Preparation of Ultrafine beta-Sialon Powder by Citrate Sol-Gel and Carbothermal Reduction Nitridation

摘要

Ultrafine beta-sialon powder is synthesized by citrate sol-gel and carbothermal reduction and nitridation (CRN) process. The presence of small amounts of beta-sialon as crystal seed can obviously accelerate the formation of final beta-sialon product and lower its formation temperature. The effects of nitriding temperature on the formation of the final beta-sialon are investigated. The mean particle size of the prepared beta-sialon powder is 100 - 150 nm. The beta-sialon precursor gel and the ultrafine beta-sialon powder are characterized by XRD, TG-DTA and SEM. The isoelectric point of ultrafine beta-sialon is pH 2.46.