(東北大學 冶金資源與環(huán)境工程研究所，沈陽110819)
摘 要: 以高鈦渣、硅灰和高鋁礬土熟料為原料，采用碳熱還原氮化法合成TiN/O′-Sialon導電陶瓷粉體。利用XRD、SEM和EDS檢測手段研究合成溫度及恒溫時間對粉體相組成和顯微形貌的影響，并探討合成機理。結果表明：隨合成溫度的升高和恒溫時間的延長，產物中O′-Sialon的含量逐漸增加，并在1 375~1 400 ℃、恒溫7 h時成為產物主晶相，此時產物中還有較多TiN和少量β′-Sialon生成。繼續(xù)提高溫度和延長反應時間，體系氣氛的改變導致O′-Sialon迅速向β′-Sialon轉化。合成粉體中O′-Sialon晶粒多呈等軸狀，粒度約2 μm，TiN晶粒為細小粒狀。此外，反應體系中還有大量白色β′-Sialon晶須狀沉積物生成。
關鍵字: 高鈦渣；碳熱還原氮化；TiN/O′-Sialon；粉體；合成
（Institute of Metallurgical Resources and Environmental Engineering, Northeastern University,
Shenyang 110819, China）
Abstract:Electroconductive TiN/O′-Sialon ceramic powders were synthesized by a carbothermal reduction-nitridation (CRN) method using high-titania slag, silicon fume and bauxite chalmette as the starting materials. The influences of synthesis temperature and holding time on the phase compositions and microstructures of the synthesized products were determined by XRD, SEM and EDS, and the synthesis mechanism was discussed. The results show that the content of O′-Sialon increases gradually with the increase of synthesis temperature and holding time. The content O′-Sialon reaches the maximum in the range of 1 375−1 400 ℃ at a holding time of 7 h, under which the crystalline phases also include TiN and small amount β′-Sialon. With further increase in the synthesis temperature and holding time, the atmosphere of the reaction system makes O′-Sialon rapidly converted to β′-Sialon. The equiaxed O′-Sialon grains are about 2 μm and fine TiN particles are observed in the synthesized powders. Moreover, a mass of the white whisker shape sediments appear on the surface of the samples and the inner wall of the crucible.
Key words: high titania slag; carbothermal reduction-nitridation (CRN); TiN/O′-Sialon; powders; synthesis
