PTFE促发TiC陶瓷粉体低温固相合成研究

doi:10.15541/jim20140307

摘要/Abstract

摘要：

在Ti-C体系中引入PTFE(聚四氟乙烯树脂)作为反应促进剂, 实现了TiC粉体的低温固相合成。分别利用热分析仪、X-射线衍射仪和场发射扫描电子显微镜, 测定了体系的反应温度, 表征了生成物的物相和微观形貌, 并对其反应过程和反应机理进行了分析。结果表明: 当添加3wt% PTFE时, 能够在530℃通过燃烧合成制备平均粒径小于100 nm的TiC陶瓷粉体, 接近于利用Scherrer 公式取XRD最强衍射峰计算出的平均晶粒尺寸81 nm, 可以推测所合成的TiC颗粒为单晶颗粒。燃烧合成过程分为两个步骤: 首先, 在低温下PTFE和Ti发生反应并释放出大量的热; 然后, 诱发Ti和C的固相反应生成TiC。

关键词: TiC, 燃烧合成, PTFE, 反应机理

Abstract:

TiC powders were prepared at low temperature from the Ti-C system with polytetrafluoroethylene (PTFE) as a chemical activator. The reaction temperature, phase composition and morphology were determined via differential scanning calorimetry (DSC), X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) to explore the reaction mechanism, respectively. The FESEM result shows that TiC powders with average particle size less than 100 nm are synthesized via low-temperature combustion synthesis at 530 ℃ by adding 3wt% PTFE into Ti-C system. Based on the most intensive diffraction peak (200) of the XRD pattern, the crystallite size of prepared TiC powders is calculated to be about 81 nm by the Scherrer formula, which is close to the average particle size observed from the FESEM image. It indicates that TiC particles consist of a single crystal as the result of fast, low-temperature, solid-state synthesis process. According to DSC results, the combustion synthesis mainly includes two reaction processes. Firstly, the initial reaction between titanium and PTFE particles releases a great amount of heat, and subsequently, the heat induced combustion reaction between titanium and carbon particles.

Key words: TiC, combustion synthesis, PTFE, reaction mechanism

中图分类号:

TQ174

鱼银虎, 汪涛, 张洪敏, 张度宝, 潘剑锋. PTFE促发TiC陶瓷粉体低温固相合成研究[J]. 无机材料学报, 2015, 30(3): 272-276.

YU Yin-Hu, WANG Tao, ZHANG Hong-Min, ZHANG Du-Bao, PAN Jian-Feng. Low Temperature Combustion Synthesis of TiC Powder Induced by PTFE[J]. Journal of Inorganic Materials, 2015, 30(3): 272-276.

图/表 5

图1 TiC的二元平衡相图

Fig. 1 Binary equilibrium phase diagram of TiC

图2 不同PTFE含量下Ti-C体系在530℃反应产物的XRD图谱

Fig. 2 XRD patterns of the products from Ti-C system with different PTFE contents prepared at 530℃ (a) 0; (b) 1wt%; (c) 2wt%; (d) 3wt%; (e) 4wt%

图3 添加3wt% PTFE 的Ti-C体系在530℃反应并经500℃空气处理1 h后产物的XRD图谱

Fig. 3 XRD pattern of the products from Ti-C system with 3wt% PTFE prepared at 530℃ and removed the free carbon

图4 添加3wt% PTFE 的Ti-C体系在530℃反应产物的FESEM形貌

Fig. 4 FESEM micrograph of the products from Ti-C system with 3wt% PTFE and without prepared at 530 ℃ carbon

图5 不同PTFE含量的Ti-C体系的DSC曲线

Fig. 5 DSC curves of Ti-C systems with different PTFE contents (a) 0; (b) 1wt%; (c) 2wt%; (d) 3wt%; (e) 4wt% PTFE

参考文献 25

[1]	XING Y, DENG J, ZHAO J, et al.Cutting performance and wear mechanism of nanoscale and microscale textured Al2O3/TiC ceramic tools in dry cutting of hardened steel.Int. J. Refract. Met. Hard Mater., 2014, 43: 46-58.
[2]	PIERSON H O.Handbook of Refractory Carbides and Nitrides: Properties, Characteristics, Processing and Applications. New Jersey: Noyes, 1996.
[3]	WEIMER A W.Carbide, Nitride and Boride Materials Synthesis and Processing. London: Chapman & Hall, 1997.
[4]	SEN W, SUN H, YANG B, et al.Preparation of titanium carbide powders by carbothermal reduction of titania/charcoal at vacuum condition.Int. J. Refract. Met. Hard. Mater., 2010, 28(5): 628-632.
[5]	MISHRA S K, DAS S, GOEL R P, et al.Self-propagating high temperature synthesis (SHS) of titanium carbide.J. Mater. Sci. Lett., 1997, 16(12): 965-967.
[6]	CETINKAYA S, EROGLU S.Chemical vapor deposition of carbon on particulate TiO2 from CH4 and subsequent carbothermal reduction for the synthesis of nanocrystalline TiC powders.J. Eur. Ceram. Soc., 2011, 31(5): 869-876.
[7]	ZHANG H J, LI F L, JIA Q L, et al.Preparation of titanium carbide powders by Sol-Gel and microwave carbothermal reduction methods at low temperature.J. Sol-Gel Sci. Technol., 2008, 46(2): 217-222.
[8]	YIN F S, ZHOU L, XU Z F, et al.Synthesis of nanocrystalline titanium carbonitride during milling of titanium and carbon in nitrogen atmosphere.J. Alloys Compd., 2009, 470(1/2): 369-374.
[9]	PAN J S, CAO R X, YUAN Y W.A new approach to the mass production of titanium carbide, nitride and carbonitride whiskers by spouted bed chemical vapor deposition.Mater. Lett., 2006, 60(5): 626-629.
[10]	NERSISYAN H H, NIKOGOSOV V N, KHARATYAN S L, et al.The chemical mechanism of transformations and combustion in the Si-C-teflon system.Fiz. Goreniya Vzryva, 1991, 27(6): 77-81.
[11]	ABOVYAN L S, NERSISYAN H H. KHARATYAN S L, et al.Synthesis of alumina-silicon carbide composites by chemically activated self-propagating reactions.Ceram. Int., 2001, 27(2): 163-169.
[12]	HAMBARTSUMYAN A A, KHACHATRYAN H L, KHARATYAN S L.Mechanically and chemically activated SHS in the Mo-Si-C system: synthesis of MoSi2-SiC composites.Inter. J. SHS, 2007, 16(2): 87-91.
[13]	ZURNACHYAN A R, KHARATYAN S L, KHACHATRYAN H L, et al.Self-propagating high temperature synthesis of SiC-Cu and SiC-Al cermets: role of chemical activation.Int. J. Refract. Met. Hard Mater., 2011, 29(2): 250-255.
[14]	MANUKYAN K, VARDAN D, YEVAET G, et al.Phase formation mechanism of the Ni-Zr-polytetrafluoroethylene reactive mixture.J. Therm. Anal. Calorim., 2012, 110(2): 619-623.
[15]	BAGHDASARYAN A M, HOBOSYAN M A, KHACHATRYAN H L, et al.The role of chemical activation on the combustion and phase formation laws in the Ni-Al-promoter system.Chem. Eng. J., 2012, 188(0): 210-215.
[16]	LEE I, REED R R, BRADY V L, et al.Energy release in the reaction of metal powders with fluorine containing polymers.Therm. Anal. Calorim., 1997, 49(3): 1699-1705.
[17]	KUWAHARA T, MATSUO S, SHINOZAKI N.Combustion and sensitivity characteristics of Mg/TF pyrolants.Propell. Explos. Pyrotech., 1997, 22(4): 198-202.
[18]	BINNEWIES M, MILKE E.Thermochemical data of elements and compounds, 2nd ed. Weinheim: Wiley-VCH, 2002: 505.
[19]	LICHERI R, ORRU R, CAO G.Chemically-activated combustion synthesis of TiC-Ti composites.Mater. Sci. Eng. A, 2004, 367(1/2): 185-197.
[20]	戴永年. 二元合金相图. 北京: 科学出版社, 2009.
[21]	LEE W C, CHUNG S L.Ignition phenomena and reaction mechanisms of the self-propagating high-temperature synthesis reaction in the Ti+C system.J. Mater. Sci., 1995, 30(6): 1487-1494.
[22]	BARIN I.Thermochemical Data of Pure Substances, third ed. Weinheim: VCH, 1995.
[23]	KOCH E C.Metal-fluorocarbon Based Energetic Materials. Weinheim: John Wiley & Sons, 2012.
[24]	殷声. 燃烧合成. 北京:冶金工业出版社, 1999.
[25]	DUNMEAD S D, READEY D W, SEMLER C E, et al.Kinetics of combustion synthesis in the Ti-C and Ti-C-Ni systems.J. Am. Ceram. Soc., 1989, 72(12): 2318-2324.