The study of the volume expansion of aluminum during porous oxide formation at galvanostatic regime

2004 ◽  
Vol 222 (1-4) ◽  
pp. 215-225 ◽  
Author(s):  
I. Vrublevsky ◽  
V. Parkoun ◽  
V. Sokol ◽  
J. Schreckenbach ◽  
G. Marx
Keyword(s):  
Volume Expansion ◽  
Oxide Formation ◽  
Galvanostatic Regime ◽  
Porous Oxide

INVESTIGATION OF POROUS ANODIC FILM FORMATION ON AA1050 BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY

2019 ◽  
Vol 27 (08) ◽  
pp. 1950186
Author(s):  
M. DANIŞMAN ◽  
M. KOCABAŞ ◽  
M. CURIONI ◽  
N. CANSEVER
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Film Formation ◽  
Oxide Formation ◽  
Porous Oxide ◽  
A Charge ◽  
Eis Analysis ◽  
Scanning Electron

In this study, the formation of porous Al2O3 on commercial 1050 aluminium alloy (AA1050) in 2[Formula: see text]M sulfuric acid (H2SO4) electrolyte was investigated. Anodization was performed at 12[Formula: see text]V and 15[Formula: see text]V specimens for a charge density of 757[Formula: see text]mC/cm2 and 3231[Formula: see text]mC/cm2. The resulting oxides were analyzed using scanning electron microscopy (SEM). According to analysis, a hexagonal oxide formation containing more than one nano pore was observed on the surface of the specimen. The structural properties of the porous oxide film were analyzed with electrochemical impedance spectroscopy (EIS) analysis and film-related features such as thickness of the porous and the barrier layer were obtained.

scholarly journals Long-time Oxidation of Ti3(Al,Si)C2 Carbides at 400-800 oC

2020 ◽  
Vol 58 (3) ◽  
pp. 182-189 ◽  
Author(s):  
Junhee Hahn ◽  
Sang Whan Park ◽  
Dong Bok Lee
Keyword(s):  
Grain Size ◽  
Volume Expansion ◽  
Oxidation Behavior ◽  
Titanium Oxides ◽  
Oxide Scales ◽  
Oxidation Condition ◽  
Oxidation Rates ◽  
The Matrix ◽  
Long Time ◽  
Porous Oxide

Quarternay carbides of Ti<sub>3</sub>Al<sub>x</sub>Si<sub>1-x</sub>C<sub>2</sub> (x=0.3, 0.5, and 0.7) were oxidized at 400, 600, and 800 °C for 0.5-6 months in order to study their long-time oxidation behavior in air. When they were oxidized at 400-600 <sup>o</sup>C for 0.5-3 months, oxidation proceeded relatively slowly with moderate weight gains. However, further oxidation at 400-600 <sup>o</sup>C for 6 months resulted in the oxidation-induced microcracking of oxide scales due to large volume expansion and large stress induced owing to the formation of Al<usb>2</sub>O<sub>3</sub>, SiO<sub>2</sub>. TiO<sub>3</sub>, and TiO<sub>2</sub> in oxide scales. However, at 800 <sup>o</sup>C, microcracking of oxide scales, which could lead to pulverization of Ti<sub>3</sub>Al<sub>x</sub>Si<sub>1-x</sub>C<sub>2</sub>, did not occur due to stress relaxation in oxide scales. Instead, at 800 <sup>o</sup>C, Ti<sub>3</sub>Al<sub>x</sub>Si<sub>1-x</sub>C<sub>2</sub> oxidized rapidly to form thick, somewhat porous oxide scales, which consisted primarily of an outer TiO<sub>2</sub> layer with some Al<sub>2</sub>O<sub>3</sub>, an intermediate Al<sub>2</sub>O<sub>3</sub> layer with some TiO<sub>2</sub>, and an inner TiO<sub>2</sub> layer with some (SiO<sub>2</sub>+Al<sub>2</sub>O<sub>3</sub>). The overall longtime oxidation resistance of Ti<sub>3</sub>Al<sub>x</sub>Si<sub>1-x</sub>C<sub>2</sub> at 400-800 °C was considered to be poor. Factors that determined the oxidation rates of Ti<sub>3</sub>Al<sub>x</sub>Si<sub>1-x</sub>C<sub>2</sub> were; (1) How fast titanium oxidized to semi-protective titanium oxides, (2) How fast Al and Si oxidized to Al<sub>2</sub>O<sub>3</sub> and SiO<sub>2</sub> barrier oxides, and (3) Whether oxidation-induced microcracking occurred in oxide scales or not. The ratio of Al/Si in Ti<sub>3</sub>Al<sub>x</sub>Si<sub>1-x</sub>C<sub>2</sub> and the matrix grain size were apparently not dominant factors, because the basic oxidation mode of Ti<sub>3</sub>Al<sub>0.3</sub>Si<sub>0.7</sub>C<sub>2</sub>, Ti<sub>3</sub>Al<sub>0.5</sub>Si<sub>0.5</sub>C<sub>2</sub>, and Ti<sub>3</sub>Al<sub>0.7</sub>Si<sub>0.3</sub>C<sub>2</sub> was similar under the identical oxidation condition.

Radiation Damage Studies with the HVEM

1972 ◽  
Vol 30 ◽  
pp. 680-681
Author(s):  
J. J. Laidler ◽  
B. Mastel
Keyword(s):  
Radiation Damage ◽  
Stainless Steels ◽  
Volume Expansion ◽  
Austenitic Stainless Steels ◽  
Test Facility ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Under Construction ◽  
Development Laboratory ◽  
Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

STEM and ELS Observation of Early Oxide Formation on the Surface of Cr Thin Films

1980 ◽  
Vol 38 ◽  
pp. 412-413
Author(s):  
Fumio Watari ◽  
J. M. Cowley
Keyword(s):  
Thin Films ◽  
Optical System ◽  
Room Temperature ◽  
Oxide Formation ◽  
Initial Nucleation ◽  
Diffraction Patterns ◽  
Relationship Of ◽  
Multiple Twinning ◽  
Moderately High Temperature

STEM coupled with the optical system was used for the investigation of the early oxidation on the surface of Cr. Cr thin films (30 – 1000Å) were prepared by evaporation onto the polished or air-cleaved NaCl substrates at room temperature and 45°C in a vacuum of 10−6 Torr with an evaporation speed 0.3Å/sec. Rather thick specimens (200 – 1000Å) with various preferred orientations were used for the investigation of the oxidation at moderately high temperature (600 − 1100°C). Selected area diffraction patterns in these specimens are usually very much complicated by the existence of the different kinds of oxides and their multiple twinning. The determination of the epitaxial orientation relationship of the oxides formed on the Cr surface was made possible by intensive use of the optical system and microdiffraction techniques. Prior to the formation of the known rhombohedral Cr2O3, a thin spinel oxide, probably analogous to γ -Al203 or γ -Fe203, was formed. Fig. 1a shows the distinct epitaxial growth of the spinel (001) as well as the rhombohedral (125) on the well-oriented Cr(001) surface. In the case of the Cr specimen with the (001) preferred orientation (Fig. 1b), the rings explainable by spinel structure appeared as well as the well defined epitaxial spots of the spinel (001). The microdif fraction from 20A areas (Fig. 2a) clearly shows the same pattern as Fig. Ia with the weaker oxide spots among the more intense Cr spots, indicating that the thickness of the oxide is much less than that of Cr. The rhombohedral Cr2O3 was nucleated preferably at the Cr(011) sites provided by the polycrystalline nature of the present specimens with the relation Cr2O3 (001)//Cr(011), and by further oxidation it grew into full coverage of the rest of the Cr surface with the orientation determined by the initial nucleation.

Routes of metal oxide formation from metal β-diketonates used as CVD precursors

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-65-Pr8-72 ◽  
Author(s):  
A. E. Turgambaeva ◽  
V. V. Krisyuk ◽  
A. F. Bykov ◽  
I. K. Igumenov
Keyword(s):  
Metal Oxide ◽  
Oxide Formation

Early Volume Expansion Improves the Outcome of Shigatoxin-Associated Hemolytic Uremic Syndrome. Data from the North Italian HUS Network

PEDIATRICS ◽  
2016 ◽  
Vol 137 (Supplement 3) ◽  
pp. 299A-299A
Author(s):  
Gianluigi Ardissino ◽  
Francesca Tel ◽  
Ilaria Possenti ◽  
Sara Testa ◽  
Dario Consonni ◽  
...  
Keyword(s):  
Hemolytic Uremic Syndrome ◽  
Volume Expansion ◽  
The North ◽  
Uremic Syndrome

Early Volume Expansion Improves the Outcome of Shigatoxin-Associated Hemolytic Uremic Syndrome. Data from the North Italian HUS Network

2017 ◽  
Author(s):  
Gianluigi Ardissino ◽  
Francesca Tel ◽  
Ilaria Possenti ◽  
Sara Testa ◽  
Dario Consonni ◽  
...  
Keyword(s):  
Hemolytic Uremic Syndrome ◽  
Volume Expansion ◽  
The North ◽  
Uremic Syndrome
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