The Morphology of Corrosion Products in FeAl Alloys after Heat-Resistance Tests at Different Temperatures

2015 ◽  
Vol 227 ◽  
pp. 409-412 ◽  
Author(s):  
Agnieszka Fornalczyk ◽  
Janusz Cebulski ◽  
Pasek Dorota
Keyword(s):  
Heat Resistance ◽  
Surface Condition ◽  
Intermetallic Phases ◽  
Passive Layer ◽  
Operating Conditions ◽  
Corrosion Products ◽  
X Ray ◽  
Physico Chemical ◽  
Different Temperatures ◽  
Resistance Tests

The alloys based on intermetallic phases involving Al belong to a new group of heat-resistant materials. Their physico-chemical and mechanical properties allow to apply them in the operating conditions in corrosive environment and elevated temperature. Research conducted for many years has shown that these materials can work at temperature up to 1100°C without degradation of their occurrence in the environment containing oxygen and sulphur. Heat resistance of these materials is provided by forming the Al2O3 passive layer on the surface. This layer is a protective barrier, which hinders the oxygen diffusion into the surface. This paper presents the morphology of passive Al2O3 layer depending on the temperature of its formation. The study allows to define the surface condition for corrosion products carried out using scanning electron microscopy together with EDS X-ray microanalysis.

scholarly journals Synchrotron X-ray diffraction investigation of the surface condition of artefacts from King Henry VIII's warship the Mary Rose

2020 ◽  
Vol 27 (3) ◽  
pp. 653-663
Author(s):  
Mark G. Dowsett ◽  
Pieter-Jan Sabbe ◽  
Jorge Alves Anjos ◽  
Eleanor J. Schofield ◽  
David Walker ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Surface Condition ◽  
Corrosion Products ◽  
X Ray Diffraction ◽  
Chemical Corrosion ◽  
X Ray ◽  
Surface Corrosion ◽  
Conservation Treatment ◽  
Three Samples ◽  
Peak Widths

Synchrotron X-ray diffraction (XRD) measured on the XMaS beamline at the ESRF was used to characterize the alloy composition and crystalline surface corrosion of three copper alloy Tudor artefacts recovered from the undersea wreck of King Henry VIII's warship the Mary Rose. The XRD method adopted has a dynamic range ∼1:105 and allows reflections <0.002% of the height of major reflections in the pattern to be discerned above the background without smoothing. Laboratory XRD, scanning electron microscopy–energy dispersive spectroscopy, synchrotron X-ray fluorescence and X-ray excited optical luminescence–X-ray near-edge absorption structure were used as supporting techniques, and the combination revealed structural and compositional features of importance to both archaeology and conservation. The artefacts were brass links believed to be fragments of chainmail and were excavated from the seabed during 1981 and 1982. Their condition reflects very different treatment just after recovery, viz. complete cleaning and conservation, chemical corrosion inhibition and chloride removal only, and distilled water soaking only (to remove the chlorides). The brass composition has been determined for all three at least in the top 7 µm or so as Cu(73%)Zn(27%) from the lattice constant. Measurement of the peak widths showed significant differences in the crystallite size and microstrain between the three samples. All of the links are found to be almost chloride-free with the main corrosion products being spertiniite, sphalerite, zincite, covellite and chalcocite. The balance of corrosion products between the links reflects the conservation treatment applied to one and points to different corrosion environments for the other two.

scholarly journals Physico-chemical studies of some aminobenzoic acid hydrazide complexes

2004 ◽  
Vol 69 (4) ◽  
pp. 255-264 ◽  
Author(s):  
Abd El ◽  
Abd El ◽  
Gamel El ◽  
Abd El
Keyword(s):  
Acid Hydrazide ◽  
Conductometric Titration ◽  
Aminobenzoic Acid ◽  
X Ray ◽  
Physico Chemical ◽  
Coordination Process ◽  
Different Temperatures ◽  
Chemical Studies ◽  
The Stability ◽  
Thermal Stability Of

The stability constants and related thermodynamic functions characterizing the formation of divalent Ni, Cu, Zn, Cd and Hg complexes with o- and p-aminobenzoic acid hydrazide were determined potentiometrically at different temperatures. The formations of the complexes are endothermic processes. The formed bonds are mainly electrostatic. Conductometric titration was carried out to determine the stoichiometry and stability of the formed complexes. The structures of complexes were characterized by their IR, 1H-NMR and 13C-NMR spectra, as well as X-ray diffractograms. The coordination process takes place through the carbonyl group and the terminal hydrazinic amino group. The thermal stability of the complexes was followed in the temperature range 20?600 ?C.

scholarly journals Effects of Sucrose Palmitate on the Physico-Chemical and Mucoadhesive Properties of Buccal Films

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5248
Author(s):  
András Kelemen ◽  
Bálint Katona ◽  
Szilvia Módra ◽  
Zoltán Aigner ◽  
István Sebe ◽  
...  
Keyword(s):  
Hydroxypropyl Methylcellulose ◽  
Permeation Enhancer ◽  
X Ray ◽  
Positron Annihilation Lifetime ◽  
Physico Chemical ◽  
Different Temperatures ◽  
Measured Contact Angle ◽  
Buccal Films

In our current research, sucrose palmitate (SP) was applied as a possible permeation enhancer for buccal use. This route of administration is a novelty as there is no literature on the use of SP in buccal mucoadhesive films. Films containing SP were prepared at different temperatures, with different concentrations of SP and different lengths of hydroxypropyl methylcellulose (HPMC) chains. The mechanical, structural, and in vitro mucoadhesive properties of films containing SP were investigated. Tensile strength and mucoadhesive force were measured with a device and software developed in our Institute. Positron annihilation lifetime spectroscopy (PALS) and X-ray powder diffractometry (XRPD) were applied for the structure analysis of the films. Mucoadhesive work was calculated in two ways: from the measured contact angle and compared with direct mucoadhesive work, which measured mucoadhesive force, which is direct mucoadhesion work. These results correlate linearly with a correlation coefficient of 0.98. It is also novel because it is a new method for the determination of mucoadhesive work.

scholarly journals Au Doping ZnO Nanosheets Sensing Properties of Ethanol Gas Prepared on MEMS Device

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 945
Author(s):  
Yempati Nagarjuna ◽  
Yu-Jen Hsiao
Keyword(s):  
Gas Sensing ◽  
Micro Electro Mechanical System ◽  
Operating Conditions ◽  
Structural Morphology ◽  
X Ray ◽  
Zno Nanostructure ◽  
Zno Nanosheets ◽  
Different Temperatures ◽  
Doped Zno ◽  
Mems Device

Sensitivity of the Micro Electro Mechanical System (MEMS) device ZnO nanosheets sensor and the Au doped ZnO nanosheets sensor has been investigated. The ZnO samples have been prepared using Hydrothermal synthesis at 90 °C. The prepared ZnO nanostructure is tested for structural morphology and crystallinity properties. The elemental analysis of the ZnO sample and Au–ZnO samples are tested by using Energy Dispersive X-ray Spectroscopy (EDS) spectrum analysis. MEMS device microheater is designed and prepared for testing the sensitivity of Ethanol gas. Thermal properties of the MEMS microheater is studied for better gas testing at different temperatures. Both the ZnO nanosheets sensor and Au doped ZnO nanosheets sensor are tested using Ethanol gas, and the gas concentrations are taken to be 15, 30, 45, and 60 ppm at 300 °C. The gas sensing response of pure ZnO nanosheets tested for ethanol gas at 60 ppm showed 20%, while the Au–ZnO nanosheets showed 35%, which is increased by 15% at similar operating conditions.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

On corrosion properties of ceramic materials for pump friction pairs in lead – bismuth environment

2019 ◽  
pp. 116-122
Author(s):  
V. V. Stepanov ◽  
A. D. Kashtanov ◽  
S. U. Shchutsky ◽  
A. N. Agrinsky ◽  
N. I. Simonov
Keyword(s):  
Composite Materials ◽  
Heat Resistance ◽  
Experimental Research ◽  
Ceramic Materials ◽  
Operating Conditions ◽  
Metallic Materials ◽  
Corrosion Properties ◽  
Liquid Coolant ◽  
Radial Bearing ◽  
Axial Pump

We consider the results of studies on the choice of material of the lower radial bearing of the pump, designed to circulate the coolant lead – bismuth. The circulation of the liquid coolant is provided by a vertical axial pump having a “long” shaft. In this design it is necessary to provide for the lower bearing the lubrication carried out with lead – bismuth coolant. Having analyzed the operating conditions of the axial pump, we decided to carry out the lower bearing in accordance with the scheme of a hydrodynamic sliding bearing. The materials of friction pairs in such a bearing must withstand the stresses arising from the operation of the pump, as well as the aggressive conditions of the coolant. Non-metallic materials – ceramics and carbon-based composite materials – were selected basing on the study of literature data for experimental research on the corrosion and heat resistance in the lead-bismuth environment. 

scholarly journals A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu
Keyword(s):  
Stearic Acid ◽  
Antibacterial Properties ◽  
Alkali Resistance ◽  
Poplar Wood ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Acid And Alkali Resistance ◽  
The Stability

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

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