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Effect of electrochemical treatment in eutectic solvent and deposition of SiO2 sol-gel coating on corrosion resistance of 316L steel in Ringer’s solution

Mazur-Nowacka Anna, Marczewski Marek, Tylus Włodzimierz, Szczygieł Bogdan, Chęcmanowski Jacek

Ochrona przed Korozją

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2022

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nr 5

152--156

EN

The 316L stainless steel samples were subjected to anodic polarization in a eutectic solvent and then theSiO2 coatings were deposited on them using the sol-gel method. The coatings were prepared from a sol containing TEOS as a precursor and ethanol as a solvent. The obtained samples were exposed in Ringer’s solution. Studies have shown that electrochemical treatment of 316L steel affects both the morphology, topography and roughness of the metallic material. Potentiodynamic tests showed that the best barrier properties after exposure to Ringer’s solution were obtained for 316L steel subjected to electrochemical treatment, additionally covered with a SiO2 coating. The deposition of the three-layer SiO2 coatings reduces the corrosion current density and an increase in the polarization resistance relative to the uncoated 316L steel.

PL

Próbki ze stali nierdzewnej 316L poddano polaryzacji anodowej w rozpuszczalniku eutektycznym, a następnie metodą zol-żel osadzono na nich powłoki SiO2. Powłoki otrzymywano z zolu zawierającego TEOS jako prekursor i etanol jako rozpuszczalnik. Otrzymane próbki eksponowano w roztworze Ringera. Badania dowiodły, że elektrochemiczna obróbka stali 316L wpływa zarówno na morfologię oraz topografię, jak i chropowatość materiału metalicznego. Potencjodynamiczne badania wykazały, że najlepsze właściwości barierowe po ekspozycji w roztworze Ringera uzyskano dla stali 316L poddanej obróbce elektrochemicznej i dodatkowo pokrytej powłoką SiO2. Osadzenie trójwarstwowych powłok SiO2 powoduje zmniejszenie gęstości prądu korozji oraz wzrost oporu polaryzacji względem niepokrytej stali 316L.

2

Polycyclic aromatic hydrocarbons removal from produced water by electrochemical process optimization

Yaqub A., Isa M. H., Ajab H., Kutty S. R., Ezechi E. H.

Ecological Chemistry and Engineering. S

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2017

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Vol. 24, nr 3

397--404

EN

Produced water is actually the wastewater separated from petroleum crude oil. Electrochemical-oxidation experiments was conducted for degradation of 16 priority polycyclic aromatic hydrocarbons (PAHs) using DSA type Ti/IrO2 anode. Laboratory scale batch reactor was used for degradation studies. To get the maximum PAHs removal electrochemical process optimized on three independent variable current density, pH and electrolysis time. The response surface modelling (RSM) based on a Box-Behnken design was applied to get appropriate experimental design. X1, X2 and X3 are the coded factors of independent variables such as the current density, pH and electrolysis time, respectively. Maximum removal was 95.29% at optimized conditions such as current density of 9 mA/cm2, pH 3 and electrolysis time 3.7 h. Quadratic model was suggested best fit model. The results of the Analysis of Variances (ANOVA) for PAHs demonstrated that the model was highly significant.

3

Projekt stanowiska badawczego do realizacji hybrydowej technologii mikroskrawania wspomaganego elektrochemicznie

Skoczypiec S., Ruszaj A., Grabowski M.

Inżynieria Maszyn

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2011

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R. 16, z. 4

27-34

PL

W mikroskrawaniu, wraz ze zmniejszeniem grubości warstwy skrawanej następuje nieproporcjonalny wzrost sił skrawania. Wprowadzenie oddziaływań elektrochemicznych w warstwie powierzchniowej przedmiotu obrabianego umożliwia zmniejszenie wytrzymałości oraz twardości usuwanego materiału, co w efekcie prowadzi do poprawy wskaźników technologicznych obróbki. W artykule przedstawiono uproszczoną analizę sił podczas procesu mikrotoczenia oraz zaprezentowano projekt stanowiska do badań procesu mikroskrawania intensyfikowanego elektrochemicznie.

EN

In case of microcutting the main problem during machining is connected with size effect. Significant forces in machining area limit microcutting process application to machine 3D parts made of soft materials and dimensions > 50 m. One of effective methods to overcome these problems and achieves high performance for micromachining process is combining various physical and chemical processes into one machining process, defined as hybrid machining. One of the possibilities to decrease cutting forces is to decrease the mechanical properties by workpiece surface layer electrochemical passivation before or during cutting process. Between workpiece and additional electrode the electrolyte is supplied and the thin oxide layer occurs. This layer is fragile and softer than core material, so can be easily removed with relatively smaller cutting forces, what increases tool life, decrease probability of tool damage, and increase accuracy of shaping by decreasing tool and workpiece deformation. In the paper analysis of cutting forces, stresses and deformation during microturning process has been presented. Based on obtained information the test stand design has been described.

4

Elektrochemiczne właściwości stopów metali szlachetnych badane metodą chronowoltamperometrii cyklicznej

Łukaszewski M., Czerwiński A.

Wiadomości Chemiczne

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2007

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[Z] 61, 5-6

361-386

EN

In this paper are summarized the results concerning studies on fundamental electrochemical properties of binary and ternary noble metal alloys in acidic solution. The systems were characterized electrochemically using cyclic voltammetry technique (CV). A CV curve can be treated as a basic mean of in situ surface analysis of electrodes of this type. The voltammogram recorded under given experimental conditions is characteristic of the individual noble metal or alloy and it is an electrochemical 'fingerprint' of the investigated sample. Qualitative and quanti-tative conclusions can be drawn about the surface state of noble metal alloys on the basis of the course of CV curves by the use of the distinctive features associated with each component. Such an analysis is possible due to the fact that the voltammograms for pure metals differ markedly from each other in respect of the region of surface oxide formation and its reduction as well as the appearance of the region where hydrogen electrosorption takes place. In particular, the potential of the oxygen desorption peak is a linear function of the alloy surface composition. The influence of the procedure of prolonged potential cycling on electrochemical behavior of the alloys is presented. During the electrochemical treatment the alloy surface becomes enriched with components that are more resistant to electrochemical dissolution, occurring at sufficiently high potentials. The course of the voltammogram undergoes dramatic changes concerning the signals originating from hydrogen and oxygen electrosorption. As a result of the procedure of potential cycling both alloy surface and bulk can become heterogeneous. Selective removal of alloy components during the electrochemical treatment allows for in situ preparation of alloy electrodes possessing a variety of electrocatalytic properties.

5

Electrochemical formation of bioactive surface layer on titanium

Krasicka-Cydzik E., Kowalski K., Glazowska I.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

147--150

EN

Purpose: Electrochemical oxidation method to form thin gel-like layer and activate titanium surface for calcium phosphate deposition Design/methodology/approach: Titanium was anodised galvanostatically with low current density from cathodic potential in 2 M H 3PO 4 solution up the steady state potential. This treatment produced two-layer surface film with thin (about 100 nm) gel-like phosphate film over the oxide layer with thickness of about 30 nm on the titanium surface. The composition and chemistry of electrochemically treated titanium surfaces were examined by X-ray photoelectron spectroscopy (XPS). The effectiveness of the new treatment was examined by comparing the behavior of treated and untreated titanium when used for biomimetic coating with the Electrochemical Impedance Spectroscopy (EIS) used for this purpose. Findings: A thick Ca-P coating was formed on the treated titanium after immersion in SBF solution and surface morphology was then examined using SEM equipped with EDS facilities. Practical implications: new electrochemical method of coating titanium and its implant alloys with bioactive surface layer is more efficient and faster than the other in practical use. Originality/value: This study continues to support the further investigation of active phosphates for improved orthopedic applications.