This document summarizes research on the deposition of nickel/titanium nitride (Ni/TiN) composite coatings by plasma-assisted metal organic chemical vapor deposition using organometallic and metal-organic precursors. Titanium nitride coatings alone cannot be used for corrosion protection, so hybrid coatings with nickel are investigated. The researchers synthesized Ni/TiN films using dichlorobis(η5-cyclopentadienyl)titanium (IV) for titanium and N,N'-ethylene-bis(2,4-pentanedion-iminoato)nickel(II) for nickel as vapor sources in a nitrogen plasma environment. Characterization showed the films were nanocomposites
Simulation of curing process of carbon/epoxy composite during autoclave degas...Darkdragon766
Simulation of curing process of carbon/epoxy composite during
autoclave degassing molding by considering phase changes of epoxy
resin
Seong-Hwan Yoo a, b
, Min-Gu Han a
, Jin-Ho Hong a
, Seung-Hwan Chang a, *
a School of Mechanical Engineering, Chung-Ang University (CAU), 221, Huksuk-Dong, Dongjak-Gu, Seoul 156-756, Republic of Korea
b Korea Photonics Technology Institute Lighting Solution R&BD Center, Gwangju, Republic of Korea
Deactivation Modeling through Separable Kinetics of Coking On Ni/CZ Catalyst ...IOSR Journals
Abstract : Steam methane reforming (SMR) is a very significant technique to produce hydrogen from fossil fuels. In this particular work, nickel is used as the active metal and ceria-zirconia (CZ) bi-metallic oxide is used as the support. The foremost challenge to this process is sooting or coking over the catalyst surface and blocking the active sites. For the economic viability of the catalyst, it is very significant to make it coke deposition resistant. This is the reason that the kinetic modeling of the deactivation is very important. Therefore, this paper is aimed to model the deactivation and activity of the catalyst. A rate model of the deactivation process is also developed using separable kinetics. A comparison with commercial catalyst is also reported to show that the Ni/CZ catalyst is much more stable towards the coking. Keywords –Coking, Deactivation, Methane, Separable kinetics, Steam reforming.
Low Temperature Pyrolysis of Graptolite Argillite (Dictyonema Shale) in Autoc...IJERA Editor
The results of the systematic experimental study obtained in this work on the effects of temperature (340–420
°C) and exposure time (0–8h) at nominal temperature on the yield of pyrolysis products from Estonian
graptolite argillite (GA) generated in autoclaves without any solvent are described. The yields of solid residue
(SR), gas, pyrogenetic water (W) and extractable with benzenemix ofthermobitumen and oil (TBO) were
estimated. The compound groups of TBO were assessed. The highest yield of TBO, 2.18% on dry GA basis and
13.2% of organic matter (OM) was obtained at temperature of 420 °C and duration 0.5 h. The main compound
groups in TBO obtained at 400 ᵒC are polar hetero-atomic compounds and polycyclic hydrocarbons surpassing
45% and 30% of TBO. The shares of aliphatic and monocyclic hydrocarbons are below 15% of TBO. The yield
of W from GA is – about 10-15% of OM. The quantity of OM left in SR after pyrolysis is high, about 65% of
OM. The yield of pyrolysis products from GA and the composition of its TBO are compared with those obtained
under similar conditions from different oil shales: Estonian Kukersite, US Utah Green River, and Jordanian
Attarat.
Toxicity immobilization of refinery sludge containing heavy metals via vitrif...eSAT Journals
Abstract Heavy metals are known to be toxic to human and the environment. Despite the growing of petrochemical and refinery industries, the world is facing problems with the heavy metals contamination from the sludge by the industries. Many methods have been applied to address these issues from the refinery sludge. In this study, stabilization and solidification of refinery sludge containing heavy metals using vitrification method was utilized to solve this problem. The ashing temperature of 550oC was selected in preparing the ash of the dried sludge prior to the vitrification process at 1110oC to 1400oC. After vitrification, all samples were morphologically, thermally and toxically analyzed using Scanning Electron Microscopy, Thermogravimetric Analysis and Toxicity Characteristic Leaching Procedure. The sludge contained high amount of iron and aluminum, followed by some amount of magnesium, gold, arsenic and zinc with some traces of nickel and lead. Results showed that at maximum vitrified temperature of 1400oC, no magnesium, nickel and lead were detected in the sludge and only some traces of other heavy metals with less than 1 ppm. The vitrification method exhibits excellent output in immobilizing the transition metals leading to a reduction in environmental pollution caused by petrochemical and refinery sludge containing heavy metals. Index Terms: Vitrification, Heavy metals contamination, Refinery sludge, Toxicity, Leaching analysis
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Simulation of curing process of carbon/epoxy composite during autoclave degas...Darkdragon766
Simulation of curing process of carbon/epoxy composite during
autoclave degassing molding by considering phase changes of epoxy
resin
Seong-Hwan Yoo a, b
, Min-Gu Han a
, Jin-Ho Hong a
, Seung-Hwan Chang a, *
a School of Mechanical Engineering, Chung-Ang University (CAU), 221, Huksuk-Dong, Dongjak-Gu, Seoul 156-756, Republic of Korea
b Korea Photonics Technology Institute Lighting Solution R&BD Center, Gwangju, Republic of Korea
Deactivation Modeling through Separable Kinetics of Coking On Ni/CZ Catalyst ...IOSR Journals
Abstract : Steam methane reforming (SMR) is a very significant technique to produce hydrogen from fossil fuels. In this particular work, nickel is used as the active metal and ceria-zirconia (CZ) bi-metallic oxide is used as the support. The foremost challenge to this process is sooting or coking over the catalyst surface and blocking the active sites. For the economic viability of the catalyst, it is very significant to make it coke deposition resistant. This is the reason that the kinetic modeling of the deactivation is very important. Therefore, this paper is aimed to model the deactivation and activity of the catalyst. A rate model of the deactivation process is also developed using separable kinetics. A comparison with commercial catalyst is also reported to show that the Ni/CZ catalyst is much more stable towards the coking. Keywords –Coking, Deactivation, Methane, Separable kinetics, Steam reforming.
Low Temperature Pyrolysis of Graptolite Argillite (Dictyonema Shale) in Autoc...IJERA Editor
The results of the systematic experimental study obtained in this work on the effects of temperature (340–420
°C) and exposure time (0–8h) at nominal temperature on the yield of pyrolysis products from Estonian
graptolite argillite (GA) generated in autoclaves without any solvent are described. The yields of solid residue
(SR), gas, pyrogenetic water (W) and extractable with benzenemix ofthermobitumen and oil (TBO) were
estimated. The compound groups of TBO were assessed. The highest yield of TBO, 2.18% on dry GA basis and
13.2% of organic matter (OM) was obtained at temperature of 420 °C and duration 0.5 h. The main compound
groups in TBO obtained at 400 ᵒC are polar hetero-atomic compounds and polycyclic hydrocarbons surpassing
45% and 30% of TBO. The shares of aliphatic and monocyclic hydrocarbons are below 15% of TBO. The yield
of W from GA is – about 10-15% of OM. The quantity of OM left in SR after pyrolysis is high, about 65% of
OM. The yield of pyrolysis products from GA and the composition of its TBO are compared with those obtained
under similar conditions from different oil shales: Estonian Kukersite, US Utah Green River, and Jordanian
Attarat.
Toxicity immobilization of refinery sludge containing heavy metals via vitrif...eSAT Journals
Abstract Heavy metals are known to be toxic to human and the environment. Despite the growing of petrochemical and refinery industries, the world is facing problems with the heavy metals contamination from the sludge by the industries. Many methods have been applied to address these issues from the refinery sludge. In this study, stabilization and solidification of refinery sludge containing heavy metals using vitrification method was utilized to solve this problem. The ashing temperature of 550oC was selected in preparing the ash of the dried sludge prior to the vitrification process at 1110oC to 1400oC. After vitrification, all samples were morphologically, thermally and toxically analyzed using Scanning Electron Microscopy, Thermogravimetric Analysis and Toxicity Characteristic Leaching Procedure. The sludge contained high amount of iron and aluminum, followed by some amount of magnesium, gold, arsenic and zinc with some traces of nickel and lead. Results showed that at maximum vitrified temperature of 1400oC, no magnesium, nickel and lead were detected in the sludge and only some traces of other heavy metals with less than 1 ppm. The vitrification method exhibits excellent output in immobilizing the transition metals leading to a reduction in environmental pollution caused by petrochemical and refinery sludge containing heavy metals. Index Terms: Vitrification, Heavy metals contamination, Refinery sludge, Toxicity, Leaching analysis
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Thermo catalytic decomposition of methane over Pd/AC and Pd/CB catalysts for ...IJERA Editor
Hydrogen production studies have been carried using Thermo Catalytic Decomposition (TCD) Unit. Thermo catalytic decomposition of methane is an attractive route for COx free production of hydrogen required in fuel cells. Although metal based catalysts produce hydrogen at low temperatures, carbon formed during methane decomposition reaction rapidly deactivates the catalyst. The present work compares the results of 10 wt% Pd supported on commercially available activated carbon and carbon black catalysts (samples coded as Pd10/AC and Pd10/CB respectively) for methane decomposition reaction. Hydrogen has been produced by thermo catalytic decomposition of methane at 1123K and Volume Hourly Space Velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts has been studied. XRD of the above catalysts revealed, moderately crystalline peaks of Pd which may be responsible for the increase in catalytic life and formation of carbon fibers. Also during life studies (850°C and 54 sccm of methane) it has been observed that the activity of carbon black is sustainable for a longer time compared to that of activated carbon.
Phase Transformations and Thermodynamics in the System Fe2О3– V2О5 – MnО – Si...IJERA Editor
Thermodynamic characteristics in the system Fe2O3 – MnO – V2O5 –SiO2 have been investigated. Two mixtures
have been prepared. The first mixture was synthetic, prepared from pure oxides in proportion according to the
chemical composition of the waste catalyst and manganese concentrate. The second one contained the waste
vanadium catalyst and manganese concentrate. The synthetic mixture has been used as a standard in order to
establish the influence of impurities in the concentrate, and the waste catalyst on the thermodynamics of the
studied system.
Experiments carried out in the temperature up to 1473 K for the system containing waste vanadium catalyst and
manganese concentrate occur to formation of new phases formation as FeV2O4 and Iron Vanadium Oxide type
and Jacobsite types MnFe2O4 and (Mn6Fe4)(Mn4Fe1.6)O4. EMF method with difference reference electrode
(Ni/NiO, Mo/MoO2 and air) relationship of delta GoT = f(T) in the temperature range 1073 – 1173 К of mixtures
was obtained. The experimental data for the system show that the reference electrodes air and Ni/NiO are more
suitable than Mo/MoO2.
The obtained results will be used as an investigations base to the production of complex iron vanadium
manganese alloy using the waste materials.
Computational Analysis of CuO Nano Coolant in a Car RadiatorIOSRJMCE
Nanofluids are basically nanoparticles in base fluids. Nanofluids have unique features different from conventional solid-liquid mixtures in which nano sized particles of metals and nonmetals are dispersed. Due to improvement of mechanical properties, nanofluids are widely used in heat transfer industries. The coolant is used water-based, with the addition of glycols to prevent freezing and other additives to limit corrosion, erosion and cavitations. In this study 50-50 mixture of Ethylene Glycol with water (EGW) is tested and compared with another mixture by adding 2 percent Copper oxide (CuO). The geometric model of radiator is uploaded in Autodesk CFD software for its computational analysis. It is analyzed up to 100 iterations. Both the results are compared to find the improved heat transfer rate due to the addition of 2% CuO with Ethylene Glycol and water
Development of Nanocomposite from Epoxy/PDMS-Cyanate/Nanoclay for Materials w...IJMER
Dicyanate monomer viz bis-4-cyanato-polydimethylsiloxane(PDMS-CY) containing
siloxane known as thermally stable structural unit was prepared. The PDMS-CY/DGEBA-stability, thermal degradation kinetics and microstructures
Parameters Analysis of the Assisted Combustion of Residual Biodiesel Glycerol drboon
With the increased production of biodiesel, an excess of glycerol is being generated worldwide. One way to reduce the surplus of glycerol would be to use it as low calorific fuel in the own process of biodiesel production. However, being a high viscosity fuel with also high ignition point, its combustion requires severe control and monitoring due to the formation of the toxic pollutants. It is common practice mainly in developing countries to use biomass fuels in rural regions and it looks that with glycerol will not be different. The present article had as objective the construction of a simple chamber for the LPG assisted combustion of the biodiesel residual glycerol and the evaluation of all parameters related to the combustion itself. At a fixed mass flow of LPG different mass flows of glycerol were burnt and parameters such as O2, CO, CO₂, NOx, exhaust gases temperature, combustion efficiency and excess air were measured.
Effect of sintering time on the particle size and dielectric properties of La...ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Fabrication of ceramic matrix composite by using microwave energyIJARIDEA Journal
Abstract— Nowadays, ceramic matrix composites are being extensively used for industries and household
purposes. However, these ceramic composites materials are substantially resistant to biodegradation. In this
experimental study the specimen of silicon carbide with varying percentage of titanium carbide (TiC) has
been fabricated by using microwave sintering. Different samples having TiC 5%, 10%, 15% (wt%) were
prepared by die pressing. Then sample were heated in microwave furnace at different range of temperatures
i.e. 1150°C, 1250°C and 1350°. It was found that with increase in the weight percentage (wt %) of TiC, the
porosity was maximum in 1150°C and minimum porosity achieved maximum temperature 1350°C. The
maximum hardness was achieved in 1350°C when 15 wt % of TiC. Density was also increased with respect to
the increase in temperature and TiC wt %.
Keywords— Ceramic Matrix Composite; Hardness; Microwave Heating; SiC; TiC.
Reduction of cold start emissions in automotive catalytic converter using the...Asheesh Padiyar
Catalytic converters are used to convert harmful exhaust gases like CO, NOx and unburnt hydrocarbons released by
internal combustion engine of automobiles into less harmful gases like CO2, H2O and N2. During the start-up of engine run, catalytic converters suffer cold start problems as the catalyst does not remain active in cold conditions. This results in emission of unconverted harmful gases into the atmosphere. This work attempts to eliminate cold start problems using a heat storage system to keep the catalytic converter hot even under engine off conditions. A eutectic alloy of Mg-Zn-Al is used as the Phase Change Material (PCM) to store the heat around the catalyst. This alloy has high latent heat of fusion, high specific heat, suitable melting point and high thermal stability. Mg-Zn-Al eutectic alloy changes its state between liquid and solid on application and removal of heat. Thus this phase change material acts as a heat storage mechanism in the catalytic converter. Catalytic converter design also involves Rockwool insulation in order to aid longer heat storage. This thermal energy storage system as a combination of PCM and insulation, keeps the catalytic converter hot for several hours even after the engine is shut of
THERMAL ANALYSIS OF MANGANESE (II) BAKELITE COMPOSITES IAEME Publication
Manganese (II) Bakelite composites with variable salt concentration of MnCl2.4H2O were prepared. The composite samples were characterized by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). From the TGA and DSC, it was seen that there was beneficial effect of increasing salt concentration on thermal stability of the composite in comparison to pure Bakelite resin.
Thermo catalytic decomposition of methane over Pd/AC and Pd/CB catalysts for ...IJERA Editor
Hydrogen production studies have been carried using Thermo Catalytic Decomposition (TCD) Unit. Thermo catalytic decomposition of methane is an attractive route for COx free production of hydrogen required in fuel cells. Although metal based catalysts produce hydrogen at low temperatures, carbon formed during methane decomposition reaction rapidly deactivates the catalyst. The present work compares the results of 10 wt% Pd supported on commercially available activated carbon and carbon black catalysts (samples coded as Pd10/AC and Pd10/CB respectively) for methane decomposition reaction. Hydrogen has been produced by thermo catalytic decomposition of methane at 1123K and Volume Hourly Space Velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts has been studied. XRD of the above catalysts revealed, moderately crystalline peaks of Pd which may be responsible for the increase in catalytic life and formation of carbon fibers. Also during life studies (850°C and 54 sccm of methane) it has been observed that the activity of carbon black is sustainable for a longer time compared to that of activated carbon.
Phase Transformations and Thermodynamics in the System Fe2О3– V2О5 – MnО – Si...IJERA Editor
Thermodynamic characteristics in the system Fe2O3 – MnO – V2O5 –SiO2 have been investigated. Two mixtures
have been prepared. The first mixture was synthetic, prepared from pure oxides in proportion according to the
chemical composition of the waste catalyst and manganese concentrate. The second one contained the waste
vanadium catalyst and manganese concentrate. The synthetic mixture has been used as a standard in order to
establish the influence of impurities in the concentrate, and the waste catalyst on the thermodynamics of the
studied system.
Experiments carried out in the temperature up to 1473 K for the system containing waste vanadium catalyst and
manganese concentrate occur to formation of new phases formation as FeV2O4 and Iron Vanadium Oxide type
and Jacobsite types MnFe2O4 and (Mn6Fe4)(Mn4Fe1.6)O4. EMF method with difference reference electrode
(Ni/NiO, Mo/MoO2 and air) relationship of delta GoT = f(T) in the temperature range 1073 – 1173 К of mixtures
was obtained. The experimental data for the system show that the reference electrodes air and Ni/NiO are more
suitable than Mo/MoO2.
The obtained results will be used as an investigations base to the production of complex iron vanadium
manganese alloy using the waste materials.
Computational Analysis of CuO Nano Coolant in a Car RadiatorIOSRJMCE
Nanofluids are basically nanoparticles in base fluids. Nanofluids have unique features different from conventional solid-liquid mixtures in which nano sized particles of metals and nonmetals are dispersed. Due to improvement of mechanical properties, nanofluids are widely used in heat transfer industries. The coolant is used water-based, with the addition of glycols to prevent freezing and other additives to limit corrosion, erosion and cavitations. In this study 50-50 mixture of Ethylene Glycol with water (EGW) is tested and compared with another mixture by adding 2 percent Copper oxide (CuO). The geometric model of radiator is uploaded in Autodesk CFD software for its computational analysis. It is analyzed up to 100 iterations. Both the results are compared to find the improved heat transfer rate due to the addition of 2% CuO with Ethylene Glycol and water
Development of Nanocomposite from Epoxy/PDMS-Cyanate/Nanoclay for Materials w...IJMER
Dicyanate monomer viz bis-4-cyanato-polydimethylsiloxane(PDMS-CY) containing
siloxane known as thermally stable structural unit was prepared. The PDMS-CY/DGEBA-stability, thermal degradation kinetics and microstructures
Parameters Analysis of the Assisted Combustion of Residual Biodiesel Glycerol drboon
With the increased production of biodiesel, an excess of glycerol is being generated worldwide. One way to reduce the surplus of glycerol would be to use it as low calorific fuel in the own process of biodiesel production. However, being a high viscosity fuel with also high ignition point, its combustion requires severe control and monitoring due to the formation of the toxic pollutants. It is common practice mainly in developing countries to use biomass fuels in rural regions and it looks that with glycerol will not be different. The present article had as objective the construction of a simple chamber for the LPG assisted combustion of the biodiesel residual glycerol and the evaluation of all parameters related to the combustion itself. At a fixed mass flow of LPG different mass flows of glycerol were burnt and parameters such as O2, CO, CO₂, NOx, exhaust gases temperature, combustion efficiency and excess air were measured.
Effect of sintering time on the particle size and dielectric properties of La...ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Fabrication of ceramic matrix composite by using microwave energyIJARIDEA Journal
Abstract— Nowadays, ceramic matrix composites are being extensively used for industries and household
purposes. However, these ceramic composites materials are substantially resistant to biodegradation. In this
experimental study the specimen of silicon carbide with varying percentage of titanium carbide (TiC) has
been fabricated by using microwave sintering. Different samples having TiC 5%, 10%, 15% (wt%) were
prepared by die pressing. Then sample were heated in microwave furnace at different range of temperatures
i.e. 1150°C, 1250°C and 1350°. It was found that with increase in the weight percentage (wt %) of TiC, the
porosity was maximum in 1150°C and minimum porosity achieved maximum temperature 1350°C. The
maximum hardness was achieved in 1350°C when 15 wt % of TiC. Density was also increased with respect to
the increase in temperature and TiC wt %.
Keywords— Ceramic Matrix Composite; Hardness; Microwave Heating; SiC; TiC.
Reduction of cold start emissions in automotive catalytic converter using the...Asheesh Padiyar
Catalytic converters are used to convert harmful exhaust gases like CO, NOx and unburnt hydrocarbons released by
internal combustion engine of automobiles into less harmful gases like CO2, H2O and N2. During the start-up of engine run, catalytic converters suffer cold start problems as the catalyst does not remain active in cold conditions. This results in emission of unconverted harmful gases into the atmosphere. This work attempts to eliminate cold start problems using a heat storage system to keep the catalytic converter hot even under engine off conditions. A eutectic alloy of Mg-Zn-Al is used as the Phase Change Material (PCM) to store the heat around the catalyst. This alloy has high latent heat of fusion, high specific heat, suitable melting point and high thermal stability. Mg-Zn-Al eutectic alloy changes its state between liquid and solid on application and removal of heat. Thus this phase change material acts as a heat storage mechanism in the catalytic converter. Catalytic converter design also involves Rockwool insulation in order to aid longer heat storage. This thermal energy storage system as a combination of PCM and insulation, keeps the catalytic converter hot for several hours even after the engine is shut of
THERMAL ANALYSIS OF MANGANESE (II) BAKELITE COMPOSITES IAEME Publication
Manganese (II) Bakelite composites with variable salt concentration of MnCl2.4H2O were prepared. The composite samples were characterized by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). From the TGA and DSC, it was seen that there was beneficial effect of increasing salt concentration on thermal stability of the composite in comparison to pure Bakelite resin.
Electrospun Nanofibers Reinforced Aluminium Matrix Composites, A Trial to Imp...IJAMSE Journal
A comparison between TiO2 nanofibers and carbon nanofibers as fibers reinforced metal matrix composites with respect to mechanical properties improvements have been made in this paper. Al and Mg have been chosen as metal matrices. The used carbon and ceramic nanofibers (Titanium Oxide) were successfully synthesized using electrospinning technique. Various weight percentage of calcined
electrospun TiO2 and carbon nanofibers (1, 3, 5 and 10%) were mixed with metal matrix and fabricated by route of powder metallurgy using High Frequency Induction heat Sintering (HFIHS). Mechanical properties of the sintered composites have been investigated. The manufactured pellets were tested for compression test, hardness and microstructures by the field emission scanning electron microscopes (FESEM), which reveals the homogeneous distribution of nanofibers in the Al/Mg matrices. In addition,
energy-dispersive X-ray spectroscopy (EDS) was employed to obtain the chemical analysis of each composite. The result shows that, the ultimate compressive strength increased to 415 MPa at 5% TiO2, which is 13.5% more than the pure Al. The hardness increased up to 64% in case of using the ceramic nanofibers as reinforcement. While using CNFs as reinforcement to the Al matrix deteriorates the
mechanical properties.
We'd like to understand how you use our websites in order to improve them. Re...Pawan Kumar
The present work demonstrates for the first time the facile fabrication of TiO2 nanotube arrays (TNTAs) by a fluoride-free solid-state anodization process using LiClO4 containing solid polymeric electrolyte. The resulting nanotubes were tested for photoelectrochemical water splitting. The elimination of liquid electrolytes in electrochemical anodization constitutes a paradigm shift for the formation of nanoporous and nanotubular metal oxides. Our results open a new area of research that uses the distinctive properties of solid polymer electrolytes to achieve targeted doping and nano-morphologies. Characterization of the grown TNTAs indicated solid state anodized TNTAs to consist purely of the anatase phase of titania. The solid-state anodization process provides several advantages over conventional liquid electrolytes such as easy handling and processing, better charge transport, environmentally benign …
COMPARATIVE EMISSION ANALYSIS OF CNG AND OCTANE IN RETROFITTED CAR ENGINESIAEME Publication
Aluminium (Al) reinforced with Titanium Nitride (TiN) Metal Matrix composites find its application for elevated temperature operating conditions. 5, 10 and 15 weight percentage of TiN particles was added to aluminium to prepare the composite through powder metallurgy technique. The mixed powder was compacted at two compacting pressure of 250 MPa and 300 MPa to produce the specimens having h/d ratio in the range of 1.1 to 1.2. The specimens were sintered in nitrogen atmosphere at two different sintering temperatures of 4000C and 5000C with sintering time of 4 hours for each. Physical properties namely, green density, sintered density and mechanical properties such as hardness, compression strength and surface roughness were studied.
Thermal Barrier Coating For Gas Turbine EnginesNelsonkandulna
This presentation describes the thermal barrier coating process, its anatomy, types, material selection, failure, and characterization. Thermal barrier coatings (TBCs) were introduced to protect the external surface of gas turbine engine components from thermal resistance and thereby decrease the temperature of the metal surfaces. Yttria stabilized zirconia (YSZ) is one of the most popular and widely used TBC materials as it provides the best performance in high-temperature zones such as diesel engines and gas turbines. The columnar microstructure of YSZ coating provides excellent strain tolerance and adhesion to the coating. Gas turbines are used to power aircraft, trains, ships, electrical generators, pumps, gas compressors, and tanks.
The effect of functionalized carbon nanotubes on thermalmechanical performanc...IJRTEMJOURNAL
The new approaches for preparing nanocomposite coating by modificated carbon nanonotubes
(CNTs) and epoxy resin was done in the study. thermal-mechanical performance of nanocomposite coating was
investigated and the results were reported in this paper. The physic-chemical techniques such as Differential
scanning calorimetry (DSC) and Thermal gravimetric analysis (TGA) were used to characterize the thermal
performance of Epoxy nanocomposite coating. The test techniques for mechanical properties of paint coating as
adhesion, hardness, impact resistance and bending strength were employed in the work. The results indicated
that CNTs were dispersed in epoxy coating with only ratio of 0.1 wt% enhanced the Glass Transition
Temperature (Tg), decomposition temperature of epoxy coating and improved mechanical properties
significantly. Also functionalized CNTs can be reinforced thermal-mechanical of the epoxy coating better than
neat CNTs.
Similar to Deposition of ni ti n coatings by a plasma assisted mocvd using an organometallic precursor (20)
Dynamic and Equilibrium Studies on the sorption of Basic dye (Basic Brown 4) ...madlovescience
Dynamic and Equilibrium Studies on the sorption of Basic dye (Basic Brown 4) onto Multi-walled Carbon Nanotubes Prepared from Renewable Carbon Precursors
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
2. 200 Micro and Nanosystems, 2012, Vol. 4, No. 3
Arockiasamy et al.
an organo-metallic titanium complex as precursors.
However, for a successful deposition of thin films for
industrial applications using CVD, it is necessary to have a
precursor which is commercially available at a reasonable
price, has sufficient thermal stability and vapour pressure and
good shelf life. Therefore, the decomposition and thermal
stability of the precursor of Ti complex is also investigated.
2. EXPERIMENTAL PROCEDURES
2.1. Non-Isothermal TG/DTA of Ti Complex
Thermo-gravimetry (TG) was used to study the
decomposition pattern of Ti complex because it can throw
light on thermal stability, melting, decomposition and more
importantly volatility which is a primary condition for
chemical vapour deposition. TG was recorded in an inert
atmosphere like argon or nitrogen with a heating rate of
10°C min-1 to avoid oxidation of the complexes. The calcined
-alumina powder of even weight was used as the reference.
The dynamic TG runs on all the compounds were
recorded at a linear heating rate of 10oC/min using a thermoanalyser (Perkin-Elmer, Pyris-Diamond). High purity
nitrogen/argon (purity >99.99%) dried by passing through
refrigerated molecular sieves (Linde 4A) was used as the
purge gas. The complex was dried under vacuum with
anhydrous calcium chloride as a desiccant prior to the TG
runs. Sample weighing 1.579 mg was loaded in an -alumina
crucible (5m 5 mm x mm) and placed in the sample pan and
was subsequently dried in situ at 50oC for a few minutes to
remove adsorbed moisture, if any. The purpose of the runs
was to observe the mass loss steps besides identifying the
final temperature for attaining nil residue or constant weight
or decomposition pattern.
2.2. Vapour Pressure Measurement of Ti Complex
Prior to the deposition of the thin films using OMCVD,
vapour
pressure
measurement
of
dichlorobis( 5cyclopentadienyl)titanium (IV) or titanocene dichloride
(Ti(Cp)2Cl2) complex was carried out using the TG-based
transpiration technique. The block diagram of the thermoanalyser, modification for its functioning in the transpiration
mode, including precise flow calibration of the carrier gas,
using a capillary glass flow meter and corrections for
apparent weight losses in isothermal modes have been
described elsewhere [15]. The configuration of the thermoanalyser with horizontal dual-arm single-furnace has
eliminated/minimized the apparent weight changes caused
by temperature gradients, convection currents within the
furnace tube (made of alumina), buoyancy, thermomolecular drag and electrostatic effects. The arms of the
thermo-balance served as the temperature-cum-DTA sensors.
The calibration of the R-type thermocouple (Pt-13%Rh/Pt)
was carried out using the recommended melting point
standards (such as indium and tin) in order to make the Tscale of the balance conform to the International Practical
Temperature Scale 1968 (IPTS-68) amended in 1975.
o
o
Heating the furnace to 900 C at a rate of 15 C/min under
nitrogen gas at the purge rate of 12 dm3h-1 and then cooling
under the same conditions to near-ambient temperature
(about 40oC) was done for heat cleaning the furnace before
every vapour pressure measurement. Thereafter, the samples,
finely powdered using an agate mortar and pestle, weighing
in the range of 40-46 mg were spread out on a shallow
alumina crucible mounted for vapour pressure measurements
and was carefully flushed with nitrogen at a rate of 6 dm3h-1
at ambient temperature.
The initial heating to just below 10oC of the actual vapour
pressure measurement temperature for all the complexes was
rather rapid (10oC/min). After the stabilization of the
temperature, the complexes were heated at 2oC/min in steps of
10oC to the respective isothermal temperatures. The flow rate
of 6 dm3h-1 for nitrogen gas was employed to ensure
isothermal equilibrium vapourisation in all the isothermal
steps. The flow rates were monitored by a mass flow
controller (model-MKS, Type 1179A, USA). The accuracy of
the temperature measurements was adjusted to be better than
±0.05 K, using the recommended melting point standards
namely indium, tin and aluminium. The reproducibility of the
T-scale was assessed to be better than ±0.2 K.
2.3. Designing of Plasma Assisted CVD System
PAOMCVD was performed in a custom built dual wall
semi-cylindrical chamber made up of type 304 stainless steel
with an internal diameter of 430 mm and a height of 310 mm
(Fig. 1). The chamber of the PAOMCVD was evacuated
using a rotary pump (model VT-4012; Vacuum Techniques,
India) connected to one port and the electrical connection to
substrate heater and thermocouple were connected to the
other two ports. The port at the back was for the line which
carried the complex vapour and the other port at left was to
pass the by-pass gas. The two ports at the right hand side
were used to monitor the vacuum and air leaking
respectively. A pair of parallel plate circular electrodes of
diameter of 270 mm, made of stainless steel was used to
establish the symmetric reactor. The bottom grounded
electrode worked as a substrate holder as well. The diameter
of the substrate platform was large enough, so that 13 wafers
of 2 inch (50 mm) can be processed at a time. The heater
(halogen lamp of 800W) provided at the bottom of the lower
electrode served the purpose of heating the substrate.
Pulsed plasma source (ENI, RPG 50, 5000 W, USA)
connected to the upper electrode was used to sustain the
plasma in the reactor at 100 kHz with pulse time of 2976 ns.
The power of the plasma were varied by changing the
voltage and current. Four mass flow controllers (MFCS)
(MKS, type 1179A, USA) were used to control and monitor
(using four channel readout, MKS, type 247, USA) the flow
of various reactant gases like nitrogen, argon and hydrogen.
By-pass gas flow was attached with two 100g capacity
precursor tanks and a mixing chamber, which facilitated the
heating of precursors separately and mixing them in the
vapour phase prior to their entry into the CVD chamber.
Temperature controllers (Eurotherm) were used to
control/monitor the temperature of the substrate, precursor
chambers and vapour line by using K-type thermocouple.
2.4. Deposition and Characterization Methods
It is deemed as essential to optimize the process
parameters since they play a vital role in determining the
composition and properties of the thin film grown by CVD
[16]. Therefore, various process parameters such as chamber
pressure, substrate temperature, precursor chamber
3. Deposition of Ni/TiN Composite Coatings by a Plasma Assisted
Micro and Nanosystems, 2012, Vol. 4, No. 3
Substrates
Anode
By-Pass line
201
MFC4
View port
MFC3
Vapour line
HT Valve
Cathode
CVD Chamber
Mixing
Chamber
H2
Gas in
MFC1
Butterfly Valve
Valves
Ar
N2
PC1
MFC2
PC2
Precursor
Pellets
Cold
Trap
Rotary
Pump
Exhaust
Temperature-controlled
region
PC = Precursor Chamber
MFC = Mass Flow Controller
Fig. (1). Schematic diagram of the PA-MO(Organo Metallic)CVD system used in the present study.
temperature (based on the temperature of melting and
congruent sublimation of precursor), carrier gas flow rates,
pulsed plasma power, inter-electrode distance were
optimised by carrying out repeated trial and error
experiments for the deposition of Ni/TiN composite films.
The optimised deposition conditions for the coating of
Ni/TiN thin-films are summarized in Table 1.
The solid precursor of nickel, namely N,N’-ethylenebis(2,4-pentanedione-iminoato)nickel(II), Ni(acac)2en was
synthesized at the laboratory scale and was used for the
deposition of Ni/TiN thin film. The commercial grade
organo-metallic,
dichlorobis( 5-cyclopentadienyl)titanium
Table 1. Typical Growth Parameters for the Deposition of
Ni/TiN Nanocomposite Coatings using [Ti(Cp)2Cl2]
for Ti and Ni(acac)2en for Ni as Vapour Sources
Precursors for Ti
Cp2TiCl2
Precursors for Ni
Ni(acac)2en
Substrate temperature
550oC
Colour of the coating
Golden Yellow
Substrates
SS 316 and Silicon (100) oriented wafer
Pulsed DC voltage
201 V
Plasma current
150 mA
Electrode distance
45 mm
Base vacuum
220 x 10-3 mbar
Deposition pressure
0.5-1 mbar
Precursor chamber
temperature
150-250oC
Temperature of line heater
195-205oC
Gas flow rate
Carrier gas: nitrogen, 50sccm
By-pass gas: nitrogen, 200sccm
Deposition time
60 min
Growth rate
0.5<m
(IV), Ti(Cp)2Cl2 was used as titanium precursor. The choice
of Ti(Cp)2Cl2 as vapour source of titanium stems from the
fact that it does not contain any oxygen atom in its ligand
moiety and could be considered as a precursor of the
deposition of non-oxygen-based thin films of titanium. A
solid metallo-organic precursor was chosen for its thermal
stability, sufficient volatility, less toxicity and easy handling.
The silicon wafers with <100> orientation and
metallographically polished (with 0.2
m roughness)
stainless steel (SS) substrates were used after ultrasonic
cleaning by acetone and methanol. Substrates of dimension
of 10 mm 10 mmx0.5 mm were loaded in the chamber and
the chamber was evacuated to a base pressure of 30 10-3
mbar. After the initial evacuation of the CVD chamber, a
base pressure value of 1.2 10-1 mbar was obtained by
discharging nitrogen gas through the bypass line to strike the
plasma in the deposition zone. The temperature of the
substrate (Ts) was then increased slowly to the desired value
of 550oC at a heating rate of 12.5oCmin-1 and it was
maintained constant during the course of the complete
deposition process. When the temperature reached a value of
100oC, plasma was created in the chamber by applying high
voltage between the two electrodes. This helped in surface
etching of the substrates. After reaching the desired substrate
temperature of 550oC, the temperature of the line heater was
increased slowly and maintained in the range of 200-210oC
for most of the depositions. This followed the heating of the
precursor chambers. After reaching the vapour flow zone,
the rate of increase in the temperature was kept rather low in
order to ensure complete vapourisation and transportation of
precursors vapour continuously to the CVD chamber. This
helped in achieving uniform thin-film coating over the
substrates. After all the vapour was consumed, the supply of
carrier gas was stopped and the high temperature valve
(Swage Lock, SS-4BW) was closed to arrest vapour flow.
The flow through the by-pass was continued until the
samples were cooled down to room temperature in a reactive
plasma environment.
The thickness of the films was measured by SloanDektok-3010 surface profilometry. The deposited films were
4. 202 Micro and Nanosystems, 2012, Vol. 4, No. 3
Arockiasamy et al.
Fig. (2). Non-Isothermal TG/DTA of Ti(Cp)2Cl2 compound.
characterized by glancing incidence x-ray diffraction
(GIXRD) by employing STOE high-resolution X-ray
diffractometer with CuK ( = 1.5406 ) radiation and the
scan was performed in 2 mode over a 2 range of 20-80o.
For all the measurements, the angle of incidence of X-rays
was kept at 0.3o. The surface morphology of the films was
examined using a Philips XL-30 scanning electron
microscope equipped with an energy dispersive X-ray (EDX)
spectrometer.
3. RESULTS AND DISCUSSION
3.1. Thermal Analysis and Vapour Pressure Measurements of the Precursor
The compound bis( 5-cyclopentadienyl) titanium (II)
chloride, Ti(Cp2)Cl2 was found to satisfy almost all the
conditions for a ideal precursors [17, 18] and hence chosen
as the precursor for the deposition of Ni/TiN thin film using
CVD. The thermal analysis and vapour pressure
measurements of nickel complex namely, N,N’-ethylenebis(2,4-pentanedione-iminoato)nickel(II), Ni(acac)2en used
in the present investigation for the co-deposition of Ni/TiN
has been reported earlier from our group [19, 20].
The crucial test for any precursor is its thermal
characterization and hence Ti(Cp)2Cl2 was subjected to
thermal analysis. The recorded TG/DTA graph using a
horizontal dual arm single furnace thermo-analyser at a
heating rate of 10oC/min using high purity (99.99%) N2 as a
purge gas is produced in Fig. (2). The thermal behaviour of
Ti(Cp)2Cl2 as observed from Fig. (2) shows that the
compound is thermally stable up to a temperature of 191oC
and looses only 3% (0.5H2O), which could be ascribed to the
evaporation of adsorbed moisture and not due to the loss of
any component from the compound. It undergoes
vapourisation after melting at 267oC as evidenced by a small
endotherm in DTA. The melting temperature, volatility and
Table 2. Equilibrium Vapour Pressure of Titanium Compound
Against the Temperature
s. no
T (K)
W (mg)
Pe (Pa)
1
402.18
0.0048
0.011
2
412.44
0.0130
0.029
3
422.82
0.0249
0.058
4
433.21
0.0472
0.113
5
443.54
0.0983
0.242
6
454.01
0.2067
0.522
7
464.34
0.4513
1.166
8
474.92
0.8624
2.279
9
485.30
1.3444
3.631
10
495.64
1.8829
5.194
11
506.16
2.7060
7.623
the complete thermal history of this compound as the
precursor for CVD have been corroborated by the earlier
investigation [21] including its mass spectral study
confirming its molecular weight of 248Da. For a solid or
liquid compound to be really suitable for CVD, it should
exhibit thermal stability under a variety of ambient,
sufficient volatility and good gas phase transportability (visà-vis higher vapour pressure) [22, 23] for maintaining
adequate feed stock of the precursor.
In the present work, the vapour pressure measurement of
Ti(Cp)2Cl2 was carried out in the temperature range of 402485 K (129-212oC). The equilibrium vapour pressure (pe)
(Table 2) could be calculated using the following relation,
pe = WRT/MVc
(1)
derived from Dalton’s law of partial pressures for a mixture
of ideal gases, where W is the mass loss (mg) at temperature
5. Deposition of Ni/TiN Composite Coatings by a Plasma Assisted
Micro and Nanosystems, 2012, Vol. 4, No. 3
203
2.8
T (K)
402.18
412.44
422.82
433.21
443.54
454.01
464.34
474.92
485.30
485.64
506.16
2.4
Mass loss (mg)
2.0
1.6
1.2
0.8
0.4
0.0
0
10
20
30
40
50
60
Time (min)
Fig. (3). Plot of mass loss against isothermal time for each 1h holding during the vapour pressure measurement of Ti(Cp)2Cl2 compound.
2
R = 0.995
4.0
3.5
log pe
3.0
2.5
2.0
1.5
1.0
0.5
1.9
2.0
2.1
2.2
2.3
1000 K/T
2.4
2.5
2.6
Fig. (4). Clausius-Clapeyron plot for the Ti compound.
T(K) due to vapourisation, Vc (dm3) is the integral volume
of the carrier gas, R is the Gas constant (8.314 J mol-1 K-1)
and M (g mol-1) is the molar mass.
When the Eq. 1 is used, it is implied that only a single
metal precursor species is present in the vapour phase and
the congruent nature of vapourisation is confirmed by
TG/DTA under equilibrium condition. The monomeric
nature is confirmed by their mass spectral analysis [18].
Attainment of equilibrium conditions was evident from the
isothermal-time against mass loss plots (not exceeding 10%
of initial mass) at all the isothermal steps as seen from the
straight line plots (as shown in Fig. 3) passing through the
origin showing equal masses are vapourised in equal
intervals of time. The Clausius-Clapeyron plot of log (pe)
against the reciprocal temperature (1/T) is shown in Fig. (4).
The temperature dependence of pe could be represented
by the least squares expressions
log (pe/Pa) =(15.23±1.27)(A)–(5704.7±53.7)(B)/T(K) (402506 K)
(2)
Multiplying the slope (B) of the equation 2 by –2.303 R,
a value of 109.2 ± 5.6 kJ mol-1 could be derived for the
standard enthalpy of sublimation,
Hosub for the Ti
compound. A higher entropy of vapourisation and lower
enthalpy of sublimation would both contribute to higher
vapour pressure (e.g., pe = 7.62 Pa at 506 K) at constant
temperature as observed in the present investigation. The
higher value of sublimation enthalpy is an indicative of
moderate sublimation/volatilisation behaviour of any
compound. The sublimation studies are restricted to a
maximum temperature of 233oC (506 K). This restriction
stems from the fact that the values of pe approach the upper
periphery of applicability of the TG-based transpiration
technique which could not be fit into the linear regression
equation plot. The restriction in the temperature for both
6. 204 Micro and Nanosystems, 2012, Vol. 4, No. 3
Arockiasamy et al.
15
2
Intensity
10
0
T (2 0
iN 0 )
7
5
N (2 0
i 0)
5
0
T (4 0
iN 0 )
T (3 1
iN 1 )
N (3 1
i 1)
2
5
0
4
0
6
0
8
0
10
0
2th ta
e
Fig. (5). XRD pattern of Ni/TiN thin-film deposited on Si (100) substrate at 550oC; For TiN: JCPDS 381420 and Ni: JCPDS 040850.
Fig. (6). GIXRD of Ni/TiN thin film deposited at 550oC on Si (100) substrate.
vapour pressure measurement and for the deposition of films
by heating Ti(Cp)2Cl2 well below 280oC was also evident
from the fact that the complex releases HCl in the vapour
phase beyond 290oC [21].
3.2. Characterisation of Ni/TiN Thin Film
The conventional XRD and GIXRD patterns of Ni/TiN
composite thin film deposited under nitrogen plasma at a
substrate temperature of 550oC are shown in Figs. (5 and 6),
respectively, which reveal the crystalline film structure
indicated by the strong reflections from fcc phases TiN and
Ni. Both the patterns indicated the preferred orientation for
(200) reflection. Since the thickness of the films is ~500 nm,
we could not see any reflection from the substrate. Since
GIXRD could probe the surface of the film better, additional
peaks from metallic Ti was also seen. The observation of
TiN (200) textured orientation in the present investigation
could be due to the deposition of thin-films with higher
energy (but low temperature) produced by the electrons of
the plasma. This observation was corroborated by the
predominant formation of (200) orientation than (111) for
TiN, when deposited using ammonia and nitrogen plasma by
Weber et al. [24]. It is reported [25] that the microstructure
of Ni/TiN coatings deposited by magnetron sputtering has a
strong dependency for a bias voltage. At the higher bias
voltage (higher energy), there was a more rapid change of
orientation from (111) to (220) for TiN [25].
The size of the crystallite of Ni and TiN in the composite
Ni/TiN film was evaluated from the full width at half
maxima of the TiN (200) and Ni(200) peaks of the X-ray
diffraction using the Debye-Scherrer formula (D =
is the
0.9 / cos B, where D is size of the crystallite,
wavelength of the radiation used (in the present case CuK
of
= 0.15418 nm),
is the full width at half maxima
(FWHM) of the peak measured at the Bragg angle, B). It
must be noted that the calculation of crystallite size did not
take instrumental broadening and strain into consideration.
The Ni/TiN thin film deposited at 550 °C (Fig. 5) showed
crystallite sizes of 12.1nm for TiN(200) and 15.5 for
Ni(200).
7. Deposition of Ni/TiN Composite Coatings by a Plasma Assisted
Micro and Nanosystems, 2012, Vol. 4, No. 3
205
Fig. (7). SEM picture of Ni/TiN thin-film deposited at 550oC on Si(100) substrate in N2 plasma.
Fig. (8). EDX spectrum of Ni/TiN thin-film deposited at 550oC on Si (100) substrate.
The surface morphology and microstructure of thin films
depend closely on the deposition kinetics and substrate
temperature. The composite thin films of Ni/TiN were
analysed for their microstructure using SEM and EDX and
are shown in Figs. (7 and 8), respectively. The
microstructure analysis of the thin film confirms the densely
packed particles when deposited using high energy plasma at
550oC. It also reveals the nano-crystalline Ni/TiN grains
which are aggregated significantly. The EDX spectrum of the
composite film confirmed the chemical composition of the
thin films due to Ti, Ni and N only. Contamination of Cl in
the films was not noticed since the temperature of the
precursor chamber was maintained at about 290oC, a
temperature at which the compound could release HCl
vapour [21].
(a
linear
perfluoropolyalkylether
(PFPAE),
CF3O[CF2 CF2O]n-[CF2O]m-CF3; n/m=1.5) is a candidate oil
which can be operated at higher temperature, of 370oC [26],
but it chemically reacts with steel surfaces causing corrosion.
While surface chemistry controls the reactions between
PFPAE and TiN or Ni/TiN, the coating microstructure is also
extremely important for determining its protective capability.
A porous coating with columnar microstructure would
provide little protection [25]; fluid could penetrate the steel
surface and cause corrosion. A fully dense composite coating
with fine-grained microstructure would be the best to prevent
fluid penetration. Hence, the deposition of composite thinfilms using high energy plasma, which could enhance the
corrosion resistance nature of TiN has great industrial
importance.
The TiN hard coating is resistant to chemicals and is used
in aerospace turbine engines. Aircraft engines can be made
more efficient by operating at higher temperature. Fomblin Z
It must also mentioned that the strength and hardness of
the TiN thin-film could be increased by forming two-phase
nanostructure or multilayer thin-films, which help in
8. 206 Micro and Nanosystems, 2012, Vol. 4, No. 3
restricting the movement of dislocations. In multilayers,
dislocations are prevented from crossing from one layer to
the next by interfaces at layer thicknesses below a few nm
due to Kohler effect [27-31], which states that the dislocation
occurs from layers with higher elastic modulus at a layer
thickness below 10 nm [29, 30] or by a field of coherent
compressive/tensile stress originating from lattice
mismatches at layer thickness below 5 nm [30]. These
concepts were employed to increase hardness and toughness,
which was achieved in so-called super modulus [32] and
super lattice [33] multilayer coatings. Though no
nanomechanical properties have been reported in the present
work, it is proposed that the nanocomposite materials such as
Ni/TiN could be designed through the plasma assisted CVD
technique to create super hard coatings [34, 35]. Though
such coatings have been in practice by magnetron sputtering,
the present work provides a means to coat on objects with
irregular geometries and holes.
4. CONCLUSIONS
1.
2.
The Ni/TiN nanocomposite thin film deposited by
PAOMCVD showed the formation of fcc structured
TiN and Ni with (200) as the preferred orientation.
In the present investigation Ni/TiN film of about ~500
nm are obtained using the oxygen free precursor,
titanocene dichloride by using N2 plasma. This could
be ascribed to the efficiency of the plasma, in,
enhancing molecular dissociation and producing free
radicals to stimulate the chemical reactions in the
CVD chamber.
Arockiasamy et al.
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
3.
The particle sizes of the Ni and TiN in the thin film
are found to be 15.5 and 12.1 nm respectively.
[15]
4.
The titanium and nickel complexes exhibited
good/sufficient volatility to be used as precursors for
MO(OM)CVD. The titanium compound Ti(Cp)2Cl2
o
which was stable up to a temperature of 191 C with a
weight loss of about only 3% yielded a value of 109.2
± 5.6 kJ mol-1 for the standard enthalpy of sublimation
by a TG-based transpiration method.
[16]
[17]
CONFLICT OF INTEREST
The author confirms that this article content has no
conflicts of interest.
[18]
[19]
ACKNOWLEDGEMENT
Declared none.
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