Applications in metallurgy

In addition to the various types of concentration cells described above there is one form of the concentration cell which has certain important applications in metallurgy this is the oxygen concentration cell. The cell is represented schematically as ... 

K2TiF6, in addition to applications in metallurgy, is used in the preparation of dental fillings.3 [Ti(H20)6]Cl3 is used as a bleaching agent in cases where chlorine is inapplicable.4... 

In Table 13 the interactions of Si3N4 ceramics with common metals are summarised (see also [18, 472, 473]). For application in metallurgy not only the interaction with the metal but also the interaction of oxide slags on the surface of the metals has to be taken into account. At higher temperatures most metal oxides react with the grain boundary phase. For example, V205,... 

Iwase, M., Ichise, E. and Jacob, K.T. (1984) Mixed ionic and electronic conduction in zirconia and its application in metallurgy. Adv. Ceram., 12 (Sci Technol Zirconia 2), 646-59. 

Ray, W. H. and Szekely, J. (1973). Process Optimization with Applications in Metallurgy and Chemical Engineering, Wiley, New York. 

Indirectly fired furnaces find applications in metallurgy, paint enameling, the pharmaceutical industry, and other situations where it is necessary to control the chemistry of the furnace atmosphere [186]. An important aspect of the heat treatment of metals, for example, is the effect of the furnace atmosphere on the stock being heated. In most cases, the need is to minimize or eliminate completely the undesirable effects of furnace gases, such as oxidation or decarbonization. Both directly [187,188] and indirectly [189,190], natural-gas-fired furnaces have been analyzed, but the details cannot be included here. 

Electrochemically and chemically produced metal powders from aqueous solutions are of high purity. These powders find applications in metallurgy, automotive, aerospace, energy device, electronics, and biomedical industries. Disperse deposits and electrochemically produced metal powders are also very suitable for use as catalytic surfaces in chemical industry. 

Nuclear Applications. Powder metallurgy is used in the fabrication of fuel elements as well as control, shielding, moderator, and other components of nuclear-power reactors (63) (see Nuclearreactors). The materials for fuel, moderator, and control parts of a reactor are thermodynamically unstable if heated to melting temperatures. These same materials are stable under P/M process conditions. It is possible, for example, to incorporate uranium or ceramic compounds in a metallic matrix, or to produce parts that are similar in the size and shape desired without effecting drastic changes in either the stmcture or surface conditions. OnlyHttle post-sintering treatment is necessary. 

The synthetic method used in preparing a particular boride phase depends primarily on its intended use. Whereas for basic research borides of high purity are desirable, for industrial applications, e.g., in coatings, tools and crucibles, as a refining agent in metallurgy or in control rods in nuclear energy plants, pure borides are unnecessary. 

Rhines, F.N. (1956) Phase Diagrams in Metallurgy Their Development and Application (McGraw-Hill Book Company, New York). 

If we were only interested in bulk copper and its oxides, we would not need to resort to DFT calculations. The relative stabilities of bulk metals and their oxides are extremely important in many applications of metallurgy, so it is not surprising that this information has been extensively characterized and tabulated. This information (and similar information for metal sulfides) is tabulated in so-called Ellingham diagrams, which are available from many sources. We have chosen these materials as an initial example because it is likely that you already have some physical intuition about the situation. The main point of this chapter is that DFT calculations can be used to describe the kinds of phase stability that are relevant to the physical questions posed above. In Section 7.1 we will discuss how to do this for bulk oxides. In Section 7.2 we will examine some examples where DFT can give phase stability information that is also technologically relevant but that is much more difficult to establish experimentally. 

The most important applications of hydrogen sulfide involve the production of sodium sulfide and other inorganic sulfides. Hydrogen sulfide obtained as a by-product often is converted into sulfuric acid. It also is used in organic synthesis to make thiols or mercaptans. Other applications are in metallurgy for extracting nickel, copper, and cobalt as sulfides from their minerals and in classical qualitative analytical methods for precipitation of many metals (see Reactions). It also is used in producing heavy water for nuclear reactors. 

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