Oxidation of Rolled and Flash Anodized 3000 Aluminum in Air, Nitrogen, Oxygen, and Carbon Dioxide Atmospheres

2011 ◽  
Vol 693 ◽  
pp. 63-70
Author(s):  
Darcy Stevens ◽  
Anne Kvithyld ◽  
Thorvald Abel Engh
Keyword(s):  
Oxide Layer ◽  
Mass Gain ◽  
Pure Oxygen ◽  
Total Oxidation ◽  
Tem Analysis ◽  
Thermogravimetric Analyzer ◽  
Surface Versus ◽  
Transmission Electron ◽  
Before And After ◽  
Rolled Surface

Thermal oxidation of a 3000 Al sheet rolled alloy was carried out in various atmospheres with a thermogravimetric analyzer (TGA). The effect of a flash anodized surface versus an untreated rolled surface is investigated. All samples were oxidized for 4 hours at 800°C. Samples oxidized in air, 100 % CO2 and 50% CO2–50% air, showed no difference in total oxidation. The flash anodized samples oxidized in 10% CO2–90% air had approximately half of the mass gain of the rolled samples. Oxidation of anodized samples in pure oxygen and nitrogen showed a drastic decrease in the amount of mass gained compared to the other atmospheres. Flash anodized samples gave consistent results, and the oxidation behavior tended to be linear or S-shaped for the 4 hours investigated. Rolled samples gave less consistent data and tended to be decelerating curves. Transmission electron microscope (TEM) analysis of the oxide layer before and after showed magnesium diffusion toward the surface of the sample, with a steep gradient over a distance of 400 µm. The flash anodized oxide layer was often difficult to find, having been removed during of the TEM sample preparation, but was found to double in size from 200 to 400 µm when located.

scholarly journals A Novel Coloration of Polyester Fabric through Green Silver Nanoparticles (G-AgNPs@PET)

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 569 ◽  
Author(s):  
K. Hasan ◽  
Md. Pervez ◽  
Md. Talukder ◽  
Mst. Sultana ◽  
Sakil Mahmud ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Low Cost ◽  
Antibacterial Properties ◽  
Polyester Fabric ◽  
Bacterial Reduction ◽  
Tem Analysis ◽  
Pet Fabric ◽  
Thermogravimetric Analyzer ◽  
Transmission Electron ◽  
Fabric Surface

This paper reports a novel route for the coloration of polyester fabric with green synthesized silver nanoparticles (G-AgNPs@PET) using chitosan as a natural eco-friendly reductant. The formation of AgNPs was confirmed by UV-visible spectroscopy. The morphologies and average particles size of G-AgNPs was investigated by transmission electron microscope (TEM) analysis. The uniform deposition of G-AgNPs on the PET fabric surface was confirmed with scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. The thermal properties were investigated using a thermogravimetric analyzer (TGA). The coloration and fastness properties of fabric were found to be significantly improved, a result related to the surface plasmon resonance of G-AgNPs. The antibacterial properties of fabric were also found to be excellent as more than 80% bacterial reduction was noticed even after 10 washing cycles. Overall, the proposed coating process using green nanoparticles can contribute to low-cost production of sustainable textiles.

scholarly journals Evaluation of effects of selenium nanoparticles on Bacillus subtilis

2019 ◽  
Vol 10 (4) ◽  
pp. 544-552
Author(s):  
N. O. Tymoshok ◽  
M. S. Kharchuk ◽  
V. G. Kaplunenko ◽  
V. S. Bityutskyy ◽  
S. I. Tsekhmistrenko ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Morphological Characteristics ◽  
Visible Spectrum ◽  
Drug Carriers ◽  
Biologically Active ◽  
Selenium Nanoparticles ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Before And After ◽  
Active Substances

The present study was performed to characterize of selenium nanoparticles (Nano-Se) which were synthesized by pulsed laser ablation in liquids to obtain the aqueous selenium citrate solution. The study was conducted using bacteriological and electronic-microscopic methods. Transmission electron microscopy (TEM) and spectroscopy analyses demonstrated that nano-selenium particles obtained by the method of selenium ablation had the size of 4–8 nm. UV-Visible Spectrum colloidal solution Nano-Se exhibited absorption maxima at 210 nm. To clarify some effects of the action of Nano-Se on Bacillus subtilis, we investigated the interaction of Nano-Se with B. subtilis IMV B-7392 before and after incubation with Nano-Se, examining TEM images. It has been shown that exposure to B. subtilis IMV B-7392 in the presence of Nano-Se is accompanied by the rapid uptake of Nano-Se by bacterial culture. TEM analysis found that the electron-dense Nano-Se particles were located in the intracellular spaces of B. subtilis IMV B-7392. That does not lead to changes in cultural and morphological characteristics of B. subtilis IMV B-7392. Using TEM, it has been shown that penetration of nanoparticles in the internal compartments is accompanied with transient porosity of the cell membrane of B. subtilis IMV B-7392 without rupturing it. The effective concentration of Nano-Se 0.2 × 10–3 mg/mL was found to increase the yield of biologically active substances of B. subtilis. In order to create probiotic nano-selenium containing products, the nutrient medium of B. subtilis IMV B-7392 was enriched with Nano-Se at 0.2 × 10–3 mg/mL. It was found that particles Nano-Se are non-toxic to the culture and did not exhibit bactericidal or bacteriostatic effects. The experimentally demonstrated ability of B. subtilis to absorb selenium nanoparticles has opened up the possibility of using Nano-Se as suitable drug carriers.

Structure of Shear Bands in Zirconium-Based Metallic Glasses Observed by Transmission Electron Microscopy

2002 ◽  
Vol 754 ◽  
Author(s):  
Xiaofeng Gu ◽  
Kenneth J. T. Livi ◽  
Todd C. Hufnagel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Metallic Glasses ◽  
Defect Structure ◽  
Shear Bands ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Before And After ◽  
High Resolution Tem ◽  
Band Spacing

ABSTRACTWe have used transmission electron microscopy (TEM) to investigate the structure of shear bands produced by bending electron-transparent Zr52.5Cu17.9Ni14.6Al10Ti5 metallic glass specimens. Shear bands were located by comparing the structure of the specimens before and after deformation. The shear band spacing is influenced by the structure of the specimen; portions of the specimen with a significant population of nanocrystals show a smaller separation between shear bands. Quantitative high resolution TEM analysis based on ratio technique has been used to explore the defect structure in shear bands. High density and void-like defects with size of about 1 nm were found in shear bands formed in both amorphous and nanocrystalline areas. A simple model was proposed to explain the formation of these defects.

Dual Implantations of Ti and C into Sintered Α-Sic and Hot Pressed Si3n4

1989 ◽  
Vol 157 ◽  
Author(s):  
R.S. Bhattacharya ◽  
A.K. Rai ◽  
S.C. Kung ◽  
D. Patrizio
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Chemical Nature ◽  
No Oxidation ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Close Proximity ◽  
Before And After ◽  
D Values

ABSTRACTDual ion implantations of Ti+ and C+ into sintered a-SiC and hot pressed SÌ3N4 have been studied by Rutherford backscattering spectroscopy (RBS) combined with plan/cross section view transmission electron microscopy (TEM). The samples were analyzed before and after annealing at 1200°C for 2 hours in a vacuum of 1x10-6 torr. The results were compared with single ion implantation of Ti+. RBS analysis showed that no oxidation occurred during annealing and Ti diffused toward the surface in both SiC and SigN^ Cross section TEM analysis revealed the formation of TiC precipitates in SiC due to both dual (Ti+ + C+) and single (Ti+) ion implantations. Precipitates were found to form in SÌ3N4 as well; however, because of very close proximity of observed d values with those of TiC, TiN and β-SiC, it was not possible to uniquely identify the chemical nature of these precipitates. Thermo-dynamic calculations were performed to explain the observed results.

An Electron Microscope Study of Interdiffusion and Compound Formation in Ta-Au Thin Films

1973 ◽  
Vol 31 ◽  
pp. 32-33 ◽  
Author(s):  
T. C. Tisone ◽  
S. Lau
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Thermally Grown Oxide ◽  
Ion Milling ◽  
Compound Formation ◽  
Technology Application ◽  
Transmission Electron ◽  
Before And After ◽  
Au Thin Films

In a study of the properties of a Ta-Au metallization system for thin film technology application, the interdiffusion between Ta(bcc)-Au, βTa-Au and Ta2M-Au films was studied. Considered here is a discussion of the use of the transmission electron microscope(TEM) in the identification of phases formed and characterization of the film microstructures before and after annealing.The films were deposited by sputtering onto silicon wafers with 5000 Å of thermally grown oxide. The film thicknesses were 2000 Å of Ta and 2000 Å of Au. Samples for TEM observation were prepared by ultrasonically cutting 3mm disks from the wafers. The disks were first chemically etched from the silicon side using a HNO3 :HF(19:5) solution followed by ion milling to perforation of the Au side.

TEM Analysis of Long-Period Polytypes in SiC—S

1976 ◽  
Vol 34 ◽  
pp. 630-631
Author(s):  
S. Shinozaki ◽  
J. W. Sprys
Keyword(s):  
Electron Diffraction ◽  
Isothermal Annealing ◽  
Tem Analysis ◽  
Long Period ◽  
Transmission Electron ◽  
Average Grain Size ◽  
High Resolution Tem ◽  
Structural Lattice ◽  
The Stability ◽  
Continuous Curves

In reaction sintered SiC (∽ 5um average grain size), about 15% of the grains were found to have long-period structures, which were identifiable by transmission electron microscopy (TEM). In order to investigate the stability of the long-period polytypes at high temperature, crystal structures as well as microstructural changes in the long-period polytypes were analyzed as a function of time in isothermal annealing.Each polytype was analyzed by two methods: (1) Electron diffraction, and (2) Electron micrograph analysis. Fig. 1 shows microdensitometer traces of ED patterns (continuous curves) and calculated intensities (vertical lines) along 10.l row for 6H and 84R (Ramsdell notation). Intensity distributions were calculated based on the Zhdanov notation of (33) for 6H and [ (33)3 (32)2 ]3 for 84R. Because of the dynamical effect in electron diffraction, the observed intensities do not exactly coincide with those intensities obtained by structure factor calculations. Fig. 2 shows the high resolution TEM micrographs, where the striped patterns correspond to direct resolution of the structural lattice periodicities of 6H and 84R structures and the spacings shown in the figures are as expected for those structures.

Transmission Electron Microscopy of an Aluminum-Silver-Stainless Steel Solid State Bond

1985 ◽  
Vol 43 ◽  
pp. 172-173
Author(s):  
M. J. Carr ◽  
J. F. Shewbridge ◽  
T. O. Wilford
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Specimen Preparation ◽  
Dimensional Control ◽  
Tem Analysis ◽  
Metal Parts ◽  
Dissimilar Metal ◽  
Transmission Electron ◽  
Short Time

Strong solid state bonds are routinely produced between physical vapor deposited (PVD) silver coatings deposited on sputter cleaned surfaces of two dissimilar metal parts. The low temperature (200°C) and short time (10 min) used in the bonding cycle are advantageous from the standpoint of productivity and dimensional control. These conditions unfortunately produce no microstructural changes at or near the interface that are detectable by optical, SEM, or microprobe examination. Microstructural problems arising at these interfaces could therefore easily go undetected by these techniques. TEM analysis has not been previously applied to this problem because of the difficulty in specimen preparation. The purpose of this paper is to describe our technique for preparing specimens from solid state bonds and to present our initial observations of the microstructural details of such bonds.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

Effect of MWCNT doping on the structural and optical properties of PVC/PVDF polymer blend

2017 ◽  
Vol 13 (2) ◽  
pp. 4640-4647
Author(s):  
A. M. Abdelghany ◽  
M.S. Meikhail ◽  
S.I. Badr ◽  
A. S. Momen
Keyword(s):  
Surface Damage ◽  
X Ray Diffraction ◽  
Dopant Content ◽  
Casting Technique ◽  
Transmission Electron ◽  
Dopant Level ◽  
Before And After ◽  
Carbon Nano Tubes ◽  
Small Band ◽  
Vibrational Bands

Thin film samples of pristine polyvinyl chloride (PVC), poly vinyldine fluoride (PVDF) in combination with their blend in addition to samples containing factorial mass fraction of multi wall carbon nano-tubes (MWCNTs) in the dopant level were prepared via routine casting technique using tetrahydrofurane (THF) as a common solvent. X-ray diffraction and transmission electron microscopy (TEM) depict the nano-scale (15-25 nm) of functionalized MWCNTs with no surface damage results from functionalization process.X-ray diffraction (XRD) shows a semi-crystalline nature of PVDF with evidence for more than one phase namely a and b phases. The fraction of b phase was calculated and correlated to the dopant content. FTIR optical absorption spectra revels a preservation of the main vibrational bands before and after addition of MWCNTs in the doping level with a presence of new small band 1151 cm-1 assigned for the interaction and complexation between constituents.

TEM Sample Preparation Tricks for Advanced DRAMs

2015 ◽  
Author(s):  
Ching Shan Sung ◽  
Hsiu Ting Lee ◽  
Jian Shing Luo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Integrated Circuit ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Characterization Of Materials

Abstract Transmission electron microscopy (TEM) plays an important role in the structural analysis and characterization of materials for process evaluation and failure analysis in the integrated circuit (IC) industry as device shrinkage continues. It is well known that a high quality TEM sample is one of the keys which enables to facilitate successful TEM analysis. This paper demonstrates a few examples to show the tricks on positioning, protection deposition, sample dicing, and focused ion beam milling of the TEM sample preparation for advanced DRAMs. The micro-structures of the devices and samples architectures were observed by using cross sectional transmission electron microscopy, scanning electron microscopy, and optical microscopy. Following these tricks can help readers to prepare TEM samples with higher quality and efficiency.

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