| 摘要 |
<p>A process for preparing an alpha-phase silicon nitride material and thereafter converting to non-densified beta-phase silicon nitride material includes comminuting a slurry including a mixture of silicon powder and water to form fresh, non-oxidized surfaces on the silicon powder and to allow substantial chemical reaction between the silicon and the water, reducing the water content of the reacted slurry to a degree sufficient to form a resultant dry mass, nitriding the dry mass by exposure to a sufficient amount of a nitriding gas including at least nitrogen at a sufficient temperature for a sufficient length of time to form a mass of substantially alpha-phase silicon nitride, and converting the resultant silicon nitride mass at a conversion temperature of from about 1450 °C to about 2100 °C for a sufficient length of time to convert the silicon nitride from a predominantly alpha-phase material to a predominantly non-densified beta phase silicon nitride material.</p> |
