scholarly journals Preparation and properties of nanocrystalline Ni/graphene composite coatings deposited by electrochemical method

2018 ◽  
Vol 20 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Grzegorz Cieślak ◽  
Maria Trzaska
Keyword(s):  
Steel Substrate ◽  
Composite Coatings ◽  
X Ray Diffraction ◽  
Dispersion Phase ◽  
X Ray ◽  
Graphene Layers ◽  
Nano Crystalline ◽  
Graphene Flakes ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Abstract The paper presents results of studies of composite nickel/graphene coatings produced by electrodeposition method on a steel substrate. The method of producing composite coatings with nanocrystalline nickel matrix and dispersion phase in the form of graphene is presented. For comparative purposes, the study also includes nano-crystalline Ni coatings produced by electrochemical reduction without built-in graphene flakes. Graphene was characterized by Raman spectroscopy, transmission and scanning electron microscopes. Results of studies on the structure and morphology of Ni and Ni/graphene layers produced in a bath containing different amounts of graphene are presented. Material of the coatings was characterized by SEM, light microscopy, X-ray diffraction. The microhardness of the coatings was examined by Knoop measurements. The adhesion of the coatings with the substrate was tested using a scratchtester. The influence of graphene on the structure and properties of composite coatings deposited from a bath with different graphene contents was determined.

Analysis on Microstructure of Laser Brazing Diamond Grits with a Ni-Based Filler Alloy

2010 ◽  
Vol 97-101 ◽  
pp. 3879-3883 ◽  
Author(s):  
Zhi Bo Yang ◽  
Jiu Hua Xu ◽  
Ai Ju Liu
Keyword(s):  
Active Element ◽  
Steel Substrate ◽  
Parameters Optimization ◽  
Interfacial Region ◽  
Filler Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cross Diffusion ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Brazing diamond grits onto steel substrate using a Ni-based filler alloy was carried out via laser beam in an argon atmosphere. The microstructure of the interfacial region among the Diamond grits and the filler layer were investigated by means of scanning electron microscopes (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). Meanwhile, the formation mechanism of carbide layers was discussed. All the results indicated that the active element chromium in the Ni-based alloy concentrated preferentially to the surface of the grits to form a chromium-rich layer, and the hard joint between the alloy and the steel substrate is established through a cross-diffusion of iron and Ni-based alloy through parameters optimization.

Laser Brazing of Diamond Grits with a Ni-Based Brazing Alloy

2007 ◽  
Vol 359-360 ◽  
pp. 43-47 ◽  
Author(s):  
Zhi Bo Yang ◽  
Jiu Hua Xu ◽  
Yu Can Fu ◽  
Hong Jun Xu
Keyword(s):  
Active Element ◽  
Steel Substrate ◽  
Interfacial Region ◽  
X Ray Diffraction ◽  
Laser Brazing ◽  
X Ray ◽  
Cross Diffusion ◽  
Filler Layer ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Brazing diamond grits onto steel substrate using a Ni-based filler alloy was carried out by laser beam in an argon atmosphere. The microstructure of the interfacial region among the Diamond grits, the filler layer and the steel substrate, were investigated by means of scanning electron microscopes (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). Meanwhile, the formation mechanism of carbide layers was discussed. All the results indicated that the active element chromium in the Ni-based alloy concentrated preferentially to the surface of the grits to form a chromium-rich layer, and the hard joint between the alloy and the steel substrate is established through a cross-diffusion of iron and Ni-based alloy.

Experimental Research on Laser Brazing of Diamond Grits with a Ni-Based Filler Alloy

2009 ◽  
Vol 416 ◽  
pp. 396-400 ◽  
Author(s):  
Zhi Bo Yang ◽  
Ai Ju Liu ◽  
Jiu Hua Xu
Keyword(s):  
Active Element ◽  
Steel Substrate ◽  
Parameters Optimization ◽  
Interfacial Region ◽  
Filler Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cross Diffusion ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Brazing diamond grits onto steel substrate using a Ni-based filler alloy was carried out via laser beam in an argon atmosphere. The microstructure of the interfacial region among the Diamond grits and the filler layer were investigated by means of scanning electron microscopes (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). Meanwhile, the formation mechanism of carbide layers was discussed. All the results indicated that the active element chromium in the Ni-based alloy concentrated preferentially to the surface of the grits to form a chromium-rich layer, and the hard joint between the alloy and the steel substrate is established through a cross-diffusion of iron and Ni-based alloy through parameters optimization.

Otosclerotic Stapes: Morphological and Microchemical Correlates

1977 ◽  
Vol 86 (4) ◽  
pp. 525-540 ◽  
Author(s):  
David J. Lim ◽  
William H. Saunders
Keyword(s):  
Calcium Salt ◽  
Mineral Deposit ◽  
Ground Substance ◽  
X Ray Diffraction ◽  
Typical Pattern ◽  
X Ray ◽  
Initial Stage ◽  
Electron Microscopes ◽  
Sclerotic Lesions ◽  
Scanning Electron Microscopes

A total of 32 otosclerotic stapes is thin-sectioned without decalcification and examined using transmission and scanning electron microscopes, with a nondispersive x-ray analyzer attached to the latter. These otosclerotic stapes are classified as spongiotic, sclerotic, or preotosclerotic, according to their pathologic characteristics and state of mineralization. Either diffuse or patchy demineralization in the ground substance appears to be the initial stage of otosclerosis, and this area coincides with preotosclerotic lesions (also known as blue mantle) in light microscopy. Therefore, it is interpreted that demineralization precedes the destruction of ground substance in the preotosclerotic lesion. Bone mineral deposits in new otosclerotic bone appear to be related to the collagen fibrils that are embedded in the ground substance. No mineral deposit could be seen without the ground substance deposition; therefore, it is suggested that this ground substance is the single most important factor in the poor mineralization of the otosclerosis. The sclerotic lesions are well mineralized and show a typical pattern of hydroxyapatite by x-ray diffraction study. We could not confirm the notion that the sclerotic lesion is hypermineralized as compared to the normal stapes. The spongiotic lesions are poorly mineralized, with low calcium salt. Using the Ca/P ratio and x-ray diffraction pattern as criteria, it was determined that spongiotic lesions belong to unstable, immature bone.

Microstructure, Hardness and Oxidation Resistance of CrN and CrAlN Coatings Synthesized by Multi-Arc Ion Plating Technology

2010 ◽  
Vol 168-170 ◽  
pp. 2430-2433 ◽  
Author(s):  
Zhi Hai Cai ◽  
Zhang Ping ◽  
Yue Lan Di
Keyword(s):  
Oxidation Resistance ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Arc Ion Plating ◽  
X Ray ◽  
Ion Plating ◽  
Al Content ◽  
Crn Coatings

Approximately 2 μm thick CrN and CrAlN coatings were synthesized on silicon and spring steel substrate by multi-arc ion plating technology. The nanoindentation techniques, Auger electron spectroscopy (AES) analysis, scanning electron microscopy, X-ray diffraction and oxidation furnace were used to investigate the mechanical property, oxidation resistance and microstructure of the coatings. The XRD data showed that the CrN and CrAlN coatings exhibited B1 NaCl structure. Nanoindentation measurements showed that as-deposited CrN and CrAlN coatings exhibited a hardness of 19 and 30 GPa respectively. Compared with CrN coatings, the CrAlN composite coatings show much better oxidation resistance. And the oxidation resistance ability will enhance with increasing Al content, because A12O3 will form after oxidation in high temperature condition which could reduce the diffusivity ability of oxygen.

scholarly journals Fe-Based Amorphous Composite Coating Prepared by Plasma Remelting

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Zhisheng Li ◽  
Zongde Liu ◽  
Yongtian Wang ◽  
Shunv Liu ◽  
Runsen Jiang ◽  
...  
Keyword(s):  
Composite Coating ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Arc Spraying ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microhardness And Microstructure ◽  
Internal Relationship ◽  
Scanning Electron ◽  
Microhardness Tester

Fe-based amorphous composite coating was deposited on the carbon steel substrate by arc spraying and then remelted by a plasma remelting system, in order to improve the mechanical properties of the coatings. The composition, microstructure, and properties of the composite coating were analyzed by means of the metallographic microscope, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and microhardness tester. The results showed that the amorphous composite coatings had more homogeneous and finer microstructure after the plasma remelting. The coating is metallurgically bonded with the substrate, and the hardness of the Fe-based amorphous composite coating is up to 1220 HV. The internal relationship between microhardness and microstructure has been discussed.

Laser Welding of AISI 316 Steel: Microstructural and Stress Analysis

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
B. S. Yilbas ◽  
Sohail Akhtar
Keyword(s):  
Residual Stress ◽  
Base Material ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cooling Period ◽  
Thermal Stress Field ◽  
Electron Microscopes ◽  
Aisi 316 ◽  
Scanning Electron Microscopes

Thermal-stress field in the welded region was modeled incorporating the finite element model. Temperature and stress fields were predicted at different cooling periods. The morphological and metallurgical changes in the welded region were examined using optical and scanning electron microscopes, energy dispersive spectroscopy and X-ray diffraction. The residual stress formed at the surface vicinity of the weld was determined using the X-ray diffraction technique. It was found that the residual stress predicted agreed well with the experimental data. The solidification cracking did not occur in the weld section during the cooling period. The microhardness in the weld cross-section was almost 1.4 times the base material hardness.

Failure Analysis of the Pressure Vessel by Stainless Steel: 1Cr18Ni9Ti

2004 ◽  
Vol 126 (4) ◽  
pp. 414-418 ◽  
Author(s):  
Junbo Zhou ◽  
Kuisheng Wang ◽  
Liping Gao
Keyword(s):  
Stainless Steel ◽  
Pressure Vessel ◽  
Electrochemical Corrosion ◽  
Chloride Ions ◽  
X Ray Diffraction ◽  
Corrosion Failure ◽  
X Ray ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Welding Position

The corrosion failure of 1Cr18Ni9Ti stainless steel pressure vessel was studied with the aid of metallurgical microscopes, scanning electron microscopes, scanning Auger energy spectra and X-ray diffraction meters. The main causes of the failure included: inter-crystalline corrosion initiated at or near welding position between head and body of cylinder, electrochemical corrosion due to chloride ions in electrolyte and corrosive action formed by oxygen separator and hydrogen separator. Some measures of corrosion resistance and design improvement were proposed.

scholarly journals The Effect of Zn and Zn–WO3 Composites Nano-Coatings Deposition on Hardness and Corrosion Resistance in Steel Substrate

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2253
Author(s):  
Channagiri Mohankumar Praveen Kumar ◽  
Manjunath Patel Gowdru Chandrashekarappa ◽  
Raviraj Mahabaleshwar Kulkarni ◽  
Danil Yurievich Pimenov ◽  
Khaled Giasin
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Tungsten Trioxide ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Nanocomposite Coatings ◽  
X Ray Diffraction ◽  
Electrodeposition Technique ◽  
X Ray ◽  
Scanning Electron

Pure Zn (Zinc) and its Zn–WO3 (Zinc–Tungsten trioxide) composite coatings were deposited on mild steel specimens by applying the electrodeposition technique. Zn–WO3 composites were prepared for the concentration of 0.5 and 1.0 g/L of particles. The influence of WO3 particles on Zn deposition, the surface morphology of composite, and texture co-efficient were analyzed using a variety of techniques, such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) with Energy Dispersive X-ray analysis (EDX). Higher corrosion resistance and microhardness were observed on the Zn–WO3 composite (concentration of 1.0 g/L). The higher corrosion resistance and microhardness of 1.0 g/L Zn–WO3 nanocomposite coatings effectively protect the steel used for the manufacture of products, parts, or systems from chemical or electrochemical deterioration in industrial and marine ambient environments.

scholarly journals The Scanning Electron Microscope As A Precision Instrument

1996 ◽  
Vol 4 (6) ◽  
pp. 30-34
Author(s):  
Douglas Hansen
Keyword(s):  
Diffraction Gratings ◽  
Stray Field ◽  
X Ray Diffraction ◽  
Precision Instrument ◽  
X Ray ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
The University ◽  
Straight Lines ◽  
Scanning Electron

I began using scanning electron microscopes to solve problems encountered in the fabrication of x-ray diffraction gratings. Since these diffraction gratings consist of very regular lines and spaces, and produce high contrast images from the SEM. my microscopy work often points out problems with the microscope.One time, for example, I went to the university SEM lab I often use, and was advised that the microscope was down that day due to major field problems. This lab often had problems with stray fields for reasons no one could explain. Usually I was the only one to complain about stray field distortions since they are most obvious when imaging straight lines at high magnification, but on this occasion, the problem was serious and obvious to all.The microscope had just been serviced and as the lens coils had been replaced, they were expected to be the cause. The service technician was called in and determined that neither the coils nor the microscope electronics were the problem.

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