Electrodeposition Process of Composite Ni-P+Ni(OH)2+PTFE Coatings

2015 ◽  
Vol 228 ◽  
pp. 108-115
Author(s):  
B. Łosiewicz ◽  
Magdalena Popczyk

Co-deposition process of amorphous nickel and PTFE particles in the presence of Ni (OH)2carrier suspended in the bath by magnetic stirring, was investigated. Composite Ni-P+Ni (OH)2+PTFE coatings and comparative Ni-P deposits, were electrodeposited on low carbon steel substrate under galvanostatic conditions at room temperature. The physical and chemical characterization of the coatings was carried out using X-Ray diffraction analysis and microanalysis, stereometric quantitative microscopy and atomic absorption spectroscopy. The optimum production conditions of the composite coatings based on the Ni-P matrix into which PTFE and Ni (OH)2components can be embedded uniformly, were found.

2011 ◽  
Vol 179-180 ◽  
pp. 253-256
Author(s):  
Hao Chen ◽  
Jian Gao Yang ◽  
Mi Song Chen

The Fe-based composite coatings were formed by plasma jet surface metallurgy using Fe, C, W, Cr and Al alloy powders on the low carbon steel. The morphology, microstructure, interface structure and the distribution of the in situ particles in the coatings were observed with optical microscope, scanning electron microscope and x-ray diffraction analysis. The results show that metallurgical bonding is obtained between coating and substrate, and the microstructure of coatings is mainly composed of γ-Fe, (Fe,Cr,W,Nb)7C3 and AlFe particles which are synthesized in stiu, are dispersivly distributed in the coatings. The micro-hardness gradually increased from bottom to the top of the coating, the maximum is 986 Hv0.1, about 4 times larger than that of the steel substrate.


2015 ◽  
Vol 228 ◽  
pp. 125-131
Author(s):  
B. Łosiewicz ◽  
Grzegorz Dercz ◽  
Magdalena Popczyk

The object of this work was to obtain the Ni+MoS2composite electrocoatings byin situco-deposition of molybdenum (IV) sulfide particles (< 2 μm) and nickel from a suspension plating bath. Physical and chemical characterization of the coatings was carried out using SEM, EDS, and XRD methods. The chemical composition of these coatings of a diphase structure (Ni, MoS2) was found to be dependent on the current density and temperature of electrodeposition. The optimal electrochemical conditions for embedding of the maximum amount of 26.4 wt.% of MoS2into the crystalline nickel matrix, were experimentally determined. The co-deposition process of MoS2particles and metallic nickel was discussed based on the adsorption mechanism. Such porous Ni+MoS2composite coatings can be proposed as electrode material for hydrogen electroevolution.


2011 ◽  
Vol 214 ◽  
pp. 89-92
Author(s):  
Hao Chen ◽  
Jian Gao Yang ◽  
Mi Song Chen

The Fe-based composite coatings with RE oxides were prepared on low-carbon steel substrate by use of the plasma jet surface metallurgy, and the effect of RE on microstructure of coating was investigated. The result shows that the microstructure and properties with a proper amount of RE oxides are better than these of the coatings without RE oxides. In addition, the modifying effect of RE oxide on inclusions in metallurgical coating was studied by means of thermodynamics. The thermodynamics analysis shows that RE oxide (Ce2O3) can be reduced to RE by carbon, then the RE element can react with oxygen and sulfur to form the RE oxide-sulfide in metallurgical pool. As a result, the coating is purified and the solidification crack of coating can be restrained by deoxidization and desulphurization.


2016 ◽  
Vol 849 ◽  
pp. 677-682
Author(s):  
Hao Chen ◽  
Yang Rong Zhang ◽  
Zhu Huang

By plasma jet surface metallurgy, the thick composite coatings reinforced by in-situ TiC were produced on low carbon steel. Composition, microstructures and performance were characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), micro-hardness tester and wear tester. The results showed that the excellent bonding between the coating and the carbon steel substrate was achieved by strong metallurgical interface. The microstructure of the coating is mainly composed of γ-(Fe, Ni) dendrite, M23C6, CrB and in-situ synthesized TiC ceramic particle. Because of the particulate reinforcement, the dispersion strengthening, refinement strengthening, micro-hardness and wear resistant of Fe-based coating can be enhanced.


Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 388
Author(s):  
Teresa Pi-Puig ◽  
Dante Yosafat Animas-Torices ◽  
Jesús Solé

The detailed mineralogical, physical and chemical characterization of nine samples of imported cosmetic talc and of two samples of talc from currently non-productive Mexican ore deposits (Oaxaca and Puebla States) is presented. The imported cosmetic talc was classified into two groups, considering whether they are packed in the country of origin or in Mexico and considering their price. X-ray diffraction, infrared short wave, thermogravimetric analysis and scanning electron microscopy were used for mineralogical characterization. For the physical characterization, colorimetry and laser granulometry were used. The chemical composition (major, trace elements) was studied by ICP-MS. It was concluded that only the highest priced and imported in packaged form talcs meet the specific purity requirements for a talc of cosmetic type. The talcs that are packed in Mexico and the talc of the studied Mexican deposits present mineralogical and chemical impurities that make their use difficult in the manufacture of high-quality cosmetic talc. The low-price talc should not be sold as cosmetic talc, and the regulations in Mexico on this subject should be reviewed and updated.


1990 ◽  
Vol 5 (1) ◽  
pp. 74-82 ◽  
Author(s):  
A. L. Cabrera ◽  
J. F. Kirner ◽  
R. Pierantozzi

The reaction of SiH4/H2 mixtures with iron and steels was studied at a total pressure of 1 atm and temperatures above 500 °C. When the amount of water vapor in the gas mixture is carefully controlled, a metal silicide diffusion coating forms at low temperatures (below 900°C). Composition and structure of the Si diffusion coatings were determined with Auger depth profiling and x-ray diffraction. Kinetics of the surface reaction between SiH4, and the metal substrate as well as the behavior of these films in severe environments at high temperatures were studied by a microgravimetric technique. Characterization of these Si coatings on iron, low carbon steel (1010), 9% Cr/1% Mo steel (alloy A182F9), and stainless steels (310) and their applications to reduce oxidation, nitriding, or coking at high temperatures or corrosion in mineral acids are described.


2018 ◽  
Vol 21 (1) ◽  
pp. 82
Author(s):  
Mofeed A. Jaleel ◽  
Eilaf Z. Gurji

The Electrodeposition process has been used to prepare Nickel-Tungsten alloys on low carbon steel substrate by using ammonical citrate bath. The influence of deposition condition by variation of current density (0.04-0.2 A/cm2) and solution temperature (60-70 °C), on the microstructure was studied. The optical microscope and the scanning electron microscopy (SEM) were used to study the morphology of the deposit while the energy dispersive spectroscopy (EDS) was used to approximate the composition, in addition to X-Ray diffraction examination. The results show that the current efficiency has the major influence on the tungsten content in the alloys due to the formation of ternary complex which reflected into the properties of the deposit. Keywords: 


2014 ◽  
Vol 896 ◽  
pp. 586-590 ◽  
Author(s):  
Sugiarti Eni ◽  
Kemas Zaini ◽  
Yong Ming Wang ◽  
N. Hashimoto ◽  
Shigenari Hayashi ◽  
...  

The corrosion of carbon steel is major infrastructure degradation problem in practically all industries, including chemical materials, mineral, and petrochemical industries. Coating on carbon steel is one of the techniques which required improving corrosion resistance in extreme environments. In present work, NiCoCrAl was diffusion-coated onto low carbon steel by electrodeposition for NiCo and pack cementation for Cr and Al. The cross section of coated specimen was observed and analyzed using SEM and TEM. Two types of coating processes have been challenging the formation of bond-coat layer on carbon steel substrate with different temperature coating process. SEM and EDS results show that the coating comprises three layers: intermetallics zone of Ni (Al) and Al (Cr), interdiffusion zone of Ni (Co), and there is the substrate. By XTEM observation, it was found that γ (Ni,Fe) and ζ hexagonal structure were identified in all specimens. Orthorhombic structure with the Al3Ni was identified in specimen developed at temperature of 800OC. Further, the top surface of a 1000OC specimen has two phases of β-NiAl and ζ hexagonal structure. In order to understand the performance of two types coating system with different temperature process, oxidation test at temperature of 800OC for 100 hours has been carried out and the result shows that coating system which was developed at 800OC has better oxidation resistance compare to 1000OC coating system.


2019 ◽  
Vol 25 (2) ◽  
pp. 107
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Okba Belahssen

<p class="AMSmaintext1"><span lang="EN-GB">In this paper, we are interested in the study of electrochemical, morphological and structural characteristics of the properties of the deposits of Zn-Ni-TiO<sub>2</sub> obtained by electrodeposition on the mild steel substrate in a bath of sulfate. The principal aim is to improve the coatings with better properties, by incorporation of titanium oxide, which is a hard compound, chemically stable and irreducible. The characterization of the coatings was carried out by scanning electron microscopy (SEM) and by X-ray diffraction. The morphology of the film surface varies with the concentration of oxide titanium and it was found higher values of microhardness. Electrochemical characterization of the composites had been carried out through potentiodynamic polarization. The results showed that better corrosion resistance with the incorporation of oxide titanium.</span></p>


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