共查询到20条相似文献,搜索用时 46 毫秒
1.
T. S. Sidhu A. Malik S. Prakash R. D. Agrawal 《Journal of Thermal Spray Technology》2007,16(5-6):844-849
The present work evaluates the oxidation and hot corrosion resistance of high velocity oxy-fuel (HVOF) sprayed WC-NiCrFeSiB
coating deposited on Ni-based superalloy (Superni 75) and Fe-based superalloy (Superfer 800H). The coated as well as uncoated
specimens were exposed to air and molten salt (Na2SO4-25% NaCl) environment at 800 °C under cyclic conditions. The thermogravimetric technique was used to establish the kinetics
of corrosion. The corrosion products were characterized using the combined techniques of x-ray diffraction (XRD), scanning
electron microscopy (SEM), and electron probe micro analyser (EPMA). The WC-NiCrFeSiB coating provides necessary resistance
against oxidation and hot corrosion to both the nickel and iron-based superalloys in the given environmental conditions at
800 °C. The oxides of active elements of the coatings, formed in the surface scale as well as at the boundaries of nickel
and tungsten rich splats, have contributed for the oxidation and hot corrosion resistance of WC-NiCrFeSiB coatings, as these
oxides act as barriers for the diffusion/penetration of the corrosive species through the coatings.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
2.
Thermal spraying is a widely used technology for industrial applications to provide coatings that improve the surface characteristics.
According to the specificities of processes (APS, VPS, flame, electric arc), any kind of material can be sprayed. Among materials,
ceramic coatings present several interesting aspects such as wear resistance, corrosion protection as well as thermal or electrical
insulation; particularly alumina coatings which appear as the most commonly used. From all spraying processes, atmospheric
plasma spraying (APS) is a rather well-established process but some others can also be used with a lower economical impact
such as the flame technology. The aim of this study was to analyze the alumina coating properties according to the technology
employed such as APS or wire flame spraying using the Rokide™ and the Master Jet? guns. After micrographic analyses by SEM, physical and mechanical properties were measured considering the thermal conductivity
and the hardness.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
3.
J. Wilden J. P. Bergmann S. Jahn S. Knapp F. van Rodijnen G. Fischer 《Journal of Thermal Spray Technology》2007,16(5-6):759-767
Nowadays, wire-arc spraying of chromium steel has gained an important market share for corrosion and wear protection applications.
However, detailed studies are the basis for further process optimization. In order to optimize the process parameters and
to evaluate the effects of the spray parameters DoE-based experiments had been carried out with high-speed camera shoots.
In this article, the effects of spray current, voltage, and atomizing gas pressure on the particle jet properties, mean particle
velocity and mean particle temperature and plume width on X46Cr13 wire are presented using an online process monitoring device.
Moreover, the properties of the coatings concerning the morphology, composition and phase formation were subject of the investigations
using SEM, EDX, and XRD-analysis. These deep investigations allow a defined verification of the influence of process parameters
on spray plume and coating properties and are the basis for further process optimization.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
4.
Influence of Silver Doping on Photocatalytic Activity of Liquid-Flame-Sprayed-Nanostructured TiO2 Coating 总被引:1,自引:0,他引:1
Guan-Jun Yang Chang-Jiu Li Xin-Chun Huang Cheng-Xin Li Yu-Yue Wang 《Journal of Thermal Spray Technology》2007,16(5-6):881-885
Silver ion was added to liquid feedstock to deposit Ag+-doped-nanostructured TiO2 photocatalytic coatings through liquid-flame spraying. The coating microstructure was characterized by x-ray diffraction
(XRD). The photocatalytic performance of coatings was examined by photodegradation of acetaldehyde. The XRD analysis showed
that the phase structure of coatings was not significantly influenced by the silver ion doping. However, a shift was found
for XRD peaks of anatase TiO2. The photocatalytic activity of the TiO2 coatings increased and then decreased with the increase of dopant concentration. The photocatalytic activity of doped coatings
was higher than that of pure TiO2 coating, regardless of the dopant concentration. The enhancement of photocatalytic performance of doped coatings is attributed
to co-doping of Ag+ ion and metallic Ag.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
5.
Hong-Tao Wang Chang-Jiu Li Guan-Jun Yang Cheng-Xin Li Qiang Zhang Wen-Ya Li 《Journal of Thermal Spray Technology》2007,16(5-6):669-676
It is difficult to deposit dense intermetallic compound coatings by cold spraying directly using the compound feedstock powders
due to their intrinsic low-temperature brittleness. A method to prepare intermetallic compound coatings in-situ employing
cold spraying was developed using a metastable alloy powder assisted with post-heat treatment. In this study, a nanostructured
Fe/Al alloy powder was prepared by ball-milling process. The cold-sprayed Fe/Al alloy coating was evolved in-situ to intermetallic
compound coating through a post-heat treatment. The microstructural evolution of the Fe-40Al powder during mechanical alloying
and the effect of the post-heat treatment on the microstructure of the cold-sprayed Fe(Al) coating were characterized by optical
microscopy, scanning electron microscopy, transmission electron microscopy (TEM), and x-ray diffraction analysis. The results
showed that the milled Fe-40Al powder exhibits lamellar microstructure. The microstructure of the as-sprayed Fe(Al) coating
depends significantly on that of the as-milled powder. The heat-treatment temperature significantly influences the in-situ
evolution of the intermetallic compound. The heat treatment at a temperature of 500 °C results in the complete transformation
of Fe(Al) solid solution to FeAl intermetallic compound.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
6.
Eric Irissou Jean-Gabriel Legoux Bernard Arsenault Christian Moreau 《Journal of Thermal Spray Technology》2007,16(5-6):661-668
Coating build-up mechanisms and properties of cold-sprayed aluminum-alumina cermets were investigated using two spherical
aluminum powders having average diameters of 36 and 81 μm. Those powders were blended with alumina at several concentrations.
Coatings were produced using a commercial low-pressure cold spray system. Powders and coatings were characterized by electronic
microscopy and microhardness measurements. In-flight particle velocities were monitored for all powders. The deposition efficiency
was measured for all experimental conditions. Coating performance and properties were investigated by performing bond strength
test, abrasion test, and corrosion tests, namely, salt spray and alternated immersion in saltwater tests. These coating properties
were correlated to the alumina fraction either in the starting powder or in the coating.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
7.
Kazunori Sakata Kosuke Nakano Hirofumi Miyahara Yasuhiro Matsubara Keisaku Ogi 《Journal of Thermal Spray Technology》2007,16(5-6):991-997
This article describes microstructure control aimed for wear-resistance improvement of Co-based (Co-Cr-W-B-Si) self-fluxing
alloy coating by diffusion treatment. The diffusion treatments of thermally sprayed Co-based self-fluxing alloy coating on
steel substrate were carried out at 1370-1450 K for 600-6000 s under an Ar gas atmosphere. Microstructural variations of the
coating and the interface between the substrate and the coating were investigated in detail. A proper diffusion treatment
precipitates two kinds of fine compounds in Co-based matrix. X-ray diffractometer (XRD) and electron probe microanalyzer (EPMA)
analysis revealed these precipitates to be a chromium boride dissolving cobalt and a tungsten boride containing cobalt and
chromium. The size of each precipitate became larger with increasing treatment temperature and time. A coating with the proper
size borides showed a superior wear-resistance.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
8.
Gas atomized feedstock particles of an Al-13Co-26Ce alloy system were sprayed using the Cold Spray deposition technique. The
microstructures of the coatings produced are examined and the mechanical characteristics, in particular the bending fatigue
and the bond strength, of the Al-Co-Ce coatings are reported. The results show that the Al-Co-Ce coatings improved the fatigue
behavior of AA 2024-T3 specimens when compared to uncoated and Alclad specimens. During the bond strength tests, the bonding
agent failed and no delamination of the coating from the substrate occurred. The microstructural features of the feedstock
powder were also found in the coatings. It is suggested that the increase in the fatigue properties of the specimens can be
attributed to the residual compressive stresses induced in the coatings and to the high adhesion strength of the coatings
to the substrates.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
9.
L. Xie M.R. Dorfman A. Cipitria S. Paul I.O. Golosnoy T.W. Clyne 《Journal of Thermal Spray Technology》2007,16(5-6):804-808
It has been found that reducing the level of impurity oxides (particularly SiO2 and Al2O3) in 7YSZ, from about 0.2 wt% to below 0.1 wt% raises the sintering resistance and the phase stability of plasma-sprayed coatings.
The implications for the usage of these coatings at elevated temperatures are examined. It is concluded that using relatively
high-purity powder of this type is likely to confer substantial benefits in terms of the thermomechanical stability of the
coatings under service conditions.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
10.
High-velocity oxygen/air fuel (HVO/AF) WC-17Co and WC-10Co4Cr coatings exhibit great potential in the replacement of electrolytic
hard chrome (EHC) plating, and comprehensive properties of such coatings should be superior to those of electrolytic hard
chrome plating. The impingement resistance of HVAF WC-based coatings sprayed on 300M ultrahigh-strength steel was studied
in this paper. As an important property index, the fracture toughness of HVAF WC-based coatings was measured using the microindentation
method at loads of 9.8, 19.6, 24.5, 29.4, and 49.0 N, respectively. The cracks resulting from stress concentration in the
microindentation were analyzed. The impingement resistance for two HVAF WC coatings and EHC was evaluated according to the
ASTM D 3170 standard, and steel ball free-fall experiment was performed at the height of 0.61, 1.52, 1.83, 2.36, and 2.59 m,
respectively. The cracks caused by both impingements were analyzed using scanning electron microscopy (SEM) and optical microscopy
(OM) in comparison with the cracks in microindentation test.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
11.
In previous studies, it has been demonstrated that nanostructured Al2O3-13 wt.%TiO2 coatings deposited via air plasma spray (APS) exhibit higher wear resistance when compared to that of conventional coatings.
This study aimed to verify if high-velocity oxy-fuel (HVOF)-sprayed Al2O3-13 wt.%TiO2 coatings produced using hybrid (nano + submicron) powders could improve even further the already recognized good wear properties
of the APS nanostructured coatings. According to the abrasion test results (ASTM G 64), there was an improvement in wear performance
by a factor of 8 for the HVOF-sprayed hybrid coating as compared to the best performing APS conventional coating. When comparing
both hybrid and conventional HVOF-sprayed coatings, there was an improvement in wear performance by a factor of 4 when using
the hybrid material. The results show a significant antiwear improvement provided by the hybrid material. Scanning electron
microscopy (SEM) at low/high magnifications showed the distinctive microstructure of the HVOF-sprayed hybrid coating, which
helps to explain its excellent wear performance.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
12.
Stephan Siegmann Philippe Kern Lukas Rohr Partha P. Bandyopadhyay 《Journal of Thermal Spray Technology》2007,16(5-6):947-953
This investigation deals with a study of the friction, wear, and corrosion behavior of vacuum plasma sprayed quasicrystalline
(QC) Ti41.5Zr41.5Ni17 coatings. During pin on disc experiments, a change in the mode of wear has been found to occur with corresponding changes
in normal load and sliding velocity. The low thermal conductivity of quasicrystals and its brittleness play a vital role in
determining the friction and wear behavior of such materials. When these coatings are subjected to rubbing for a longer period
of time, wear occurs by subsurface crack propagation, and subsequent delamination within the coated layer. By comparing the
QC to its polycrystalline counterpart during potentiodynamic measurements according to ASTM G 31, higher currents were found
over the whole range of potentials for QC when immersed in 1 M HCl solution.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
13.
B.R. Marple R.S. Lima C. Moreau S.E. Kruger L. Xie M. R. Dorfman 《Journal of Thermal Spray Technology》2007,16(5-6):791-797
Thermal barrier coatings were produced using both Ar and N2 as the primary plasma gas. Various aspects of the process and the coatings were investigated. It was found that higher in-flight
particle temperatures could be produced using N2, but particle velocities were lower. Deposition efficiencies could be increased by a factor of two by using N2 as compared to Ar. Coatings having similar values of porosity, hardness, Young’s modulus, and thermal diffusivity could be
produced using the two primary gases. The coatings exhibited similar changes (increased hardness, stiffness, and thermal diffusivity)
when heat-treated at 1400 °C. However, the N2-processed coatings tended to have lower values of Young’s modulus and thermal diffusivity following such treatment. The results
point to the potential advantage, in terms of reduced powder consumption and increased production rate, of using N2 as compared to Ar as the primary plasma gas for TBC deposition.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
14.
L. Jackson M. Ivosevic R. Knight R. A. Cairncross 《Journal of Thermal Spray Technology》2007,16(5-6):927-932
Polymer and polymer/ceramic composite coatings were produced by ball-milling 60 μm Nylon-11 together with nominal 10 vol.%
of nano and multiscale ceramic reinforcements and by HVOF spraying these composite feedstocks onto steel substrates to produce
semicrystalline micron and nanoscale reinforced polymer matrix composites. Room temperature dry sliding wear performance of
pure Nylon-11, Nylon-11 reinforced with 7 nm silica, and multiscale Nylon-11/silica composite coatings incorporating 7-40 nm
and 10 μm ceramic particles were characterized using a pin-on-disk tribometer. Coefficient of friction and wear rate were
determined as a function of applied load and coating composition. Surface profilometry and scanning electron microscopy were
used to characterize and analyze the coatings and wear scars. The pure Nylon-11 coating experienced less wear than the composites
due to the occurrence of two additional wear mechanisms: abrasive and fatigue wear.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
15.
Carl Christoph Stahr Sabine Saaro Lutz-Michael Berger Jiri Dubský Karel Neufuss Mathias Herrmann 《Journal of Thermal Spray Technology》2007,16(5-6):822-830
A phase change from α-alumina (corundum) in the feedstock powder to predominantly other alumina phases, such as γ-alumina
in the coating normally takes place, as a result of the spray process. It is expected that the prevention of this phase transformation
will significantly improve the mechanical, electrical, and other properties of thermally sprayed alumina coatings. The results
regarding the possibility of stabilization of α-alumina through addition of chromia published in the literature are ambiguous.
In this work, stabilization using different spray processes (water-stabilized plasma (WSP), gas-stabilized plasma (APS), and
high-velocity oxy-fuel spray (HVOF)) was studied. Mechanical mixtures of alumina and chromia were used, as were prealloyed
powders consisting of solid solutions. The investigations focused on mechanical mixtures with both APS and WSP and on prealloyed
powders with WSP. The coatings were studied by x-ray diffraction, including Rietveld analysis, and analysis of the lattice
parameters. Microstructures were investigated by optical microscopy using metallographic cross-sections. It was shown that
in the case of the mechanically mixed powders, the stabilization predominantly depends on the applied spray process. The stabilization
of the α phase by use of the WSP process starting from mechanical mixtures was confirmed. It appears that stabilization exhibits
a complex dependence on the spray process, the process parameters (in particular the thermal history), the nature of the powder
(mechanically mixed or prealloyed), and the chromia content.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
16.
This article reports on a series of experiments with various high-velocity oxygen fuel spray systems (Jet Kote, Top Gun, Diamond
Jet (DJ) Standard, DJ 2600 and 2700, JP-5000, Top Gun-K) using different WC-Co and WC-Co-Cr powders. The microstructure and
phase composition of powders and coatings were analyzed by optical and scanning electron microscopy and x-ray diffraction.
Carbon and oxygen content of the coatings were determined to study the decarburization and oxidation of the material during
the spray process. Coatings were also characterized by their hardness, bond strength, abrasive wear, and corrosion resistance.
The results demonstrate that the powders exhibit various degrees of phase transformation during the spray process depending
on type of powder, spray system, and spray parameters. Within a relatively wide range, the extent of phase transformation
has only little effect on coating properties. Therefore, coatings of high hardness and wear resistance can be produced with
all HVOF spray systems when the proper spray powder and process parameters are chosen.
This paper originally appeared in Thermal Spray: Meeting the Challenges of the 21st Century; Proceedings of the 15th International Thermal Spray Conference, C. Coddet, Ed., ASM International, Materials Park, OH, 1998. This proceedings paper has been extensively reviewed according
to the editorial policy of the Journal of Thermal Spray Technology. 相似文献
17.
Dowon Seo Kazuhiro Ogawa Tetsuo Shoji Shozo Murata 《Journal of Thermal Spray Technology》2007,16(5-6):954-966
The effect of particle size distribution on the degradation behavior of plasma sprayed CoNi- and CoCrAlY coatings during isothermal
oxidation was investigated, in terms of the oxygen content, porosity, surface roughness, and oxide scale formation. The results
show that the degradation of both coatings was considerably influenced by the starting particle size distribution. It also
shows that in the as-sprayed vacuum plasma spray (VPS) coatings the oxygen content on the coating surface increased significantly
with decreased average particle size. But after thermal exposure, the difference of the oxygen contents between the coatings
with different particle size was decreased. The powder with various particle size resulted in low porosity inside the coatings
during the deposition process. The surface roughness of the coatings increased with increased particle size. The small particles
produced a relatively smooth surface, and the oxide growth in the coating deposited by small particle was slower than that
in the large particle coating.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
18.
In this article, we proposed a rapid and continuous process for the production of nanoporous coatings for functional applications.
Experiments following two statistical designs were implemented to screen and investigate the spraying parameters’ effects
on coating crystallinity and porosity in order to gain a better understanding. The spraying standoff distance, solution flow
rate and power were identified as having significant effects on coating porosity and crystallinity. The result yielded a peculiar
microstructure comprised of interpenetrating pores and layered structures with embedded pores. A deposition mechanism was
postulated to explain this microstructure. Ethanol gas sensors that are constructed from the coatings had comparable sensitivities
to those reported in the literature for thick-film coatings and had a maximum sensitivity near 200 °C.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
19.
Solution Precursor Plasma Spray of Nickel-Yittia Stabilized Zirconia Anodes for Solid Oxide Fuel Cell Application 总被引:1,自引:0,他引:1
In conventional plasma spray of SOFC components, the large NiO and YSZ particles used, about 50-150 microns for high porosity
coating, reduce the density of three-phase sites for electrode reaction. In this article, the SPPS process was used to synthesize
and deposit Ni-YSZ anodes. The results show that several process parameters have significant effects on the microstructure
and phase composition of the deposited material. The deposits were composed of tower-like, irregularly shaped agglomerates
and smooth surface deposits. The sizes of the agglomerates increase with the decrease of the plasma-torch power and most are
not completely molten during the impact. After heat treatment to reduce the NiO present in the as deposited coatings, the
coatings were found to contain spherical YSZ particles about 0.5 μm in diameter distributed in a continuous Ni matrix, which
is verified by both SEM observation and electrical resistance measurement. The coatings have 30-50% porosity.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
20.
In the current study, Cr3C2-NiCr coating was deposited on the Ni-base superalloys by using high velocity oxyfuel (HVOF) process for high temperature
corrosive environment applications. Optical microscopy (OM), x-ray diffraction (XRD), scanning electron microscopy/energy-dispersive
analysis (SEM/EDAX), microhardness tester, and electro probe microanalyzer (EMPA) techniques were used to characterize the
coating with regard to coating thickness, porosity, microhardness, and microstructure. The thermogravimetric technique was
used to establish kinetics of corrosion. The hot corrosion behaviors of the bare and Cr3C2-NiCr coated superalloys were studied after exposure to aggressive environment of Na2SO4-60% V2O5 salt mixture at 900 °C under cyclic conditions. The structure of the as-sprayed Cr3C2-NiCr coating mainly consisted of γ-nickel solid solution along with minor phases of Cr7C3 and Cr2O3. Coating has porosity less than 1.5% and microhardness in the range of 850–900 Hv (Vickers hardness). Some inclusions, unmelted
and semimelted powder particles were observed in the structure of the coatings. The Cr3C2-NiCr coating has imparted necessary resistance to hot corrosion, which has been attributed to the formation of oxides of
nickel and chromium, and spinel of nickel-chromium.
This article was originally published inBuilding on 100 Years of Success, Proceedings of the 2006 International Thermal Spray Conference (Seattle, WA), May 15–18, 2006, B.R. Marple, M.M. Hyland, Y.-Ch. Lau, R.S. Lima, and J. Voyer, Ed., ASM International, Materials
Park, OH, 2006. 相似文献