(1. 北京科技大學(xué) 材料科學(xué)與工程學(xué)院，北京 100083；
2. 北京科技大學(xué) 冶金生態(tài)與工程學(xué)院，北京 100083；
3. 萊蕪市能源監(jiān)測站，萊蕪 271100)
摘 要: 以醇鹽水解−氨氣氮化法在SiC顆粒表面包覆TiN，研究TiO2前軀體的種類、醇鹽水解方式和加水量對水解反應(yīng)生成的TiO2顆粒的粒徑和分散性的影響，分析TiO2包覆層在不同氮化溫度下的結(jié)構(gòu)演變，重點對醇鹽水解−氨氣氮化反應(yīng)的機理和TiN包覆層的形貌、物相組成和熱穩(wěn)定性進行討論。結(jié)果表明：醇−水溶液加熱法比沉淀法更容易獲得均勻連續(xù)的TiO2包覆層，加水量是有效減少TiO2團聚顆粒的關(guān)鍵因素。TiO2包覆層在1 000 ℃于氨氣中進行氮化能夠完全轉(zhuǎn)變?yōu)門iN，所得的TiN包覆層均勻連續(xù)，TiN顆粒的粒徑為30~70 nm。在溫度高于546 ℃時，TiN包覆層在空氣氣氛中容易發(fā)生氧化而導(dǎo)致穩(wěn)定性降低。
關(guān)鍵字: 醇鹽水解；表面涂層；復(fù)合粉末；TiN包覆SiC；熱穩(wěn)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
