MODELING MATERIALS IN EXTREME ENVIRONMENTS

MODELING MATERIALS IN EXTREMEENVIRONMENTS

PERSPECTIVE FOR CERAMIC MATERIALS

Ali Sayir

NASA GRC and Case Western Reserve University

OUTLINE1. CURRENT APPROACH: MATERIAL SELECTION

CRITERIA

2. PERSPECTIVES ; an example HfC

* Time scale t <1000 s

* Time scale t > hours

* Thermodynamic compatability of polyphase structures;

Role of carbon

3. EXPERIMENTAL CAPABILITIES

* Phase diagram study; T > 3500 °C

* Activity measurements; T>2400 °C

* Functional properties emissivity, conductivity, etc.

* Rocket testing

0

1000

2000

3000

4000

100

101

102

103

104

105

106

107

TE

MP

ER

AT

UR

E, °C

SECONDS

SMALL

SPACE

BOOSTERS

SOLID ROCKETS

AIRCRAFT

ENGINES

SATELLITE PROPULSION BOOSTERS

ADVANCED

AIRCRAFT

CONCEPTS

LIQUID ROCKETENGINENOZZLES

CRUISE MISSILES

THRUST

CHAMBERS

SOLID STAGED COMBUSTION

1 MINUTE 1 HOUR 10 HOURS 1000 HOURS

The operating temperature - time regimes for aeropropulsionsystems

WC, W2C, VC, MoC, Mo2C,

ZrN, TiN

WB, TiB2, Nb3B4, WB2

YB2, ZrB, W2B

HfO2, UO2, ThZrO4, MgO

ZrO2-Er2O3, ZrO2, SrZrO3

HfC, TaC, NbC, ZrC, Ta2C, TiC,HfN, TaN,

HfB, HfB2, TaB2, ZrB2, NbB2, ThO2

Refractory MetalCeramics

SiC, B3SiLight Ceramics

ReW, Re3W, Re2Ti5,Intermetallics

W, Mo, Ir, Os, TaMetals

Diamond, graphiteCarbon

Marginal MaterialsTm << 3000 °C

Prime MaterialsTm > 3000 °C

Type ofMaterial Classification of

materials usingsingle criteria;melting pointN. J. Shaw, J. A. DiC arlo, N. Jacobson, S. R . Levine, J. A. Nesbi t t , H. B. Probst , W.Sanders and C . A. Stearns, NASA Techn. Memorandum, 100169 (1987).

E. L. C ourt right , H. C . Graham, A. P. Katz, and R . J. Kerans, R pt . No, WL-TR -91-4061,Wright Pat t erson Ai r Force Base, OH (1991).

W. B. Hi l l i g, “prospect s for Ul t ra-High Temperature C eramic C omposi t es, ” JOM (1989) 697-704.

ADDITONAL CRITERIAS:Total vapor pressure of nitrides and borides Total vapor pressure of carbides

Material Selection Criteria ?

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

0.0003 0.0004 0.0005 0.0006

ZrB2

BN

HfN

TiN

TaN

ZrN

TiB2

AlN

Si3N4

1/T, K

PRESSURE, ATM

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

0.0003 0.0004 0.0005 0.0006

ZrC

TaC

NbC

HfC

TiC

SiC

Al4C

PRESSURE, ATM

1/T, K

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

0.0003 0.0004 0.0005 0.0006

HfO2

Y2O3

ZrO2

Al2O3

La2O3

CaO

MgO

SrO

CeO2

PRESSURE, ATM

1/T, K

Total Vapor Pressure of Oxides

These data weretaken from Shaw etal. [19] whocompiled the datafrom originalsources.

Critical review of theavailable data wasnot available.

ZrO2, Y2O3 and HfO2have quite lowvapor pressures;however, at 1925 °Conly HfO2 has thelowest recessionrate.

OUTLINE1. CURRENT APPROACH: MATERIAL SELECTION CRITERIA

2. PERSPECTIVES -- An example: HfC

* Time scale t <1000 s* Time scale t > hours* Thermodynamic compatability of polyphase

structures; Role of carbon

3. EXPERIMENTAL CAPABILITIES

* Phase diagram study; T > 3500 °C

* Activity measurements; T>2400 °C

* Functional properties emissivity, conductivity, etc.

* Rocket testing

0

1000

2000

3000

4000

100

101

102

103

104

105

106

107

TE

MP

ER

AT

UR

E, °C

SECONDS

SMALL

SPACE

BOOSTERS

SOLID ROCKETS

AIRCRAFT

ENGINES

SATELLITE PROPULSION BOOSTERS

ADVANCED

AIRCRAFT

CONCEPTS

LIQUID ROCKETENGINENOZZLES

CRUISE MISSILES

THRUST

CHAMBERS

SOLID STAGED COMBUSTION

1 MINUTE 1 HOUR 10 HOURS 1000 HOURS Perspective for shorter time regime foraeropropulsion systems: t < 1000 s

Functionality and immediatestructural integrity

Hemispherical Reflectance

0

20

40

60

80

100

0.8 1.2 1.6 2 2.4 2.8

Wavelength (microns)

Refl

ecta

nce (

%)

TaC

shiny Pt

graphite

HfC (01N16)

HfC (01N17)

HfC (01N17)shiny

HfC/TaC(01N18)

Functionality: Reflectance ?

(a) (b)

(c) (d)

HfC deposition on the PC coated fiber fabrics. Highermagnification micrographs ((b) and (d)). [Run# 01N14].

Integrity: Does the oxidation reactioncause high transient thermal stresses ?

0

1000

2000

3000

4000

100

101

102

103

104

105

106

107

TE

MP

ER

AT

UR

E, °C

SECONDS

SMALL

SPACE

BOOSTERS

SOLID ROCKETS

AIRCRAFT

ENGINES

SATELLITE PROPULSION BOOSTERS

ADVANCED

AIRCRAFT

CONCEPTS

LIQUID ROCKETENGINENOZZLES

CRUISE MISSILES

THRUST

CHAMBERS

SOLID STAGED COMBUSTION

1 MINUTE 1 HOUR 10 HOURS 1000 HOURS

Perspective for longer time regime foraeropropulsion systems: t > hours1. The interlayer HfCxOy is an oxygen diffusion barrier. How good is this

statement true?

2. Can models predict the adherence strength for both the residual carbide and outer oxide ?

3. The outer HfO2 contains discontinuities (pores) scaling in 0.01 µm. How efficient can they act as TBC?

4. HfO2 is one the most stable oxide. Can the phase transition can be eliminated using Ta2O5.

0

0.2

0.4

0.6

0.8

PA

RT

IAL

PR

ES

SU

RE

S, A

TM

DISTANCE FROM THE CARBIDE / OXIDE INTERFACE

0 1 L

CO CO2

O2

N2

HfC

+3

CO

2=

HfO

2+

4C

O

4C

O2+

2O

2=

4C

O2

"R

EA

CT

IO

NS

"

JCO

= 4a

JCO2

= 3a

JO2

= 2a

JCO2

= 1a

POROUS HfO2

JO = 2a

JC = 1a

"F

LU

XE

S"

5. Need solid and gaseous diffusion model ?

6. Need oxygen diffusion constants ?

2.6 x 10-7

1.6 x 10-5

1400

2060

Carbide

7.9 x 10-9

1.1 x 10-7

1400

2060

Interlayer:

HfCxOy

8.1 x 10-8

3.0 x 10-6

1400

2060

Outeroxidelayer: HfO2

Oxygen DiffusionConstants, Dieff

[Cm2/s]

Temperature

[°C]

Layer

(a)

(b) (c) (d)

(e) (f)

An Engineered Composite: Role of Carbon for UHTC

(a) Fracture morphology of the composite,

(b) outer surface morphology of HfC,

(c) columnar growth of high strength HfC, crystal at the start ofthe growth,

(d) Compliant (porous) layer,

(e) surface morphology of the fiber.

0

10

20

30

40

50

60

0 0.5 1 1.5 2

STR

ESS

, MP

a

STRAIN, %

PHASE II PHASE II FOCUS AREAFOCUS AREA

The thermodynamic stability of the coexisting phases; compatiblity ?

OUTLINE1. CURRENT APPROACH: MATERIAL SELECTION CRITERIA

2. PERSPECTIVES ; an example HfC

* Time scale t <1000 s

* Time scale t > hours

* Thermodynamic compatability of polyphase structures;

Role of carbon

3. EXPERIMENTAL CAPABILITIES

* Phase diagram study; T > 3500 °C* Activity measurements; T>2400 °C* Functional properties emissivity, conductivity, etc.* Rocket testing

(1) PHASE DIAGRAM STUDY

MEASUREDTEMPERATURE

PRESETTEMPERATURE

TEMPERATUREADJUSTMENT

COMPARE

RECEIVER

PRESET FIBERDIAMETER

FIBER DIAMETERADJUSTMENT

COMPARE

He-Ne LASERFOR FIBERDIAMETERADJUST-MENT

He-Ne

LASER

VACUUMCHAMBER

600WATTCOLASERBEAM

2

INFRARED TEMPERATURE SYSTEM MEASURES AND CONTROLSTHE TEMPERATURE OF THE MOTION ZONE. He-Ne LASER SYSTEM

MEASURES AND CONTROLS FIBER DIAMETER.

FIBER

CD-88-37299

Controlled Parameters:

• Temperature

• Diameter

• Feed-rate / pull-rate

• Heat Distribution

• Heating Rate

• Environment

• Seeding

Spectrographical analysis ofimpurity elements in HfO2

and Ta2O5

< 0.0001 % Ca

0.0001 % Mg

99.997 %pure

Cerac Inc.

Ta2O5

0.002 % Al

< 0.0001 %Ca

< 0.0005 % Nb

99.999 %pure

Cerac Inc.

Hafnium Oxide,

HfO2

SpectrographicalAnalysis

PuritySupplier

StartingCompositions

Experimentally determined phase diagram and hypotheticalphases (solid lines) in the Ta2O5 – HfO2 system

1000

1500

2000

2500

3000

0 20 40 60 80 100

Mel

tin

g P

oin

t, °

C

HfO2, %

Ta2Hf

8O

21

Ta2Hf

5O

15

HfO2S S

Ta2Hf

2O

9

Ta2O

5/HfO

2 =49/2

Ta2O

5/HfO

2 =59/6

Ta2O

5 SS

Ta6HfO

17

thermodynamic data useful models…

component activities provide solution behavior

"effective concentration"

)Al(lnAlAl aRTl =µµ =

i

imix )i(ln aXRTG

Vapor Pressure Technique: directly compare sublimation behavior:

solution phase and reference state

ii)i( Xa =

(Al)

(Al)(Al)

op

pa =

measure pressure ratio as function ( measure pressure ratio as function ( comp.comp., , TT ) )

(2) THERMODYNAMIC DATA

Multiple effusion-cell vapor source

• Pressure range: 10-9 – 10-4 atm. -- temperature range: 1000 – 2500K (depending on p(i))

• Include primary temperature reference(s) (Tmp(Au)…) accurate temperature measurements

• Determine phase transformations

• Vaporization coefficient measurements are possible. Routine measurements in the following systems:

Al-O, Ti-Al-O, Zr-Al-O, Ni-Al-Pt-O and Nb-Ti-Hf-Si

Pt effect on -NiAl / Al2O3

1.1515.039.545.4B

1.12~47.252.8A

Ni/AlPtAlNiAlloy

4/3Al(l) + 1/3Al2O3(cr) =

Al2O(g)

O

Al(l) = Al(g)Al Al(l) + -

Al2O3(cr)

(in Al2O3 cell)

Ni(cr) = Ni(g)pure-Ni (Al2O3

cell)

Ni

Reaction(s)Reference StateComp.

a(Al) vs. Xi and T

1.E-04

1.E-03

1.E-02

1.E-01

0.00056 0.00061 0.00066 0.00071 0.00076

1/T

a(A

l)

Ni-47.2Al (A)

Ni-39.5Al-15.0Pt (B)

+ Pt

A

B

• Propellants- Gaseous O2/H2

• Oxygen/Fuel Ratios – have run from 1-22

and 75-175

• Chamber Pressure

- round hardware,100-1000psia

- square hardware, 100-500psia

• Thrust level –designed for 1000lbf

• Coolants – H2O, GH2, N2

• Max coolant pressure, 1200psi

• Max coolant flow, 300gpm

• Run Durations –determined by H2O and

propellant supply required - up to ~ 9 min

for low Pc and H2O requirements

• Cumulative Run Time per Day –

Determined by O/F and Pc, ~ 30 mins per

trailer

(3) REALISTIC TEST CONDITIONS: Cell 22 - Facility Cell 22 - Facility CapabilitesCapabilites

(H2O)

(H2O)

Cell 22 Cooled Panels Set UpCell 22 Cooled Panels Set Up

Nozzl

e

Injector

Cooled Panel

Water cooled fences

H2 burnoff torch

Advanced Materials and Cooling Concept

Validation in Engine Testing

Advanced Materials and Cooling Concept

Validation in Engine Testing

Cell 22 Testing Supporting Air Force Research Lab

IHPRPT and ALCAN Programs

Transpiration Cooled Liners

•Ceramic and metallic foam liners

•H2 coolant

Radiation Cooled Nozzles

•CMC Materials Screening

•Use temperature to 3500oF

Transpiration Cooled Chambers

•Woven CMC coolant channels

•H2 Coolant

MODELING MATERIALS IN EXTREMEENVIRONMENT

• ACCEPTABLE MATERIAL SELECTION CRITERIA

• PREDICTIVE MODELING IN SHORT TIME SCALE ANDTRANSIENTS

• PREDICTIVE MODELING IN LARGER TIMES SCALES

• THERMODYNAMIC DATA AND REALISTIC TEST CONDITION