Electrochemistry galvanic corrosion

Liquid Solid S/L Wetting, spreading, lubrication, friction, surface tension, capillarity, electrochemistry, galvanic effects, corrosion, adsorption, nucleation and growth, ion electromigration, optical properties, cleaning techniques. 

This chapter presents electrochemical reactions and corrosion processes of Mg and its alloys. First, an analysis of the thermodynamics of magnesium and possible electrochemical reactions associated with Mg are presented. After that an illustration of the nature of surface films formed on Mg and its alloys follows. To comprehensively understand the corrosion of Mg and its alloys, the anodic and cathodic processes are analyzed separately. Having understood the electrochemistry of Mg and its alloys, the corrosion characteristics and behavior of Mg and its alloys are discussed, including self-corrosion reaction, hydrogen evolution, the alkalization effect, corrosion potential, macro-galvanic corrosion, the micro-galvanic effect, impurity tolerance, influence of the chemical composition of the matrix phase, role of the secondary and other phases, localized corrosion and overall corrosivity of alloys. 

Tower, Stephen. All About Electrochemistry. Available online. URL http //www.cheml.com/acad/webtext/elchem/. Accessed May 28, 2009. Part of a virtual chemistry textbook, this excellent resource explains the basics of electrochemistry, which is important in understanding how fuel cells work. Discussions include galvanic cells and electrodes, cell potentials and thermodynamics, the Nernst equation and its applications, batteries and fuel cells, electrochemical corrosion, and electrolytic cells and electrolysis. 

Galvanized iron is steel sheet that has been coated with zinc tin cans are made of steel sheet coated with tin. Discuss the functions of these coatings and the electrochemistry of the corrosion reactions that occur if an electrolyte contacts the scratched surface of a galvanized iron sheet or a tin can. 

The tendency of many electrochemical reactions to move toward complete formation of products presents a significant challenge in the case of corrosion, but it also provides opportunities for using these reactions positively. The most familiar example of this is the battery, a cell or series of cells that generates an electric current. Batteries are composed of many different materials and find many uses, but they all share one common property—they provide a means by which we harness the electrical work of a galvanic cell and use it productively. We will see, however, that batteries have something else in common—they are susceptible to corrosion. So even when we intend to put electrochemistry to work for us, we still need to think about corrosion. Let s develop some ideas about batteries in general as we consider some specific examples. 

Galvanized iron, which is iron coated with a thin layer of zinc, uses the principles of electrochemistry to protect the iron from corrosion even after the surface coat is broken. The standard reduction potentials for iron and zinc are... 

Of course, Antropov s scale cannot be used for thermodynamic calculations (directions of redox reactions, emf of a galvanic ceU, etc.). However, it proved to be very useful for studies of the electric double layer, specific adsorption and the nature of adsorbed particles and, eventually, for corrosion studies and development of corrosion inhibitors—L. I. Antropov was a well-known expert in this field. It is worthwhile to note that two distinguished Western electrochemists, J. O M. Bockris and B. E. Conway, mentioned L. I. Antropov among the 12 scientists who created the fundamentals of modem electrochemistry. ... 

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