自然科学版 英文版
自然科学版 英文版
自然科学版 英文版

您目前所在的位置:首页 - 期刊简介 - 详细页面

中南大学学报(自然科学版)

Journal of Central South University

第36卷    第5期    总第165期    2005年10月

[PDF全文下载]    [Flash在线阅读]

    

文章编号:1672-7207(2005)05-0771-05
纳米V8C7粉末的制备
吴恩熙,颜练武,钱崇梁

(中南大学粉末冶金国家重点实验室,湖南长沙, 410083)

摘 要: 将V2O5溶解于有机酸溶液中,通过喷雾干燥制得非晶态含钒的粉末前驱体,将前驱体粉末还原/碳化后得到V8C7粉末。采用X射线衍射仪、扫描电镜、透射电镜、碳氧分析仪对工艺过程产品进行分析。结果表明:前驱体是粒度为10~20μm非晶态球形粉末,当温度升高到400℃时,前驱体粉末开始分解;当温度升高到600℃时,前驱体粉末全部转变为V2O3与游离C原子级别混合均匀的复合粉末;随着温度的升高,游离C还原碳化V2O3,当温度升高到800℃时,出现V4C3相;在约1 100℃时,得到相成分均一的V8C7粉末,其形貌是粒径为30~50 nm的一次颗粒形成的多孔空壳球形,其总C含量为17.38%,游离C含量为0.47%。前驱体粉末在加热过程中相成分转变过程为: V2O3→V4C3→V8C7,不经历V2O3转变为VO的过程。

 

关键字: 碳化钒;纳米;喷雾干燥;还原/碳化;晶粒抑制剂

Preparation of nanometer V8C7powder
WU En-xi, YAN Lian-wu, QIAN Chong-liang

State Key Laboratory of Powder Metallurgy, Central South University,
Changsha 410083, China

Abstract:Dissolving V2O5in organic acid solution, the amorphous powder precursor which contained vanadium was obtained by spray drying, and the nanometer V8C7powder was prepared through reduction/carbonization of the precursor powder. The technological process was investigated and analyzed using X-ray diffractometer, scanning electron microscope (SEM), transmission electron microscope (TEM) and carbon & oxygen analyzer. The results show that the precursor is amorphous spherical powder of 10 20μm. When the temperature rises to 400℃in vacuum, the precursor begins to decompose; when the temperature rises to 600℃, all the precursor powder is transformed into the composite powder in which V2O3 mixes with free carbon homogeneously atom-level; V2O3 is reduced and carbonized by free carbon with the temperature, and when the temperature goes up to 800℃, the V4C3phase occurs. At about 1 100℃, the V8C7 powder is obtained with single phase, and its morphology is of porous hollow sphere formed by many first particles of 30-50 nm. The total carbon content is 17.38% and the free carbon content is 0.47%.In the process of reduction/carbonization, the precusor powders undergo the following phase transformation: V2O3→V4C3→V8C7, without undergoing the process of phase transformation from V2O3into VO phase.

 

Key words: vanadium carbide; nanometer; spray dried; reduction/carburization; grain growth
inhibitor

中南大学学报(自然科学版)
  ISSN 1672-7207
CN 43-1426/N
ZDXZAC
中南大学学报(英文版)
  ISSN 2095-2899
CN 43-1516/TB
JCSTFT
版权所有:《中南大学学报(自然科学版、英文版)》编辑部
地 址:湖南省长沙市中南大学 邮编: 410083
电 话: 0731-88879765 传真: 0731-88877727
电子邮箱:zngdxb@csu.edu.cn 湘ICP备09001153号