11

EF 152EF 152Materials RecitationMaterials Recitation

August 31, 2009August 31, 2009

Materials Science and EngineeringMaterials Science and EngineeringDepartmentDepartment

22

Materials RecitationMaterials Recitation

Space Elevator Material RequirementsSpace Elevator Material Requirements

Hot Wire & Shape Memory DemoHot Wire & Shape Memory Demo

Material ApplicationsMaterial Applications Heat SinkHeat Sink Biomimetic Biomimetic LensLens SpaceShipOneSpaceShipOne

Affect of Heat Treatment DemoAffect of Heat Treatment Demo

MSE Dept. InformationMSE Dept. Information

33

Space ElevatorSpace Elevator

44

LifterLifter

55

Space ElevatorSpace Elevator

rocket: $20,000/kg to orbitrocket: $20,000/kg to orbitelevator: $200/kg to orbitelevator: $200/kg to orbitelevator much saferelevator much safer no rocketsno rockets no re-entry heatno re-entry heat

~$10 billion to build elevator~$10 billion to build elevator NASA budget = $15 billion/yrNASA budget = $15 billion/yr $0.5 billion per shuttle launch$0.5 billion per shuttle launch

8 days one way8 days one way

material for cable?material for cable?

66

Material requirements forcable?

strength

density

77

Geostationary OrbitGeostationary Orbit

=!

hrsec

dayhr 600,324

2 R"

Fg

v

R

( )

m 42.24x10

360024

4

6

22

2

2

2

gravity

=

=!

=

=

R

R

mmG

Rm

R

mmG

R

mv

Fma

E

E

n

"

Geostationary: satellitestays above same point onearth’s surface(geosynchronous)

88

Force on CableForce on Cable

Cable must support weight of cable beneath itCable must support weight of cable beneath it

dRR

GMrdF cableg 2

2!"=

[ ]112

R

6456

2

2

)m645.6()kg 246)(1167.6(

1)(

2

3 !! !!=

= "

REEEr

dRR

GMrRF

skg

m

E.

cable

g

#$

#$

!"

#

"!

2

2

2

2

7E3.5

7E3.5

m, 42.24E6 Rat

2

2

s

m

cable

gcable

s

mcable

g

r

F

rF

==

=

=

99

Material Requirement for CableMaterial Requirement for Cable

32

2

kg/m

Pa

s

m 73.5735 EE.ñ

óUTS

==

“Specific Strength”

1010

StrengthStrength

1111

DensityDensity

1212

Specific StrengthSpecific Strength

Material _ (kg/m3) _UTS (MPa) _UTS/_ (m2/s

2)

7075 T6 Al 2,800 505 1.8E+05

Ti-6Al-4V 4,430 1,172 2.6E+05

440A Stainless steel 7,800 1,790 2.3E+05

Nylon 6,6 1,140 90 7.9E+04

Polyester 1,250 85 6.8E+04

Kevlar 49 1,440 4,100 2.8E+06

Spectra 2000 970 3,340 3.4E+06

Silicon Carbide 3,200 825 2.6E+05

Silicon Nitride 3,300 1,000 3.0E+05

Diamond 3,400 1,400 4.1E+05

C fiber 1,790 6,350 3.5E+06

E-glass 2,580 3,450 1.3E+06

1313

Specific StrengthSpecific Strength

σ UTS/ρ

= 5.3E

7 m2 /s

2

1414

Carbon Carbon NanotubesNanotubes

11stst produced in 1991 produced in 1991C=C double bonds C=C double bonds stronger than diamond stronger than diamond~ 1 nm in diameter~ 1 nm in diameter

1515

Carbon Carbon NanotubesNanotubes

100 X stronger than diamond100 X stronger than diamond1/6 density of steel1/6 density of steelup to 500 X specific strength of steelup to 500 X specific strength of steelρρ = 1,300 kg/m= 1,300 kg/m33

highest measured strength = 63 highest measured strength = 63 GPaGPa 4.8E7 m 4.8E7 m22/s/s22 90% of target90% of targettheoretical strength = 150 theoretical strength = 150 GPaGPa 11.4E7 m 11.4E7 m22/s/s22

suitable for space elevator cablesuitable for space elevator cable

1616

Carbon Carbon Nanotubes Nanotubes ChallengesChallenges

CNTs CNTs are 4 cm long, 1 nm diameterare 4 cm long, 1 nm diameterneed 36,000 km long, 0.5 mm diameter cableneed 36,000 km long, 0.5 mm diameter cable composites containing 50% composites containing 50% CNTsCNTs

binding between binding between CNTs CNTs and matrixand matrixkm long composite fibers (3% CNT) have beenkm long composite fibers (3% CNT) have beenproduced with 2 produced with 2 GPa GPa strengthstrength

twisted CNT yarntwisted CNT yarnCost, ~ $25,000 per kgCost, ~ $25,000 per kg

1717

Hot Wire & Shape MemoryHot Wire & Shape MemoryDemonstrationsDemonstrations

1818

Thermal ManagementThermal Management

Heat generated by electronic devices must beHeat generated by electronic devices must bedissipated to improve reliability and prevent failure.dissipated to improve reliability and prevent failure.

1919

Thermal ManagementThermal Management

Heat Sink DesignHeat Sink Design

2020

Thermal ManagementThermal Management

Which has highest thermal conductivity?Which has highest thermal conductivity?

AluminumAluminum

DiamondDiamond

GoldGold

SilverSilver

2121

Thermal ManagementThermal Management

2222

Chemical Vapor Deposition (CVD)Chemical Vapor Deposition (CVD)

methane (CH4) is heated: CHmethane (CH4) is heated: CH44 C + 4H C + 4Hgaseous C can deposit on substrate as diamondgaseous C can deposit on substrate as diamond

Synthetic DiamondSynthetic Diamond

2323

ProblemsProblems

Difficult to produce large areas (cmDifficult to produce large areas (cm22))

Slow growth ratesSlow growth rates

CostCost

Synthetic DiamondSynthetic Diamond

2424

Lenses in NatureLenses in Nature

Hierarchical layered protein structuresHierarchical layered protein structures

Refractive index gradientsRefractive index gradients Enhance focusing powerEnhance focusing power

Correct aberrationsCorrect aberrations

Reduce number of components neededReduce number of components neededfor optical systemfor optical system

2525

Traditional LensTraditional Lens

Focus is a result of geometry and refractionFocus is a result of geometry and refractionRefractive index does not vary within lensRefractive index does not vary within lens

2626

Focusing by an index gradient aloneFocusing by an index gradient alone

2727

Multilayer Polymer Gradient Index (GRIN) LensMultilayer Polymer Gradient Index (GRIN) Lens(Case Western Reserve University*)(Case Western Reserve University*)

* funded by DARPA 2828

Multilayer FilmsMultilayer Films

10 10 splittings splittings 2048 layers 2048 layers50 50 µµm m film film 24 nm layers (must be < 50 nm for transmission) 24 nm layers (must be < 50 nm for transmission)Polycarbonate (PC), n = 1.58Polycarbonate (PC), n = 1.58 CD, DVD substrates, eyeglasses, water bottlesCD, DVD substrates, eyeglasses, water bottles

Poly(methyl Poly(methyl methacrylatemethacrylate) (PMMA), n = 1.49) (PMMA), n = 1.49 PlexiglassPlexiglass, latex paint, countertops, lenses, aircraft cockpits, latex paint, countertops, lenses, aircraft cockpits

2929

Multilayer FilmsMultilayer Films

Refractive index of film corresponds to a thickness-weightedRefractive index of film corresponds to a thickness-weightedaverage of the indices of the component polymersaverage of the indices of the component polymers

3030

GRIN FilmGRIN Film

...

...

100/0 PMMA/PC, n = 1.490

0/100 PMMA/PC, n = 1.580

99/1 PMMA/PC, n = 1.491

98/2 PMMA/PC, n = 1.492

50/50 PMMA/PC, n = 1.535

2/98 PMMA/PC, n = 1.578

1/99 PMMA/PC, n = 1.579

3131

GRIN Lens FabricationGRIN Lens Fabrication

3232

X-PrizeX-Prize

US $10M prize for the first non-government organization tolaunch a reusable manned spacecraft into space twice withintwo weeksSpaceShipOneSpaceShipOne, October 2004, October 2004

3333

X-PrizeX-Prize

3434

SpaceShipOne

produced by Scaled Composites, LLC.designed by Burt Rutanproject funded at $20M by Paul Allen (Microsoft)carried to 14 km by White Knight aircraft(afterburning twin turbojets)hybrid rocket motor generates 88 kN thrust for 87sec.reached altitude of112 kmnow on display at National Air and Space Museum

3535

WhiteKnightOne and SpaceShipOneWhiteKnightOne and SpaceShipOne

3636

SpaceShipTwo

produced by Scaled Composites & Virgin (RichardBranson)2X size of SpaceShipOneprivate spaceflight service starting 2009 or 2010two pilots and six passengers110 km target altitudecarried to 15 km by White Knight Two$200,000 per flight200 customers have pre-paidpassengers must pass 6-8 g centifruge test

3737

MaterialsCarbon fiber composites have excellent strength toweight ratio (specific strength)Glass and Kevlar fibers also usedHigh performance, toughened epoxy matrixCarbon fiber panels sandwiched around honeycombcoreWhite Knight Two largest all-carbon-fiber aircraft ever built 140 ft wing spar is the longest single carbon

composite aviation component ever manufactured most fuel efficient airplane ever created

3838

Affect of HeatAffect of HeatTreatmentTreatment

BrassBrassTool SteelTool Steel

3939

Materials Science & EngineeringMaterials Science & Engineering

Structure

Processing PropertiesEngineering

Science Scienc

e

MATERIALS DEVELOPMENT4040

MSE at UTMSE at UT

Class Size ~ 10-15 per yearClass Size ~ 10-15 per yearScholarships, ~ 75% receivingScholarships, ~ 75% receivingscholarships from dept: $800 - $2600scholarships from dept: $800 - $2600per yearper year28 Faculty28 Faculty~ $5 M in annual research funding~ $5 M in annual research fundingUG research, thesis or paidUG research, thesis or paid

4141

MSE ScholarshipsMSE Scholarships

FreshmanFreshman $800 - $1,200 per year$800 - $1,200 per year

SophomoreSophomore $1,200 - $1,600 per year$1,200 - $1,600 per year

JuniorJunior $1,600 - $2,100 per year$1,600 - $2,100 per year

SeniorSenior $2,100 - $2,600 per year$2,100 - $2,600 per year

4242

MSE CurriculumMSE Curriculum

FundamentalsFundamentals

ThermodynamicsThermodynamicsKinetics & Transport PhenomenaKinetics & Transport PhenomenaProcessingProcessingMechanical BehaviorMechanical BehaviorDiffusion & Phase TransformationsDiffusion & Phase TransformationsStructural CharacterizationStructural CharacterizationMaterials Lab (2 semesters)Materials Lab (2 semesters)

4343

MSE CurriculumMSE Curriculum

Material ClassesMaterial Classes

PolymersPolymersCeramicsCeramicsMetal AlloysMetal AlloysElectrical & Optical MaterialsElectrical & Optical Materials

4444

MSE CurriculumMSE Curriculum

DesignDesign

Materials SelectionMaterials SelectionMaterials DesignMaterials Design

ElectivesElectives

Electronic DevicesElectronic DevicesPolymer ProcessingPolymer ProcessingBiomaterialsBiomaterialsPolymer EngineeringPolymer Engineering

Cell & Tissue-Cell & Tissue-Biomaterials InteractionBiomaterials InteractionIntermetallics & CompositesIntermetallics & CompositesAdvanced BiomaterialsAdvanced Biomaterials

4545

Biomaterials ConcentrationBiomaterials Concentration

4 required courses4 required courses

2 MSE 4XX Electives2 MSE 4XX Electives

2 Technical Electives2 Technical Electives

Nanomaterials Concentration planned forNanomaterials Concentration planned for2010-2011 Catalog2010-2011 Catalog

4646

Research OpportunitiesResearch Opportunities

• ~ $5 M in annual research funding• Subsidized research opportunities for freshmen &

sophomores• Several research opportunities at ORNL• Recent undergraduate research topics include

Piezoelectric Polymer Fibers Computer Modeling of Micro-Scale Grains Infrared Dichroism of Nonwoven Polymer Fibers Nanocrystalline Biosynthesized Magnetite Retained Austenite in Magnetically Processed Steel Processing of Graphite Carbon Foams

4747

For more information, contact:For more information, contact:Dr. Kevin KitDr. Kevin Kitkkit@utk.edukkit@utk.edu510 Dougherty510 Dougherty974-7055974-7055