Materials and Structures for AerospacePropulsion Systems

Materials and Structures for AerospacePropulsion Systems

X-43b

Image courtesy of ATK

Scramjets Rocket

Aeroturbine

High By-pass Aeroturbine

http://www.aip.org/tip/INPHFA/vol-10/iss-4/p24.html

Air flow

Scramjets integrate air and space by Dean Andreadis

Efficiency of Various Propulsion Cycles:Specific Impulse (Thrust/weight)

Turbojets

Scramjets

Ramjets

TurbojetsRamjets

Scramjets

Hydrocarbon Fuels

Hydrogen Fuel

0

2000

4000

6000

8000

0 10 20

MACH NUMBER

Isp

RocketRBCCTBCC

Rockets

0

1

2

3

4

5

6

7

8

9

10

0 1 2 3 4 5 6 7 8 9 10 11 12

Flight Mach Number

TSFC

(Lbm

/Lbf

/Hr.)

Ramjet Take Over

Scram/Rocket

Ram/Scram Operation

Rocket Off

Conventional RocketTu

rbin

e En

gine

s

Hydrogen Fuel

Specific Fuel Consumption for Various Concepts

Fuel Efficiency In the Aero-turbine Industry:

PW4098PW4084

JT8D-217

JT8D-9

JT3D-1

JT9D-7R4G2

JT9D-3A

JT9D-7A

PW4056PW2037

V2500 A1

PW4168

CJ805

CF6-6DCFM56-2

CFM56-5A

GE90-85B

CF6-80ACFM56-5C4

CF6-80C2-B6F

CF6-80E1-A2

RB-211-535E4

TRENT 895

RB-211-524D

TAY 620

BR 715

1950 1960 1970 1980 1990 2000 2010 2020

Certification Date

Spec

ific

Fuel

co

nsum

ptio

n

JT3C

Low Bypass Turbofan

2nd Gen High Bypass Turbofan

High Bypass Turbofan

Turbojet

GE90-115B

R. SHAFRICK, GE Aircraft Engines

62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 00 02 04 06 08 10 12

Engine Certification Date

Gas

Tem

pera

ture

, FR

T

CF6-50E CF6-50E2

CF6-80A3

CFM56-2B

CF6-80C2A5CF6-80E1

CFM56-3B1

CFM56-3C

CFM56-5A

CFM56-5BCFM56-5C4

CFM56-5C2CFM56-7B

CF34-8C1

CF34-10

GE90-115B

GE90-94B

GE90-90B

CF6-80C2D1F

CF6-80C2B1F

CF6-80C2A1CFM56-3B2

CF34-3BCF34-3A

Trent 556

PW 6024

Trent 892

PW 4090

BR 715

BR 710

V2533Trent 772

PW 4062

JT8D-219

PW 2037

JT9D

RB 211

TF33

Engine Temperature Trend

Role of Airfoil Materials

IncreasedTemperature Capability(K)

1985 1990 1995 2000 2005

Introduction Date

GEN1GEN2

GEN3

GEN4

CMCs

Advanced Thermal B

arrier S

ystems

Turbine Airfoil Material Advancements

Superalloys

1000

1300

1600

Specific Strengths of Metallic Systems

Superalloys &Refractories

More High Temperature Materials

Role of Airfoil Materials

IncreasedTemperature Capability(K)

1985 1990 1995 2000 2005

Introduction Date

GEN1GEN2

GEN3

GEN4

CMCs

Advanced Thermal B

arrier S

ystems

Turbine Airfoil Material Advancements

Superalloys

1000

1300

1600

Superalloy Turbine Air Foils

Equiaxed (EQ) Dir. Sol. (DS) Single Xtal (SX)

ASM-TMS NY042198 16

Year of Introduction

840

860

880

900

920

940

960

980

1000

1020

1969 1972 1982 1984 1988 1989 1994

Ρ80

Ρ125

Ρ80Η

Ρ142

Ν4

Ν5

Ν6

Tem

pera

ture

Cap

abili

ty -

°C

ΜΞ

4

2000

Ni Superalloy Improvements

ModelingModeling at the scale of the grainsat the scale of the grains

Single crystal turbine Single crystal turbine bladeblade

Role of Airfoil Materials

IncreasedTemperature Capability(K)

1985 1990 1995 2000 2005

Introduction Date

GEN1GEN2

GEN3

GEN4

CMCs

Advanced Thermal B

arrier S

ystems

Turbine Airfoil Material Advancements

Superalloys

1000

1300

1600

Airfoil TechnologyAirfoil TechnologyHeatTransfer

High Performance Coating Systems:Enabling technology for advanced gas turbines

Transverse Section

Al Reservoir

Thermal Barrier Multilayer

Nanoscale Porosity

Deposition Effects on MicrostructureDeposition Effects on Microstructure

Platform Mode

Airfoil Mode

• Reduced coating thickness within recess, quantitatively consistent with reduction in integrated flux due to shadowing by corners.

• Reduced inter-columnar gap width—and increased propensity to sintering—due to elimination of most oblique vapor flux.20 µm

5 µm2 µm

Interplay withComponentGeometry

Interplay withComponentGeometry

Role of Airfoil Materials

IncreasedTemperature Capability(K)

1985 1990 1995 2000 2005

Introduction Date

GEN1GEN2

GEN3

GEN4

CMCs

Advanced Thermal B

arrier S

ystems

Turbine Airfoil Material Advancements

Superalloys

1000

1300

1600

Ceramic Matrix Composites (CMC)

CMC’s Reduce Weight and Improve Performance

CMC Combustor Liner

Cooling Air Reduction Weight Reduction20% NOx Reduction

CMC Vane CMC Blade

Weight ReductionReduced Cooling AirIncreased Efficiency

(MI) SiC/SiC (DENSE MATRIX)

T = 1400C (Metals < 1100C)

High Thermal Conductivity

Inter-laminar Shear Strength

Reduced Sensitivity to Pesting

Integrally woven CMC Structures

Transition duct

Braided SiC/SiCHyper-Therm Inc.

Alumina anchor tube in CMC skin for pin joint

Metallic struts with CMC skin

Nozzles

±45°

Angle Interlock Sylramic/SiC

CMC Inner Combustor Liner After Engine Testing

Hi-Nicalon, Slurry Cast Successful Engine TestingPre and Post Engine Test NDE

Revealed DegradationAdditional Engine Testing

CMC Combustor Liner Rig & Engine Testing Successful

CMC Combustor Liners

CMC Applications in Utility Gas Turbines

Vanes

Annular Combustors ShroudSegments

Benefits:• NOx reductions (50%)• CO reductions (50%)• Improved stability• Life improvement

Benefits:• 90% cooling air reduction• Efficiency gains of >1%• NOx reductions (50%)

Benefits:• >90% cooling air reduction• 0.4% efficiency gain• Cost savings over SOA technology

Benefits:• 90% cooling air reduction• 0.2% efficiency gain• Reduced tip clearance

These efficiency, power, and emissions benefits translate to $M in annual savings for each installation.

These efficiency, These efficiency, power, and emissions power, and emissions benefits translate to benefits translate to $M in annual savings $M in annual savings for each installation.for each installation.

Hybrid CMC Concept

The "hybrid" concept involves use of a moderate temperature (~1100° -1200°C) CMC structural member bonded to a ceramic insulating materialhaving good stability at 1600°C and good erosion resistance.

• Oxide fiber available• Insulating material technology available• Reduces cooling needs drastically

CeramicAdhesiveBond Line

Temp.1100°C Structural CMC ~4mm

~3mm

Hot Face Temp1600°C

Cold Face Temp750°C

FGI Insulation LayerFGI Insulation Layer

Role of Airfoil Materials

IncreasedTemperature Capability(K)

1985 1990 1995 2000 2005

Introduction Date

GEN1GEN2

GEN3

GEN4

SiC/SiC CMCs

Advanced Thermal B

arrier S

ystems

Turbine Airfoil Material Advancements

Superalloys

1000

1300

1600

Thermal Barrier Multilayer:Challenging Thermo-Chemo-Mechanical System

Thermal Property Interplay

RESIDUAL STRESS IN TGORESIDUAL STRESS IN TGO

Thermal Property Interplay

Slide 24

Thermal Barrier Multilayer:Challenging Thermo-Chemo-Mechanical System

As Deposited

TGO

EB-PVD on FeCrAlY substrate

TGO

After 100h at 1200°C

YSZ Compatibility with TGOYSZ Compatibility with TGO

1200°C

Limit of thermochemicalcompatibility ~21%YO1.5

Zirconatereactive with TGO

1 µm

7YSZ compatible with TGO(no inter-phases formed)

Degradation Modes In Engines

40%

80%

TBC

spal

latio

n

ImpactDamage

1820 engine cycles

TBCspallation

Delay Spalling By UnderstandingMechanisms

And Adjusting ConstituentProperties

Step I:Identify All Mechanisms Limiting DurabilityStep I:Identify All Mechanisms Limiting Durability

Step II: Develop Models that Relate Durability to Material Properties

• Strain misfits cause cyclic stresses that motivate cycle-by-cycle crack growth in TBC

• Highly non-linear:Requires numerical code.

Example I (Intrinisc): Failure by TGO RumplingExample I (Intrinisc): Failure by TGO Rumpling

• Phenomena include TGO lateral growth, thermal expansion misfit (martensite), cyclic plasticity.

Martensite

Swelling

LARGE SCALE BUCKLE: THE END OF LIFELARGE SCALE BUCKLE: THE END OF LIFE••WHAT HAPPENED EARLIERWHAT HAPPENED EARLIER??

Fails at Oxide/Oxide Interface

DISPLACEMENT INSTABILITYDISPLACEMENT INSTABILITY

Relevant Phenomena:•Elongation/Thickening of TGO

•Plastic Flow of Bond Coat•Strain Misfit of Bond Coat

Multi-Parameter Phenomenon:

Need Model

Plus

Critical Experiments

DESCRIBE CONJOINTLY

OBJECTIVE: DEVISE MECHANISM MAPS THAT SPECIFY SALIENT NON-DIMENSIONAL PARAMETERS

UNDERSTAND THE FUNDAMENTALS

TGO

Deformation Mechanism Map Synchotron Measurements

Synchotron Measurements

•Thermal Expansion•Martensite•Swelling

“Soften” Bond Coat

STRAIN MISFITS: MARTENSITE TRANSFORMATION

41 42 43 44 45 46 47 48 49

41 42 43 44 45 46 47 48 49

600C

650C

L10

B2

Model Validation: Example

1. Elastic properties of constituents

2. Thermal expansion mismatch between layers.

3. Power-law creep.

4. Reversible phase transformation in bond coat.

5. Growth stress in TGO.

6. Thickening and lateral growth strain in the TGO

7. Initial Interface Imperfections

VALIDATION EXPERIMENTS: AN EXAMPLE

QuickTime™ and aGIF decompressor

are needed to see this picture.

ANIMATION OF TGO DISTORTION AND ELONGATION

BC

Substrate

Code now in use at GE

Balint-Hutchinson CodeModel

Validation:Transition

to GE

Model Validation:Transition

to GE

TGO

SENSITIVITY STUDY USING MECHANISM MAP:CAN MECHANISM BE SUPPRESSED?

USE MECHANISM MAP TO ELIMINATE RATCHETING

Interface ToughnessBecomes Key

Parameter:

Gside =12

Sπ4

δb

⎛ ⎝

⎞ ⎠

4

+2Dπb

⎛ ⎝

⎞ ⎠

2 π4

δb

⎛ ⎝

⎞ ⎠

2

f=0.26 f=1.0

NEW INTERFACE TOUGHNESS TEST

Γ = 20Jm-2

Mode I Adhesion Energy of Metal / Alumina Interfaces

Work of Separation: Ni/Al2O3 interfaces

1.30J/m2

Al-termination O-termination

3.79 J/m2

6.84 J/m2 3.25 J/m2

TBC Ni(Al)/Al2O3 interface:Fracture at interfaceMode I toughness ~ 20 J/m2

Pure Ni/Al2O3 interface:Fracture in AluminaMode I toughness > 300 J/m2

Expt.

Theo.

Failure Modes After Engine TestDelay Spalling

By UnderstandingMechanisms

AndAdjusting Constituent

Properties

50µm

50µm

Two Basic Erosion and FOD MechanismsTwo Basic Erosion and FOD Mechanisms

I:Elastodynamic

II:Viscoplastic

4

LESimulations

Viscoplastic Domain

QuickTime™ and aBMP decompressor

are needed to see this picture.

Soft at High Temperature

ELASTO-DYNAMICDOMAIN

Identify Importance of Material Properties:

High ToughnessSoft at High Temperature

Erosion Threshold MapErosion Threshold Map