(东北大学 冶金资源与环境工程研究所，沈阳110819)
摘 要: 以高钛渣、硅灰和高铝矾土熟料为原料，采用碳热还原氮化法合成TiN/O′-Sialon导电陶瓷粉体。利用XRD、SEM和EDS检测手段研究合成温度及恒温时间对粉体相组成和显微形貌的影响，并探讨合成机理。结果表明：随合成温度的升高和恒温时间的延长，产物中O′-Sialon的含量逐渐增加，并在1 375~1 400 ℃、恒温7 h时成为产物主晶相，此时产物中还有较多TiN和少量β′-Sialon生成。继续提高温度和延长反应时间，体系气氛的改变导致O′-Sialon迅速向β′-Sialon转化。合成粉体中O′-Sialon晶粒多呈等轴状，粒度约2 μm，TiN晶粒为细小粒状。此外，反应体系中还有大量白色β′-Sialon晶须状沉积物生成。
关键字: 高钛渣；碳热还原氮化；TiN/O′-Sialon；粉体；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
