Growing alpha-alumina whiskers of the long wool type

摘要

Growing alpha-alumina whiskers of the long wool type.. B6A. Comprises heating Al in a reaction chamber of which the upper portion is made of a SiO2 contng. refractory material in an H2-atmosphere (opt. contng. sulphur) at a reaction temp. of 1290-1400 degrees C (esp. about 1325 degrees C) to effect reaction between the Al and SiO2. The reaction chamber is partially closed at one end and the Al and SiO2 maintained within the reaction temp. range for a time (usually about 4 hrs.) to produce the required growth of Al2O3 whiskers which are then allowed to cool.