scholarly journals The Influence of Nicraly Coatings Roughness on Oxidation Kinetics During Static Oxidation Test at Temperature 1000ºC And 1100ºC / Wpływ Przygotowania Powierzchni Na Kinetykę Utleniania Warstw Typu Nicraly Pod Wpływem Statycznego Utleniania W Temperaturze 1000ºC I 1100ºC

2015 ◽  
Vol 60 (4) ◽  
pp. 2671-2680
Author(s):  
D. Niemiec ◽  
G. Moskal ◽  
A. Jasik
Keyword(s):  
Oxidation Kinetics ◽  
Thermal Spraying ◽  
Oxidation Test ◽  
Nicraly Coating ◽  
Static Oxidation ◽  
Plasma Sprayed ◽  
The Impact ◽  
Kinetics Of ◽  
Microscopic Investigations

The article presents the results of research related to the impact of pretreatment plasma sprayed NiCrAlY coating on the kinetics of the oxidation. The analysis covered the shell subjected to thermal spraying. The test were performed at a temperature of 1000ºC and 1100ºC the samples were removed from the furnace after 25, 300, 500, 750 and 1000 hours. The investigations range included analysis of top surface of coatings by XRD characterization oxides formed types and microscopic investigations of coatings morphology.

scholarly journals Microstructure and Oxidation Resistance of Laser Remelted Plasma Sprayed Nicraly Coating

2016 ◽  
Vol 61 (2) ◽  
pp. 1183-1191
Author(s):  
D. Niemiec ◽  
G. Moskal ◽  
Ł. Carski
Keyword(s):  
Laser Treatment ◽  
Oxidation Resistance ◽  
Laser Melting ◽  
Nicraly Coating ◽  
Plasma Sprayed Coatings ◽  
Plasma Sprayed ◽  
The Impact ◽  
Sprayed Coatings ◽  
Microscopic Investigations

Abstract The article presents results of research relating to the impact of laser treatment done to the surface of plasma sprayed coatings NiCrAlY. Analysis consisted microstructure and oxidation resistance of coatings subjected to two different laser melting surfaces. The test were performed at a temperature 1000°C the samples were removed from the furnace after 25, 300, 500, 750 and 1000 hours. The investigations range included analysis of top surface of coatings by XRD characterization oxides formed types and microscopic investigations of coatings morphology

Influence of Surface Condition on Oxides Layer Morphology on NiCrAlY Coating during Oxidation at Temperature 1000°C and 1100°C

2015 ◽  
Vol 227 ◽  
pp. 385-388 ◽  
Author(s):  
Grzegorz Moskal ◽  
Dawid Niemiec
Keyword(s):  
Cross Sections ◽  
Surface Characterization ◽  
Surface Condition ◽  
Point Of View ◽  
Inconel 625 ◽  
Oxidation Test ◽  
Nicraly Coating ◽  
Static Oxidation ◽  
Plasma Spraying Process

Characterization of top-surface of NiCrAlY coating deposited by plasma spraying process on Inconel 625 Ni based superalloys was analyzed in two different completely conditions. First of them was as sprayed state of NiCrAlY coating and the second one was condition after grinding process. The basic aim of this treatment was related to obtain totally different conditions of coatings surface especially from roughness point of view. Those two types of top surface morphology was a base to comparison of oxidation resistant during static oxidation test at temperature of 1000°C and 1100°C. The temperature of static oxidation test was 1000°C and 1100°C. The specimens were moved out from furnace after 25, 300, 500, 750 and 1000 hours of exposition in laboratory air. The range of investigations after each interval included top surface characterization of specimens by SEM, XRD and EDS method. Those investigations showed that different types of top surface conditions had a fundamental influence on oxides layer morphology. Especially in the case of phase`s constituent of oxides zone. More detailed investigations were made on the cross sections of two types of investigated specimens. Analysis of oxides layer morphology showed in this case basic differences in thickness of oxides zone which was much higher in the case of as sprayed NiCrAlY coating.

Impact Of Synthesis Route on the Water Oxidation Kinetics of Hematite Photoanodes

2020 ◽  
Author(s):  
Camilo A. Mesa ◽  
Ludmilla Steier ◽  
Benjamin Moss ◽  
Laia Francàs ◽  
James E. Thorne ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Reaction Kinetics ◽  
Water Oxidation ◽  
Oxidation Kinetics ◽  
Oxidation Reaction ◽  
Charge Accumulation ◽  
Optical Signals ◽  
Current Voltage ◽  
Voltage Performance ◽  
Kinetics Of

<p><i>Operando</i> spectroelectrochemical analysis is used to determine the water oxidation reaction kinetics for hematite photoanodes prepared using four different synthetic procedures. Whilst these photoanodes exhibit very different current / voltage performance, their underlying water oxidation kinetics are found to be almost invariant. Lower photoanode performance was found to correlate with the observation of optical signals indicative of charge accumulation in mid-gap oxygen vacancy states, indicating these states do not contribute directly to water oxidation.</p>

Oxidation Kinetics of Fe(II) in a Eutrophic Swiss Lake

1998 ◽  
Vol 32 (19) ◽  
pp. 2990-2996 ◽  
Author(s):  
Lukas Emmenegger ◽  
D. Whitney King ◽  
Laura Sigg ◽  
Barbara Sulzberger
Keyword(s):  
Oxidation Kinetics ◽  
Swiss Lake ◽  
Kinetics Of

Oxidation Kinetics of Oil Shale Semicokes: Reactivity as a Function of Pyrolysis Temperature and Shale Origin

2013 ◽  
Vol 27 (2) ◽  
pp. 666-672 ◽  
Author(s):  
Jillian L. Goldfarb ◽  
Anthony D’Amico ◽  
Christopher Culin ◽  
Eric M. Suuberg ◽  
Indrek Külaots
Keyword(s):  
Oxidation Kinetics ◽  
Oil Shale ◽  
Pyrolysis Temperature ◽  
Kinetics Of

scholarly journals Ice Coverage Induced by Depositing a Water Drop onto the Supercooled Substrate at Extreme Low Vapor Pressure

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 691
Author(s):  
Yugang Zhao ◽  
Zichao Zuo ◽  
Haibo Tang ◽  
Xin Zhang
Keyword(s):  
Vapor Pressure ◽  
Substrate Temperature ◽  
Water Drop ◽  
Industrial Processes ◽  
Aircraft Icing ◽  
Ice Coverage ◽  
Fundamental Understanding ◽  
Order Of Magnitude ◽  
The Impact ◽  
Kinetics Of

Icing/snowing/frosting is ubiquitous in nature and industrial processes, and the accretion of ice mostly leads to catastrophic consequences. The existing understanding of icing is still limited, particularly for aircraft icing, where direct observation of the freezing dynamics is inaccessible. In this work, we investigate experimentally the impact and freezing of a water drop onto the supercooled substrate at extremely low vapor pressure, to mimic an aircraft passing through clouds at a relatively high altitude, engendering icing upon collisions with pendant drops. Special attention is focused on the ice coverage induced by an impinging drop, from the perimeter pointing outward along the radial direction. We observed two freezing regimes: (I) spread-recoil-freeze at the substrate temperature of Ts = −15.4 ± 0.2 °C and (II) spread (incomplete)-freeze at the substrate temperature of Ts = −22.1 ± 0.2 °C. The ice coverage is approximately one order of magnitude larger than the frozen drop itself, and counterintuitively, larger supercooling yields smaller ice coverage in the range of interest. We attribute the variation of ice coverage to the kinetics of vapor diffusion in the two regimes. This fundamental understanding benefits the design of new anti-icing technologies for aircraft.

scholarly journals Morphology and crystallization kinetics of Rubber-modified Nylon 6 Prepared by Anionic In-situ Polymerization

2020 ◽  
Vol 27 (1) ◽  
pp. 204-215
Author(s):  
Hongkai Zhao ◽  
Dengchao Zhang ◽  
Yingshuang Li
Keyword(s):  
Crystallization Kinetics ◽  
In Situ Polymerization ◽  
Good Description ◽  
Nylon 6 ◽  
Avrami Equation ◽  
Infrared Analysis ◽  
Chain Segment ◽  
The Impact ◽  
Kinetics Of

AbstractIn this work, we modified nylon 6 with liquid rubber by in-situ polymerization. The infrared analysis suggested that HDI urea diketone is successfully blocked by caprolactam after grafting on hydroxyl of HTPB, and the rubber-modified nylon copolymer is generated by the anionic polymerization. The impact section analysis indicated the rubber-modified nylon 6 resin exhibited an alpha crystal form.With an increase in the rubber content, nylon 6 was more likely to generate stable α crystal. Avrami equation was a good description of the non-isothermal crystallization kinetics of nylon-6 and rubber-modified nylon-6 resin. Moreover, it is found that the initial crystallization temperature of nylon-6 chain segment decreased due to the flexible rubber chain segment. n value of rubber-modified nylon-6 indicated that its growth was the coexistence of two-dimensional discoid and three-dimensional spherulite growth. Finally, the addition of the rubber accelerated the crystallization rate of nylon 6.

scholarly journals Single entity electrochemistry and the electron transfer kinetics of hydrazine oxidation

Nano Research ◽  
2021 ◽  
Author(s):  
Ruiyang Miao ◽  
Lidong Shao ◽  
Richard G. Compton
Keyword(s):  
Electron Transfer ◽  
Bulk Solution ◽  
Relative Contribution ◽  
Rate Determining Step ◽  
Multistep Process ◽  
Ph Range ◽  
Electro Catalytic Oxidation ◽  
Single Particle Impact ◽  
The Impact ◽  
Kinetics Of

AbstractThe mechanism and kinetics of the electro-catalytic oxidation of hydrazine by graphene oxide platelets randomly decorated with palladium nanoparticles are deduced using single particle impact electrochemical measurements in buffered aqueous solutions across the pH range 2–11. Both hydrazine, N2H4, and protonated hydrazine N2H5+ are shown to be electroactive following Butler-Volmer kinetics, of which the relative contribution is strongly pH-dependent. The negligible interconversion between N2H4 and N2H5+ due to the sufficiently short timescale of the impact voltammetry, allows the analysis of the two electron transfer rates from impact signals thus reflecting the composition of the bulk solution at the pH in question. In this way the rate determining step in the oxidation of each specie is deduced to be a one electron step in which no protons are released and so likely corresponds to the initial formation of a very short-lived radical cation either in solution or adsorbed on the platelet. Overall the work establishes a generic method for the elucidation of the rate determining electron transfer in a multistep process free from any complexity imposed by preceding or following chemical reactions which occur on the timescale of conventional voltammetry.

Sign in / Sign up

Export Citation Format

Share Document