11

EF 152EF 152Materials RecitationMaterials Recitation

February 3, 2009February 3, 2009

Materials Science and Engineering Materials Science and Engineering DepartmentDepartment

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 LensBiomimetic Lens 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 orbit

elevator: $200/kg to orbit elevator: $200/kg to orbit

elevator 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 for cable?

strength

density

77

Geostationary OrbitGeostationary Orbit

hr

secdayhr 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: satellite stays above same point on earth’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

64562

2

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

1)(

2

3

REEEr

dRR

GMrRF

skgm

E.

cableg

2

2

2

2

7E3.5

7E3.5

m, 42.24E6 Rat

2

2

sm

cablegcable

smcable

g

r

F

rF

99

Material Requirement for CableMaterial Requirement for Cable

32

2

kg/mPa

sm 73.5735 EE.

ρ

σUTS

“Specific Strength”

1010

StrengthStrength

1111

DensityDensity

1212

Specific StrengthSpecific Strength

Material ρ (kg/m3) σUTS (MPa) σUTS/ρ (m2/s2)

7075 T6 Al 2,800 505 1.8E+05Ti-6Al-4V 4,430 1,172 2.6E+05440A Stainless steel 7,800 1,790 2.3E+05Nylon 6,6 1,140 90 7.9E+04Polyester 1,250 85 6.8E+04Kevlar 49 1,440 4,100 2.8E+06Spectra 2000 970 3,340 3.4E+06Silicon Carbide 3,200 825 2.6E+05Silicon Nitride 3,300 1,000 3.0E+05Diamond 3,400 1,400 4.1E+05C fiber 1,790 6,350 3.5E+06E-glass 2,580 3,450 1.3E+06

1313

Specific StrengthSpecific Strength

σ UTS/ρ

= 5.

3E7 m

2 /s2

1414

Carbon NanotubesCarbon Nanotubes

11stst produced in 1991 produced in 1991

C=C double bonds C=C double bonds stronger than diamond stronger than diamond

~ 1 nm in diameter~ 1 nm in diameter

1515

Carbon NanotubesCarbon Nanotubes

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 GPahighest measured strength = 63 GPa 4.8E7 m4.8E7 m22/s/s22 90% of target90% of targettheoretical strength = 150 GPatheoretical strength = 150 GPa 11.4E7 m11.4E7 m22/s/s22 suitable for space elevator cablesuitable for space elevator cable

1616

Carbon Nanotubes ChallengesCarbon Nanotubes Challenges

CNTs are 4 cm long, 1 nm diameter CNTs are 4 cm long, 1 nm diameter

need 36,000 km long, 0.5 mm diameter cable need 36,000 km long, 0.5 mm diameter cable composites containing 50% CNTscomposites containing 50% CNTs

binding between CNTs and matrixbinding between CNTs and matrix

km long composite fibers (3% CNT) have been km long composite fibers (3% CNT) have been produced with 2 GPa strengthproduced with 2 GPa strength

twisted CNT yarntwisted CNT yarn

Cost, ~ $25,000 per kgCost, ~ $25,000 per kg

1717

Hot Wire & Shape Memory Hot Wire & Shape Memory DemonstrationsDemonstrations

1818

Thermal ManagementThermal Management

Heat generated by electronic devices must be Heat generated by electronic devices must be dissipated 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?

A.A. AluminumAluminum

B.B. DiamondDiamond

C.C. GoldGold

D.D. 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 + 4H

gaseous 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 needed Reduce number of components needed

for optical systemfor optical system

2525

Traditional LensTraditional Lens

Focus is a result of geometry and refractionFocus is a result of geometry and refraction

Refractive 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 splittings 10 splittings 2048 layers 2048 layers

50 50 μμm film m 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 methacrylate) (PMMA), n = 1.49Poly(methyl methacrylate) (PMMA), n = 1.49 Plexiglass, latex paint, countertops, lenses, aircraft cockpitsPlexiglass, latex paint, countertops, lenses, aircraft cockpits

2929

Multilayer FilmsMultilayer Films

Refractive index of film corresponds to a thickness-weighted Refractive index of film corresponds to a thickness-weighted average 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 to launch a reusable manned spacecraft into space twice within two weeks

SpaceShipOneSpaceShipOne, October 2004, October 2004

3333

X-PrizeX-Prize

3434

SpaceShipOne

produced by Scaled Composites, LLC.

designed by Burt Rutan

project 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 87 sec.

reached altitude of112 km

now on display at National Air and Space Museum

3535

WhiteKnightOne and SpaceShipOneWhiteKnightOne and SpaceShipOne

3636

SpaceShipTwo

produced by Scaled Composites & Virgin (Richard Branson)

2X size of SpaceShipOne

private spaceflight service starting 2009 or 2010

two pilots and six passengers

110 km target altitude

carried to 15 km by White Knight Two

$200,000 per flight

200 customers have pre-paid

passengers must pass 6-8 g centifruge test

3737

Materials

Carbon fiber composites have excellent strength to weight ratio (specific strength)

Glass and Kevlar fibers also used

High performance, toughened epoxy matrix

Carbon fiber panels sandwiched around honeycomb core

White 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 Heat Affect of Heat TreatmentTreatmentBrassBrassTool SteelTool Steel

3939

Materials Science & EngineeringMaterials Science & Engineering

Structure

Processing PropertiesEngineering

Science Scienc

eMATERIALS DEVELOPMENT

4040

MSE at UTMSE at UT

Class Size ~ 10-15 per yearClass Size ~ 10-15 per year

Scholarships, ~ 75% receiving Scholarships, ~ 75% receiving scholarships from dept: $800 - $2600 scholarships from dept: $800 - $2600 per yearper year

28 Faculty 28 Faculty

~ $5 M in annual research funding~ $5 M in annual research funding

UG 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

PolymersPolymers

CeramicsCeramics

Metal AlloysMetal Alloys

Electrical & Optical Materials Electrical & Optical Materials

4444

MSE CurriculumMSE Curriculum

DesignDesign

Materials SelectionMaterials Selection

Materials DesignMaterials Design

ElectivesElectives

Electronic DevicesElectronic DevicesPolymer ProcessingPolymer ProcessingBiomaterialsBiomaterials

Polymer EngineeringPolymer Engineering

Cell & Tissue-Cell & Tissue-Biomaterials InteractionBiomaterials InteractionIntermetallics & CompositesIntermetallics & Composites

Advanced BiomaterialsAdvanced Biomaterials

4545

Biomaterials ConcentrationBiomaterials Concentration

4 required courses 4 required courses

2 MSE 4XX Electives2 MSE 4XX Electives

2 Technical Electives2 Technical Electives

Nanomaterials Concentration planned for Nanomaterials Concentration planned for

2010-2011 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 Kit

kkit@utk.edukkit@utk.edu

510 Dougherty510 Dougherty

974-7055974-7055