High-temperature kinetics of the oxidation and nitridation of pyrolytic silicon carbide in dissociated gases

Active to passive transition in the oxidation of silicon carbide at high temperature and low pressure in molecular and atomic oxygen

“…This was observed by Rosner and Allendorf [14] in the case of very low pressures (10-2-10 Pa) and at high temperatures (1750-2400 K) on pyrolytic SiC. According to these authors, in contradiction to the thermodynamical prediction, for any temperature below 2100 K, passive behaviour occurs for a much lower reactant pressure with O(g) than with O2(g ).…”

Compatibility/Stability Issues in the Use of Nitride Kernels in LWR TRISO Fuel

“…Hydrogen was included in all the experiments as literature on nitriding silicon indicates enhanced kinetics when hydrogen is present. [3] The resulting exposed particles were characterized using x-ray diffraction (XRD) on a Panalytical Xpert Diffractometer, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) on Hitachi microscopes models 3400 and 4800, and Thermo Scientific K-Alpha X-ray Photoelectron Spectroscopy (XPS) using a Thermo Scientific K-Alpha. Continuous Θ-2Θ scans were performed on the Panalytical Xpert diffractometer from nominally 5 to 80° 2Θ in under 60 min.…”

“…Rosner and Allendorf [3] investigated oxidation and nitridation of SiC in dissociated gases using a fast flow vacuum technique. Thus their measurements related to removal of SiC and thus the kinetics are not instructive for TRISO fuel.…”

Computational and experimental investigations of carbon-ceramic composite materials thermochemical resistance in combustion products of liquid rocket engine

“…The temperature of transition from active to passive conditions depends on the environment parameters such as pressure, concentration, and composition of oxidant components, as well as availability of carbon and other side components (including technical additives, determining the chemical bond energy between carbon and carbide during SiC covering formation) in the ¦lm. In some cases [1], the transition from active to passive conditions can be attributed to the temperature of 1967 K. More detailed information can be found in [2].…”