Resistance to Electrochemical Corrosion of Extruded Magnesium Alloy AZ61

2014 ◽  
Vol 607 ◽  
pp. 31-36 ◽  
Author(s):  
Joanna Przondziono ◽  
Eugeniusz Hadasik ◽  
Witold Walke ◽  
Janusz Szala ◽  
Jakub Wieczorek
Keyword(s):  
Magnesium Alloy ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Molar Concentration ◽  
Test Results ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Protective Layers ◽  
Anodic Polarisation ◽  
Electrochemical Corrosion Resistance

The purpose of the study was the evaluation of the electrochemical corrosion resistance of extruded magnesium alloy AZ61 in solutions with concentration of 0.012 M NaCl. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves by means of potentiodynamic method. Immersion tests were performed in NaCl solution and time periods of 1-6 days. Scanning microscopy was used to obtain images of the alloy microstructure after immersion tests. Electrochemical impedance spectroscopy was used to evaluate phenomena that take place on the surface of the tested alloy. The results of all performed tests prove explicitly deterioration of corrosion properties of magnesium alloy AZ31 with the increase of molar concentration of NaCl solution. It was found that irrespective of molar concentration of NaCl solution, pitting corrosion can be detected on the surface of the tested alloy. Test results prove that it is necessary to apply protective layers on elements made of the tested alloy.

Resistance to Electrochemical Corrosion of Extruded Magnesium Alloy AZ31

2015 ◽  
Vol 227 ◽  
pp. 35-38 ◽  
Author(s):  
Joanna Przondziono ◽  
Eugeniusz Hadasik ◽  
Witold Walke ◽  
Janusz Szala
Keyword(s):  
Magnesium Alloy ◽  
Electrochemical Impedance ◽  
Measurement Data ◽  
Electrochemical Corrosion ◽  
Chloride Ions ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31 ◽  
Electrochemical Corrosion Resistance

The purpose of the study was evaluation of electrochemical corrosion resistance of extruded magnesium alloy AZ31. Corrosion tests were performed in NaCl solutions featuring chloride ions concentration from 0.01 to 2 M NaCl. Potentiodynamic tests enabled to register anodic polarisation curves. Immersion tests were performed in NaCl solution and time 1-5 days. Electrochemical impedance spectroscopy (EIS) was used to evaluate phenomena that take place on the surface of the tested alloy. Impedance spectra of the system were made in the tests, and obtained measurement data was matched to the equivalent system. The results of all performed tests prove explicitly deterioration of corrosion properties of extruded magnesium alloy AZ31 with the increase of molar concentration of NaCl solution. Options of magnesium alloy AZ31 application in aircraft and automotive industry are connected with the need for application of protective layers on elements made of the tested alloy.

scholarly journals Effect of surface treatment by sandblasting on the quality and electrochemical corrosion properties of a C-1020 carbon steel used by an Algerian oil company

2019 ◽  
Vol 272 ◽  
pp. 01001
Author(s):  
Nadia HAMMOUDA ◽  
Kamel BELMOKRE
Keyword(s):  
Carbon Steel ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Surface Preparation ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Good Surface ◽  
Oil Company ◽  
Mechanical Surface ◽  
Effect Of Surface

The purpose of the different operations under the term surface preparation is to get a clean surface able to be coated. It is essential to adapt this preparation in terms of the metallurgical nature of the substrate, cleanliness, its shape and roughness. Surface preparations especially the operations of sandblasting, polishing, or grinding prove of capital importance. It allows to modify the superficial properties of these materials, after these treatments the surface becomes very active. This paper evaluates the mechanical surface treatments effect by sandblasting (Sa 1.5 and Sa 2.5) on the electrochemical corrosion characteristics of C-1020 carbon steel in 3% NaCl solution electrolyte simulating aggressive sea atmosphere. Investigations are conducted using stationary (free potential "E-t, polarization curves "E-i", the Tafel rights and the Rp) and nonstationary electrochemical tools such as electrochemical impedance. The results obtained allowed us to highlight that sandblasted carbon steel degrades with immersion time because of the roughness of the surface. These results were confirmed by the plot of the electrochemical impedance diagrams, confirming that the process governing kinetics is under charge transfer control. Good protection against corrosion cannot be obtained only with a good surface preparation of the adapted steel.

Potentiodynamic Tests of Magnesium Alloy AZ31 with Lithium Additive

2013 ◽  
Vol 211 ◽  
pp. 93-100
Author(s):  
Joanna Przondziono ◽  
Witold Walke ◽  
Eugeniusz Hadasik ◽  
Stanisław Lalik
Keyword(s):  
Magnesium Alloy ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Az31 Alloy ◽  
Chloride Ions ◽  
Molar Concentration ◽  
Lithium Content ◽  
Nacl Solution ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31

The purpose of the study is to assess electrochemical corrosion resistance of magnesium alloy AZ31 with additives of 4.5, 7.5 and 15 % lithium in NaCl solutions. Corrosion tests were performed in solutions with concentration 0.01 2 M NaCl with application of electrochemical testing system VoltaLab®PGP201. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves by means of potentiodynamic method. Results of performed tests show unequivocally deterioration of corrosion characteristics of the alloy together with increase of molar concentration of NaCl solution. As chloride ions concentration increases, decrease of corrosion potential and polarisation resistance, as well as increase of corrosion current density are observed. Deterioration of corrosion characteristics of AZ31 alloy was shown with the increase of lithium content. It must be highlighted that irrespective of molar concentration of NaCl solution, there is also presence of pitting corrosion in the tested alloy. It proves that magnesium alloy AZ31-Li is not resistant to that type of corrosion. Test results prove that it is necessary to apply protective films on elements made of magnesium alloy with lithium additive.

scholarly journals Corrosion resistance of the microarc oxidation coatings prepared on magnesium alloy

2018 ◽  
Vol 38 ◽  
pp. 02009
Author(s):  
Ying Lv ◽  
Jun Gang Li ◽  
Ming Zhong Wu ◽  
Zhen Ma ◽  
Jing Qiang Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Microarc Oxidation ◽  
Electrochemical Corrosion ◽  
Ceramic Coatings ◽  
Nacl Solution ◽  
Oxide Coatings ◽  
Az91d Magnesium Alloy ◽  
Oxidation Technology ◽  
Electrochemical Corrosion Resistance

Ceramic coatings were prepared on the surface of AZ91D magnesium alloy by microarc oxidation technology. The effects of different voltages on morphology, phase composition and thickness of the coatings were characterized by SEM and XRD. The corrosion resistance of the coatings was measured by electrochemical workstation. Results indicated that the microarc oxidation coatings prepared in sodium silicate electrolyte exhibited porous surface and mainly comprised MgO, Mg2SiO4 and a small amount of MgAl2O4. The thickness of the oxide coatings increased rapidly with the increase of voltage. The coating prepared at 400V voltage had good electrochemical corrosion resistance in 3.5wt% NaCl solution.

scholarly journals Electrochemical Corrosion of Magnesium Alloy AZ31 with Additive Lithium

2017 ◽  
Vol 62 (4) ◽  
pp. 2359-2363
Author(s):  
J. Przondziono ◽  
E. Hadasik ◽  
J. Szala
Keyword(s):  
Magnesium Alloy ◽  
Electrochemical Corrosion ◽  
Solution Concentration ◽  
Corrosion Process ◽  
Nacl Solution ◽  
Scanning Microscope ◽  
Corrosion Properties ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31 ◽  
Electron Scanning Microscope

AbstractThe purpose of performed tests was evaluation of resistance to electrochemical corrosion of extruded magnesium alloy AZ31 with additive of 4.5% Li. Corrosion tests were performed in 0.01-2.0 M NaCl solutions. Potentiodynamic tests enabled to register polarisation curves. With application of stereoscopic microscope Nikon SMZ745T and electron scanning microscope Hitachi S-4200, the surface of the alloy was observed after immersion tests performed in 1-6 days. Results of performed tests prove explicitly deterioration of corrosion properties of the alloy with the increase of molar concentration of NaCl solution. It can be seen that corrosion process is intensive and that intensity increases with the increase of solution concentration and extension of exposure time.

Mechanical properties and wear-corrosion resistance of a new compound extrusion process for magnesium alloy AZ61

2020 ◽  
Vol 62 (4) ◽  
pp. 395-399
Author(s):  
Jiehui Liu ◽  
Hongjun Hu ◽  
Yang Liu ◽  
Dingfei Zhang ◽  
Zhongwen Ou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Magnesium Alloy ◽  
Equal Channel Angular Extrusion ◽  
Extrusion Process ◽  
Corrosion And Wear ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Manufacturing Method ◽  
Az61 Magnesium Alloy

Abstract Compound extrusion (CE) is a newly developed plastic deformation technique which combines direct extrusion (DE) with a two-pass equal channel angular extrusion (ECAE). This paper focuses on the strength, ductility and anti-corrosion properties of an NaCl solution at certain concentrations and the wear-resistance of dry sliding AZ61 magnesium alloy prepared by CE and DE. It is found that the strength and elongation of the AZ61 alloy prepared by CE are enhanced because of grain refinement. Furthermore, AZ61 magnesium alloy made by CE displays higher corrosion and wear resistance than that prepared by DE. Experimental results prove that CE is a prospective manufacturing method for improving the mechanical properties, anti-corrosion and anti-wear of AZ61 magnesium alloy.

scholarly journals Electrochemical Corrosion Resistance of Ni and Co Bonded Near-Nano and Nanostructured Cemented Carbides

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 224 ◽  
Author(s):  
Tamara Aleksandrov Fabijanić ◽  
Marin Kurtela ◽  
Irbas Škrinjarić ◽  
Johannes Pötschke ◽  
Markus Mayer
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Grain Growth ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Common Interest ◽  
Cemented Carbides ◽  
Wear Resistant ◽  
Two Samples ◽  
Electrochemical Corrosion Resistance

The advantages of nanostructured cemented carbides are a uniform, homogenous microstructure and superior, high uniform mechanical properties, which makes them the best choice for wear-resistant applications. Wear-resistant applications in the chemical and petroleum industry, besides mechanical properties, require corrosion resistance of the parts. Co as a binder is not an optimal solution due to selective dissolution in an acidic environment. Thus, the development of cemented carbides with alternative binders to increase the corrosion resistance but still retaining mechanical properties is of common interest. Starting mixtures with WC powder, grain growth inhibitors GGIs; VC and Cr3C2, and an identical binder amount of 11-wt.% were prepared. GGIs were added to retain the size of the starting WC powder in the sintered samples. The parameters of the powder metallurgy process were adapted, and samples have been successfully consolidated. A very fine homogeneous microstructure with relatively uniform grain-size distribution and without microstructural defects in the form of carbide agglomerates and abnormal grain growth was achieved for both Ni-bonded and Co-bonded samples. Achieved mechanical properties, Vickers hardness, and Palmqvist toughness, of Ni-bonded near-nanostructured cemented carbides are slightly lower but still comparable to Co-bonded nanostructured cemented carbides. Two samples of each grade were researched by different electrochemical direct current corrosion techniques. The open circuit potential Ecorr, the linear polarisation resistance (LPR), the Tafel extrapolation method, and the electrochemical impedance spectroscopy (EIS) at room temperature in the solution of 3.5% NaCl. From the carried research, it was found that chemical composition of the binder significantly influenced the electrochemical corrosion resistance. Better corrosion resistance was observed for Ni-bonded samples compared to Co-bonded samples. The corrosion rate of Ni-bonded cemented carbides is approximately four times lower compared to Co-bonded cemented carbides.

scholarly journals Impact Of Strain In Drawing Process And Surface Modification On Resistance To Electrochemical Corrosion Of Wires Used In Dentistry

2015 ◽  
Vol 60 (3) ◽  
pp. 1865-1870
Author(s):  
J. Przondziono ◽  
E. Hadasik ◽  
W. Walke ◽  
J. Szala
Keyword(s):  
Surface Modification ◽  
Electrochemical Impedance ◽  
Artificial Saliva ◽  
Maxillofacial Surgery ◽  
Electrochemical Corrosion ◽  
Sudden Increase ◽  
Drawing Process ◽  
Corrosion Properties ◽  
The Impact ◽  
Modification Treatment

Abstract The study presents the results of research into the impact of strain in cold drawing and surface modification treatment on corrosion properties of wires made of X10CrNi 18-8 steel used in maxillofacial surgery. Scanning microscopy enabled to make images of the surface of wires after drawing process as well as after surface modification treatment. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves in artificial saliva. In order to evaluate physical and chemical properties of the surface, electrochemical impedance spectroscopy was performed. Test results show deterioration of corrosion properties of wires along with strain taking place in drawing process. It was proved that electrochemical polishing and chemical passivation caused sudden increase of resistance of wires made of stainless steel to pitting corrosion in artificial saliva.

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.

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