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1.
Ajdelsztajn L. Tang F. Schoenung J. M. Kim G. E. Provenzano V. 《Journal of Thermal Spray Technology》2005,14(1):23-30
Thermal barrier coating systems protect turbine blades against high-temperature corrosion and oxidation. They consist of a
metal bond coat (MCrAlY, M = Ni, Co) and a ceramic top layer (ZrO2/Y2O3). In this work, the oxidation behavior of conventional and nanostructured high-velocity oxyfuel (HVOF) NiCrAlY coatings has
been compared. Commercially available NiCrAlY powder was mechanically cryomilled and HVOF sprayed on a nickel alloy foil to
form a nanocrystalline coating. Freestanding bodies of conventional and nanostructured HVOF NiCrAlY coatings were oxidized
at 1000 °C for different time periods to form the thermally grown oxide layer. The experiments show an improvement in oxidation
resistance in the nanostructured coating when compared with that of the conventional one. The observed behavior is a result
of the formation of a continuous Al2O3 layer on the surface of the nanostructured HVOF NiCrAlY coating. This layer protects the coating from further oxidation and
avoids the formation of mixed oxide protrusions present in the conventional coating.
The original version of this article was published as part of the ASM Proceedings, Thermal Spray 2003: Advancing the Science and Applying the Technology, International Thermal Spray Conference (Orlando, FL), May 5–8 2003, Basil R. Marple and Christian Moreau, Ed., ASM International,
2003. 相似文献
2.
New attachment for controlling gas flow in the HVOF process 总被引:1,自引:0,他引:1
During the decade, the high-velocity oxyfuel (HVOF) process proved to be a technological alternative to the many conventional
thermal spray processes. It would be very advantageous to design a nozzle that provides improved performance in the areas
of deposition efficiency, particle in-flight oxidation, and flexibility to allow deposition of ceramic coatings. Based on
a numerical analysis, a new attachment to a standard HVOF torch was modeled, designed, tested, and used to produce thermal
spray coatings according to the industrial needs mentioned above. Performance of the attachment was investigated by spraying
several coating materials including metal and ceramic powders. Particle conditions and spatial distribution, as well as gas
phase composition, corresponding to the new attachment and the standard HVOF gun, were compared. The attachment provides better
particle spatial distribution, combined with higher particle velocity and temperature.
The original version of this article was published as part of the ASM Proceedings, Thermal Spray 2003: Advancing the Science and Applying the Technology, International Thermal Spray Conference (Orlando, FL), 5–8 May, 2003, Basil R. Marple and Christian Moreau, Ed., ASM International,
2003. 相似文献
3.
High-velocity oxyfuel (HVOF) spraying of WC-12Co was performed using a feedstock in which the WC phase was either principally
in the micron size range (conventional) or was engineered to contain a significant fraction of nanosized grains (multimodal).
Three different HVOF systems and a wide range of spray parameter settings were used to study the effect of in-flight particle
characteristics on coating properties. A process window with respect to particle temperature was identified for producing
coatings with the highest resistance to dry abrasion. Although the use of a feedstock containing a nanosized WC phase produced
harder coatings, there was little difference in the abrasion resistance of the best-performing conventional and multimodal
coatings. However, there is a potential benefit in using the multimodal feedstock due to higher deposition efficiencies and
a larger processing window.
The original version of this article was published as part of the ASM Proceedings, Thermal Spray 2003: Advancing the Science and Applying the Technology, International Thermal Spray Conference (Orlando, FL), May 5–8, 2003, Basil R. Marple and Christian Moreau, Ed., ASM International,
2003. 相似文献
4.
S. Niezgoda V. Gupta R. Knight R. A. Cairncross T. E. Twardowski 《Journal of Thermal Spray Technology》2006,15(4):731-738
The high-velocity oxyfuel (HVOF) combustion spraying of dry ball-milled nylon-11/ceramic composite powders is an effective,
economical, and environmentally sound method for producing semicrystalline micron and nanoscale reinforced polymer coatings.
Composite coatings reinforced with multiple scales of ceramic particulate material are expected to exhibit improved load transfer
between the reinforcing phase and the matrix due to interactions between large and small ceramic particles. An important step
in developing multiscale composite coatings and load transfer theory is determining the effect of reinforcement size on the
distribution of the reinforcement and the properties of the composite coating.
Composite feedstock powders were produced by dry ball-milling nylon-11 together with 7, 20, and 40 nm fumed silica particles,
50 and 150 nm fumed alumina particles, and 350 nm, 1, 2, 5, 10, 20, 25, and 50 μm white calcined alumina at 10 vol.% overall
ceramic phase loadings. The effectiveness of the ball-milling process as a function of reinforcement size was qualitatively
evaluated by scanning electron microscopy+energy dispersive x-ray spectroscopy (SEM+EDS) microanalysis and by characterizing
the behavior of the powder during HVOF spraying. The microstructures of the sprayed coatings were characterized by optical
microscopy, SEM, EDS, and x-ray diffraction (XRD). The reinforcement particles were found to be concentrated at the splat
boundaries in the coatings, forming a series of interconnected lamellar sheets with good three-dimensional distribution. The
scratch resistance of the coatings improved consistently and logarithmically as a function of decreasing reinforcement size
and compared with those of HVOF sprayed pure nylon-11.
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
5.
Microstructure and properties of thermally sprayed Al-Sn-based alloys for plain bearing applications
T. Marrocco L. C. Driver S. J. Harris D. G. McCartney 《Journal of Thermal Spray Technology》2006,15(4):634-639
Al-Sn plain bearings for automotive applications traditionally comprise a multilayer structure. Conventionally, bearing manufacturing
involves casting the Al-Sn alloy and roll-bonding to a steel backing strip. Recently, high-velocity oxyfuel (HVOF) thermal
spraying has been used as a novel alternative manufacturing route. The present project extends previous work on ternary Al-Sn-Cu
alloys to quaternary systems, which contain specific additions for potentially enhanced properties. Two alloys were studied
in detail, namely, Al-20wt.%Sn-1wt.%Cu-2wt.%Ni and Al-20wt.%Sn-1wt.%Cu-7wt.%Si. This article will describe the microstructural
evolution of these alloys following HVOF spraying onto steel substrates and subsequent heat treatment. The microstructures
of powders and coatings were investigated by scanning electron microscopy, and the phases were identified by x-ray diffraction.
Coating microhardnesses were determined under both as-sprayed and heat-treated conditions, and by the differences related
to the microstructures that developed. Finally, the wear behavior of the sprayed and heat-treated coatings in hot engine oil
was measured using an industry standard test and was compared with that of previous work on a ternary alloy.
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
6.
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
7.
Nanocrystalline Al−Mg coatings were produced using the cold gas dynamic-spraying technique. Unsieved Al−Mg powder of average
nanocrystalline grain size in the range of 10 to 30 nm and with a particle size distribution from 10 to >100 μm was used as
the feedstock powder. The resulting coatings were evaluated using scanning electron microscopy (SEM), transmission electron
microscopy, as well as microhardness and nanoindentation measurements. Coating observations suggest that the wide particle
size distribution of the feedstock powder has a detrimental effect on the coating quality but that it can be successfully
mitigated by optimizing the spraying parameters. Nanohardness values close to 3.6 GPa were observed in both the feedstock
powder and coatings, suggesting the absence of cold-working hardening effects during the process. The effects of the substrate
surface roughness and thickness on coating quality were investigated. The deposited mass measurements performed on the coatings
showed that the effect of using different grit sizes for the substrate preparation is limited to small changes in the deposition
efficiency of only the first few layers of deposited material. The SEM observation showed that the substrate surface roughness
has no significant effect on the macrostructures and microstructures of the coating. The ability to use the cold gas dynamic
spraying process to produce coatings on thin parts without noticeable substrate damage and with the same quality as coatings
produced on thicker substrates was demonstrated in this work.
The original version of this paper was published in the CD ROM Thermal Spray Connects: Explore Its Surfacing Potential, International Thermal Spray Conference, sponsored by DVS, ASM International, and IIW International Institute of Welding,
Basel, Switzerland, May 2–4, 2005, DVS-Verlag GmbH, Düsseldorf, Germany. 相似文献
8.
Nanostructured titania (TiO2) coatings were produced by high-velocity oxyfuel (HVOF) spraying. They were engineered as a possible candidate to replace
hydroxyapatite (HA) coatings produced by thermal spray on implants. The HVOF sprayed nanostructured titania coatings exhibited
mechanical properties, such as hardness and bond strength, much superior to those of HA thermal spray coatings. In addition
to these characteristics, the surface of the nanostructured coatings exhibited regions with nanotextured features originating
from the semimolten nanostructured feedstock particles. It is hypothesized that these regions may enhance osteoblast adhesion
on the coating by creating a better interaction with adhesion proteins, such as fibronectin, which exhibit dimensions in the
order of nanometers. Preliminary osteoblast cell culture demonstrated that this type of HVOF sprayed nanostructured titania
coating supported osteoblast cell growth and did not negatively affect cell viability.
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
9.
Ivosevic M. Knight R. Kalidindi S. R. Palmese G. R. Sutter J. K. 《Journal of Thermal Spray Technology》2005,14(1):45-51
High-velocity oxyfuel (HVOF) sprayed polyimide/WC-Co functionally graded (FGM) coatings with flame-sprayed WC-Co topcoats
have been investigated as solutions to improve the solid-particle erosion and oxidation resistance of polymer matrix composites
(PMCs) in the gas flow path of advanced turbine engines. Porosity, coating thickness, and volume fraction of the WC-Co phase
retained in the graded coating architecture were determined using standard metallographic techniques and computer image analysis.
The adhesive bond strength of three different types of coatings was evaluated according to ASTM D 4541. Adhesive/cohesive
strengths of the FGM coating were measured and compared with those of pure polyimide and polyimide/WC-Co composite coatings
and also related to the tensile strength of the uncoated PMC substrate perpendicular to the thickness. The FGM coatings exhibited
lower adhesive bond strengths (∼6.2 MPa) than pure polyimide coatings (∼8.4 MPa), and in all cases these values were lower
than the tensile strength (∼17.6 MPa) of the reference uncoated PMC substrate. The nature and locus of the failures were characterized
according to the percent adhesive and/or cohesive failure, and the interfaces tested and layers involved were analyzed by
scanning electron microscopy.
The original version of this paper was published as part of the ASM Proceedings, Thermal Spray 2003: Advancing the Science and Applying the Technology, International Thermal Spray Conference (Orlando, FL), 5–8 May, 2003, Basil R. Marple and Christian Moreau, Eds., ASM International,
2003. 相似文献
10.
Elastic modulus measurements via laser-ultrasonic and knoop indentation techniques in thermally sprayed coatings 总被引:1,自引:0,他引:1
R. S. Lima S. E. Kruger G. Lamouche B. R. Marple 《Journal of Thermal Spray Technology》2005,14(1):52-60
Nondestructive techniques for evaluating and characterizing coatings were extensively demanded by the thermal spray community;
nonetheless, few results have been produced in practice due to difficulties in analyzing the complex structure of thermal
spray coatings. Of particular interest is knowledge of the elastic modulus values and Poisson’s ratios, which are very important
when seeking to understand and/or model the mechanical behavior or to develop life prediction models of thermal spray coatings
used in various applications (e.g., wear, fatigue, and high temperatures). In the current study, two techniques, laser-ultrasonics
and Knoop indentation, were used to determine the elastic modulus of thermal spray coatings. Laser-ultrasonics is a noncontact
and nondestructive evaluation method that uses lasers to generate and detect ultrasound. Ultrasonic velocities in a material
are directly related to its elastic modulus value. The Knoop indentation technique, which has been widely used as a method
for determining elastic modulus values, was used to compare and validate the measurements of the laser-ultrasonic technique.
The determination of elastic modulus values via the Knoop indentation technique is based on the measurement of elastic recovery
of the dimensions of the Knoop indentation impression. The approach used in the current study was to focus on evaluating the
elastic modulus of very uniform, dense, and near-isotropic titania and WC-Co thermal spray coatings using these two techniques.
Four different coatings were evaluated: two titania coatings produced by air plasma spray (APS) and high-velocity oxyfuel
(HVOF) and two types of WC-Co coatings, conventional and multimodal (nanostructured and microsized particles), deposited by
HVOF.
The original version of this article was published as part of the ASM Proceedings, Thermal Spray 2003: Advancing the Science and Applying the Technology, International Thermal Spray Conference (Orlando, FL), 5–8 May, 2003, Basil R. Marple and Christian Moreau, Eds., ASM International,
2003. 相似文献
11.
Microstructural evaluation of tungsten carbide-cobalt coatings 总被引:1,自引:0,他引:1
Tungsten carbide-12 wt.% cobalt coatings were deposited using optimized high-energy plasma (HEP) and high-velocity oxygen
fuel (HVOF) thermal spray techniques. The coatings were evaluated using transmission electron microscopy, differential thermal
analysis, X-ray diffraction, and subjected to wear tests to relate the coating structure to wear performance. Coatings were
evaluated in the assprayed condition, as well as after heat treatments in inert atmosphere. The results indicate that a substantial
amount of amorphous matrix material is created during the thermal spray process. Carbon and tungsten, liberated through the
dissociation of the WC, combine with cobalt present in the starting powder to form amorphous material on solidification. Differential
thermal analysis revealed an exothermic reaction for both the HVOF and HEP coatings at approximately 853 and 860 °C, respectively,
which did not occur for the powder. Post-coating heat treatment in an inert atmosphere resulted in the recrystallization of
the amorphous material into Co6W6C and Co2W4C, which was dependent on the time and temperature of the heat treatment. Wear testing showed improvement in the wear performance
for coatings that were subjected to the heat treatment. This was related to the recrystallization of the amorphous matrix
into eta phase carbides.
Editor’s Note: This paper was presented at the 4th National Thermal Spray Conference, Pittsburgh, 6-10 May, 1991. The proceedings
of this conference will be published by ASM International. Dr. T.F. Bernecki is the Editor of these proceedings. 相似文献
12.
Perovskite-type LaMnO3 powders and coatings have been prepared by a novel technique: reactive suspension plasma spraying (SPS) using an inductively
coupled plasma of approximately 40 kW plate power and an oxygen plasma sheath gas. Suitable precursor mixtures were found
on the basis of solid state reactions, solubility, and the phases obtained during the spray process. Best results were achieved
by spraying a suspension of fine MnO2 powder in a saturated ethanol solution of LaCl3 with a 1 to 1 molar ratio of lanthanum and manganese. A low reactor pressure was helpful in diminishing the amount of corrosive
chlorine compounds in the reactor. As-sprayed coatings and collected powders showed perovskite contents of 70 to 90%. After
a posttreatment with an 80% oxygen plasma, an almost pure LaMnO3 deposit was achieved in the center of the incident plasma jet.
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
13.
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
14.
The high velocity air fuel (HVAF) system is a high-velocity combustion process that uses compressed air and kerosene for combustion.
Two WC-cermet powders were sprayed by the HVAF and the high-velocity oxyfuel (HVOF) processes, using an AeroSpray gun (Browning
Thermal Systems Inc., Enfield, New Hampshire) and a CDS-100 gun (Sulzer Plasma Technik, Wohlen, Switzerland) respectively.
Several techniques, including x-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy, were used
to characterize the microstructures and phase distribution of the powders and coatings. In addition, mechanical properties
such as hardness and wear resistance (pin-on-disk) were investigated. A substantial amount of W2C was found in the HVOF coatings, as well as a high concentration of tungsten in the binder phase, indicating that oxidation
and dissolution processes change the composition and microstructure from powder to coating during spraying. This was in contrast
to the HVAF coatings in which composition and microstructure were unchanged from that of the powder. Additionally, the wear
resistance of the HVAF coatings was superior to that of the HVOF coatings. 相似文献
15.
The application of thick high-velocity oxyfuel (HVOF) coatings on metallic parts has been widely accepted as a solution to
improve their wear properties. The adherence of these coatings to the substrate is strongly influenced by the residual stresses
generated during the coating deposition process. In an HVOF spraying process, due to the relatively low processing temperature,
significant peening stresses are generated during impact of molten and semimolten particles on the substrate. At present,
finite-element (FE) models of residual stress generation for the HVOF process are not available due to the increased complexities
in modeling the stresses generated due to the particle impact. In this work, an explicit FE analysis is carried out to study
the effect of molten particle impingement using deposition of an HVOF sprayed copper coating on a copper substrate as an example
system. The results from the analysis are subsequently used in a thermomechanical FE model to allow the development of the
residual stresses in these coatings to be modeled.
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
16.
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
17.
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
18.
Effect of Powder Injection Location on Ceramic Coatings Properties When Using Plasma Spray 总被引:1,自引:0,他引:1
The effect of powder injecting location of the plasma spraying on spraying properties was studied. Three different powder-injecting
methods were applied in the experiment. In the first method, the particles were axially injected into the plasma flow from
the cathode tip. In the second method, the particles were radially injected into the plasma flow just downstream of the anode
arc root inside the anode nozzle. In the third method, the particles were radially injected into the plasma jet at the nozzle
exit. The alumina particles with a mean diameter of 20 μm were used to deposit coatings. Spraying properties, such as the
deposition efficiency, the melting rate of the powder particles, and the coating quality were investigated. The results show
that the spraying with axial particle injecting can heat and melt the powder particles more effectively, produce coatings
with better quality, and have higher deposition efficiency.
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.
20.
Hybrid plasma spraying combined with yttrium-aluminum-garnet laser irradiation was studied to obtain optimum zirconia coatings
for thermal barrier use. Zirconia coatings of approximately 150 μm thickness were formed on NiCrAlY bond coated steel substrates
both by means of conventional plasma spraying and hybrid plasma spraying under a variety of conditions. Post-laser irradiation
was also conducted on the plasma as-sprayed coating. The microstructure of each coating was studied and, for some representative
coatings, thermal barrier properties were evaluated by hot erosion and hot oxidation tests. With hybrid spraying, performed
under optimum conditions, it was found that a microstructure with appropriate partial densification and without connected
porosity was formed and that cracks, which are generally produced in the post-laser irradiation treatment, were completely
inhibited. In addition, hybrid spraying formed a smooth coating surface. These microstructural changes resulted in improved
coating properties with regard to hardness, high temperature erosion resistance, and oxidation resistance.
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