scholarly journals In-Situ Irradiation Studies on the Effects of Helium on the Microstructural Evolution of V-3.8Cr-3.9Ti

1996 ◽  
Vol 439 ◽  
Author(s):  
N. Doraiswamy ◽  
B. Kestel ◽  
D. E. Alexander
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantitative Analysis ◽  
Microstructural Evolution ◽  
Room Temperature ◽  
Defect Density ◽  
Number Density ◽  
Transmission Electron

AbstractThe role of helium on the microstructural evolution of V-3.8Cr-3.9Ti has been investigated by in-situ transmission electron microscopy observations of as-prepared and He implanted (<10 appm) samples subjected to 200keV He irradiation at room temperature. Quantitative analysis of the defects showed an increase in the defect density and size with irradiation in both types of samples. The unimplanted sample showed a defect density consistent with electron irradiation experiments. In comparison, the He preimplanted sample had slightly larger defects and a substantially greater increase in the number density of defects. This result is consistent with a mechanism of He trapping by the formation of He-vacancy-X (X= C, N, O) complexes.

scholarly journals In situ environmental HRTEM discloses low temperature carbon soot oxidation by ceria–zirconia at the nanoscale

2019 ◽  
Vol 55 (27) ◽  
pp. 3876-3878 ◽  
Author(s):  
Eleonora Aneggi ◽  
Jordi Llorca ◽  
Alessandro Trovarelli ◽  
Mimoun Aouine ◽  
Philippe Vernoux
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Room Temperature ◽  
Soot Oxidation ◽  
Environmental Transmission ◽  
Transmission Electron ◽  
Carbon Soot ◽  
Environmental Transmission Electron Microscopy

In situ environmental transmission electron microscopy discloses room temperature carbon soot oxidation by ceria–zirconia at the nanoscale.

scholarly journals Unravelling the characteristics of Al-alloy corrosion at the atomic to nanometre scale by transmission electron microscopy

2020 ◽  
Vol 326 ◽  
pp. 01007
Author(s):  
Shravan K. Kairy ◽  
Nick Birbilis
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Al Alloy ◽  
Second Phase ◽  
Clear Understanding ◽  
Transmission Electron ◽  
Second Phase Particles ◽  
Al Matrix

The localised corrosion associated with Mg2Si in the Al-matrix of an Al-Mg-Si alloy was studied in 0.1 M NaCl at pH 6 by quasi in-situ transmission electron microscopy. Herein, physical imaging of corrosion at the atomic to nanometre scale was performed. Phase transformation and subsequent chemical composition variations associated with the localised corrosion of Mg2Si were studied. It was observed that corrosion initiated upon Mg2Si, often preferentially at the interface with the Al-matrix, and propagated until Mg2Si was completely dealloyed by Mg-dissolution, resulting in an amorphous SiO-rich phase remnant. The SiO-rich remnant became electrochemically inert and did not initiate corrosion in the Al-matrix. This study provides a clear understanding on the localised corrosion of Al-alloys associated with Mg2Si. In addition, the methodology followed in this study can also be applied to understand the role of precipitates and second phase particles in the localised corrosion of Al-alloy systems.

Solid-State Reactions in Fe/Si Multilayer Nanofilms

2014 ◽  
Vol 215 ◽  
pp. 144-149 ◽  
Author(s):  
Sergey M. Zharkov ◽  
Roman R. Altunin ◽  
Evgeny T. Moiseenko ◽  
Galina M. Zeer ◽  
Sergey N. Varnakov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Electron Diffraction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Reaction Processes

Solid-state reaction processes in Fe/Si multilayer nanofilms have been studied in situ by the methods of transmission electron microscopy and electron diffraction in the process of heating from room temperature up to 900ºС at a heating rate of 8-10ºС/min. The solid-state reaction between the nanolayers of iron and silicon has been established to begin at 350-450ºС increasing with the thickness of the iron layer.

Clarifying the Role of Mg2Si and Si in Localized Corrosion of Aluminum Alloys by Quasi In Situ Transmission Electron Microscopy

CORROSION ◽  
10.5006/3457 ◽  
2020 ◽  
Vol 76 (5) ◽  
pp. 464-475 ◽  
Author(s):  
Shravan K. Kairy ◽  
Nick Birbilis
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnesium Silicide ◽  
Localized Corrosion ◽  
In Situ Tem ◽  
Al Alloy ◽  
Transmission Electron ◽  
Al Matrix

The role of magnesium silicide (Mg2Si) and silicon (Si) particles in the localized corrosion of aluminum (Al) alloys was investigated herein. Sub-micrometer-sized Mg2Si and Si particles were grown in the Al matrix of Al-Mg-Si and Al-Si alloys, respectively, and characterized by transmission electron microscopy (TEM). A quasi in situ TEM technique was used to study an identical location containing Mg2Si or Si particle in the Al matrix, prior to and following a period of immersion in 0.1 M NaCl at pH 6, 2, and 12. At pH 6 and 2, Mg2Si was initially “anodic,” preferentially dealloying via selective dissolution of Mg, resulting in the development of SiO-rich remnants that are electrochemically inert. The SiO-rich remnants at pH 2 physically detached from the Al matrix. Silicon particles were electrochemically inert at pH 6, while “cathodic” at pH 2, dissolving the Al matrix at their periphery. It was observed that copper (Cu) was redeposited on Si particles at pH 2. At pH 12, Mg2Si and Si were “cathodic” to the Al matrix. This study clarifies, and provides new insights into, the characteristics of Al alloy physical manifestation of corrosion associated with Mg2Si and Si at the nanoscale.

Visualization of film-forming polymer particles with a liquid cell technique in a transmission electron microscope

The Analyst ◽  
2015 ◽  
Vol 140 (18) ◽  
pp. 6330-6334 ◽  
Author(s):  
Lili Liu ◽  
Yi Liu ◽  
Wenjun Wu ◽  
Christopher. M. Miller ◽  
Elizabeth C. Dickey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Staining Technique ◽  
Polymer Particles ◽  
Microscopy Technique ◽  
Transmission Electron ◽  
Film Forming ◽  
Liquid Cell

Liquid cell transmission electron microscopy technique provides the opportunity to image room-temperature film-forming polymer particles in solution. Together with staining technique, it can also be used as a tool to characterize the internal structure of polymer particles in situ.

Role of Interface Boundaries in the Deformation Behavior of TiAl Polysynthetically Twinned Crystal: In situ Transmission Electron Microscopy Deformation Study

2005 ◽  
Vol 20 (7) ◽  
pp. 1888-1901 ◽  
Author(s):  
Sung G. Pyo ◽  
Nack J. Kim
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Deformation Behavior ◽  
Localized Deformation ◽  
Deformation Twins ◽  
Thin Foils ◽  
Transmission Electron ◽  
Longitudinal Orientation

To understand the role of boundaries in the deformation behavior of TiAl, in situ straining experiments in transmission electron microscopy have been performed on thin foils of polysynthetically twinned (PST) crystal of Ti–49.3 at.% Al. The deformation behavior of PST TiAl is anisotropic, depending on the angle between the lamellar boundaries and the straining axes. For L-orientation, deformation twins and ordinary dislocations transmit across the true-twin (TT) boundaries but are reflected at the pseudo-twin (PT) and rotational order-fault (RO) boundaries. For transverse (T) orientation, deformation twins are transmitted across all TT, PT, and RO boundaries. For I-orientation, shear deformation occurs parallel to the lamellar boundaries. There is a transmission of deformation across the interphase (IP) boundary in longitudinal orientation, but deformation is blocked and reflected at the IP boundary in T-orientation. The role of the various types of boundaries in localized deformation behavior was evaluated by considering Schmid factors and geometric compatibility factors.

Role of the Interfaces on the Activation of Slip Systems in The PST TiAl Alloy

1998 ◽  
Vol 552 ◽  
Author(s):  
Slim Zghal ◽  
Haruyuki Inui ◽  
Masaharu Yamaguchi ◽  
Alain Couret
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tial Alloy ◽  
Slip Systems ◽  
Post Mortem ◽  
Transmission Electron ◽  
In Situ Observations ◽  
Deformation Modes

ABSTRACTThe operative slip systems in the so-called PST alloy are determined by transmission electron microscopy. Both post-mortem analyses and in situ observations are presented. It is shown that glide of ordinary dislocations and twinning are the most easily deformation modes activated at yield. The role of the interfaces on the activation of these operative slip systems is then examined and discussed.

Sign in / Sign up

Export Citation Format

Share Document