Metal carbides combustion synthesis

Grebe, H. A., Advani, A., Thadani, N. N., and Kottke, T., Combustion synthesis and subsequent explosive densification of titanium carbide ceramics. Metall. Trans. A, 23A, 2365 (1992). 

It is not essential that, for combustion synthesis, the reactants are elements and initially solid (at least one of them). Refractory carbides and nitrides with complex chemical compositions (metal halogenides, organometallics, etc.) are also formed in combustion of gaseous systems. The special features of combustion synthesis in the gas phase were analyzed in the recent review by Brezinsky (5). The synthesis in a gaseous system proceeds at a stationary combustion front with moving flows of reactants and product. Consequently, these processes differ in essence from combustion of condensed systems by the conditions of nucleation and growth of the new phase, which manifest themselves in the product morphologies. 

Occurrence. Carbon monoxide is a product of incomplete combustion and is not likely to result where a flame bums in an abundant air supply, yet may result when a flame touches a cooler surface than the ignition temperature of the gas. Gas or coal heaters in the home and gas space heaters in industry have been frequent sources of carbon monoxide poisoning when not provided with effective vents. Gas heaters, though properly adjusted when installed, may become hazardous sources of carbon monoxide if maintained improperly. Automobile exhaust gas is perhaps the most familiar source of carbon monoxide exposure. The manufacture and use of synthesis gas, calcium carbide manufacture, distillation of coal or wood, combustion operations, heat treatment of metals, fire fighting, mining, and cigarette smoking represent additional sources of carbon monoxide exposure (105—107). 

In this book, we briefly examine the different types of reactions and methods employed in the synthesis of inorganic solid materials. Besides the traditional ceramic procedures, we discuss precursor methods, combustion method, topochemical reactions, intercalation reactions, ion-exchange reactions, alkali-flux method, sol-gel method, mechanochemical synthesis, microwave synthesis, electrochemical methods, pyrosol process, arc and skull methods and high-pressure methods. Hydrothermal and solvothermal syntheses are discussed separately and also in sections dealing with specific materials. Superconducting cuprates and intergrowth structures are discussed in separate sections. Synthesis of nanomaterials is dealt with in some detail. Synthetic methods for metal borides, carbides, nitrides, fluorides, sili-cides, phosphides and chalcogenides are also outlined. 

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