FORFARANDE FOR FRAMSTELLNING AV ETT FINKORNIGT, KRISTALLINT, KERAMISKT, FIBROST HOGTEMPERATURMATERIAL

摘要

1481133 Ceramic refractory fibrous material BABCOCK & WILCOX CO 12 May 1975 [30 May 1974] 19876/75 Heading ClJ A fine-grained crystalline product suitable for thermal insulation which can be compressed and will return to at least 85 to 90% of its original configuration when the compression force is released, is obtained from an amorphous alumina-silica ceramic refractory fibre by heating the refractory fibre at a temperature above its devitrification temperature for a selected period of time producing devitrification of the refractory fibre, and terminating the heat treatment subsequent to formation of the fine-grained crystalline product but prior to the onset of excessive grain growth. The Example discloses the heat treatment of samples of ceramic refractory fibre blanket possessing a devitrification temperature of about 950‹ C, at temperatures ranging from 950‹ to 1050‹ C for selected periods of time ranging from ten minutes to one hour. The resistance of the treated samples to a permanent set and defermation was tested by compressing them to 70% of their initial thickness and exposing the compressed samples to a temperature of 815‹ C for 18 hours.