High-temperature corrosion ceramics

If local stresses exceed the forces of cohesion between atoms or lattice molecules, the crystal cracks. Micro- and macrocracks have a pronounced influence on the course of chemical reactions. We mention three different examples of technical importance for illustration. 1) The spallation of metal oxide layers during the high temperature corrosion of metals, 2) hydrogen embrittlement of steel, and 3) transformation hardening of ceramic materials based on energy consuming phase transformations in the dilated zone of an advancing crack tip. 

Desmaison, J., 1990, High temperature oxidation of nonoxide structural ceramics use of advanced protective coatings, in High Temperature Corrosion of Technical Ceramics (RJ. Fordham, Ed.), Elsevier Applied Science, London, U.K., p. 93. 

Nonporous spinel oxide ceramics of MgAl204 are notable for their very good high temperature corrosion resistance to alkaline media. Sintered yttrium oxide exhibits still better corrosion resistance at high temperatures (Y2O3 melting point ca. 2400°C), but its utilization possibilities are limited by its high price. 

V. Coen, H. Kolbe, L. Orechia, and M. Della Rossa, High Temperature Corrosion of Technical Ceramics, Elsevier Applied Science, Amsterdam, 1989. 

Blachere R, Pettit FS (1989) High temperature corrosion of ceramics. Noyes, Park Ridge, NJ Brandmp J, Immergut EH, Gmlke EA, Abe A (eds) (1999) Polymer handbook, 4th edn. Wiley, New York... 

J. R. Blachere and F. S. Pettit, High Temperature Corrosion of Ceramics, Noyes Data Corporation, Park Ridge, NJ, 1989, pp. 188. 

An understanding of solid state reactions is necessary for designing microstructures, properties, and processes for making novel solids. Processes that depend on solid state reactions and atomic transport are conversion reactions, ceramics processing, high-temperature corrosion, and ionic device operation. 

A few high-temperature corrosive properties of ceramics are mentioned here as examples. The book by Samsonov and Vinitskii has many details on high-tempera-ture reactions with various ambients. Table 6.6 compares the corrosion resistance of several refractories in combustion gases. 

V.A. Izhevskyi, L.A. Genova, A.H.A. Bressiani, and J.C. Bressiani, Liquid Phase Sintered SiC. Processing and Transformation Controlled Microstructure Tailoring, MatRes., 3(4), 131-38 (2000). V.A. Lavrenko, D.J. Baxter, A.D. Panasyuk, and M. Desmanion-Brut, High-Temperature Corrosion of AIN-Based Composite Ceramic in Air and in Combustion Products of Commercial Fuel. 1. Corrosion of Ceramic Composites in the AIN-SiC System in Air and in Combustion Products of Kerosene and Diesel Fuel, Powder Metallurgy and Meta Ceramics, 43(3-4), 179-86 (2004). 

Glass fibres, metal fibres, ceramic fibres, and high-performance polymer fibres are able to meet special requirements in special applications, such as filtration in high-stress, high-temperature, corrosive, or chemical hazardous environments. Filters containing fine glass fibres or glass microfibers are resistant to chemical attack but relatively brittle when pleated, and produce undesirable yield losses. 

Corrosion is a process that occurs at the surface of various materials. Traditionally, it is subdivided into the dry and hot and the wet part, i.e., corrosion in hot gases or within electrolytes. The attack of any material may be understood as corrosion, including metals, semiconductors, insulators, ceramics, polymers, etc. This chapter will introduce the fundamentals and the electrochemical basis of the corrosion of metals in an aqueous environment. Other chapters will concentrate on high temperature corrosion and special topics in detail. This chapter intends to provide the basis for a better understanding of the following more specialized contributions to aqueous corrosion. Therefore, it will mention briefly methods and phenomena, some of which will be discussed later more in detail. 

The variables to be considered here include both the type of ceramic and the environment to which it is exposed. Non-oxide ceramics include borides, nitrides, and carbides. Most high temperature corrosion environments contain oxygen and hence the emphasis of this chapter will be on oxidation processes of the type (Shaw et al., 1987 Jacobson and Opila, 1999) ... 

There are two objectives in high temperature corrosion studies understanding the interaction of the ceramic and corrodent on a fundamental level and assessing the behavior of the ceramic in an actual applica-... 

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