scholarly journals STRUCTURE AND CORROSION RESISTANCE OF VACUUM-ARC MULTI-PERIOD CrN/Cu, ZrN/Cu, AND NbN/Cu COATINGS

2020 ◽  
pp. 139-144
Author(s):  
H.O. Postelnyk ◽  
O.V. Sobol’ ◽  
V.A. Stolbovoy ◽  
I.V. Serdiuk ◽  
O. Chocholaty
Keyword(s):  
Corrosion Resistance ◽  
Composite Coatings ◽  
Chloride Ions ◽  
Vacuum Arc ◽  
Structure And Properties ◽  
Corrosion Properties ◽  
Anodic Reaction ◽  
Fcc Lattice ◽  
Nanolayer Thickness ◽  
Nitride Layers

The structure and properties of vacuum-arc multi-period composite coatings of the MeN/Cu system (where Me is Cr, Zr, and Nb) are studied. It was found that at the smallest nanolayer thickness (about 8…10 nm) of composites in the layers of all systems, only a phase with an fcc lattice is formed, without a pronounced texture in the nitride layers. For ZrN and CrN, the phases with an fcc lattice are equilibrium, and for NbN, they are nonequilibrium. An increase in the thickness of nitride layers leads to the appearance of a texture in ZrN/Cu and CrN/Cu systems and the formation of an equilibrium ε-NbN phase in the layers of the NbN/Cu system. Tests for corrosion resistance in the environment of the formation of chloride ions showed that the coatings are anodic reaction. The best corrosion properties were obtained for coatings with the smallest layer thickness (about 8…10 nm).

scholarly journals Structure, Adhesion Strength and Corrosion Resistance of Vacuum Arc Multi-Period NbN/Cu Coatings

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Hanna Oleksandrivna Postelnyk
Keyword(s):  
Corrosion Resistance ◽  
Crystal Lattice ◽  
Layer Thickness ◽  
Adhesive Strength ◽  
Nitrogen Atmosphere ◽  
Niobium Nitride ◽  
Chloride Ions ◽  
Thin Layers ◽  
Vacuum Arc ◽  
Nitride Layers

The influence of deposition modes on the phase-structural state, corrosion resistance, and adhesive strength of vacuum-arc multi-period NbN/Cu coatings is studied. It was found that in thin layers (about 8 nm, in a constant rotation mode), regardless of the change in the pressure of the nitrogen atmosphere, a metastable δ - NbN phase forms (cubic crystal lattice of the NaCl type). At a layer thickness of ~ 40 nm or more, a phase composition changes from the metastable δ - NbN to the equilibrium ε - NbN phase with a hexagonal crystal lattice. In the presence of the ε - NbN phase in the niobium nitride layers, the highest adhesive strength is achieved with a value of LС5 = 96.5 N. Corrosion resistance tests have shown that for all the studied samples the corrosion process has mainly an anodic reaction. The highest corrosion resistance was shown by coatings obtained at a pressure of 7·10-4 Torr, with the smallest bias potential of -50 V and the smallest layer thickness; with a thickness of such a coating of about 10 microns, its service life in the environment of the formation of chloride ions is about a year.

Study of Hardness and Corrosion Resistance of Electroless Ni-P-TiO2 Composite Coatings

2017 ◽  
pp. 1303-1326
Author(s):  
Prasanna Gadhari ◽  
Prasanta Sahoo
Keyword(s):  
Corrosion Resistance ◽  
Annealing Temperature ◽  
Composite Coatings ◽  
Electroless Nickel ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Nickel Coatings ◽  
Nodular Structure ◽  
Grey Relational ◽  
Electroless Ni

Electroless nickel coatings are widely popular in various industrial sectors due to their excellent tribological properties. The present study considers optimization of coating parameters along with annealing temperature to improve microhardness and corrosion resistance of Ni-P-TiO2 composite coatings. Grey relational analysis is used to find out the optimal combination of coating parameters. From the analysis, it is confirmed that annealing temperature of the coating has the most significant effect and amount of titanium particles in the coating has some significant effect on corrosion properties of the coating. The same trend is observed in case of combined study of corrosion behavior and microhardness. The surface morphology, phase transformation and the chemical composition are examined using scanning electron microscopy, X-ray diffraction analysis and energy dispersive analysis respectively. The Ni-P-TiO2 composite coating revealed nodular structure with almost uniform distribution of titanium particles and it turns in to crystalline structure after heat treatment.

Influence of the Organic Additions on Structure, Corrosion Resistance and Tribological Properties of Ni/Al2O3 Composite Coatings

2013 ◽  
Vol 765 ◽  
pp. 663-667
Author(s):  
Marek Nowak ◽  
Mieczysław Opyrchał ◽  
Sonia Boczkal ◽  
Janusz Żelechowski
Keyword(s):  
Corrosion Resistance ◽  
Tribological Properties ◽  
Composite Coatings ◽  
Electrochemical Behaviour ◽  
Wear Test ◽  
Standard Test ◽  
Properties Of Coatings ◽  
Corrosion Properties ◽  
X Ray ◽  
Xrd Techniques

Composite Ni/Al2O3 coatings were electrochemically deposited from a Watts bath modified with the organic additions of dioctyl sulphosuccinate sodium salt C20H37NaO7S–(DSS) and 2,3-dihydroxy-1,2 benzisothiazol-3-one 1,1-dioxide C7H5NO3–(LSA). The effect of different amount (50 and 100 g/l) of Al2O3 powder and organic additions on microstructure, microhardness, corrosion resistance and tribological properties was investigated. The coatings were examined by optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) techniques. The electrochemical behaviour of the coatings in corrosive solutions (1 M NaCl and 1 M Na2SO4) was investigated by potentiodynamic polarisation. The tribological properties were investigated by the Taber abrasive wear test, a standard test often applied in industrial practice. The results show that Al2O3 particles are uniformly distributed in the composite coatings compared with coatings without organic additions. The addition of organic compounds also reduced the size of the forming nickel crystallites and improved the tribological and corrosion properties of coatings containing the dispersed hard particles of Al2O3 added in an amount of 50 g/l and the addition of organic LSA and DSS compounds.

Microstructure and Corrosion of Laser Cladding Coatings on Titanium Alloy With Nd2O3

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Guangyu Han ◽  
Youfeng Zhang
Keyword(s):  
Corrosion Resistance ◽  
Titanium Alloy ◽  
Laser Cladding ◽  
Electrical Impedance ◽  
Composite Coatings ◽  
Electrical Impedance Spectroscopy ◽  
Corrosion Properties ◽  
Capacitive Behavior ◽  
Refined Microstructure

Abstract Composite coatings of TiB were successfully obtained on the surface of a Ti–6Al–4V alloy by in situ laser cladding technology using Ti/B/Nd2O3 powders. The microstructure and corrosion resistance of the fabricated composite coatings were investigated because relevant studies have been thus far limited in this field. The results indicate that the cladding coating and the substrate combined well via metallurgy after laser cladding treatment, and no obvious cracks were observed in the cladding coatings. The coatings comprise only the TiB and the α-Ti phase. The addition of Nd2O3 promoted the formation of a uniform and refined microstructure of the cladding coatings, and a well-defined structure was obtained when the added Nd2O3 content was 2 wt%. The microhardness of the cladding coating obviously improved by 3 to 4 fold above that of the Ti–6Al–4V substrate. Moreover, the corrosion properties significantly improved by adding Nd2O3 into the coatings. Electrical impedance spectroscopy and polarization tests showed that the best corrosion resistance of the cladding coating was achieved with the addition of 2 wt% Nd2O3. All samples revealed obvious near-capacitive behavior after immersion in a corrosive medium.

scholarly journals Tribological Properties and Corrosion Resistance of Porous Structure Ni-Mo/ZrO2 Alloys

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 767
Author(s):  
Ning Li ◽  
Hong Xu ◽  
Xinhui Li ◽  
Weizeng Chen ◽  
Lijuan Zheng ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Tribological Properties ◽  
Salt Water ◽  
Composite Coatings ◽  
Wear Test ◽  
High Hardness ◽  
Zro2 Nanoparticles ◽  
Zro2 Content ◽  
Corrosion Properties ◽  
Alloy Matrix

Ni-Mo-ZrO2 composite coatings were produced by pulse electrodeposition technique from alkaline electrolytes containing dispersed ZrO2 nanopowder. The structure, microhardness, corrosion properties and tribological properties of Ni-Mo-ZrO2 composites with different content of molybdenum and ZrO2 have also been examined. Structural characterization was performed using X-ray diffraction (XRD) and a scanning electron microscope (SEM). It was found that an increase in molybdate concentration in the electrolyte affects the microstructure, microhardness, corrosion properties and tribological properties of the amount of co-deposited ZrO2 nanoparticles. The incorporation of ZrO2 nanoparticles into the Ni-Mo alloy matrix positively affects the microhardness and also slightly improves the corrosion properties of Ni-Mo alloy coatings. In addition, both the coefficient of friction and the salt-water lubrication sliding wear rate of Ni-Mo-ZrO2 coatings decreased with increasing the ZrO2 content. Wear test and corrosion resistance test results indicated that the intermetallic composite had an excellent wear-resistance and corrosion resistance at room-temperature, which is attributed to the high hardness and strong atomic bonding of constituent phases Ni-Mo and polarization effect of ZrO2 nanoparticles.

Evaluation of Corrosion Properties of Electroless NiP/Nano-SiC Composite Coatings

2011 ◽  
Vol 471-472 ◽  
pp. 203-208
Author(s):  
Arman Zarebidaki ◽  
Saeed Reza Allahkaram
Keyword(s):  
Corrosion Resistance ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Electroless Ni ◽  
Different Content ◽  
Scanning Electron

Ni-P/nano- SiC composite coatings were deposited in different concentrations of SiC nano-particles in the bath. The hardness and corrosion resistance of the composite coatings with different content of SiC nano-particles were measured. Moreover, the structure of the composite coatings was investigated by means of X-ray diffraction (XRD), while their morphologies and elemental composition were analyzed using scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Results showed that co-deposited SiC nano-particles contributed to increase the hardness but corrosion resistance of electroless Ni-P coatings decreased due to agglomeration of nano-particles and increasing porosity of coatings.

Study of Hardness and Corrosion Resistance of Electroless Ni-P-TiO2 Composite Coatings

2015 ◽  
Vol 3 (2) ◽  
pp. 18-40
Author(s):  
Prasanna Gadhari ◽  
Prasanta Sahoo
Keyword(s):  
Corrosion Resistance ◽  
Annealing Temperature ◽  
Composite Coatings ◽  
Electroless Nickel ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Nickel Coatings ◽  
Industrial Sectors ◽  
Nodular Structure ◽  
Grey Relational

Electroless nickel coatings are widely popular in various industrial sectors due to their excellent tribological properties. The present study considers optimization of coating parameters along with annealing temperature to improve microhardness and corrosion resistance of Ni-P-TiO2 composite coatings. Grey relational analysis is used to find out the optimal combination of coating parameters. From the analysis, it is confirmed that annealing temperature of the coating has the most significant effect and amount of titanium particles in the coating has some significant effect on corrosion properties of the coating. The same trend is observed in case of combined study of corrosion behavior and microhardness. The surface morphology, phase transformation and the chemical composition are examined using scanning electron microscopy, X-ray diffraction analysis and energy dispersive analysis respectively. The Ni-P-TiO2 composite coating revealed nodular structure with almost uniform distribution of titanium particles and it turns in to crystalline structure after heat treatment.

scholarly journals Electroless Deposition of Ni-Cu-P Coatings Containing Nano-Al2O3Particles and Study of Its Corrosion Protective Behaviour in 0.5 M H2SO4

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
H. Ashassi-Sorkhabi ◽  
H. Aminikia ◽  
R. Bagheri
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Composite Coatings ◽  
Electrochemical Methods ◽  
Sem Images ◽  
Corrosion Properties ◽  
Plating Bath ◽  
Nanoparticles Concentration ◽  
Good Agreement

Ni-Cu-P/nano-Al2O3composite coatings are prepared on mild steel from an alkaline electroless plating bath containing different concentrations of Al2O3nanoparticles. The protective effect of codeposited nanoparticles on the corrosion behaviour of the coatings is studied in 0.5 M H2SO4solution. The electrochemical methods, that is, electrochemical noise (ECN), electrochemical impedance spectroscopy (EIS), and polarization measurements, are used to characterize the corrosion properties of the coatings. The results show that the inclusion of nanosized particles leads to significant improvement of corrosion resistance of the coatings. The highest corrosion resistance is obtained at 20 ppm of nanoparticles concentration in the plating bath. The ECN measurements results are in good agreement with results obtained from two other electrochemical methods after trend removal. The SEM images prove that nano-Al2O3particles were embedded in the Ni-Cu-P matrix and are dispersed uniformly on the coating surface.

scholarly journals Microstructure and Corrosion Resistance of Aluminium and Copper Composite Coatings Deposited by LPCS Method

2016 ◽  
Vol 61 (4) ◽  
pp. 1945-1952 ◽  
Author(s):  
M. Winnicki ◽  
M. Rutkowska-Gorczyca ◽  
A. Małachowska ◽  
T. Piwowarczyk ◽  
A. Ambroziak
Keyword(s):  
Corrosion Resistance ◽  
Working Conditions ◽  
Atmospheric Corrosion ◽  
Composite Coatings ◽  
Salt Spray ◽  
Cold Spraying ◽  
Chloride Ions ◽  
Copper Coatings ◽  
Copper Composite ◽  
Spraying Method

Abstract The paper presents the study of microstructure and corrosion resistance of composite coatings (Al+Al2O3 and Cu+Al2O3) deposited by Low Pressure Cold Spraying method (LPCS). The atmospheric corrosion resistance was examined by subjecting the samples to cyclic salt spray and Kesternich test chambers, with NaCl and SO2 atmospheres, respectively. The selected tests allowed reflecting the actual working conditions of the coatings. The analysis showed very satisfactory results for copper coatings. After eighteen cycles, with a total time of 432 hours, the samples show little signs of corrosion. Due to their greater susceptibility to chloride ions, aluminium coatings have significant corrosion losses.

Corrosion Resistance of Nickel-Based Composite Coatings Reinforced by Spherical Tungsten Carbide

2020 ◽  
Vol 993 ◽  
pp. 1075-1085
Author(s):  
Li Fan ◽  
Hai Yan Chen ◽  
Hai Liang Du ◽  
Yue Hou ◽  
Qian Cheng
Keyword(s):  
Corrosion Resistance ◽  
Tungsten Carbide ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Salt Spray ◽  
Electrochemical Corrosion ◽  
Corrosion Properties ◽  
Oil Drilling ◽  
Passivation Film ◽  
Spherical Tungsten Carbide

Nickel-based composite coatings reinforced by spherical tungsten carbide were deposited on 42CrMo alloy steel using plasma transfer arc welding (PTAW) process. Their electrochemical corrosion properties in NaCl solution under atmospheric and high pressure were studied by polarization curve, electrochemical impedance spectroscopy. The corrosion and erosion resistance of the coatings were also investigated by salt spray corrosion and erosion corrosion tests. The results show that the self-corrosion potential of the composite coatings increased with the increase of tungsten carbide content, and the Cr element in Ni60 sample formed a stable and compact passivation film. Compared with corrosion at atmospheric pressure, the adsorption and penetration of Cl- on the coating surface enhanced due to the increase of Cl- activity under pressure, thereby to weaken the corrosion resistance. The Samples that passivated in salt spray environment, cannot completely hinder the corrosion of the coating, just only to slow down the corrosion. This study can provide theoretical basis for deep-sea oil drilling and production engineering equipment.

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