Microstructure Studies of Microstructure Studies of Carbon-Carbon Composite Carbon-Carbon Composite
MaterialsMaterials
Kei YamamotoKei Yamamoto
Purdue UniversityPurdue University
Advisor: Prof. Alex KingAdvisor: Prof. Alex King
Presentation OutlinePresentation Outline
Background information on Carbon-Background information on Carbon-Carbon CompositesCarbon Composites
Optical Microscopy imagesOptical Microscopy images X-ray diffraction resultsX-ray diffraction results SEM imagesSEM images ConclusionsConclusions Future WorkFuture Work
What are Carbon-Carbon Composites?What are Carbon-Carbon Composites?
Amorphous carbon Amorphous carbon matrix compositematrix composite
Carbon matrix Carbon matrix reinforced by graphitic reinforced by graphitic carbon fiberscarbon fibers
First developed in First developed in 1958, but not 1958, but not intensively researched intensively researched until the Space Shuttle until the Space Shuttle Program (for Program (for insulation)insulation)
How are Carbon-Carbon How are Carbon-Carbon composites made?composites made?
First carbon fibers are made by pyrolizing Poly-acrylo-First carbon fibers are made by pyrolizing Poly-acrylo-nitrile (PAN) fibers nitrile (PAN) fibers
Pyrolized fibers then woven into the desired patternPyrolized fibers then woven into the desired pattern
Spaces between the fibers are filled by Chemical Spaces between the fibers are filled by Chemical Vapor Deposition (CVD)Vapor Deposition (CVD)
http://www.fibermaterialsinc.com/frSW.htm
Properties of Carbon-Carbon Properties of Carbon-Carbon CompositesComposites
Outstanding durability at temperatures over Outstanding durability at temperatures over 2000ºC2000ºC
Low coefficient of thermal expansionLow coefficient of thermal expansion Great thermal shock resistanceGreat thermal shock resistance High strength High strength Low weightLow weight High melting pointHigh melting point Corrosion resistantCorrosion resistant ExpensiveExpensive Long time to manufacture (weeks to months)Long time to manufacture (weeks to months)
Properties of Carbon-Carbon Properties of Carbon-Carbon
http://www.hitco.com/products/corrosion/chemical/index.html
http://www.hitco.com/products/corrosion/chemical/index.html
Uses of Uses of Carbon-CarbonCarbon-Carbon CompositesComposites
Aircraft, F-1 racing Aircraft, F-1 racing cars and train cars and train brakesbrakes
Space shuttle nose Space shuttle nose tip and leading tip and leading edgesedges
Rocket nozzles and Rocket nozzles and tipstips
http://www.futureshuttle.com/conference/ThermalProtectionSystem/Curry_73099.pdf
http://www.fibermaterialsinc.com/frSW.htm
http://www.fibermaterialsinc.com/frSW.htm
Original goals of my projectOriginal goals of my project
To determine how the microstructure of the To determine how the microstructure of the carbon-carbon composites affect the carbon-carbon composites affect the properties of aircraft brakesproperties of aircraft brakes
To find out the best methods to determine To find out the best methods to determine porosity and fiber alignment to be used as porosity and fiber alignment to be used as quality control testsquality control tests
Sample 1Sample 1
Sample 2Sample 2
Sample 3Sample 3
Sample 4Sample 4
Optical MicroscopyOptical MicroscopySample 1:
Optical MicroscopyOptical MicroscopySampleSample 22::
Optical MicroscopyOptical MicroscopySample 3:Sample 3:
X-ray Diffraction Results X-ray Diffraction Results
Sample1
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10 20 30 40 50 60
2-Theta - Scale
Lin
(C
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X-ray Diffraction ResultsX-ray Diffraction Results
Sample2
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5 15 25 35 45 55 65
2-Theta - Scale
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X-ray Diffraction ResultsX-ray Diffraction Results
Sample3
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X-ray Diffraction ResultsX-ray Diffraction Results
Sample4
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2-Theta - Scale
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MicrotomeMicrotome Cuts thin slices (microns Cuts thin slices (microns
thick) of your specimen thick) of your specimen Specimen must be soft Specimen must be soft
Beem Capsule Microtome
Microtomy ResultMicrotomy Result
Sample #Sample # Mass Mass Before Before HeatingHeating
Mass After Mass After HeatingHeating
% Mass % Mass ChangeChange
11 2.03582g2.03582g 2.035472.03547 0.01719%0.01719%
22 1.78192g1.78192g 1.78138g1.78138g 0.0303%0.0303%
33 1.16317g1.16317g 1.13793g1.13793g 2.1699%2.1699%
44 2.74388g2.74388g 2.72870g2.72870g 0.55323%0.55323%
SEM ImagesSEM Images
Sample 1:Sample 1:
SEM ImagesSEM Images
Sample 2:Sample 2:
SEM ImagesSEM ImagesSample 3:Sample 3:
SEM ImagesSEM ImagesSample 4:Sample 4:
ConclusionsConclusions
Crystallinity of carbon fibers varies considerably Crystallinity of carbon fibers varies considerably between specimensbetween specimens
In samples 2, 3 and 4 the amorphous carbon matrix In samples 2, 3 and 4 the amorphous carbon matrix and carbon fibers are not well bound together, thus and carbon fibers are not well bound together, thus matrix is not providing any benefits to the structurematrix is not providing any benefits to the structure
In sample 1 amorphous carbon matrix and carbon In sample 1 amorphous carbon matrix and carbon fibers are bound together but it is not inter-grown fibers are bound together but it is not inter-grown together, thus matrix is still not providing any together, thus matrix is still not providing any benefits to the structurebenefits to the structure
Carbon was only deposited on the surface in one of Carbon was only deposited on the surface in one of the specimens: amorphous carbon nucleation is the specimens: amorphous carbon nucleation is found only very rarely on the fiber surfaces in this found only very rarely on the fiber surfaces in this specimenspecimen
Future WorkFuture Work
Improvement of the sectioning process to Improvement of the sectioning process to retain shell and core structure of carbon-retain shell and core structure of carbon-carbon composite carbon composite
Refine techniques for embedding the material Refine techniques for embedding the material Develop a capacity for thin section specimens Develop a capacity for thin section specimens
for transmitted light microscopy and TEMfor transmitted light microscopy and TEM Routine SEM and XRDRoutine SEM and XRD Relate results to processing the samples Relate results to processing the samples
have been exposed tohave been exposed to
AcknowledgementsAcknowledgements
Prof. Alex King Prof. Alex King Indiana 21Indiana 21stst Century fund Century fund HoneywellHoneywell
Questions?Questions?