Inhibition Layer Breakdown by a Fast Diffusion Procedure of Zinc in Galvanized Coatings

2005 ◽  
Vol 480-481 ◽  
pp. 585-588 ◽  
Author(s):  
Eleni Pavlidou ◽  
N. Pistofidis ◽  
G. Vourlias ◽  
F. Stergioudis
Keyword(s):  
Steel Sheet ◽  
Oxide Particle ◽  
Fast Diffusion ◽  
Inhibition Layer ◽  
Oxide Formation ◽  
Oxide Particles ◽  
Al Additions ◽  
Intergranular Diffusion ◽  
Galvanized Coatings ◽  
Substrate Steel

Thick sheets of steel were galvanized in a bath containing Al additions. A Fe2Al5 layer is formed at the substrate steel sheet, which leads to a desirable transient inhibition of Fe-Zn reactions. Thus the more protective (eta) phase rich in zinc is favored. However an appreciable intergranular diffusion and a gradual formation of internal and surface oxide particles influence the growth and stability of the inhibition layer. The location of some oxide particles at the Fe2Al5 surface or inside of this layer, led to conclude that oxide particles might cause Fe-Zn outburst growths to form. This is because zinc diffuses along the oxide particle/Fe2Al5 interface. Moreover the mechanism of oxide formation causes a local depletion of the atoms concentration in the bath in the vicinity of the formed oxide. This in turn diminishes the probability of the formation of the Fe2Al5 layer. So the whole mechanism provides a fast diffusion bath for Zn, which reacts with Iron atoms forming Fe-Zn phases. The formation of the phases, were determined by XRD measurements (PHILIPS diffractometer CuKα radiation) while the dispersion of the elements was examined by SEM (20kV JEOL 840A equipped with an OXFORD ISIS 300 EDS analyzer.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

scholarly journals Aluminum Oxide Formation On Fecral Catalyst Support By Electro-Chemical Coating

2015 ◽  
Vol 60 (2) ◽  
pp. 1503-1506 ◽  
Author(s):  
H.S. Yang ◽  
D.H. Jang ◽  
K.J. Lee
Keyword(s):  
Aluminum Oxide ◽  
Catalyst Support ◽  
Electric Energy ◽  
Oxide Particle ◽  
Process Conditions ◽  
Oxide Formation ◽  
Metallic Substrates ◽  
Chemical Coating ◽  
Catalyst Life ◽  
Plasma Electrolytic

Abstract FeCrAl is comprised essentially of Fe, Cr, Al and generally considered as metallic substrates for catalyst support because of its advantage in the high-temperature corrosion resistance, high mechanical strength, and ductility. Oxidation film and its adhesion on FeCrAl surface with aluminum are important for catalyst life. Therefore various appropriate surface treatments such as thermal oxidation, Sol, PVD, CVD has studied. In this research, PEO (plasma electrolytic oxidation) process was applied to form the aluminum oxide on FeCrAl surface, and the formed oxide particle according to process conditions such as electric energy and oxidation time were investigated. Microstructure and aluminum oxide particle on FeCrAl surface after PEO process was observed by FE-SEM and EDS with element mapping analysis. The study presents possibility of aluminum oxide formation by electro-chemical coating process without any pretreatment of FeCrAl.

scholarly journals One-Step Synthesis of Copper and Cupric Oxide Particles from the Liquid Phase by X-Ray Radiolysis Using Synchrotron Radiation

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Akinobu Yamaguchi ◽  
Ikuo Okada ◽  
Takao Fukuoka ◽  
Mari Ishihara ◽  
Ikuya Sakurai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synchrotron Radiation ◽  
Cupric Oxide ◽  
Oxide Particle ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
One Step ◽  
Oxide Particles

The deposition of copper (Cu) and cupric oxide (Cu4O3, Cu2O, and CuO) particles in an aqueous copper sulfate (CuSO4) solution with additive alcohol such as methanol, ethanol, 2-propanol, and ethylene glycol has been studied by X-ray exposure from synchrotron radiation. An attenuated X-ray radiation time of 5 min allows for the synthesis of Cu, Cu4O3, Cu2O, and CuO nano/microscale particles and their aggregation into clusters. The morphology and composition of the synthesized Cu/cupric oxide particle clusters were characterized by scanning electron microscopy, scanning transmission electron microscopy, and high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy. Micro-Raman spectroscopy revealed that the clusters comprised cupric oxide core particles covered with Cu particles. Neither Cu/cupric oxide particles nor their clusters were formed without any alcohol additives. The effect of alcohol additives is attributed to the following sequential steps: photochemical reaction due to X-ray irradiation induces nucleation of the particles accompanying redox reaction and forms a cluster or aggregates by LaMer process and DLVO interactions. The procedure offers a novel route to synthesize the Cu/cupric oxide particles and aggregates. It also provides a novel additive manufacturing process or lithography of composite materials such as metal, oxide, and resin.

Gettering and Gettering Stability of Metals at Oxide Particles in Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
R. Falster ◽  
Z. Laczik ◽  
G. R. Booker ◽  
A. R. Bhatti ◽  
P. Török
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Particle Number ◽  
Oxide Particle ◽  
Internal Oxide ◽  
Transmission Electron ◽  
Metal Type ◽  
Infra Red ◽  
Oxide Particles ◽  
Thermal Stability Of

ABSTRACTSeveral aspects of metal gettering at internal oxide particle sites in Cz Si have been studied by ‘haze tests’, scanning infra-red microscopy (SIRM) and transmission electron microscopy (TEM). Haze tests indicated that complete gettering of Cu, Ni, Co and Pd can occur even when the amount of oxygen precipitated is below the detectable limit. TEM showed that the gettering of Cu, Pd and Ni proceeds by one of three different self-perpetuating mechanisms involving oxide particles and associated dislocations, the particular mechanism depending on the oxide particle size and the metal type. Haze tests and SIRM showed that for Cu and Ni there were minimum oxide particle number densities for effective gettering, and also maximum oxide particle number densities above which the additional oxide particles played no role in the gettering. These number densities depended on the metal type and specimen cooling rate. For all of these gettering behaviours, mechanisms are suggested to explain the results. The SIRM was also used to investigate for Cu and Ni the thermal stability of the gettering sites and the precipitated metals. The results showed that during repeated heat treatments the gettering occurs by a dynamic process.

PRESSURE–VOLUME CURVES IN ISOLATED ATELECTATIC RAT LUNGS AFTER ALUMINUM OXIDE MICROPARTICLE INHALATION

1963 ◽  
Vol 41 (1) ◽  
pp. 1257-1265 ◽  
Author(s):  
E. Robillard ◽  
Y. Alarie
Keyword(s):  
Guinea Pig ◽  
Aluminum Oxide ◽  
Normal Control ◽  
Oxide Particle ◽  
Aluminum Particles ◽  
Aluminum Oxide Particle ◽  
Rat Lungs ◽  
Particle Inhalation ◽  
Oxide Particles ◽  
Volume Pressure Curves

Volume–pressure curves obtained from isolated atelectatic rat lungs under normal control conditions were compared with those obtained from lungs of animals previously exposed to inhalation of submicronic aluminum oxide particles for various periods of time. A dilating effect was recorded in rat lungs after aluminum oxide particle inhalation contrasting with the constricting effect reported by many authors in guinea pig, dog, cat, and man. Inhalation of fine aluminum particles before or after inhalation of sympathomimetic aerosol resulted in a more intense dilatation. The constricting effect of carbachol was antagonized by prior inhalation of fine aluminum oxide dust and enhanced when the order of inhalations was reversed.

Molecular Dynamics Simulations of Damage Cascades Creation in Oxide-Particle-Embedded Fe

2017 ◽  
Author(s):  
A. M. Mustafa ◽  
Zhongyu Li ◽  
Lin Shao
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Oxide Particle ◽  
Oxide Dispersion Strengthened ◽  
Atomic Scale ◽  
Scale Modeling ◽  
Alloy Type ◽  
Oxide Particles ◽  
Ods Alloys ◽  
Dynamics Simulations

Oxide-dispersion-strengthened (ODS)alloys have been identified as one promising candidate alloy type for high temperature reactor applications. Understanding irradiation stability of ODS alloys relies on atomic scale modeling such as molecular dynamics simulations. In this study, yttrium and oxygen charges in Y2O3 oxide particles, which are embedded in pure Fe matrix, are optimized to achieve stabilities observed in experiments. Deviation from the optimized charges causes self-explosion and instability of oxide particles. Molecular dynamics simulations further show that under such optimized charge conditions, damage cascade creation and defect developments can be appropriately modeled.

Microstructure and Strengthening Mechanisms of Oxide Dispersion Strengthened Ferritic Alloy

2011 ◽  
Vol 87 ◽  
pp. 243-248 ◽  
Author(s):  
Jae Hoon Lee
Keyword(s):  
Oxide Particle ◽  
Oxide Dispersion Strengthened ◽  
Material Strength ◽  
Oxide Dispersion ◽  
Ferritic Alloy ◽  
Alloy Matrix ◽  
Total Strength ◽  
Treatment Conditions ◽  
Oxide Particles ◽  
Particle Strengthening

Oxide dispersion strengthened (ODS) ferritic alloys of composition Fe-19Cr-0.5Y2O3have been prepared by mechanical alloying at various heat-treatment conditions to produce a range of grain sizes and dispersed oxide particle size. Fine oxide particles appear to pin grain boundaries and result in inhibition of grain growth in the alloy matrix. Particle strengthening is shown to be a larger component of the material strength, rather than grain boundary strengthening or matrix strength, indicating that the finely dispersed oxide particles contribute very significantly to the total strength of 19Cr-ODS ferritic alloy.

PRESSURE–VOLUME CURVES IN ISOLATED ATELECTATIC RAT LUNGS AFTER ALUMINUM OXIDE MICROPARTICLE INHALATION

1963 ◽  
Vol 41 (5) ◽  
pp. 1257-1265 ◽  
Author(s):  
E. Robillard ◽  
Y. Alarie
Keyword(s):  
Guinea Pig ◽  
Aluminum Oxide ◽  
Normal Control ◽  
Oxide Particle ◽  
Aluminum Particles ◽  
Aluminum Oxide Particle ◽  
Rat Lungs ◽  
Particle Inhalation ◽  
Oxide Particles ◽  
Volume Pressure Curves

Volume–pressure curves obtained from isolated atelectatic rat lungs under normal control conditions were compared with those obtained from lungs of animals previously exposed to inhalation of submicronic aluminum oxide particles for various periods of time. A dilating effect was recorded in rat lungs after aluminum oxide particle inhalation contrasting with the constricting effect reported by many authors in guinea pig, dog, cat, and man. Inhalation of fine aluminum particles before or after inhalation of sympathomimetic aerosol resulted in a more intense dilatation. The constricting effect of carbachol was antagonized by prior inhalation of fine aluminum oxide dust and enhanced when the order of inhalations was reversed.

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