Wyniki wyszukiwania - BazTech

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Analiza potencjału elektrodowego powłok ochronnych z tworzyw sztucznych na metalach

Jamroziak K., Jarguliński W.

Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki

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2010

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Nr 4

121-129

PL

W artykule omówiono metodę i podano przykładowe wyniki pomiarów potencjału elektrodowego powłok ochronnych z tworzyw sztucznych na metalach konstrukcyjnych. Zagadnienia te związane są z ochroną przed korozją i wnikaniem wodoru do pracującej zmęczeniowo konstrukcji.

EN

The article discusses the method and provides sample results of measurements of electrode potential of plastic protective coatings on structural metals. These issues are related to anticorrosion protection and hydrogen penetration into fatigued structures.

2

Changes of electrode potential in the non-oxidative leaching

Kowalczuk P. B., Chmielewski T.

Physicochemical Problems of Mineral Processing

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2010

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Vol. 44

115-126

EN

Simultaneous measurements of pH and redox potential using a platinum electrode as well as poten-tial of copper sulphide electrodes during non-oxidative leaching of Lubin shale middlings with sulfuric acid have been applied to determine leaching kinetics and to evaluate its electrochemical parameters as well as to assess the changes taking place at the mineral/solution interface during leaching process. Significant decrease in both redox potential of the solution (from +350 mV to +50 mV, Ag,AgCl) and poten-tial of mineral electrodes were observed with increasing pH during carbonate decomposition with sulfuric acid. It is therefore concluded that the low value of red-ox potential is a parameter preventing oxidation of copper sulphide minerals present in leached material and prevents the transition of Cu and Fe to the solu-tion. It was found that the non-oxidative leaching is a rapid and selective process, resulting in decomposition of calcium and magnesium carbonates and in saturation of the leaching slurry with carbon dioxide. It was recognized that with the increasing degree of carbonate decomposition from 50 to 100 % metals-bearing minerals liberation has remarkably improved, which beneficially facilitates and intensifies further upgrading or leaching processes.

PL

Pomiary pH i potencjału redox (za pomocą elektrody platynowej) podczas nieutleniającego ługowania kwasem siarkowym pozwalają równocześnie określić kinetykę oraz zmiany parametrów elektrochemicznych zachodzących w roztworze podczas prowadzonego procesu. W czasie rozkładu węglanów za pomocą kwasu siarkowego zaobserwowano w roztworze ługującym znaczny spadek potencjału redox roztworu (od +350 mV do +50 mV, względem elektrody Ag,AgCl) przy jednoczesnym wzroście pH. Tak niskie wartości potencjału red-ox uniemożliwiają utlenianie siarczkowych minerałów miedzi obecnych w ługowanym materiale i przechodzenie metali do roztworu. Stwierdzono, że ługowanie nieutleniające jest procesem szybkim i selektywnym, powodując wyłącznie rozkład węglanów wapnia i magnezu. Uznano, że w miarę zwiększenia stopnia rozkładu węglanów wzrasta udział uwolnionych ziaren minerałów użytecznych, co ułatwia i intensyfikuje dalsze procesy wzbogacania lub ługowania.

3

The analysis of the electrode potential shift in the examination of plastic-covered metal fatigue strength

Jamroziak K., Jargulinski W.

Archives of Materials Science and Engineering

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2010

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Vol. 41, nr 1

21-27

EN

Purpose: A development of methodology of adhesive force measuring, and at the same time an estimation of its value change in the specifically designated group of materials that are used in technical objects' construction, requires defining the fatigue strength value changes. The one of the elements influencing adhesive force is electrode potential estimation in the relation to the function of adhesive force considering variable layers of the coatings. Design/methodology/approach: This paper describes an issue of electrode potential shift influence on metals' fatigue strength. The issue was presented based on the literature and conducted tests. Findings: The results of the examinations concern electrode potential shift influence on adhesion forces' increase in the materials covered with various coatings in relation to a defined coating thickness. Research limitations/implications: After earlier made tests, when it was forecast that electrode potential influences an increase in fatigue strength. It was formulated for verification of the assumed hypothesis. The tests were conducted on samples of selected metals coated with various configurations of layers. The methodology was limited to the measurement of the research results with a single kind of demonstration (standard) electrode. Practical implications: The results of the tests, in shape of charts representing the shift of electrode potential in relation to time, will allow the authors to resolve next research problem to describe a mechanism of hydrogen absorption by a metal base. This will allow to develop methodology of moist (damp) angle measure. The angle influences adhesion force that is responsible for an increase in fatigue strength. Originality/value: The value of attained results will help to develop general assumptions for methodology of moist (damp) angle measure.

4

Electric potential of biomaterials coated with dielectric carbon layer and non-coated in water and serum

Urbański S., Niedzielski P., Mitura S., Wierzchoń T., Sokołowska A.

Inżynieria Biomateriałów

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2006

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R. 9, nr 56-57

21-24

EN

Electric potentials, established in water and human blood serum, of the electrodes made of platinum, graphite, Ti6Al4V alloy, TiN, AlSi316L steel, oxidized steel and the materials coated with diamond like carbon layer (DLC) and a nanocrystalline-diamond layer (NCD) were determined. The values of the potentials of non-coated materials increased with increasing electron work function (Phi) of investigated materials in reasonable accordance. The difference between the potentials measured in serum and in water was ascribed to be differing molecular electron structure of the proteins in contact with the electrodes. Electrode potentials of different materials coated with the same thin dielectric carbon layer varied significantly depending on the (Phi) value of the substrate. In this way the selection of a substrate material permits influencing on the interaction between NCD (DLC) coating and serum compounds. The potential of an electrode has appeared to be a simple but sensitive indicator of the phenomena that take place on the biomaterial surface.