(1. 北京科技大学 材料科学与工程学院，北京 100083；
2. 北京科技大学 冶金生态与工程学院，北京 100083；
3. 莱芜市能源监测站，莱芜 271100)
摘 要: 以醇盐水解−氨气氮化法在SiC颗粒表面包覆TiN，研究TiO2前躯体的种类、醇盐水解方式和加水量对水解反应生成的TiO2颗粒的粒径和分散性的影响，分析TiO2包覆层在不同氮化温度下的结构演变，重点对醇盐水解−氨气氮化反应的机理和TiN包覆层的形貌、物相组成和热稳定性进行讨论。结果表明：醇−水溶液加热法比沉淀法更容易获得均匀连续的TiO2包覆层，加水量是有效减少TiO2团聚颗粒的关键因素。TiO2包覆层在1 000 ℃于氨气中进行氮化能够完全转变为TiN，所得的TiN包覆层均匀连续，TiN颗粒的粒径为30~70 nm。在温度高于546 ℃时，TiN包覆层在空气气氛中容易发生氧化而导致稳定性降低。
关键字: 醇盐水解；表面涂层；复合粉末；TiN包覆SiC；热稳定性
（1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China;
3. Energy Monitoring Station of Laiwu, Laiwu 271100, China）
Abstract:TiN coated SiC powders were prepared by the method of controlled hydrolysis and subsequent nitridation with NH3 gas. The effects of the type of TiO2 precursor, the way of precipitation, the amount of water on particle size and the dispersibility of hydrolysis product of TiO2 were investigated. The structural evolution of the TiO2 coated layer under varied nitridation temperature was analyzed. The main focus was put on the mechanisms of controlled hydrolysis and subsequent nitridation and the characterization of the morphology, phase constitution and thermal stability of the obtained TiN coated SiC powders. The results indicate that hydrolysis of the uniform coating of TiO2 layer can be easily achieved by controlled hydrolysis than the precipitation method. The amount of the added water is the key factor to reduce the aggregation of TiO2. TiO2 film can be transformed completely to TiN after nitridation at the temperature of 1 000 ℃. The obtained TiN film is uniform and continuous. The sizes of TiN particles covering SiC powder are 30−70 nm. When the temperature is higher than 546 ℃, TiN film is easily oxidized in air and lost its stability.
Key words: controlled hydrolysis; surface coating; coated particle; TiN coated SiC; thermal stability
