水解沉淀‒碳热还原氮化法制备碳氮化钛粉末

Synthesis of Ti(C,N)powders by hydrolysis precipitation‒carbothemal reduction and nitridation method

以四氯化钛、炭黑为原料,利用水解沉淀‒碳热还原氮化法制备了碳氮化钛粉末。利用差热分析、X射线衍射及扫描电镜等表征手段,研究了合成工艺对粉末物相、组成及形貌等的影响。结果发现:前驱体粉末经350℃煅烧2 h后,钛以TiO2的形式存在,TiO2与炭黑形成了混合均匀的团聚体;在碳热还原氮化反应时,钛氧化物向TiCxNyOz转变的温度范围为1200~1400℃;氮原子促进了钛氧化物向TiCxNyOz的转变,随着反应进一步进行,氧元素逐渐被碳、氮元素置换,形成TiCxNy固溶体;原料经1530℃还原4 h后,可合成氧质量分数0.3%、粒度~300 nm、化学式近似为TiC0.547N0.453的碳氮化钛粉末。

Ti(C,N)powders were synthesized by the hydrolysis precipitation‒carbothemal reduction and nitridation method,using TiCl4 and carbon black as the raw materials.The effects of synthesis technology on the Ti(C,N)powders were characterized by the differential thermal analysis,X-ray diffraction analysis,and scanning electron microscopy.In the results,after baking the precursor powders at 350℃for 2 h,the titanium atoms can only exist in a compound of TiO2,and a uniformly mixed aggregate of TiO2 and carbon black forms.The titanium oxide transforms into a complex compound of TiCxNyOz during the carbothermal reduction and nitridation process at 1200~1400℃.The nitrogen atoms accelerate the transformation processes from TiO2 to TiCxNyOz.As the reaction goes on,the oxygen atoms are gradually replaced by carbon and nitrogen atoms to form the solid solution of TiCxNy.The Ti(C,N)powders as the chemical formula of TiC0.547N0.453 are synthesized at 1530℃for 4 h with the oxygen mass fraction of 0.3%and the powder size of~300 nm.