The present work is a review of the substantial effort that has been made to measure and understand the effects of corrosion with respect to the properties, performance, and durability of various forms of silicon carbide and silicon nitride. The review encompasses corrosion in diverse environments, usually at temperatures of 1000 °C or higher. The environments include dry and moist oxygen, mixtures of hot gaseous vapors, molten salts, molten metals, and complex environments pertaining to coal ashes and slags.

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This paper describes a highly specialized system for studies of time-dependent compaction of nano-size and other finesize powders under a variety of atmospheres and at temperatures ranging from 77 to 1000 K. The system incorporates a 10000 kg screw-driven press with a piston-cylinder type of die and can produce cylindrical powder compacts, 3mm in diameter and of various thicknesses, utilizing pressures up to 3 GPa. The system is computer-controlled and permits measurements of the sample volume with an uncertainty of 0.07 mm, and, after appropriate calibration, can determine the rate and degree of densification of the compacting powder as pressure is applied. To illustrate its capabilities, the system was used to study the densification of several powders, including nano-size y-Al,O,, submicrometer 95% a-Si,N,, RbBr, and KCI. The results obtained on RbBr and KCl, used for calibration and testing of the equipment, are in good agreement with previously published data for these materials.