选择性氮化法制备t-ZrO_2-TiN纳米复合粉体

SYNTHESIS OF t-ZrO_2-TiN COMPOSITE NANOPOWDERS BY SELECTIVE NITRIDATION

研究了在固溶体系中以选择性反应为基础的复合粉料制备技术。应用热力学原理分析计算了tZrO2TiO2固溶系统中,利用氨气进行的选择性氮化的反应条件,探讨了不同反应温度对该体系物相组成的影响。采用氨气还原氮化法,在流动的氨气氛下原位反应生成氮化钛,同时保持四方相氧化锆含量和结构不变。用比表面积测量和透射电镜观察,对纳米粉料在氮化前后的粒径和形貌进行表征。氮化后复合粉体中tZrO2的粒径为50～70nm。元素定量分析表明:氮化效果可达到98%以上。

A novel composite powder preparation technology based on selective reaction in solid solution was studied. The principle of thermodynamics was utilized to calculate the selective nitridation conditions with ammonia in a t-ZrO2-TiO2 solid solution system. The influence of reaction temperature on the phase structure was investigated. Titanium nitride was synthesized by ammonia reduction and nitridation under flowing ammonia atmosphere while the content and tetragonal phase structure of zirconia was unchanged. The average particle size and morphology of nanopowders before and after nitridation were characterized by specific surface area measurement and transmission electron microscopy. The particle size of t-ZrO2 is about 50-70 nm in the composite powders after nitridation. Elemental quantitative analysis indicates that the nitridation ratio reaches 98%.