components dongming zhu, louis j . ghosn *, martha h …

National Aeronautics and Space Administration

Advanced Environmental Barrier Coating Development for SiC/SiC Ceramic Matrix Composite Turbine Vane

Components

Dongming Zhu, Louis J. Ghosn *, Martha H. Jaskowiak

Structures and Materials Division NASA John H. Glenn Research Center

Cleveland, Ohio 44135

• 37th Annual Conference on Composites, Materials, and Structures

January 28 - 31, 2013


Acknowledgements • • The work was supported by NASA Environmentally Responsible Aviation (ERA)

Project and Fundamental Aeronautics Program (FAP) Aeronautical Sciences Project

NASA colleagues: Jim DiCarlo, Jim Smialek, Dennis Fox, Ram Bhatt, Bryan Harder, Robert A Miller, Narottam Bansal

2


Outline

Turbine environmental barrier coating system development: needs and challenges

Advanced environmental barrier coating systems for CMC turbine airfoils • NASA coating development approaches • Current development status

•

Development of SiC/SiC ceramic matrix composite turbine vane environmental barrier coatings and advanced testing • Environmental barrier coating processing • Advanced CMC-EBC rig testing developments • Subelement and subcomponent demonstrations in high pressure

burner rig

Summary and Conclusions

3


NASA Environmental Barrier Coating (EBC) -Ceramic Matrix Composite (CMC) Development Needs •

- NASA Fundamental Aeronautics Program (FAP): Next generation high pressure turbine airfoil environmental barrier coatings with advanced CMCs • N+3 generation (2020-2025) with advanced 2700°F CMCs/2700-3000°F

EBCs (uncooled/cooled)

- NASA Environmentally Responsible Aviation (ERA) Program: Advanced environmental barrier coatings for SiC/SiC CMC combustor and turbine vane components, technology demonstrations in engine tests

• N+2 generation (2020-2025) with 2400°F CMCs/2700°F EBCs (cooled)

CMC Instability

Control

Low emission combustor High Pressure Turbine CMC vane and blade

4


NASA EBC and CMC System Development • Emphasize temperature capability, performance and long-term durability • Develop innovative coating technologies and life prediction approaches • Establish fundamental understanding of materials behavior • Meet long-term subsonic engine hot-time life requirements

- Recession: <5 mg/cm2 per 1000 h

• • Highly loaded EBC-CMCs capable of thermal and mechanical (static/low cycle

and dynamic) loading - (Strength requirements: 15-30 ksi, or 100- 207 MPa)

T Step increase in the material's temperature capability

C bl ty SupersoniCS project 3000°F SiC/SiC CMC

em perature n r=--------:-. - --:-. ----,--- ---- ----,

apa I I (T/EBC) s~~~~~------- - 3000oF+ (1650oC+) / airfoil and combustor 2800°F >--.. \ technologies

Genl

~:;busto~ 2700oF (1482oC) ...-- 2700°F SiC/SiC thin turbine EBC systems for

CMC airfoils Increase in .dT across TIEBC

2700°F (1482°C} Gen Ill SiC/SiC CMCs

Ceramic M~!~~~~!!IE~~-i!~- ---· 2400°F (1316°C) Gen I and GenII SiC/SiC CMCs

·ngle Crystal Superalloy o .-..L..:-->ooU --------------------------- - 2000°F (1093 C)

/'o...--~~-oz..__:. Gen. IV ~-- Genlll .

Gen II - Current commerc1al

Year 5


NASA Turbine Environmental Barrier Coating Development Emphasis •

Improve temperature capability, water vapor stability and long-term durability for advanced high pressure, high bypass turbine engines

Improve coating strength and toughness • Resistance to high-heat-flux, engine high pressure, combustion environment, creep

fatigue, loading interactions

Improved erosion, impact and calcium-magnesium-alumino-silicate (CMAS) resistance and interface stability

Develop and mature advanced processing for turbine airfoil EBCs

6


NASA ERA EBC Development Objectives and Approaches

OBJECTIVE

• Develop a 2700°F turbine EBC systems for advanced , 2400°F capable, high strength SiC/SiC CMC system with 1000 hr durability goals

• Develop advanced vapor based turbine environmental coating processing • Demonstrate high thermal gradient, heat flux, and mechanical loading capabilities of coated CMC systems - addressing LE, TE, cooling hole, and substructure issues

• Establish EBC-CMC airfoil property database and life prediction models

• • Demonstrate HPT CMC turbine vane viability and durability in the High Pressure Burner Rig environments

APPROACH

• Addressing component processing technologies for multicomponent turbine airfoil coating systems

• Developed simulated engine thermal gradient biaxial strength, fatigue and rupture testing to improve turbine vane EBC and CMC processing and design confidence

• Demonstrate turbine airfoil EBC-CMC systems for rig durability and performance testing Environmental barrier coating

coated SiC/SiC CMC vanes

7


• •

•

•

•

NASA Turbine Vane EBC for ERA Program Demonstrations

Focus on high technology readiness level (TRL), high stability multicomponent Hf02-RE20 3-Si02/RE2Si2_x0 7_2x environmental barrier and advanced Hf02-Si bond coat developments Processing optimization for improve coating density and composition control robustness Develop advanced NASA high toughness, Alternating Composition Layered Coating (ACLC) compositions and processing for low RE t' low rare earth dopant low k Hf02 and highe~ rare earth dopant silicates Optimize Hf02-Si based series bond coats

-Achieving high toughness has been one of key emphases for NASA coating technologies

8


Development and Processing of Directed Vapor Electron Beam -Physical Vapor Deposition (EB-PVD) •

- NASA programs in supporting processing developments and improvements with Directed Vapor Technologies International, Inc.

- Multicomponent thermal and environmental barrier coating vapor processing developments

- High toughness erosion resistant turbine coatings - Affordable manufacture of environmental barrier coatings

NAS~ond NASA Hybrid coat on SiC/SiC ESC on SiC/SiC Advanced multi-component and multilayer turbine ESC systems

Directed Vapor Processing Systems

9


•

';I(

s:£ ·c; .b en

-a ..... 0 f-

Thermal Gradient Tensile Creep Rupture Testing of Advanced Turbine Environmental Barrier Coating SiC/SiC CMCs

Advanced high stability turbine vane environmental barrier coatings demonstrated based turbine environmental barrier coatings being successfully tested for long-term creep rupture capability The new generation bond coat tested up to 2500F showed no major degradations The new CVI-MI with Hi-Nicalon TM Type S Type S fibers SiC/SiC CMCs also showed promise in creep resistance

1. 0 .---r---r---r--r---,--...,..-.,--.---r---r---r--r---,---r-r--1r--T-r--,---,

- - - -•-- -- CVI 10C3 80-P02-5 EBC ID 42 (3 .5.4), 10 ksi -- Prepreg MI1 849-02-001-2 EBC ID29 (3.5.3), 15 ksi

0.8 CVI-MI 12C-461-002 #5 APS Combustor EBC, 15ksi

0.6

0.4

0.2 ,.,

0.0 0

Tsurface = 2700F /.I Tinter face = 2500F / ' Tback = 2350F ,./ 15ksi //

i '

~_,Y • Tsurface = 2700F ./ Tsurface = 2700F Tinterface = 2350F

_,.... Tinterface = 2600F Tback = 2250F ~,,_,• Tback = 2550F 15ksi

200 400 600 800 1000 Time, hr Model ing is in progress

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• NASA Turbine Environmental Barrier Coating Testing Developments

Advanced EBC top coats tested in coupons under laser heat flux cyclic rigs up 170ooc Coated subelements coating tested up 1500C under laser thermal gradient for 200 hr EBC systems show high stability in High Pressure Burner Rig Tests Thermal conductivity of 1.2 W/m-K met program goals

4.0 ~

~ 3.5

3.0

1600

&:. ·:; 1200 fti . ., 0

2.5

" ., § 0

2.0

~ 1.5

" 1.0 .<: 1-

High pressure burner rig , 16 atm, 31 hr u 0.5 al Ul

10 20 30 40 50 Time, hours

~ ~ 800 c.

400

E ~

11


• Advanced High Pressure Burner Rig Testing for Turbine Vanes

Scale I

Cooling air

12


Advanced High Pressure Burner Rig Testing for Turbine Vanes High Pressure Burner Rig test sections manufactured Nickel base superalloys and thermal barrier coatings used inner sections Total 6 SiC/SiC vanes coated 2 uncoated SiC/SiC turbine vanes tested at 2400F 2 coated SiC/SiC turbine vanes tested at 2500F 1 film-cooled vane under testing at 2600F


General Test Conditions

Fuel to air ratio F/A 0.045, mas air flow 1.5 lbm/s, pressure 1 0 atm, internal impingement or impingement + film cooling Inlet leading edge velocity 65 m/s, trailing edge 200+ m/s Cooling flow 0.05-01 lbm/s Pressure differential between "pressure" and "suction" side of the vanes are 7 to 1 0 psi symmet ry Plane

10.7 atm (142 psi)

150 •F, H=33.7 Btu/hr.ft2.•F

~ 10 atm (132 psi) \

2814 •F Gas Temp H=173 Btu/hr.ft2.•F

/ Heat Sink

Fixed in all direc

13

14


General Test Conditions- Continued

Fuel to air ratio F/A 0.045, mas air flow 1.5 lbm/s, pressure 10 atm (132psig), internal impingement or impingement+ film cooling at up to 10.7 atm (142 psig) Inlet leading edge velocity 65 m/s, trailing edge 200+ m/s Cooling flow 0.05-0.10 lbm/s Pressure differential between "pressure" and "suction"

Patran2010236-4·6o~atH2t · 29

FnngEI HeatTmnsfer. Stepl ,TotaiTme•l _1 Tempe~31\lo) {Nodal). Lif.oMorSectiOrt P.JI"tts. , At SECTION_POINT_I

Validated FEM modeling for temperature distributions


d• filV11J.Tl9<'

2430

2387

2343

2300

2257

2214

2171

2127

2084

2041

1998

1955

1911

1868

1825 1782

M-. 2 4 •I);:J ti'Nd 715 ;..-; t-1t1 1 78•00 ~N\J 1-4::'f>

High Pressure Burner Rig Testing for Validating EBC Coating and SiC/SiC Vane Components

Uncoated vanes tested 21 hours - Coated CVI and Prepreg Ml SiC/SiC vane successfully tested 31

and 21 hours respectively, at 2500 F+, reaching TRL of 5 - Turbine EBCs generally intact (some minor partial coating top coat

spalling for the Prepreg Ml SiC/SiC vane) - Minor CMC vane degradations after the testing

Coated CVI vane after 31 hour testing at 2500°F+ coating temperature

Coated Prepreg vane after 21 hour testing at 2500°F+ coating temperature

•

15

•

16


High Pressure Burner Rig Testing for Validating EBC Coating and SiC/SiC Vane Components - continued

A first coated Prepreg Ml film-cooled SiC/SiC vane in testing at 2600F+ at 10 atm, with film cooling air flow 0.05 lbm/s Some initial coating defects Accumulated 8 hours in the high pressure burner rig rig

0 The vane had some initial defective environmental barrier coatings


,

High Pressure Burner Rig Testing and FEM Modeling - Creep

Preliminary transient and creep models for the impingement vane established Accelerated creep for uncoated vane can resulted in vane failure in high creep strain locations

' Elem 212550

Elem 213961

~Eiem22476B ,...

--Eiem 213009 """-"'-. Elem 221548

Elem 212326

Critical elements likely to fail in creep and transient thermal loading

Creep strains estimated at 1500hr

.00031

·'"'" .ooan $ .. UU'mqt M.t;.t:!~7« ~OliMO 1-lr~lf J(lti.J.Hclti\lit

17

18


High Pressure Burner Rig Testing and FEM Modeling- Thermal Transients •

Transient stress modeling for 0 degree plies

Maximum Tensile Stresses

in 0 Degree layer5o..,.1~$ i~o~mtt*>PS .,..------ ------- ~~-V,M l~lJ~fC I

,_ _ :-::;

" ~150 ~:~~~==~~~;;;;;;;;;;;;;;;-----~ """"""213961

i --2 14016

i 100 ~214685 u - 214705 ~ ~ so ~f-------------------

20 40 60 80 100 120

·SO .L....--------.;;n"'m""•. -:-::,.c:-, --------

Tr~lll>tf't lell'l9t•ahur Prolilt @)A.USS-:.

~-------~-~·-·----------,

Maximum Shear Stress in 0 Degree layers

(1-~u':'0 I:II~ Z:~UctooUU4 \------------'"""= ""'UM"----- -+-212326

- .u3009

+----- - ----- - ------ - 21&423 1 221548

0 ·--~--~--~---~--~-~ 0 20 40 80 100 120

19


High Pressure Burner Rig Testing and FEM Modeling- Thermal Transients - continued •

Transient stress modeling for 90 degree plies Tr-.tfltlt ""f'ttatul'e PIOMit I' A ,HS5 ~eoc.

Maximum Tensile Stress in 90 Degree Layers

350 .AEii- 110549 .

300

250

.......... ..__ 200 Ell:mll2C32 EIAm l002!13

150

so

20 40 60 80 100

·SO Time, sec

200

180

160

140

~110175 11 120

...-110549 1 100

~mo37 1

60

40

120 20

•c ~

MuimumShear Stresses in 90 Degree layers

Elei 110549 ;.: ~10175

. . ....... t/1--\--1,.-------_E~~.:.~~~_? ___ E.I~~~7-03 ___ -+-109703

-+110175

+t---++---------------- -.lr 110549

- 112037

40 100 120

I

20


Summary • • Vapor deposition turbine EBCs developed with some confidence for

complex large vane components • An ERA turbine coating downselected and showed high stability and

long-term durability on state of the art SiC/SiC CMCs • The vapor based EBC processing approaches demonstrated vane

EBC composition realization, acceptable coating surface roughness and thickness controls

• Multiple advanced turbine environmental barrier coating coated SiC/SiC CMC vanes tested in engine relevant rig combustion environments, showing component viability and initial durability, demonstrating TRL of 5 under the NASA ERA program

21


• Conclusions • The EBC developments have major advances for turbine airfoil

applications in composition and processing with durability and performance

• Realistic impingement and film cooled vane component testing can be achieved in the High Pressure Burner Rig environments

• Turbine EBCs can help improve the turbine durability in the harsh engine environments, addressing key HPT turbine airfoil development issues, in particular, thermal stress resistance and environment related degradations in complex transient cyclic loading, creep and harsh combustion environments

• Coating process control for large airfoil components still need improvements

22


Future Plans • Film-cooled vane(s) continued to be tested • Next generation environmental barrier coating systems also being

incorporated • CFD models for full 30 vane high pressure burner rig testing in

progress • Continued vane subelement testing for EBC-CMC cyclic durability

improvements and model developments

23

components dongming zhu, louis j . ghosn *, martha h …

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