particoat public presentation 26-06-2009 · dip-coating t/°c time binder evaporation sintering...
Post on 22-Jun-2020
2 Views
Preview:
TRANSCRIPT
PARTICOATPARTICOATTHEME 4THEME 4
NanoscienceNanoscience, nanotechnologies, materials new production technologies (NMP), nanotechnologies, materials new production technologies (NMP)
Collaborative ProjectCollaborative ProjectLargeLarge--scale integrating projectscale integrating project
Proposal full title:Proposal full title:New multipurpose coating systems based on novel particle New multipurpose coating systems based on novel particle technology for extreme environments at high temperaturestechnology for extreme environments at high temperatures
Grant agreement no.: Grant agreement no.: CPCP--IP 211329IP 211329--22
Consortium
GRGRIndustryIndustryLARCOLARCO1414
DDSMESMESteinbeis Steinbeis RR--TechTech1313
DDIndustryIndustrySiemens Power GenerationSiemens Power Generation1212
EEIndustryIndustryAccionaAcciona InfraestructurasInfraestructuras1111
IISMESMETurbocoatingTurbocoating1010
FFUniversityUniversityUniversitUniversitéé de La Rochellede La Rochelle99
EEUniversityUniversityUniversidadUniversidad Carlos III MadridCarlos III Madrid88
RURUSMESMESibthermochimSibthermochim77
CZCZIndustryIndustryWIP WIP PraguePrague66
GRGRSMESMEPyroGenesisPyroGenesis55
EEIndustryIndustryTECNATOMTECNATOM44
CZCZResearchResearchSVSVÚÚMM33
DDResearchResearchDECHEMADECHEMA22
DDResearchResearchFraunhofer ICT (Fraunhofer ICT (coco--ordinatorordinator))11
CountryCountryBusinessBusinessBeneficiaryBeneficiary namenameBeneficiaryBeneficiary no.no.
TheThe
IdeaIdea
Aluminium: 2-3 μm
Oxidation on heating from room temperature to 1100°C
(Microscopy of Oxidation, Birmingham 2005)
Intensität
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
T [°C]
IZ [n
orm
.]
Al 0.3 - 0.7μm
Al
γ-Al2O3
Θ-Al2O3
α -Al2O3
Intensität
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
T [°C]
IZ [n
orm
.]
Al 2.0 - 3.0μm
Al
α -Al2O3
ab 675°C Schmelze
Aluminium: 0,3 – 0,7 μm
The idea: oxidation of The idea: oxidation of nanonano-- and microand micro--sized Al sized Al –– particlesparticles
x
t
Parabolic Oxidation
xk
dtdx p= x² = 2kp·t
Schematic view of theTransport ProcessesDuring Oxide Scale Growth
Schematic view of theTransport ProcessesDuring Oxide Scale Growth
Oxide OxygenContainingEnvironment
Metal Cations
Oxygen Anions
Electrons
Oxide Thickness x
Metal
Bulk diffusioncoefficients
ConversionConversion of Metallic of Metallic AluminumAluminumNanoNano//MicroMicro PowderPowder ParticlesParticles
IntoInto HollowHollow AluminumAluminum Oxide Oxide SpheresSpheres
AluminumAluminum Aluminum
Aluminum Oxide Aluminum Oxide
Nano/micro size = low amount of grain boundaries
Aluminum = very creep ductile, i. e. adherence to oxide maintained during conversion
Al-diffusionAl-diffusion
Al Al sphericalspherical, 2, 2--3 3 µµmmScanning Electron Microscopy / EDX
- Homogeneous distribution, no agglomerates
- Spherical particles
- Particle size 2-5 μm
10 μm
10 μm
Potential of Nano- and Micro-Scale Metal Powders
Intensity curves iz(T)
Al 31% 0Al 31% 0--5 5 µµm, 69% 5m, 69% 5--10 10 µµmm
Potential of Nano- and Micro-Scale Metal Powders
Intens ity
0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
0 200 400 600 800 1000 1200 1400 1600
T [°C]
IZ [
no
rm.]
α-Al2O3 Al (cubic)
Al and α-Al2O3 portion as a function of temperature
Thermal stabilityDiffusion
100, 300, 1000 hHT-XRD, metallography
CHARACTERIZATION
SuspensionBase powder: AlBinder: PVAAl/BinderDispersantRheology
“GREEN“ COATING René 80347H
MCrAlY-2231
THERMAL TREATMENTS
TT1-SINTERING
•Binder evaporation•Al sintering
TT2-ASSEMBLING
•Al2O3 formation• Al diffusion
WORK FLOW CHART
Ni-Base alloys
SS steels
Production of source metal
particles by PSP and EEC
Spherical metal particles with defined size
Deposition by brushing,
spraying, rolling, sol-gel
raw coating
coating with quasi-foam top coat and diffusion layer
Heat treatment ev. pre-treatment
oxidation sintering diffusion
DEPOSITION PROCEDURE
THERMAL TREATMENTDip-coating
T/°C
time
Binder evaporation
Sintering
1 1 10
Assembling
ExamplesExamples of of CoatingsCoatingsProducedProduced So FarSo Far
Binder #1 400Binder #1 400°°CC
500:1 5000:1
Vaporization of the organic binder and beginning of Al particle sintering
Binder #1 650Binder #1 650°°CC
500:1
Densification of the metallic „green“ coating
Binder #1 650Binder #1 650°°CC
3000:1
Densified aluminum „green“ coating
Binder #1 900Binder #1 900°°C C
500:1 3000:1
Broken up „cross-section“ of the ceramic alumina „foam“
Binder #1 900Binder #1 900°°CC
2000:1 3000:1
Substrate/foam interface
Binder #2 900Binder #2 900°°CC
100:1
Opened-up surface of the ceramic alumina foam
Binder #3 650Binder #3 650°°CC
1000:15000:1
Hollow ceramic alumina spheres
Binder #3 900Binder #3 900°°CC
1000:1 5000:1
Influence of binder:
Example of reduced sintering activity and appearance of meta-stable alumina phases
Binder #3 900Binder #3 900°°CC
100:1 500:1
Possibility to influence the coating/substrate interface
(wavy interface = keying effect)
SummarySummary
►► PARTICOAT PARTICOAT isis developingdeveloping an innovative an innovative conceptconcept forforthermal thermal barrierbarrier coatingscoatings wherewhere in in oneone singlesingle thermal thermal treatmenttreatment stepstep a a combinedcombined bondcoatbondcoat//topcoattopcoat systemsystem isisbeingbeing formedformed
►► ThisThis isis achievedachieved byby thethe useuse of of sphericalspherical nanonano--//micromicro--scalescalemetal metal particlesparticles. These . These serveserve as a as a reservoirreservoir forfor thetheformationformation of of thethe Al Al richrich bondbond coatcoat and and areare convertedconverted intointohollowhollow aluminaalumina spheresspheres byby oxidationoxidation
►► TheThe toptop coatcoat, in , in thethe form of form of thethe sinteredsintered hollowhollow aluminaaluminaspheresspheres, , providesprovides a thermal a thermal barrierbarrier
►► Initial Initial resultsresults demonstratedemonstrate thethe viabilityviability of of thethe conceptconcept
PropertiesProperties►►Easy to applyEasy to apply►►Low costLow cost►►Low application temperaturesLow application temperatures►►Possibility to form dense layers with increased Possibility to form dense layers with increased
mechanical compliancemechanical compliance►►Alumina is no oxygen conductor and provides a Alumina is no oxygen conductor and provides a
very good barrier effect against ingress of very good barrier effect against ingress of corrosive speciescorrosive species
►►Significant potential for electrical and thermal Significant potential for electrical and thermal insulationinsulation
►►Al subsurface reservoir for protective alumina Al subsurface reservoir for protective alumina scale formationscale formation
ApplicationApplication areasareas►►Gas turbines in electric power generation and Gas turbines in electric power generation and
aeroaero--engines engines ►►AbradableAbradable coatingscoatings►►Steam turbines in electric power generationSteam turbines in electric power generation►►Combustion chambers, boilersCombustion chambers, boilers►►Steam generators, Steam generators, superheaterssuperheaters►►Waste incinerationWaste incineration►►Fire protection of composite materials in Fire protection of composite materials in
constructionconstruction►►Reformers and reactors in chemical and Reformers and reactors in chemical and
petrochemical industrypetrochemical industry►►Electrical insulation in arc melting furnacesElectrical insulation in arc melting furnaces
top related