scholarly journals Sulfidation of Ceramic-Based Coatings Deposited on Low-Alloyed Steel 16Mo3 Exposed at High Temperature

2021 ◽  
Author(s):  
Ewa Rząd ◽  
Tomasz Dudziak ◽  
Tomasz Polczyk ◽  
Łukasz Boroń ◽  
Paweł Figiel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Kinetic Data ◽  
Degradation Process ◽  
Ceramic Coatings ◽  
Alloyed Steel ◽  
X Ray ◽  
Degree Of Protection ◽  
Low Alloyed Steel ◽  
High Degree ◽  
Scanning Electron

AbstractThis study was carried out to evaluate a series of ceramic coatings in a sulfidation atmosphere containing 99% synthetic air and 1% H2S (vol.%) under a flow rate of 50 mL/min. The study was carried out at 773.15 K for 336 hours (heating rate 278.15 K/min). Chemically resistant glass enamels based on SiO2-B2O3-TiO2-Na2O compounds were deposited on the surface of 16Mo3 (16M) low-alloyed steel. Kinetic data were recorded periodically every 168 hours; macro- and microanalyses using scanning electron microscopy (SEM), phase analyses using x-ray diffractometry (XRD) and chemical composition using energy-dispersive x-ray spectrometry along with EDS x-ray mappings were carried out to observe the degradation process of the sulfidized coatings. The results indicated that some of the ceramic coatings exposed in the harsh atmosphere at 773.15 K for 336 hours showed a high degree of protection.

scholarly journals Defects of copper patina / Vady mìdìných patin

2015 ◽  
Vol 59 (3) ◽  
pp. 87-90 ◽  
Author(s):  
J. Stoulil ◽  
P. Šedá ◽  
M. Anisová ◽  
Z. Fencl ◽  
P. Novák ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Image Analysis ◽  
Compact Surface ◽  
Historical Buildings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Destructive Analysis ◽  
High Degree ◽  
Scanning Electron

Abstract The paper is focused on analyses of dark copper patina defects that were formed on one sheet under the same conditions. Roofs of ten historical buildings were studied by image analysis and samples of two roofs were subjected to more detailed destructive analysis. These samples were studied by means of scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction and infrared spectroscopy. Both types of patina are composed of brochantite. Green patinas consisted of a pure brochantite and they had a fl at and compact surface. Conversely, black patina contained a high degree of impurities (ammonia cations, nitrates, silicates) and the surface was rough. The proportion of dark patina was higher in south and east facing surfaces, where washing by rainfall is more difficult.

What We Really Know About Biosynthesis of Cellulose from Ficus palmate: A Novel Biomass Production

2020 ◽  
Vol 234 (2) ◽  
pp. 313-321 ◽  
Author(s):  
Sultan Alam ◽  
Noor Rehman ◽  
Inamullah Mian ◽  
Hidayat Ullah
Keyword(s):  
Electron Microscopy ◽  
Alkali Treatment ◽  
X Ray Diffraction ◽  
Biomass Waste ◽  
Research Attention ◽  
X Ray ◽  
Multistep Process ◽  
Multistep Procedure ◽  
High Degree ◽  
Scanning Electron

AbstractCurrent research attention has been motivated on the successful synthesis of cellulose from biomass waste of Ficus palmate through multistep process i.e. bleaching and alkali treatment to efficiently eradicate impurities, waxy substances like pectin, cutin, waxes, extractives, hemicellulose and lignin from F. palmate. The cellulose obtained was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). The isolated cellulose has high degree of purity and crystallinity (61%) and thermal stability as verified by XRD and TGA, respectively. SEM was used for surface morphology and shape. Highly visible pores with channels were detected on the surface. Moreover it also shows that the free surface from lignin and hemicelluloses due to chemical treatment. This study indicates that the multistep procedure is quite adequate for the extraction of cellulose.

Effects of graphene on the microstructure and properties of MAO coatings formed on AA7050

2020 ◽  
Vol 111 (6) ◽  
pp. 463-468
Author(s):  
Bo Xu ◽  
Yafeng He ◽  
Xiangzhi Wang ◽  
Weimin Gan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Composite Coatings ◽  
Ceramic Coatings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Scanning Electron

Abstract Ceramic coatings were prepared on the surface of 7050 highstrength aluminum alloy using micro-arc oxidation in an aluminate electrolyte with added graphene. To analyze the surface morphology, roughness, phase composition, and corrosion resistance, scanning electron microscopy, X-ray diffraction, X-ray photoelectron, and electrochemical measurements were used, respectively. The addition of 9 g · L-1 of graphene to the electrolyte decreased the micro-pore size of the composite coatings and improved the density. In addition, with the addition of graphene, the roughness was the lowest, and the corrosion resistance was significantly improved.

Influences of Calcination Ambiences on Morphologies, Phase Composition and Contents of the Elements of Ceramic Coatings on Ti Alloy by Micro-Arc Oxidation

2012 ◽  
Vol 512-515 ◽  
pp. 1066-1069
Author(s):  
Jin Xue Zhang
Keyword(s):  
Electron Microscopy ◽  
Phase Composition ◽  
Ceramic Coatings ◽  
Ti Alloy ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Oxidation Properties ◽  
Α Al2o3 ◽  
Scanning Electron

Compound ceramic coatings with the main crystal phase of Al2TiO5 (as-coated samples) were prepared in situ on the surface of Ti-6Al-4V alloy by means of pulsed bi-polar micro-arc oxidation (MAO) in an NaAlO2 solution. The coated samples were calcined in argon and air at 1000 oC, respectively. The phase composition, surface and section morphology, and element contents of the ceramic coatings were investigated by X-ray diffractometry (XRD), Scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (XRF). The samples were treated in argon and the as-coated ones were calcined in air at 1000 oC to study the anti-oxidation properties of the samples. The results show that Al2TiO5 had been decomposed in an hour and transformed into α-Al2O3 and rutile TiO2 in air. However, Al2TiO5 had been decomposed in four hours in argon and the final coating surface was completely composed of α-Al2O3. The content of Al2O3 was decreased from outside to inside layers and Ti2O3 was formed in the coating. Furthermore, the morphology of the ceramic coatings after the calcination was different. The coatings calcined in argon were finer; the grains and pores were smaller than those in air.

The Application of Scanning Electron Microscopy with Energy-Dispersive X-Ray Spectroscopy (SEM-EDX) in Ancient Dental Calculus for the Reconstruction of Human Habits

2017 ◽  
Vol 23 (6) ◽  
pp. 1207-1213 ◽  
Author(s):  
Dana Fialová ◽  
Radim Skoupý ◽  
Eva Drozdová ◽  
Aleš Paták ◽  
Jakub Piňos ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Elements ◽  
Energy Dispersive ◽  
Dental Calculus ◽  
X Ray ◽  
A Charge ◽  
High Degree ◽  
The 19Th Century ◽  
Scanning Electron

AbstractThe great potential of scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) is in detection of unusual chemical elements included in ancient human dental calculus to verify hypotheses about life and burial habits of historic populations and individuals. Elemental spectra were performed from archeological samples of three chosen individuals from different time periods. The unusual presence of magnesium, aluminum, and silicon in the first sample could confirm the hypothesis of high degree of dental abrasion caused by particles from grinding stones in flour. In the second sample, presence of copper could confirm that bronze jewelery could lie near the buried body. The elemental composition of the third sample with the presence of lead and copper confirms the origin of individual to Napoleonic Wars because the damage to his teeth could be explained by the systematic utilization of the teeth for the opening of paper cartridges (a charge with a dose of gunpowder and a bullet), which were used during the 18th and the 19th century AD. All these results contribute to the reconstruction of life (first and third individual) and burial (second individual) habits of historic populations and individuals.

A Novel Route to Silocon Based Ceramic Coatings on Carbon Substrates

1991 ◽  
Vol 249 ◽  
Author(s):  
Andrew N. Macinnes ◽  
Andrew R. Barron
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Fiber ◽  
Photoelectron Spectroscopy ◽  
Ceramic Coatings ◽  
Silicon Oxycarbide ◽  
X Ray ◽  
Carbon Substrates ◽  
Silicon Based ◽  
Scanning Electron

ABSTRACTCarbon fiber tows have been impregnated by ethanolic solutions of organo-silicon chlorides, and fired at temperatures up to 900°C to form silicon based coatings. Fired tows were subsequently examined by X-ray photoelectron spectroscopy and scanning electron microscopy to characterize the coated material. A uniform silicon oxycarbide is formed at temperatures upwards of 400°C, which provides an oxidation barrier in carbon fiber reinforced metals.

Influences of Different Calcination Ambiences on Phase Composition, Morphologies of Ceramic Coatings on Ti–6Al–4V Alloy by Micro-Arc Oxidation

2011 ◽  
Vol 412 ◽  
pp. 469-472
Author(s):  
Guo Dong Hao ◽  
Huan Yuan ◽  
Jing Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
Fluorescence Spectroscopy ◽  
Ceramic Coatings ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Oxidation Properties ◽  
Scanning Electron

Compound ceramic coatings with the main crystal phase of Al2TiO5(as-coated samples) were prepared in situ on the surface of Ti-6Al-4V alloy by means of pulsed bi-polar micro-arc oxidation (MAO) in an NaAlO2solution. The coated samples were calcined in argon and air at 1000°C, respectively. The phase composition, surface and section morphology, and element contents of the ceramic coatings were investigated by X-ray diffractometry (XRD), Scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (XRF). The samples were treated in argon and the as-coated ones were calcined in air at 1000°C to study the anti-oxidation properties of the samples. The results show that Al2TiO5had been decomposed in an hour and transformed intoα-Al2O3and rutile TiO2in air. However, Al2TiO5had been decomposed in four hours in argon and the final coating surface was completely composed ofα-Al2O3. The content of Al2O3was decreased from outside to inside layers and Ti2O3was formed in the coating. Furthermore, the morphology of the ceramic coatings after the calcination was different. The coatings calcined in argon were finer; the grains and pores were smaller than those in air.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Use of SEM, X-ray analysis and TEM to localize Fe3+ reduction in roots

1988 ◽  
Vol 46 ◽  
pp. 392-393 ◽  
Author(s):  
William P. Wergin ◽  
P. F. Bell ◽  
Rufus L. Chaney
Keyword(s):  
Electron Microscopy ◽  
Root Hairs ◽  
Rapid Reduction ◽  
X Ray ◽  
Physical Evidence ◽  
Transmission Electron ◽  
Young Root ◽  
Insoluble Precipitate ◽  
Uptake And Transport ◽  
Scanning Electron

In dicotyledons, Fe3+ must be reduced to Fe2+ before uptake and transport of this essential macronutrient can occur. Ambler et al demonstrated that reduction along the root could be observed by the formation of a stain, Prussian blue (PB), Fe4 [Fe(CN)6]3 n H2O (where n = 14-16). This stain, which is an insoluble precipitate, forms at the reduction site when the nutrient solution contains Fe3+ and ferricyanide. In 1972, Chaney et al proposed a model which suggested that the Fe3+ reduction site occurred outside the cell membrane; however, no physical evidence to support the model was presented at that time. A more recent study using the PB stain indicates that rapid reduction of Fe3+ occurs in a region of the root containing young root hairs. Furthermore the most pronounced activity occurs in plants that are deficient in Fe. To more precisely localize the site of Fe3+ reduction, scanning electron microscopy (SEM), x-ray analysis, and transmission electron microscopy (TEM) were utilized to examine the distribution of the PB precipitate that was induced to form in roots.

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