摘要
采用真空加压浸渍法,在C/C多孔体中浸渍TaF5溶液制备TaC晶须。通过扫描电镜(SEM)观察TaC形貌,发现晶须呈单根或束状,且晶须光滑、平直,直径小于1μm。晶须头部的球状液滴表明其生长机理为气-液-固(V-L-S)机制,但反应过程中的球状液滴不是由催化剂与反应体系形成的共融球,而是生成TaC晶须的反应组元Ta2O5液滴,由TaF5高温水解生成。热解炭原子在单个或团簇的Ta2O5液滴中扩散生长出单根或束状的TaC晶须。
Tantalum carbide （TaC） whiskers were successfully synthesized by impregnating TaF5 solution into porous carbon/carbon （C/C） preform. Morphological observation shows that TaC whiskers are fairly smooth and straight, and their diameters are less than 1 μm. The spherical liquid droplets at the tips indicate TaC whiskers are developed by vapour-liquid-solid （VLS） growth mechanism. The liquid droplets are not the melt sphere resulted from the catalyzer and reactant but the spherical Ta2O5 liquid droplets, which hydrolyzed from TaF5. The formation of single or bundle TaC whiskers is involved with the diffusion of carbon atom in single or conglomeration of Ta2O5 liquid droplets.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2014年第1期39-43,共5页
Materials Science and Engineering of Powder Metallurgy
基金
湖南省自然科学青年基金项目(11JJ4045)
青年助推(2011QNZT045)
关键词
TaC晶须
制备
生长机理
TaC whiskers
preparation
growth mechanism
