NEW METHOD FOR DEPOSITION OF CERAMIC COATING ON AL ALLOY USING DUPLEX PROCESSES OF ANODIZING AND Al2O3 MODIFIED ELECTROLYTE MICRO -ARC OXIDATION (MAO)

In this work, surfaces of Al 6061 alloy were coated using anodizing and micro–arc oxidation ( MAO) duplex processes. MAO electrolyte was modified using ( 2-6 g/l )Al2O3 additives . X-ray diffraction (XRD), scanning electron microscopy (SEM), Vickers indenter, atomic force microscopy (AFM), and Microprocessor coating thickness meter ,were employed for characterization of the deposited coatings .Results showed that the coatings contained porous oxide ?-alumina with morphologies characterized by different levels of porosity non-uniform distribution, and their thickness and hardness increased by the increasing of Al2O3 additives. The research demonstrates that a relatively hard (421-490Hv), thick (43-65?m) and uniform coatings, can successfully be deposited on preanodized Al alloy (12-15 ?m with hardness of 190Hv) using Al2O3 additives containing MAO electrolytes as a new method for more future research on surface improvements of Al alloys

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ANEW METHOD FOR DEPOSITION OF CERAMIC COATING ON AL ALLOY USING DUPLEX PROCESSES OF ANODIZING AND AL2O3MODIFIED ELECTROLYTE MICRO-ARC OXIDATION (MAO)

THE IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING ◽

10.32852/iqjfmme.v19i3.375 ◽

2019 ◽

Vol 19 (3) ◽

pp. 17

Author(s):

Samir Awad

Keyword(s):

Future Research ◽

Al Alloy ◽

X Ray Diffraction ◽

Force Microscopy ◽

Atomic Force ◽

Micro Arc Oxidation ◽

Porous Oxide ◽

Thickness Meter ◽

Different Levels

ABSTRACTIn this work, surfaces of Al 6061 alloy were coated using anodizing and micro–arc oxidation ( MAO) duplex processes. MAO electrolyte was modified using ( 2-6 g/l )Al2O3 additives . X-ray diffraction (XRD), scanning electron microscopy (SEM), Vickers indenter, atomic force microscopy (AFM), and Microprocessor coating thickness meter ,were employed for characterization of the deposited coatings .Results showed that the coatings contained porous oxide ?-alumina with morphologies characterized by different levels of porosity non-uniform distribution, and their thickness and hardness increased by the increasing of Al2O3 additives. The research demonstrates that a relatively hard (421-490Hv), thick (43-65?m) and uniform coatings, can successfully be deposited on preanodized Al alloy (12-15 ?m with hardness of 190Hv) using Al2O3 additives containing MAO electrolytes as a new method for more future research on surface improvements of Al alloys.

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Growth and Characterization of bulk GaN by Ga Vapor Transport

MRS Proceedings ◽

10.1557/proc-831-e11.33 ◽

2004 ◽

Vol 831 ◽

Cited By ~ 1

Author(s):

Phanikumar Konkapaka ◽

Huaqiang Wu ◽

Yuri Makarov ◽

Michael G. Spencer

Keyword(s):

Growth Rates ◽

Vapor Transport ◽

Spiral Growth ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Bulk Gan ◽

Diffraction Patterns

ABSTRACTBulk GaN crystals of dimensions 8.5 mm × 8.5 mm were grown at growth rates greater than 200μm/hr using Gallium Vapor Transport technique. GaN powder and Ammonia were used as the precursors for growing bulk GaN. Nitrogen is used as the carrier gas to transport the Ga vapor that was obtained from the decomposition of GaN powder. During the process, the source GaN powder was kept at 1155°C and the seed at 1180°C. Using this process, it was possible to achieve growth rates of above 200 microns/hr. The GaN layers thus obtained were characterized using X-Ray diffraction [XRD], scanning electron microscopy [SEM], and atomic force microscopy [AFM]. X-ray diffraction patterns showed that the grown GaN layers are single crystals oriented along c direction. AFM studies indicated that the dominant growth mode was dislocation mediated spiral growth. Electrical and Optical characterization were also performed on these samples. Hall mobility measurements indicated a mobility of 550 cm2/V.s and a carrier concentration of 6.67 × 1018/cm3

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Epitaxial Growth and Characterization of the Ordered Vacancy Compound CuIn3Se5 on GaAs (100) Fabricated by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-340-599 ◽

1994 ◽

Vol 340 ◽

Cited By ~ 1

Author(s):

Art J. Nelson ◽

M. Bode ◽

G. Horner ◽

K. Sinha ◽

John Moreland

Keyword(s):

Molecular Beam Epitaxy ◽

Epitaxial Growth ◽

Molecular Beam ◽

Structural Defects ◽

X Ray Diffraction ◽

Symmetric Vibration ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron

ABSTRACTEpitaxial growth of the ordered vacancy compound (OVC) CuIn3Se5 has been achieved on GaAs (100) by molecular beam epitaxy (MBE) from Cu2Se and In2Se3 sources. Electron probe microanalysis and X-ray diffraction have confirmed the composition for the 1-3-5 OVC phase and that the film is single crystal Culn3Se5 (100). Transmission electron microscopy (TEM) characterization of the material also showed it to be single crystalline. Structural defects in the layer consisted mainly of stacking faults. Photoluminescence (PL) measurements performed at 7.5 K indicate that the bandgap is 1.28 eV. Raman spectra reveal a strong polarized peak at 152 cm−1, which is believed to arise from the totally symmetric vibration of the Se atoms in the lattice. Atomic force microscopy reveals faceting in a preferred (100) orientation.

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Stability and Structural Characterization of Epitaxial NdNiO3 Films Grown by Pulsed Laser Deposition

MRS Proceedings ◽

10.1557/proc-658-gg3.27 ◽

2000 ◽

Vol 658 ◽

Cited By ~ 2

Author(s):

Trong-Duc Doan ◽

Cobey Abramowski ◽

Paul A. Salvador

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Substrate Surface ◽

Pulsed Laser ◽

Laser Deposition ◽

X Ray Diffraction ◽

Force Microscopy ◽

Atomic Force ◽

Monoclinic Distortion

ABSTRACTThin films of NdNiO3 were grown using pulsed laser deposition on single crystal substrates of [100]-oriented LaAlO3 and SrTiO3. X-ray diffraction and reflectivity, scanning electron microscopy, and atomic force microscopy were used to characterize the chemical, morphological and structural traits of the thin films. Single-phase epitaxial films are grown on LaAlO3 and SrTiO3 at 625°C in an oxygen pressure of 200 mTorr. At higher temperatures, the films partially decompose to Nd2NiO4 and NiO. The films are epitaxial with the (101) planes (orthorhombic Pnma notation) parallel to the substrate surface. Four in-plane orientational variants exist that correspond to the four 90° degenerate orientations of the film's [010] with respect to the in-plane substrate directions. Films are observed to be strained in accordance with the structural mismatch to the underlying substrate, and this leads, in the thinnest films on LaAlO3, to an apparent monoclinic distortion to the unit cell.

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Effects of Annealing on Pulsed Laser Deposited TiO2 Thin Films

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.446-447.306 ◽

2013 ◽

Vol 446-447 ◽

pp. 306-311 ◽

Cited By ~ 1

Author(s):

Sudhanshu Dwivedi ◽

Somnath Biswas

Keyword(s):

Thin Films ◽

Pulsed Laser ◽

X Ray Diffraction ◽

Force Microscopy ◽

Si Substrates ◽

Morphological Studies ◽

Atomic Force ◽

Deposited Films ◽

Type Crystal

Mixed phase TiO2 thin films of rutile and anatase type crystal orientations were deposited on Si substrates by pulsed laser deposition (PLD) technique. When annealed at 800°C at 1 mbar oxygen pressure for 3 h, the deposited films transform into a single phase of rutile type. Structural and morphological studies of the as-deposited and annealed films were performed with X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), Raman spectroscopy, and atomic force microscopy (AFM). Photoluminescence (PL) spectroscopy was used for optical characterization of the annealed thin films.

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Characterization of kaolinite in the hardsetting clay fraction using atomic force microscopy, X-ray diffraction, and the Rietveld method

Journal of Soils and Sediments ◽

10.1007/s11368-017-1654-z ◽

2017 ◽

Vol 17 (8) ◽

pp. 2144-2155 ◽

Cited By ~ 3

Author(s):

Luis Valério Prandel ◽

Nívea Maria Piccolomini Dias ◽

Sérgio da Costa Saab ◽

André Maurício Brinatti ◽

Neyde Fabíola Balarezo Giarola ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Rietveld Method ◽

Clay Fraction ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force

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Differential height characteristics of plasmid and G-wire DNA as determined by AFM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100172991 ◽

1994 ◽

Vol 52 ◽

pp. 1052-1053

Author(s):

T. C. Marsh ◽

J. Vesenka ◽

E. Henderson

Keyword(s):

Plasmid Dna ◽

Structural Characteristics ◽

Three Dimensional ◽

Helical Structure ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Dimension One

Atomic-Force Microscopy (AFM) has become an effective tool in the three dimensional characterization of biological systems and is capable of Angstrom sensitivity in the vertical dimension. One unresolved dilemma is that the observed height (diameter) of B-DNA being about 10Å, is less than half its x-ray diffraction value. In this paper we attempt to determine the source of this discrepancy by comparing plasmid DNA co-deposited with a novel form of DNA called “G-wires” (Figure 1). G-wires are formed by G-rich sequences. They are composed of G-4 DNA, a quadruple helical structure. X-ray data of G-4 DNA gives a diameter of 27Å, comparable to that expected for B-DNA (20 to 25Å). In the AFM these structures have a significantly greater height (av. = 22 Å) compared to double stranded (av. = 7 Å) or supercoiled B-DNA (av. = 14 Å) (Figure 2). Thus, the apparent height of nucleic acids in the AFM is dependent upon their innate structural characteristics.

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Comparative Abrasive Wear Study of HVOF Coatings Obtained by Spraying WC-17Co Microcrystalline and Duplex Near-Nanocrystalline Cermet Powders

Journal of Engineering Materials and Technology ◽

10.1115/1.4004689 ◽

2011 ◽

Vol 133 (4) ◽

Cited By ~ 18

Author(s):

G. C. Saha ◽

T. I. Khan

Keyword(s):

Fracture Toughness ◽

Wear Resistance ◽

Abrasive Wear ◽

Abrasive Wear Resistance ◽

X Ray Diffraction ◽

Nanocrystalline Coating ◽

Force Microscopy ◽

Coating Surface ◽

Atomic Force

High velocity oxy-fuel spraying was used to develop a near-nanocrystalline coating from a duplex Co coated WC-17Co powder feedstock. A microstructural and mechanical property characterization of the coating with a similar microcrystalline coating of the same composition was made. X-ray diffraction analysis showed less decarburization of the nanocrystalline coating and a more homogeneous coating structure than the microcrystalline coating produced under the same spraying conditions. The mechanical assessment of the coatings was performed using microhardness and indentation fracture toughness measurements. The abrasive wear resistance was determined using the ASTM G65-04 dry-sand rubber wheel test. The results showed that the hardness of the near-nanocrystalline coating was 25% greater than that of the microcrystalline coating and a sixfold increase in the abrasive wear resistance was also recorded for the near-nanocrystalline coating. Examination of the worn surfaces using atomic force microscopy after abrasive testing showed a smoother surface roughness in the near-nanocrystalline coating than that of the microcrystalline coating surface. The increase in fracture toughness of the near-nanocrystalline coating prevented brittle fracture of the coating surface.

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Growth and Characterization of AlN and GaN Thin Films Deposited on Si(111) Substrates Containing a Very Thin Al Layer

MRS Proceedings ◽

10.1557/proc-798-y10.43 ◽

2003 ◽

Vol 798 ◽

Author(s):

Zachary J. Reitmeier ◽

Robert F. Davis

Keyword(s):

Flow Time ◽

Buffer Layers ◽

Nucleation Density ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Aln Buffer ◽

Peak Widths

ABSTRACTAlN films and GaN films with AlN buffer layers were deposited via metalorganic vapor phase epitaxy on Si(111) substrates previously exposed to trimethylaluminum for increasing times. Atomic force microscopy (AFM) was used to determine the influence of Al pre-flow time on the nucleation and surface morphology of the AlN and GaN films. When preceded by a 10 second Al pre-flow, AlN films feature an increased and more uniform nucleation density as compared to films deposited without Al pre-flows. Ten second Al pre-flows were also found to result in a reduction of the RMS roughness for 100 nm thick AlN films from 3.6 nm to 1.0 nm. AFM of 0.5 μm thick GaN films deposited on AlN buffers with varying pre-flow times showed reduced roughness and decreased pit density when using Al pre-flows of 10 or 20 seconds. High resolution x-ray diffraction of the GaN films showed a reduction in the average full-width halfmaximum (FWHM) of the GaN (00.2) reflection from 1076 arcsec to 914 arcsec when the AlN buffer layer was initiated with a 10 second Al pre-flow. Increasing the pre-flow time to 20 seconds and 30 seconds resulted in average (00.2) FWHM values of 925 arcsec and 928 arcsec, respectively. Similar behavior of the peak widths was observed for the (30.2) and (10.3) reflections when the pre-flow times were varied from 0 to 30 seconds.

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