scholarly journals The Potential of the Superhydrophobic State to Protect Magnesium Alloy against Corrosion

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Kirill A. Emelyanenko ◽  
Elizaveta V. Chulkova ◽  
Alexey M. Semiletov ◽  
Alexander G. Domantovsky ◽  
Valeria V. Palacheva ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Chemical Vapor ◽  
Corrosion Current ◽  
Nanosecond Laser ◽  
X Ray Diffraction ◽  
Corrosive Solution ◽  
Superhydrophobic Coatings ◽  
Prolonged Contact ◽  
Ft Ir ◽  
Surface Morphologies

We describe the technologically simple route for the fabrication of the superhydrophobic coatings on top of wrought magnesium alloy MA8 based on nanosecond laser processing followed by the chemical vapor deposition of fluorosilane. The chemical and phase composition, surface morphologies, and variation of the coating wettability during prolonged contact with 0.5 NaCl solution or with salt aerosol were characterized using X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy measurements, and the wettability analysis. The as-prepared coatings demonstrate corrosion current of more than eight orders of magnitude lower, while after 30 days of sample immersion into corrosive solution, the current was four orders of magnitude lower than that obtained for a polished sample which was for only 2 h in contact with electrolyte. The mechanisms of the protective activity of fabricated coatings were discussed.

scholarly journals Sonochemical-assisted magnesium borate synthesis from different boron sources

2017 ◽  
Vol 19 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Meral Yildirim ◽  
Azmi Seyhun Kipcak ◽  
Emek Moroydor Derun
Keyword(s):  
High Efficiency ◽  
Synthesis Method ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Magnesium Borate ◽  
Ir And Raman Spectroscopies ◽  
Ft Ir ◽  
Surface Morphologies ◽  
Ir And Raman ◽  
Good Agreement

Abstract In this study, sonochemical-assisted magnesium borate synthesis is studied from different boron sources. Various reaction parameters are successfully applied by a simple and green method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies are used to characterize the synthesized magnesium borates on the other hand surface morphologies are investigated by using scanning electron microscope (SEM). The XRD analyses showed that the products were admontite [MgO(B2O3)3 · 7(H2O)] with JCPDS (Joint Committee on Powder Diffraction Standards) no. of 01-076-0540 and mcallisterite [Mg2(B6O7(OH)6)2 · 9(H2O)] with JCPDS no. of 01-070-1902. The results that found in the spectroscopic studies were in a good agreement with characteristic magnesium borate bands in both regions of infra-red and visible. According to SEM results, obtained borates were in micro and sub-micro scales. By the use of ultrasonication, reaction yields were found between 84.2 and 97.9%. As a result, it is concluded that the sonochemical approach is a practicable synthesis method to get high efficiency and high crystallinity in the synthesis magnesium borate compounds.

Compamson in the Growth and Properties of rf Sputtered μc-Si:H and Glow Discharge-Chemical Vapor Deposited μc-Si:H Films

1993 ◽  
Vol 321 ◽  
Author(s):  
J. Y. Lin ◽  
B. H. Tseng ◽  
K. C. Hsu ◽  
H. L. Hwang
Keyword(s):  
Glow Discharge ◽  
Rf Sputtering ◽  
Chemical Vapor ◽  
Treatment Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
Chemical Vapor Deposited ◽  
Ft Ir ◽  
Almost All

ABSTRACTProperties of μc-Si:H films grown by rf sputtering and by glow discharge-chemical vapor deposition (GD-CVD) using diluted-hydrogen and hydrogen-atom-treatment method were compared employing TEM, X-ray diffraction, Raman scattering and FT-IR. The films deposited by both methods all exhibited comparable grain sizes in the range of 10–18 nm. and showed the same tendency in almost all the Measurements.

scholarly journals Improving electrochemical corrosion properties of ZE41A magnesium alloy via hydrothermal treatment

2021 ◽  
Vol 261 ◽  
pp. 02031
Author(s):  
Yuguang Zhang ◽  
Fan Zhang ◽  
Qingpeng Cheng ◽  
Xiuling Huang ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Pure Water ◽  
Matrix Material ◽  
Electrochemical Corrosion ◽  
Chemical Compositions ◽  
Hydrothermal Time ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Hydrothermal Temperature ◽  
Surface Morphologies

ZE41A magnesium alloy was selected as matrix material, using hydrothermal method for the synthesis of the surface coating. The formation of anti-corrosion coatings on the surface of magnesium alloy was investigated in pure water. By adjusting the experimental parameters such as the hydrothermal time (1-3 h) and the hydrothermal temperature (120-160 °C), the generation of the coating on the magnesium alloy surface is regulated. The surface morphologies, composition phase, and corrosion resistance of the hydrothermal conversion coatings were investigated by the method of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and electrochemical corrosion tests. Results show that prolonged hydrothermal time and increased hydrothermal temperature change the morphologies as well as the chemical compositions of formed coatings from a relative loose structure with few magnesium hydroxides into a fine dense one with higher amount of magnesium hydroxide.

Residual service life of erbium-modified AM50 magnesium alloy under corrosion and stress environment

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 797-807
Author(s):  
Miao Yang ◽  
Liyun Xing ◽  
Xiaobo Liu ◽  
Yuqi Dong ◽  
Zhaoyu Chen ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Structural Material ◽  
Service Life ◽  
Residual Service Life ◽  
Distilled Water ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Stress Environment ◽  
Surface Morphologies ◽  
Residual Service

Abstract Magnesium alloy will decrease strength with corrosion in use, thus affecting their service life. Service life as a structural material under stress and corrosion is one focus of the magnesium alloy used as structural material, and how to improve the residual service life of magnesium alloy is an important scientific issue. The X-ray diffraction, scanning electron microscopy, and slow strain rate tensile (SSRT) tests are used to study the residual service life of erbium (Er) effect in the AM50 magnesium alloy in air, distilled water, and NaCl solution. The results show that after rare earth Er addition to the AM50, the white granular Al3Er intermetallic compound was formed. With Er content increasing, the quantity of Al3Er phase was increased and the volume of β-Mg17Al12 phase was decreased. The SSRT results show that residual service life ratio increased with the Er addition compare with no Er alloy in distilled water. However, in 3.5% NaCl solution, 0.5% Er alloy shows the best service life. Moreover, Er addition does not change the alloy fracture mode, which remains quasi-cleavage. The main cause of the decline in service life in magnesium alloys is the change in surface morphology owing to the pitting corrosion nucleation and growth, which affects the stress distribution of the sample. The mechanism of film cracking plays a major role in the fracture process with the Er increased to change the surface morphologies.

Microstructures of diamond formed by plasma-assisted chemical vapor deposition

1990 ◽  
Vol 5 (7) ◽  
pp. 1480-1489 ◽  
Author(s):  
J. L. Kaae ◽  
P. K. Gantzel ◽  
J. Chin ◽  
W. P. West
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Stacking Faults ◽  
Chemical Vapor ◽  
General Characteristic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Surface Morphologies ◽  
Deposition Conditions

The microstructures of five different diamond films formed by plasma-assisted chemical vapor deposition have been studied by transmission electron microscopy. The films were selected for study based on differences in their surface morphologies. The preferred orientations inferred from the symmetries of the crystals observed on the surfaces of these films were consistent with those measured by x-ray diffraction. A general characteristic of all of the diamond film microstructures was stacking faults and microtwins on {111} planes, but the densities and the distributions of the defects varied widely among the films. The observations of microstructure indicate that when a crystal grows so that {100} facets are formed, stacking faults and microtwins are confined to regions near its boundaries, and when a crystal grows so that {111} facets are formed, stacking faults and microtwins are distributed throughout its volume. Under some deposition conditions the defects are confined to bands in the crystal, and coincidence of these defect bands with small steps on the crystal facets suggests that the steps may be caused by the intersection of the bands with the surface.

BaTiO3 Thin Films Prepared by Organometallic Chemical Vapor Deposition

1991 ◽  
Vol 243 ◽  
Author(s):  
L.A. Wills ◽  
B.W. Wessels ◽  
D.L. Schulz ◽  
T.J. Marks
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Composition And Structure ◽  
Volatile Precursors ◽  
Surface Morphologies ◽  
Organometallic Chemical Vapor Deposition

AbstractBaTiO3 thin films have been prepared by low pressure organometallic chemical vapor deposition on (100) MgO and (100) LaAlO3 substrates using the volatile precursors, titanium(IV) tetraisopropoxide and barium (hexafluoroacetylacetonate)2 (tetraglyme). The phase composition and structure of the films depends on the reactant partial pressure, growth temperature, and substrate. High quality, epitaxial BaTiO3 films can be prepared in-situ on LaAlO3 as confirmed by x-ray diffraction measurements. These BaTiO3 films exhibit smooth surface morphologies as evidenced by scanning electron microscopy. Electrical resistivity measurements indicate that the films are semi-insulating.

Morphology of heavily B-doped diamond films

1993 ◽  
Vol 8 (11) ◽  
pp. 2845-2857 ◽  
Author(s):  
Koichi Miyata ◽  
Kazuo Kumagai ◽  
Kozo Nishimura ◽  
Koji Kobashi
Keyword(s):  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Plasma Chemical ◽  
X Ray ◽  
Plasma Chemical Vapor Deposition ◽  
Si Substrates ◽  
Surface Morphologies

B-doped diamond films were synthesized by microwave plasma chemical vapor deposition using a mixture of methane (0.5% or 1.2%) and diborane (B2H6) below 50 ppm on either Si substrates or undoped diamond films that had been synthesized using 0.5% or 1.2% methane. The surface morphologies of the synthesized films were observed by Secondary Electron Microscopy, and the infrared absorption and Raman spectra were measured. It was found that when diborane concentration was low, B-doped films preferred (111) facets. On the other hand, high diborane concentrations resulted in a deposition of needle-like material that was identified as graphite by x-ray diffraction.

Effect of Y on Microstructure and Corrosion Resistance of AZ61 Magnesium Alloy

2011 ◽  
Vol 284-286 ◽  
pp. 1529-1532
Author(s):  
Chun Xiang Xu ◽  
Zhi Ling Bai ◽  
Zhen Qiang Wang ◽  
Hui Ju ◽  
Zhi Wei Zhang
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Current ◽  
Second Phase ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Az61 Magnesium Alloy ◽  
Az61 Alloy ◽  
Refined Microstructure ◽  
The Matrix

The effect of Y addition on the microstructure of AZ61 alloy was investigated by optical microscopy (OM), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The corrosion behavior of AZ61 alloy with Y addition in 3.5 % NaCl solution was studied by static weight loss and polarization curves corrosion tests. The results show that AZ61 alloy with Y addition can refine grain size of the matrix and alter the distribution of the phase β-Mg17Al12from continuous network morphology transition to small and dispersive distribution along the grain boundary by forming the second phase Al2Y which has a high melting point. In addition, the addition of Y can decrease the corrosion current density of AZ61 magnesium alloy in 3.5% NaCl solution, thereby improving the corrosion resistance of AZ61 magnesium alloy. Results show that AZ61 magnesium alloy with 1.0% Y has the most refined microstructure and the best corrosion resistance.

SiCOI Structure Fabricated by Hot-Mesh Chemical Vapor Deposition

2006 ◽  
Vol 11-12 ◽  
pp. 257-260
Author(s):  
Kanji Yasui ◽  
T. Kurimoto ◽  
Masasuke Takata ◽  
Tadashi Akahane
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Mesh Structure ◽  
Transmission Electron ◽  
Thermal Oxide ◽  
Ft Ir ◽  
Sic Films

The growth of 3C-SiC on thermal oxide layer of Si (SiO2) was investigated by hot-mesh (HM) chemical vapor deposition (CVD), which utilizes hot tungsten (W) wires of a mesh structure as a catalyzer. The SiC films were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and cross sectional transmission electron microscopy (TEM). From the XRD spectra of SiC films grown on SiO2 layer, (100) oriented SiC films were grown at the substrate temperatures of 750-800°C and the mesh temperature of 1600°C, while polycrystalline SiC films were grown at the substrate temperature above 900°C. From the data of FT-IR, TEM and the growth rate, the growth characteristics of SiC crystal by HMCVD were discussed.

Impact of Small Miscuts of (0001) Sapphire on the Growth of AlxGa1-xN/AlN

2005 ◽  
Vol 864 ◽  
Author(s):  
Zheng Gong ◽  
Wenhong Sun ◽  
Jianping Zhang ◽  
Mikhail E. Gaevski ◽  
Hongmei Wang ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
Step Flow ◽  
Atomic Force ◽  
Full Structure ◽  
Threading Dislocation Density ◽  
Flow Morphology ◽  
Surface Morphologies

AbstractIn this paper, using chemical etching, atomic force microscope (AFM) and High- resolution X-ray diffraction (HRXRD), we report a study of the effect of various small miscuts of (0001) sapphire substrate (<1°) and the way to further improve the material quality. A set of AlN epilayers and AlN/AlxGa1-xN Superlattices (SLs) were grown by Migration-enhanced Metalorganic Chemical Vapor Deposition (MEMOCVD) on vicinal (0001) sapphire substrates. The threading dislocation density was found to be very sensitive to the miscut angles. The etch pit density reduced to 7×106 cm-2 for normal-oriented (0°-off) from the starting value of 7×107 cm-2 for 0.5°-off. We found the surface morphologies can be easily controlled by the different substrate miscut angles. The 1-2 Monolayers (MLs) step flow morphology for normal- oriented substrate changed to step bunches of 10 MLs height for 0.5°-off substrate. Correspondingly, AFM Root Mean Square (RMS) increased from 1.52 to 9.15 Å with a 5um×5um scan. This finding may help enhance the quality of full structure UVLED material and eventually improve the lifetime of UVLEDs.

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