Development of a Mach-Zehnder type electron interferometer on a 1.2-MV field-emission transmission electron microscope

Microscopy ◽  
2020 ◽  
Vol 69 (6) ◽  
pp. 411-416
Author(s):  
Tetsuya Akashi ◽  
Yoshio Takahashi ◽  
Ken Harada
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Beam Splitters ◽  
Interference Fringes ◽  
Transmission Electron ◽  
Performance Results

Abstract We have developed an amplitude-division type Mach-Zehnder electron interferometer (MZ-EI). The developed MZ-EI is composed of single crystals corresponding to amplitude-division beam splitters, lenses corresponding to mirrors and an objective aperture. The spacings and azimuth angles of interference fringes can be controlled by single crystal materials and their orientations and by diffraction spots selected by the objective aperture. We built the MZ-EI on a 1.2-MV field-emission transmission electron microscope and tested its performance. Results showed that interference fringes were created for various spacings and azimuth angles, which demonstrates the practicability of the MZ-EI as an amplitude-division type electron interferometer.

Reconstruction of electron holograms recorded in a non-FEG, non-biprism TEM

1995 ◽  
Vol 53 ◽  
pp. 618-619
Author(s):  
Z.L. Wang
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Experimental Technique ◽  
Transmission Electron Microscope ◽  
The Other ◽  
Electron Holography ◽  
Transmission Electron ◽  
Coherent Sources ◽  
Imaging Theory ◽  
Normal Specimen

An experimental technique for performing electron holography using a non-FEG, non-biprism transmission electron microscope (TEM) has been introduced by Ru et al. A double stacked specimens, one being a single crystal foil and the other the specimen, are loaded in the normal specimen position in TEM. The single crystal, which is placed onto the specimen, is responsible to produce two beams that are equivalent to two virtual coherent sources illuminating the specimen beneath, thus, permitting electron holography of the specimen. In this paper, the imaging theory of this technique is described. Procedures are introduced for digitally reconstructing the holograms.

Observation of dislocations in dynamically loaded Cu-SiO2

1986 ◽  
Vol 44 ◽  
pp. 424-425
Author(s):  
D. S. Pritchard
Keyword(s):  
Electron Microscope ◽  
Strain Rate ◽  
Single Crystal ◽  
Transmission Electron Microscope ◽  
Volume Fraction ◽  
Screw Dislocations ◽  
Spherical Inclusions ◽  
Transmission Electron ◽  
Crystal Dispersion ◽  
Strain Rate Loading

The effect of varying the strain rate loading conditions in compression on a copper single crystal dispersion-hardened with SiO2 particles has been examined. These particles appear as small spherical inclusions in the copper lattice and have a volume fraction of 0.6%. The structure of representative crystals was examined prior to any testing on a transmission electron microscope (TEM) to determine the nature of the dislocations initially present in the tested crystals. Only a few scattered edge and screw dislocations were viewed in those specimens.

In situ observation of the motion of ferroelectric domain walls in Bi4Ti3O12 single crystals

2016 ◽  
Vol 49 (5) ◽  
pp. 1645-1652 ◽  
Author(s):  
Wanneng Ye ◽  
Lingli Tang ◽  
Chaojing Lu ◽  
Huabing Li ◽  
Yichun Zhou
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Single Crystals ◽  
Transmission Electron Microscope ◽  
Domain Walls ◽  
Domain Switching ◽  
Ferroelectric Domain ◽  
In Situ Observation ◽  
Transmission Electron

Five types of ferroelectric domain walls (DWs) are present in Bi4Ti3O12 single crystals (Ye et al., 2015). Here their motion was investigated in situ using transmission electron microscopy and optical microscopy. The motion of P (a)-90° DWs, P (a)-180° DWs and P (c)-180° DWs was observed through electron beam poling in a transmission electron microscope. The growth of new P s(a)-180° nanodomains was frequently seen and they tended to nucleate at preexisting P s(a)-90° DWs. Irregularly curved P (c)-180° DWs exhibit the highest mobility, while migration over a short range occurs occasionally for faceted P s(a)-90° DWs. In addition, the motion of P s(a)-90° DWs and the growth/annihilation of new needle-like P s(a)-90° domains in a 20 µm-thick crystal were observed under an external electric field on an optical microscope. Most of the new needle-like P s(a)-90° domains nucleate at preexisting P s(a)-90° DWs and the former are much smaller than the latter. This is very similar to the situation for P s(a)-180° domain switching induced by electron beam poling in a transmission electron microscope. Our observations suggest the energy hierarchy for different domains of P s(c)-180° ≤ P s(a)-180° ≤ P s(a)-90° ≤ new needle-like P s(a)-90° in ferroelectric Bi4Ti3O12.

Cross‐section transmission electron microscope observations of diamond‐turned single‐crystal Si surfaces

1994 ◽  
Vol 65 (20) ◽  
pp. 2553-2555 ◽  
Author(s):  
Takayuki Shibata ◽  
Atsushi Ono ◽  
Kenji Kurihara ◽  
Eiji Makino ◽  
Masayuki Ikeda
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Cross Section ◽  
Transmission Electron Microscope ◽  
Transmission Electron

Morphological evolution of calcium apatites from nanorods to hollow spheres mediated by acetic acid

2009 ◽  
Vol 24 (8) ◽  
pp. 2499-2502 ◽  
Author(s):  
Junfeng Hui ◽  
Daidi Fan
Keyword(s):  
Acetic Acid ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Morphological Evolution ◽  
Hollow Spheres ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Acid Aqueous Solution ◽  
The Stability

Hydroxyapatite (HAp) and brushite (DCPD) are two important compounds of the calcium apatite family with excellent bioactivity and osteoconductive properties in vivo. This work aimed to investigate the stability of HAp nanorods synthesized by the hydrothermal method in acetic acid aqueous solution. The results illuminated that HAp nanorods were converted into hollow nanospheres, and it was found that the concentration and amount of the acetic acid and the reaction time significantly affected the degree of the morphological evolution. Transmission electron microscope, high-resolution transmission electron microscope, and x-ray diffraction were performed for characterizing the samples.

Radiation Effects in Zircon, Hafnon, and Thorite: Implications for Pu Disposal

1998 ◽  
Vol 540 ◽  
Author(s):  
A. Meldrum ◽  
S.J. Zinkle ◽  
L.A. Boatner ◽  
M. Wu ◽  
R. Mu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Optical Absorption ◽  
Single Crystal ◽  
Microstructural Evolution ◽  
Transmission Electron Microscope ◽  
Nd:Yag Laser ◽  
Radiation Effects ◽  
New Model ◽  
Transmission Electron

AbstractSynthetic ZrSiO4, HfSiO4, and ThSiO4 single-crystal specimens were irradiated by 800 keV Kr+ ions, and the microstructural evolution was observed in-situ in a transmission electron microscope. All three compounds were found to become amorphous up to temperatures in excess of 600°C. Using a new model, the activation energies for annealing were found to be in the range of 3.1 to 3.6 eV for these compounds. At temperatures above 600°C, the orthosilicates were observed to decompose into the component oxides (e.g., tetragonal ZrO2 + amorphous SiO2 in the case of zircon). A single-crystal zircon specimen was also irradiated with a pulsed picosecond Nd:YAG laser operated at 355 nm, and the resulting microstructure was investigated by optical absorption, SEM, AFM, and TEM techniques.

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