Structure and Properties of Electrolytic Zn-Mn Coatings Deposited by the Galvanostatic Method

2013 ◽  
Vol 203-204 ◽  
pp. 216-219
Author(s):  
Magdalena Popczyk ◽  
Katarzyna Wykpis ◽  
Bożena Bierska-Piech
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Chemical Composition ◽  
Surface Morphology ◽  
Phase Structure ◽  
Single Phase ◽  
Structure And Properties ◽  
Protective Properties ◽  
Galvanostatic Method ◽  
Galvanostatic Conditions

The Zn-Mn coatings were deposited under galvanostatic conditions from a sulfate galvanic bath. The influence of thiocarbamide additions in the bath on surface morphology, chemical and phase composition and corrosion resistance of the electrolytic Zn-Mn coatings was investigated. On the basis of these investigations it was found that Zn-Mn coatings can be obtained by the galvanostatic method. Morphology and chemical composition of the electrolytic Zn-Mn coatings depend on the thiocarbamide concentration in the galvanic bath. XRD investigations of obtained coatings showed a single phase structure (α-Mn1.08Zn2.92). The additions of thiocarbamide improve the protective properties of the Zn-Mn coatings.

Influence of the complexing agent sodium citrate on the chemical composition, surface morphology and corrosion resistance of Ni–Fe electrodeposits

2019 ◽  
Vol 97 (5) ◽  
pp. 230-236
Author(s):  
G. P. da Silva ◽  
R. N. de Lima ◽  
F. J. N. Santos ◽  
F. P. S. de Menezes ◽  
L. P. L. Morais ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Chemical Composition ◽  
Surface Morphology ◽  
Sodium Citrate ◽  
Complexing Agent

Structure and Corrosion Resistance of Iron Coatings Containing Silicon Powders

2011 ◽  
Vol 399-401 ◽  
pp. 1926-1931 ◽  
Author(s):  
Yi Wang ◽  
Gang Chen ◽  
Wei Dong Liu ◽  
Qiong Yu Zhou ◽  
Qing Dong Zhong
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Thermal Treatment ◽  
Surface Morphology ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Active Surface ◽  
Active Surface Area ◽  
Two Phase ◽  
Electrochemical Corrosion Resistance

Fe + Si coatings were prepared by iron deposition from a bath containing a suspension of silicon powders. These coatings were obtained at galvanostatic conditions, at the current density of jdep=−0.020 A cm−2 and at the temperature of 338 K. For determination of the influence of phase composition and surface morphology of these coatings on changes in the corrosion resistance, these coatings were modified in an argon atmosphere by thermal treatment at 873 K for 2h. A scanning electron microscope was used for surface morphology characterization of the coatings. The chemical composition of the coatings was determined by EDS and phase composition investigations were conducted by X-ray diffraction. It was found that the as-deposited coatings consist of a two-phase structure, i.e., iron and silicon. The phase composition for the Fe + Si coatings after thermal treatment is markedly different. The main peaks corresponding to Fe and Si coexist with the new phases: FeSi. Electrochemical corrosion resistance investigations were carried out in 3.5wt% NaCl, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. On the basis of these investigations it was found that the Fe + Si coatings after thermal treatment are more corrosion resistant in 3.5wt% NaCl solution than the as-deposited coatings. The reasons for this are a reduction in the amount of free iron and silicon, the presence of new phases (in particular silicides), and a decrease of the active surface area of the coatings after thermal treatment.

The Research of Micro Arc Oxidation Behavior of the Magnesium Alloy

2013 ◽  
Vol 803 ◽  
pp. 191-195
Author(s):  
Yun Long Zhang ◽  
Mu Qin Li ◽  
Yu Min Zhang ◽  
Ming Hu
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Magnesium Alloy ◽  
Surface Morphology ◽  
Electrolyte Solution ◽  
Oxidation Behavior ◽  
Corrosion Current ◽  
Positive Potential ◽  
Micro Arc Oxidation ◽  
Oxidation Technology

The ceramics coating hadobtained by the micro arc oxidation technology in order to resolve thecorrosion resistance of the Mg alloy.The phase composition, surface morphology,gained weight and polarization behavior of the micro arc oxidation coating wasinvestigated in details. After the introduce of the sodiumcitrate in the electrolyte solution, thespecimen had high relatively positive potential and low corrosion current, sodoped sodium citratewould improve the corrosion resistance properties of the Mg alloy .

Investigation of structure and properties of surfaced coatings based on titanium nickelide

2021 ◽  
Vol 4 ◽  
pp. 81-88
Author(s):  
A. I. Kovtunov ◽  
◽  
D. I. Plahotny ◽  
T. V. Semistenova ◽  
A. G. Bochkarev ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Chemical Composition ◽  
Heat Resistance ◽  
Titanium Nickelide ◽  
Nickel Electrode ◽  
Structure And Properties ◽  
Relative Wear ◽  
Relative Wear Resistance

The conditions for formation of coatings based on titanium nickelide under the argon double-arc surfacing of titanium and nickel electrode wires on the titanium samples were shown. Results of evaluating the quality of formation and geometric parameters of the weld at the double-arc surfacing were presented. Relationship between the ratio of feed rates of nickel and titanium wires and chemical composition of the deposited coatings has been established. Investigations of the structure of the surfaced metal at the surfacing modes was carried out. It has been shown that argon double-arc surfacing formed coatings based on the Ti2Ni and TiNi. Mechanical and operational properties of surfaced coatings were studied — hardness, resistance to abrasion and heat resistance at 800 °С. Relative wear resistance of surfaced coatings is higher than that of titanium samples. Dependence of the relative wear resistance of the coatings on the chemical and phase composition was shown. Dependence of heat resistance of the surfaced coatings on the modes of surfacing and the chemical composition of the weld metal is established.

Characterization of corrosion resistance of Zn-Ni-W and Zn-Ni-P-W heat-treated coatings

2021 ◽  
Vol 25 (3-4) ◽  
pp. 13-17
Author(s):  
Magdalena Popczyk ◽  
Jolanta Niedbała
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Surface Morphology ◽  
Electrochemical Corrosion ◽  
Nacl Solution ◽  
Heat Treated ◽  
Electrochemical Corrosion Resistance

The paper presents results of research concerning the evaluation of corrosion resistance of heat-treated alloy coatings (Zn-Ni-W/320°C and Zn-Ni-P-W/320°C). The surface morphology and phase composition of the obtained coatings were determined. Electrochemical corrosion resistance was studied in 5% NaCl solution. On the basis of these studies it was found that the corrosion resistance of Zn-Ni-P-W/320°C coating is higher than Zn-Ni-W/320°C coating.

Influence of Electrolytic Polishing and Anodic Passivation on Corrosion Resistance of Ti-15Mo Alloy

2015 ◽  
Vol 227 ◽  
pp. 499-502
Author(s):  
Dorota Babilas ◽  
Joanna Michalska ◽  
Elżbieta Pamuła ◽  
Wojciech Simka
Keyword(s):  
Corrosion Resistance ◽  
Chemical Composition ◽  
Oxalic Acid ◽  
Surface Morphology ◽  
Oxidation Process ◽  
Ammonium Fluoride ◽  
Physiological Solution ◽  
Anodic Passivation ◽  
Electrolytic Polishing ◽  
Anodic Oxidation Process

This paper presents the results of investigations on electrolytic polishing and anodic passivation of Ti-15Mo alloy. The influence of chemical composition of the bath used in electrolytic polishing and anodic passivation process on the morphology, wettability and corrosion resistance of the electrochemically modified vanadium-free Ti-15Mo alloy was presented. The electropolishing process was carried out in a solution containing: sulphuric acid, ethylene glycol, ammonium fluoride and oxalic acid. Moreover, the anodic oxidation process was carried out in a 1.0 M H2SO4, 1.0 M H3PO4and 0.5 M solution of K2SiO3and 5 g/dm3KOH. It was found that the electrolytic polishing and anodic passivation led to significant improvement of the surface morphology. The electrolytic polishing and anodic passivation of Ti-15Mo improved corrosion resistance of the alloy in contact with of Ringer's physiological solution. The samples anodised at 100 V in 1.0 M H3PO4presented the highest corrosion resistance.

Investigations of Microstructure and Phase Composition of Different Self-Shield Flux-Cored Wire Slag System

2016 ◽  
Vol 850 ◽  
pp. 748-754 ◽  
Author(s):  
Jiang Long Yi ◽  
Xin Xin Wang ◽  
Kai Wang ◽  
Shi Da Zheng ◽  
He Xin Chen ◽  
...  
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Grain Boundary ◽  
Phase Structure ◽  
Slag System ◽  
Framework Structure ◽  
X Ray Diffraction ◽  
Cored Wire ◽  
X Ray

A series of slag were fabricated by self-shield welding of different flux-cored wire. The microstructure and phase composition of those slag were investigated by means of metallographic microscope, SEM,EDX and X-ray diffraction respectively. The result demonstrated that the slag forming material of TiO2 and Al2O3 tenders to form the framework structure of slag, while CaO and MnO2 inclines to incorporate in the grain boundary. Furthermore, the dense and dendrite phase structure of slag was beneficial for the removal of slag. On the contrary the slag with tiny needle and skeleton-like structure was difficult to clear up. In conclusion, the detachability performance was not only affected by the microstructure, but also by the chemical composition of the slag system.

Researching of Steel Grade Influence on Structure and Properties of Silicate-Enamel Coatings of Pipelines

2020 ◽  
Vol 299 ◽  
pp. 778-786
Author(s):  
Anna Ryabova ◽  
Elena A. Yatsenko ◽  
Ludmila Klimova
Keyword(s):  
Chemical Composition ◽  
Contact Zone ◽  
Steel Grade ◽  
Chemical Processes ◽  
Structure And Properties ◽  
Protective Properties ◽  
Steel Coating ◽  
Vitreous Coating ◽  
Physical And Chemical ◽  
Composite Steel

The protective properties of enameled products are largely determined by the structure of the vitreous coating itself, and, in general, the formed composite steel – coating. The grade and chemical composition of the enameled steel influence not only the physical and chemical processes occurring in the contact zone "steel-enamel", but also, in general, the structure of the coating and its technical and operational properties.

scholarly journals Синтез квазикристаллических порошков и покрытий методом вакуумного плазменно-дугового испарения

2019 ◽  
Vol 61 (12) ◽  
pp. 2515
Author(s):  
А.В. Ушаков ◽  
И.В. Карпов ◽  
Л.Ю. Федоров ◽  
А.А. Шайхадинов ◽  
В.Г. Дёмин ◽  
...  
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Surface Morphology ◽  
Arc Discharge ◽  
Low Pressure ◽  
Subsequent Annealing ◽  
Evaporation Process ◽  
High Current ◽  
Composition Variation ◽  
Significant Change

Quasicrystalline coatings of the Al-Cu-Fe system were obtained by sputtering the cathode using a pulsed high-current low-pressure arc discharge followed by deposition on a hot (600 ° C) and cooled substrate (25 ° C). The surface morphology, chemical and phase composition of evaporation products in the form of powder and the resulting coatings were studied. Powders and coatings were also annealed and the phase composition variation was studied. It was found that during the evaporation process a significant change in the chemical composition occurs in the form of loss of Al from the surface of the particles and the coating, which leads to a decrease in the content of the ψ phase. However, subsequent annealing and sputtering on a hot substrate lead to an increase in the ψ phase, as well as the density and hardness of the coatings.

The Influence of Sodium Molybdate on the Properties of Zn-Ni Layers Obtained by Electrolytic Deposition

2010 ◽  
Vol 636-637 ◽  
pp. 1053-1058 ◽  
Author(s):  
Katarzyna Wykpis ◽  
Antoni Budniok ◽  
Eugeniusz Łągiewka
Keyword(s):  
Corrosion Resistance ◽  
Chemical Composition ◽  
Surface Morphology ◽  
Electrochemical Impedance ◽  
Chemical Elements ◽  
Steel Substrate ◽  
Sodium Molybdate ◽  
Open Circuit ◽  
Electrolytic Deposition ◽  
Structural Investigations

This study was undertaken in the aim to try the limit of extraction of Zn from Zn-Ni system. The aim was realized by the addition of MoO42- ions into the galvanic bath containing Ni2+ and Zn2+ ions. Zn-Ni-Mo layers were deposited under galvanostatic conditions on (OH18N9) austenitic steel substrate. The influence of Na2MoO4 concentration in a bath on the surface morphology, chemical and phase composition and the corrosion resistance of obtained layers, was investigated. The properties of Zn-Ni-Mo layers were compared to the properties of electrolytic Zn-Ni layer. Structural investigations were performed by the X-ray diffraction (XRD) method. The surface morphology and chemical composition and surface chemical elements distribution of deposited layers were studied using a scanning electron microscope. Electrochemical corrosion resistance investigations were done by classical Stern method and electrochemical impedance spectroscopy. The potentiodynamic curves in the range of  0.05V to the potential of open circuit, were obtained. On the base of these curves the parameters like corrosion potential- Ecor, corrosion current density- icor and the polarization resistance- Rp were determined. These values served as a measure of the corrosion resistance of obtained layers. Results of impedance investigations were presented on the Nyquist Z”= f (Z’) and the Bode log Z = f (log) and  = f (log), diagrams. On the basis on this research, it was exhibited that surface morphology, chemical composition of Zn-Ni-Mo layers are dependent on Mo contents. The optimal content of Na2MoO4 in the bath for the sake of corrosion resistance in 5% NaCl, is found to be 1.2 gdm-3.

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