Carbon Nanofibers from Pyrolysis Flame and Research on the Affecting Factors

2009 ◽  
Vol 87-88 ◽  
pp. 98-103
Author(s):  
Yuan Chao Liu ◽  
Bao Min Sun ◽  
Ti Kun Shan ◽  
Zhao Yong Ding
Keyword(s):  
Stainless Steel ◽  
Electron Microscope ◽  
Austenitic Stainless Steel ◽  
Carbon Nanofibers ◽  
Experimental System ◽  
Average Diameter ◽  
Sampling Time ◽  
Catalyst Precursor ◽  
Affecting Factors ◽  
Flame Burner

Synthesis of carbon nanofibers from the V-type pyrolysis flame is a new method and it has wide application prospects. It needs simple laboratory equipments and normal atmosphere pressure. The V-type pyrolysis flame experimental system is introduced, involving V-type pyrolysis flame burner, mass flux controllers, sampling substrate etc. The carbon nanofibers were characterized by scanning electron microscope and transmission electron microscope. Carbon nanofibers with less impurities and high quality can be captured when the temperature was from 800 to 880°C, austenitic stainless steel type304 was served as sampling substrate, nickel nitrate was served as catalyst precursor and sampling time was 5 minutes. The carbon nanofibers are from 100 to 200 nm in diameter and dozens microns in length. The average diameter of catalyst particles is approximately from 20 to 50 nm. The effects of temperature, sampling substrate materials, sampling time and catalyst were analyzed. The temperature determined the diameter and shape of carbon nanofibers. The austenitic stainless steel type304 substrate containing nickel is in favor of synthesis of carbon nanofibers. The number of carbon nanofibers got more and more while the diameter got thicker firstly and then had little change with the sampling time increased within 5 minutes. In addition, experimental results also indicated that carbon nanofibers had much impurity and worse morphology if the diameter of catalyst particles was above 50nm.

Influence Analysis of Sampling Time for Synthesis of Carbon Nanotubes in the V-Type Pyrolysis Flame

2011 ◽  
Vol 221 ◽  
pp. 235-239 ◽  
Author(s):  
Yuan Chao Liu ◽  
Bao Min Sun ◽  
Zhao Yong Ding
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Experimental System ◽  
Growth Period ◽  
Sampling Time ◽  
High Yield ◽  
Spray Pyrolysis Method ◽  
Transmission Electron ◽  
Novel Method ◽  
Synthesis Of Carbon Nanotubes

Synthesis of carbon nanotubes from V-type pyrolysis flame is a kind of novel method. It needs simple laboratory equipments and normal atmosphere pressure. The V-type pyrolysis flame experimental system is introduced. Carbon source is the carbon monoxide and heat source is from acetylene/air premixed flame. Pentacarbonyl iron, served as catalyst, is transported by spray- pyrolysis method into the flame. The carbon nanotubes were characterized by scanning electron microscope and transmission electron microscope. This study aims to find the formation rule of carbon nanotubes from the V-type pyrolysis flame in different sampling times. The carbon nanotubes with less impurity and high yield were captured successfully in the V-type pyrolysis flame. The diameter of carbon nanotubes was approximate between 10nm and 20nm, and its length was dozens of microns. When the sampling time was below 3 minutes, the growth of carbon nanotubes came into the preparation growth period. The length of the carbon nanotubes increased gradually and the diameter had no obvious change with the extension of sampling time. When the sampling time was continued to the 5th minute, the growth of carbon nanotubes came into the exuberant growth period. The carbon nanotubes growth was finished within 5minutes. Longer sampling time was meaningless after the carbon nanotubes formation.

Carbon Nanotubes Grown by Ethanol Catalytic Combustion with an Additive of Thiophene

2010 ◽  
Vol 123-125 ◽  
pp. 627-630
Author(s):  
Cui Liu Wei ◽  
Xiao Ping Zou ◽  
Jin Cheng ◽  
Zhao Xian Yu ◽  
Gang Qiang Yang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Stainless Steel ◽  
Carbon Source ◽  
Carbon Nanofibers ◽  
Catalytic Combustion ◽  
Combustion Method ◽  
Catalyst Precursor ◽  
Simple Method ◽  
Great Yield

Combustion method is a simple method to synthesize carbon nanotubes(CNTs), which employs flames of carbon-contained reactant to synthesize CNTs. It has been proved that combustion method is an effective method to synthesize carbon nanotubes and carbon nanofibers. In this paper, we reported the synthesis of CNTs by using ethanol catalytic combustion with an additive of thiophene, which employed ethanol as carbon source and fuel, nitrate as catalyst precursor, stainless steel as substrate, and thiophene as accelerant. Compared with previous reports on the synthesis of CNTs by ethanol catalytic combustion, great yield of CNTs were obtained with adding thiophene in ethanol. The reproducibility of the synthesis of CNTs in the case of adding thiophene in ethanol was greatly improved.

scholarly journals Microstructure and Microhardness of ZrO2 Reinforced PM 316L Austenitic Stainless Steel Composites Sintered in Ambient and Argon Atmosphere

2019 ◽  
Vol 8 (6) ◽  
pp. 38-42
Keyword(s):  
Stainless Steel ◽  
Electron Microscope ◽  
Austenitic Stainless Steel ◽  
Testing Machine ◽  
Argon Atmosphere ◽  
Steel Matrix ◽  
Matrix Composites ◽  
Hardness Testing ◽  
316L Austenitic Stainless Steel ◽  
Scanning Electron

The present study examines the microstructure and microhardness of zirconia (ZrO2) reinforced PM 316L austenitic stainless steel matrix composites. ZrO2 was added in a proportion of 1 wt% to 3 wt%. Powders were compacted into a disc of 11mm diameter and 2mm thick at 70kN. Compacts were sintered in an ambient and argon atmosphere at 1250oC for 30 minutes. Sintered compacts were then analyzed for microhardness using Vickers hardness testing machine, and microstructure was examined using a scanning electron microscope. The study revealed that the reinforcement of ZrO2 significantly enhanced the microhardness of PM 316L SS matrix composites with a microstructure consisting of irregular porosity and zirconia encapsulating the 316L SS particles.

Effect of Ce on Microstructure and Mechanical Properties of 21Cr-11Ni Austenitic Stainless Steel

2013 ◽  
Vol 711 ◽  
pp. 95-98
Author(s):  
Xiao Liu ◽  
Jing Long Liang
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Electron Microscope ◽  
Austenitic Stainless Steel ◽  
Scanning Electron Microscope ◽  
Tensile Test ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Metallographic Examination ◽  
Scanning Electron

The effect of Ce on structure and mechanical properties of 21Cr11Ni austenitic stainless steels were studied by metallographic examination, scanning electron microscope (SEM), tensile test. The results show that the proper amount of Ce can refine microstructure of austenitic stainless steel. Fracture is changed from cleavage to ductile fracture by adding Ce to austenitic stainless steel. 21Cr11Ni stainless steel containing 0.05% Ce can improve its high temerature strength, and the strength is increased 21.81% at 1073K respectively comparing with that of 21Cr11Ni stainless steel without Ce.

Recrystallisation Characteristics of Cold Rolled Austenitic Stainless Steel during Repeated Annealing

2013 ◽  
Vol 753 ◽  
pp. 157-162 ◽  
Author(s):  
B. Ravi Kumar ◽  
Sailaja Sharma
Keyword(s):  
Stainless Steel ◽  
Electron Microscope ◽  
Austenitic Stainless Steel ◽  
High Speed ◽  
Annealing Process ◽  
Electron Backscattered Diffraction ◽  
Kikuchi Pattern ◽  
Ultrafine Grained ◽  
316L Austenitic Stainless Steel ◽  
Cold Rolled

The aim of the present study was to understand recrystallisation behaviour of a cold rolled AISI 316L austenitic stainless steel when annealed repetitively for short durations. The results were compared with isothermal annealing process. The evolving microstructure was examined by electron microscope. Electron backscattered diffraction was performed in a FEI NANO SEM 430 Field Emission Gun scanning electron microscope using an EDAX/TSL high-speed Digiview camera for Kikuchi pattern acquisition. Also progress of recrystallisation was assessed by hardness measurements at different annealing conditions. The study revealed distinct differences in the progress of recrystallisation of repeated and isothermally annealed specimens. Also the formation of ultrafine grained microstructure by repeated annealing process was noted.

Aging Precipitation Evolving Process and its Effects on Mechanical Properties of 0Cr21Ni6Mn9N Austenitic Stainless Steel

2015 ◽  
Vol 816 ◽  
pp. 255-261
Author(s):  
Na Yun Jiang ◽  
Fu Shun Liu
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Electron Microscope ◽  
Austenitic Stainless Steel ◽  
Aging Time ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Precipitation Process ◽  
Second Phase ◽  
Aging Precipitation

The solution treatment (ST) and the the second phase morphology changing duing the aging precipitation process of 0Cr21Ni6Mn9N austenitic stainless steel were investigated using optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) with EDS and transmission electron microscope (TEM). The results showed that the precipitation phase was Cr2N which initially nucleated along austenitic grain boundaries and then grew towards into the inner grains in strip morphology. Also, with the longer aging time the proportion of Cr2N increased. The mechanical properties of alloys with and without the presence of the precipitation Cr2N were also studied. It was observed that due to the exiting of the precipitation Cr2N, the strength of 2169N stainless steel reduced during a certain range of aging time, and then improved when the aging time reached to 48h, while the elongation decreased thoroughly.

The Characteristic of Surface Layers on Austenitic Stainless Steel after Glow-Discharge Nitriding Process

2010 ◽  
Vol 165 ◽  
pp. 165-168 ◽  
Author(s):  
Artur Sitko ◽  
Marek Szkodo ◽  
Maria Gazda
Keyword(s):  
Stainless Steel ◽  
Electron Microscope ◽  
Austenitic Stainless Steel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
X Ray ◽  
Diffusion Layers ◽  
Chemical Constitution ◽  
Scanning Electron

This paper presents investigation of surface layers. The diffusion layers were produced by using different parameters of reactive atmosphere (N2:H2). The research of the surface layers was performed using scanning electron microscope (SEM). The results of energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) analysis are presented. Research reveals the influence of chemical constitution of reactive atmosphere on the change of properties of nitrided layers.

Preparation and Characterization of Carbon Nanofibers from the High Temperature Controllable Flame

2014 ◽  
Vol 1033-1034 ◽  
pp. 1086-1089
Author(s):  
Yuan Chao Liu ◽  
Li Zhi Wu ◽  
Jing Hao Ren
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Carbon Source ◽  
Carbon Nanofibers ◽  
Carbon Nanofiber ◽  
Synthesis Methods ◽  
Source Characterization ◽  
Experimental Apparatus ◽  
Flame Burner

Carbon nanofiber is a new type of carbon materials and it has wide application prospects. At present, there are many kinds of synthesis methods of carbon nanofibers. Among them, preparation of carbon nanofibers from the controllable flame is a new method. It needs simple laboratory equipments and normal atmosphere pressure in this method. Experimental apparatus is including controllable flame burner, thermocouple, mass flow meter and catalyst preparation system, etc. The key factors of synthesis experiment involving the carbon source, the catalyst and high temperature heat source. Characterization of the carbon nanofibers from the controllable flame is by scanning electron microscope (SEM) and transmission electron microscope (TEM).The experimental results indicated that carbon nanofibers with less impurity can be captured at the temperature from 720 to 880 ̊C when carbon monoxide and iron-based catalyst served as carbon source and the catalyst respectively.

Influence of Catalyst for Synthesis of Carbon Nanofibers from the Flame

2011 ◽  
Vol 236-238 ◽  
pp. 1658-1661
Author(s):  
Yuan Chao Liu ◽  
Bao Min Sun
Keyword(s):  
Electron Microscope ◽  
Carbon Nanofibers ◽  
Growth Process ◽  
Carbon Nanofiber ◽  
Experimental System ◽  
Catalyst Particle ◽  
Formation Condition ◽  
Catalyst Particle Size ◽  
Transmission Electron ◽  
Catalyst Formation

Carbon nanofibers synthesis from the flame is a new method. The method needs simple laboratory equipments and normal atmosphere pressure. The experimental system is introduced. Carbon source is the carbon monoxide and the nitric acid nickel is served as catalyst. The carbon nanofibers were characterized by scanning electron microscope and transmission electron microscope. Carbon nanofibers with less impurity were captured successfully in the flame. The diameter of carbon nanofibers was approximate from one to two hundred nanometers, and its length was dozens of microns. The growth process and mechanism of carbon nanofiber from the flame is very complicated. The influence of catalyst can reveal the growth mechanism of carbon nanofiber. This study aims to examine the catalyst formation condition for carbon nanofibers in pyrolysis flame and to characterize the morphology. Carbon nanofibers with less impurity can be prepared when the diameter of catalyst in is between twenty and thirty nanometers. The catalyst particle size can determine the morphology of carbon nanofibers.

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