Studies and Research on the Corrosion Behavior of Ni-Al2O3 Compound Coatings Obtained by Electrochemical Methods

2020 ◽  
Vol 43 (3) ◽  
pp. 21-25
Author(s):  
Simona BOICIUC ◽  
◽  
◽  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Corrosion Behaviour ◽  
Composite Coatings ◽  
Point Of View ◽  
Electrochemical Methods ◽  
Dispersed Phase ◽  
Nickel Matrix ◽  
Technical Alumina ◽  
Compound Coatings

The undertaken research which is described in this paper aims at the corrosion behaviour of composite coatings in nickel matrix using as dispersed phase technical alumina with dimensions of 5 μm and their characterization from a microstructural point of view. The corrosion resistance in the saline fog of the coatings is influenced by the microstructure, the stresses developed in the layer and the roughness.

scholarly journals Studies and Research on the Influence of Deposit Parameters on the Characteristics of Composite Coatings Ni-Al2O3 Obtained by Electrochemical Methods

2021 ◽  
Vol 44 (3) ◽  
pp. 17-21
Author(s):  
Simona BOICIUC
Keyword(s):  
Layer Thickness ◽  
Corrosion Behavior ◽  
Composite Coatings ◽  
Point Of View ◽  
Dispersed Phase ◽  
Structure And Properties ◽  
Nickel Matrix ◽  
Micro Hardness ◽  
Dispersed Phases

The paper presents the characterization of composite coatings with nickel matrix using as dispersed phases Al2O3 particles, both from the microstructural point of view and from the point of view of the layer thickness, micro-hardness and corrosion behavior in saline fog. The presence of dispersed phase particles led to the finishing of the structure because they acted as nucleus centres, reducing the size of nickel crystallites. The parameters of the deposits influence the structure and properties of the obtained layers.

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.

Correlation of Surface Alloyed Microstructure of Pure Magnesium With its Corrosion Behavior

2012 ◽  
Vol 472-475 ◽  
pp. 161-164
Author(s):  
Yu Gao Liu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Chloride Solution ◽  
Diffusion Time ◽  
Point Of View ◽  
Pure Magnesium ◽  
Corrosion Mechanism ◽  
Cross Sectional ◽  
Microstructure Characteristics ◽  
Solid Diffusion

This paper represents a summary of experimental results dealing with the time dependence of surface diffusion alloyed microstructure and its corrosion behavior at given temperature. The experiments were performed at 485°C for different solid diffusion time (6h, 12h, 18h ) and thus the surface alloyed microstructure of pure magnesium has been obtained. Optical and electrical microscopy and EDS compositions analysis were used to examine the cross sectional microstructure characteristics of alloyed layers of treated samples. It is shown that the new phases formed and its continuity, depending on the diffusion treated time at given temperature, have a noticeable influence on corrosion resistance and corrosion mechanism. The new formed phase Al5Mg11Zn4 was inert to the chloride solution compared with pure magnesium and acted as a corrosion barrier. It was concluded that the continuous Al5Mg11Zn4 phase was beneficial from the point of view of corrosion resistance.

scholarly journals Corrosion Behavior of a WC/C Coated 7075-T6 Aluminum Alloy

2013 ◽  
Vol 577-578 ◽  
pp. 217-220
Author(s):  
Sergio Baragetti ◽  
M. Daurù ◽  
Riccardo Gerosa ◽  
Barbara Rivolta
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Corrosion Behavior ◽  
Experimental Tests ◽  
Point Of View ◽  
Surface Finishing ◽  
Polished Surface ◽  
Foreign Object ◽  
Final Thickness

In the present experimental work, a WC/C coated 7075-T6 aluminum alloy was considered from the corrosion point of view. The coating was deposited by PVD technique with a final thickness of about 2.5μm. In order to study the influence of the coating on the corrosion behavior of the aluminum alloy, the samples surfaces were partially coated and the interface among the metal and the coating was analyzed after the corrosion tests described into the ASTM G110 standard. Such experimental plan was decided in order to simulate the possible in-service local removal of the thin and hard coating. This kind of damage, due for example to a foreign object impact, can occur because of the great hardness difference between the coating and the substrate. The experimental tests were carried out on samples with different surface finishing, ranging from about 0.02μm Ra (mirror-polished surface) to about 0.8μm Ra (320 grit paper). The aim of such choice was to investigate the effect of a surface roughness different from the optimal one (mirror polished) on the coating deposition. Moreover a different corrosion resistance is expected.

Investigation on corrosion performance of multilayer Ni-P/TiO2 composite coating on steel

2016 ◽  
Vol 23 (3) ◽  
pp. 309-314
Author(s):  
M. Edwin Sahayaraj ◽  
J.T. Winowlin Jappes ◽  
I. Siva ◽  
N. Rajini
Keyword(s):  
Corrosion Resistance ◽  
Mild Steel ◽  
Corrosion Behavior ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Multilayer Coating ◽  
Electroless Nickel ◽  
Corrosion Mechanism ◽  
Corrosion Performance ◽  
Electroless Ni

AbstractElectroless nickel coating treatment improves the corrosion resistance of mild steel. This work aims at studying the corrosion behavior of electroless Ni-P/TiO2 composite and multilayer coatings applied to the mild steel substrate as their as-plated state and furnace annealed at various temperatures and compared both the coatings’ corrosion performance. The corrosion behavior of the deposits was evaluated by potentiodynamic polarization studies in 3.5 wt% sodium chloride solution. The results showed that the corrosion resistance of the multilayer coating was two times higher compared to the composite coatings. Further, the corrosion mechanism was discussed in terms of microstructure, phase transformation, grain size, and microstrain.

scholarly journals Effect of Current Density on Electrodeposition of Nickel-Organic Microcapsules Composite Coatings

2014 ◽  
Vol 16 (4) ◽  
Author(s):  
O. Kholkin ◽  
A. Kurbatov ◽  
Gary W. Beall ◽  
T. Djenizian ◽  
A.K. Galeyeva ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Current Density ◽  
Mass Fraction ◽  
Composite Coatings ◽  
Particle Sizes ◽  
Nickel Matrix ◽  
Properties Of Coatings ◽  
Polymer Shell ◽  
Deposition Parameters ◽  
Electrodeposition Of Nickel

<p>A formation of protective composite coatings based on nickel and organic substance of inert nature, containing a corrosion inhibitor, encapsulated in a polymer shell, was studied. The microcapsules were synthesized in an aqueous-organic emulsion using the method of formation of shell of the modified gelatine on the surface of microdroplets. Composite coatings were obtained by electrochemical codeposition of nickel matrix and microcapsules, suspended in the electrolyte. Changes of surface morphology, microhardness and corrosive properties of coatings with respect to changes of deposition parameters of coatings were investigated.  The distribution of particle sizes in coatings depending on the current density was studied. It was shown that an increase in the mass fraction of the microcapsules in the coating leads to an increase in its corrosion resistance.</p>

scholarly journals The effect of zinc bath temperature on the morphology, texture and corrosion behaviour of industrially produced hot-dip galvanized coatings

2014 ◽  
Vol 20 (1) ◽  
pp. 41-52 ◽  
Author(s):  
A. Bakhtiari ◽  
M.R. Toroghinejad ◽  
F. Ashrafizadeh
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Texture Component ◽  
Corrosion Behaviour ◽  
Salt Spray ◽  
Bath Temperature ◽  
X Ray Diffraction ◽  
Zinc Bath ◽  
Compact Structure ◽  
Galvanized Coatings

The purpose of this work is to identify the influence of zinc bath temperature on the morphology, texture and corrosion behavior of hot-dip galvanized coatings. Hot-dip galvanized samples were prepared at temperature in the range of 450-480 °C in steps of 10 °C, which is the conventional galvanizing temperature range in the galvanizing industries. The morphology of coatings was examined with optical microscopy and scanning electron microscopy (SEM). The composition of the coating layers was determined using energy dispersive spectroscopy (EDS) analysis. The texture of the coatings was evaluated using X-ray diffraction. Corrosion behavior was performed using salt spray cabinet test and Tafel extrapolation test. From the experimental results, it was found that increasing the zinc bath temperature affects the morphology of the galvanized coatings provoking the appearance of cracks in the coating structure. These cracks prevent formation of a compact structure. In addition, it was concluded that (00.2) basal plane texture component was weakened by increasing the zinc bath temperature and, conversely, appearance of (10.1) prism component, (20.1) high angle pyramidal component and low angle component prevailed. Besides, coatings with strong (00.2) texture component and weaker (20.1) components have better corrosion resistance than the coatings with weak (00.2) and strong (20.1) texture components. Furthermore, corrosion resistance of the galvanized coatings was decreased by increasing the zinc bath temperature.

Corrosion Behaviour of Structural Ceramics in Supercritical Water

2006 ◽  
Vol 45 ◽  
pp. 173-177 ◽  
Author(s):  
Masahiro Nagae ◽  
Tetsuo Yoshio ◽  
Kohei Oda
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Supercritical Water ◽  
Intergranular Corrosion ◽  
Corrosion Behaviour ◽  
Impurity Content ◽  
Amorphous Layer ◽  
Structural Ceramics ◽  
Alumina Ceramics

The corrosion behavior of Si3N4, SiC, mullite, alumina and sapphire was investigated in supercritical water at 450 °C and 45MPa for 2 to 50h. Corrosion resistance for the ceramics was as follows in the order; Si3N4 < SiC < mullite < alumina < sapphire. Pitting corrosion with formation of amorphous layer and intergranular corrosion due to dissolution of additives were observed in PLS-Si3N4 and PLS-SiC, respectively. The corrosion behavior of mullite was characterized by dissolution of SiO2 and formation of boehmite residue layer. High purity alumina ceramics showed the highest corrosion resistance in the ceramics. Intergranular corrosion proceeded in the alumina ceramics and its corrosion rate was strongly dependent on the impurity content.

Microstructure and Corrosion Behavior of Laser Cladding Al3Ti-Based Composite Coatings on AA6063 Aluminum Alloy

2013 ◽  
Vol 634-638 ◽  
pp. 2973-2978 ◽  
Author(s):  
Huan He ◽  
Yue Chun Fu ◽  
Wei Hua Guo ◽  
Min Xiao ◽  
Xing Zhi Pang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Intermetallic Compound ◽  
Uniform Distribution ◽  
Laser Irradiation ◽  
Corrosion Behavior ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Nacl Solution ◽  
Aa6063 Aluminum Alloy

Intermetallic compound Al3Ti-based IMC coatings were formed on AA6063 aluminum alloy by laser cladding. The microstructure and corrosion characteristics in 3.5% NaCl solution were investigated. The results show that, the laser cladding coating is made up of Al3Ti dendrites, interdendritic α-Al and uniform distribution of TiC which hardly melted during laser irradiation, and shows good bonding to the substrate. The cross distribution of Al3Ti and α-Al helps to avoid the generation of cracks in the coating. The corrosion resistance of the laser cladding coatings is greatly increased as compared with the substrate, which owes mainly to the existence of hard Al3Ti and TiC. And with the increasing of TiC content in the coating, the corrosion resistance is improved simultaneously.

Corrosion behaviour of Mn‐Si‐Fe‐Cu‐Al alloy explosion suppression materials

2013 ◽  
Vol 60 (5) ◽  
pp. 234-238
Author(s):  
Yan Jing ◽  
Chao Zhang ◽  
Jun Ma ◽  
Yongzhong Jia
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Design Methodology ◽  
Room Temperature ◽  
Corrosion Behaviour ◽  
Corrosion Process ◽  
Al Alloy ◽  
Content Type ◽  
Explosion Suppression ◽  
Strengthening Phases

PurposeThe purpose of this paper is to prepare the Mn‐Si‐Fe‐Cu‐Al alloy explosion suppression materials, and determine the corrosion behavior of aluminum alloy explosion suppression materials in HCl and NaOH solutions. The different mechanism of corrosion was discussed.Design/methodology/approachIn this paper, Mn‐Si‐Fe‐Cu‐Al alloy explosion suppression materials were prepared, and the electrochemical behavior of the EAESM was studied. The corrosion parameters were calculated and the mechanism of the corrosion process was discussed. The corrosion behavior was characterized by immersion tests and SEM at room temperature.FindingsMn‐Si‐Fe‐Cu‐Al alloy explosion suppression materials have been prepared. SEM, the polarization curves showed that materials have corrosion resistance. The best content of Al alloy is Mn 0.880%, Si 0.135%, Fe 0.383% and Cu 0.0835%.Originality/valueThe results of this investigation show that adding alloying elements can form new strengthening phases that influence the corrosion resistance of alloys.

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