Silicon carbide in ablative chars.

The Physical Transformation of the Mineral Matter in Pulverized Coal Under Simulated Combustion Conditions

“…Comparison with size distribut ion of original mineral matt er or predi ctions based on I ash particle per coal particle. Such reactions have previousl y been sho wn to augment the silica vaporization rate under conditions pertinent to slagging gasifiers (Raask and Wilkins, 1965) and to ablating nosecones (Beecher and Rosensweig, 1961;Ladacki, 1966). The augmentation of the vaporization of silica and possibly other stable oxides by the locally reducing atmospheres in carbon particles accounts for only a small mass of the ash, but may be of major significance because of the subsequent formation of submicron particles which are difficult to collect and which deposit preferentially in the upper respiratory tract.…”

A study of the kinetics of high‐temperature carbon‐silica reactions in an ablative polymer composite

“…However, such an approach requires that the investigator know which reactions are occurring and to what extent. In addition, Ladacki (5) points out that kinetic analyses based quantitatively on carbon monoxide may not be valid due to the possibility of back reactions (e.g. reaction 7).…”

“…Although the three primary reactions occur between carbon and silicon dioxide, other types of reactions have been postulated. Beecher and Rosensweig (3) suggested that the silicon carbide and silicon monoxide produced by the primary reaction may react according to the equation Sic + SiOz + 2SiO + COz (5) Ladacki (5) pointed out that reaction 5 is unbalanced and is thermodynamically unfavorable when balanced.…”

“…Carey and Coulbert (6) and Blumenthal, Santy, and Burns (7) suggested that the correct reaction is (5) also suggested that a reaction between silicon monoxide and carbon monoxide may occur according to the equation…”

Modelling the Thermal Response of Composites in Fire

“…At this stage the decomposition process ceases unless the temperature is high enough to induce pyrolysis reactions between the fibres and char. When the temperature exceeds ~1000 o C then the char can react with the silica network in glass fibres, resulting in considerable mass loss [3]. In the case of carbon fibre composites, the carbon fibres and char may oxidise when exposed to fire in an oxygenrich environment.…”