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Confidential © Siemens AG 2013 All rights reserved. http://siemens.com/energy/power-generation/gas-turbines
Technology Classification: ECCN: AL: US-Content: Yes or NoThis document is subject to the U.S., Canadian, EU/German and/or other national export regulations. Diversion contrary to National law may be prohibited.
DICTRA Modeling of TLP Bonding Processes for Ni-based Superalloys
2013-09-05, Dr.-Ing. B. Laux
Thermo-Calc Users‘ Meeting
September 05/06 2013ACCESS e.V. Materials and Processes
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Table of Contents
Outline
Introduction: Diffusion Bonding
Brazing Experiments
Modeling
Summary and Next Steps
Page 2 B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Introduction: Diffusion Bonding
Page 3
• Joining technology for the repair of gas turbine components (Ni-/Co-based high temperature materials)
• Filling of cracks, build-up brazing, coupon repairs
• Idea: Filler material similar to base material + melting point depressant (MPD)
• MPD diffuses into base material during isothermal hold time
• Diffusion controlled isothermal solidification
• If hold time is long enough to provide for complete isothermal solidification, mechanical properties of braze joints are on base material level
• Epitaxial healing of SX material can be achieved
B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Introduction: Diffusion Bonding
• Material System• Braze alloy including MPD• Base material matrix
• Geometry• Width of braze gap• Bonding pressure
• Brazing temperature• Isothermal hold time• Heat treatment after brazing
Process Parameters Effect
• Braze gap widening, solubility of MPD
• Microstructure braze gap and base material
• Precipitates• Grain size and orientation• Element distribution• Morphology
• Existence and width of centerline eutectic
Page 4 B. Laux / E F PR GT EN MT 2 4
Mechanical properties of braze joint
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Brazing Experiments: Material System
Page 5
Ni Cr Co W Ta Al Hf Si B C
MBF 80 bal. 15.2 - - - - - - 4.0 0.06
MBF 50 bal. 19.0 - - - - - 7.3 1.5 0.08
Ni-Flex 110* bal. 10.0 5.0 4.0 4.0 2.0 - - 1.5 -
Ni-Flex 115* bal. 9.0 8.0 4.0 4.0 2.0 1.0 - 3.0 -
Braze Alloys (Foils, 50 m)
Base Material
Ni Cr Co W Mo Ta Al Ti B C Hf Zr
Alloy 247 CC/DS
bal. 8.1 9.2 9.5 0.5 3.2 5.6 0.7 0.01 0.07 1.4 0.01
René 80 bal. 14 9.5 4.0 4.0 - 3.0 4.8 0.015 0.17 - 0.03
* Ni-Flex foils not homogeneous, boron-free core, boron-containing boundary
B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Brazing Experiments: Set-up
Page 6
Temperature Time
Cycle 1 1204°C 0.5h
Cycle 2 1204°C 1h
Cycle 3 1204°C 2h
Cycle 4 1204°C 0.5h + post- braze heat treatment
Cycle 5 1232°C 2h
Cycle 6 1243°C 4h
Brazing Cycle
B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Brazing Experiments: Metallographic Evaluation
Page 7
Cycle 3 (2h @ 1204°C)
René 80
Ni Flex 110 Ni Flex 115
Alloy 247 CC
MBF 50 MBF 80
Alloy 247 DS
B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Brazing Experiments: Metallographic Evaluation
Page 8
Cycle 4 (0.5h @ 1204°C + heat treatment)
René 80
Ni Flex 110 Ni Flex 115
Alloy 247 CC
MBF 50 MBF 80
Alloy 247 DS
B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Brazing Experiments: Metallographic Evaluation
Page 9
Cycle 5 (2h @1232°C)
Alloy 247 CC
Ni Flex 110
Alloy 247 DS
MBF 80 Ni Flex 110 MBF 80
Cycle 6 (4h @ 1243°C)
Precipitation of secondary phases and incipient melting
B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
NiFlex 110
MBF 50 MBF 80
NiFlex 115
Modeling: Thermo-Calc – Calculation of braze alloys
TS TS TL
TS TSTL
Page 10 B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Modeling: DICTRA – Moving Boundary Model
• Simulation as Moving Boundary Model
• Variation of gap width and temperature
• Symmetrical geometry: Modeling of half gap width and base material (2 regions)
• Base material: pure Ni-matrix, René 80, Alloy 247
• Braze gap: MBF 50, MBF 80, NiFlex 110, NiFlex 115
• In-situ boride formation cannot be included in DICTRA 26
Prediction of isothermal solidification time
Page 11
Base MaterialBraze Gap
0.5 W0 20 mmt = t1 (Widening)
t = t2 (Isothermal Solidification)
Braze Gap
Base Material
Base Material
t = t0
B. Laux / E F PR GT EN MT 2 4
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Modeling: Set up in DICTRA 26 (Moving Boundary Model)
Page 12 B. Laux / E F PR GT EN MT 2 4
go datsw ttni7def-spec ni cr mo w co al brej ph *rest ph fcc_a1 liquidgetappend mobni1@@Elementsdef-sys ni cr mo w co al brej ph *rest ph fcc_a1 liquid get@@DICTRAgo d-m@@Simulation Temperatureset-con GLOBAL T 0 1477.15; * N@@Geometryent-geo 0@@Regionsent-reglotent-regbaselotYES@@Grid Braze Gapent-gridlot25e-6geo500.97
@@Grid Base Materialent-gridbase20e-4geo1001.03@@Liquid Phase in Braze Gapent-phACTIVElotMATRIXLIQUID@@FCC in Base Materialent-phACTIVEbaseMATRIXfcc@@Compositions@@Braze Gap (MBF 80) Liquident-complotLIQUIDniw-pCr LINEAR 15.2 15.2Co LINEAR 1e-5 1e-5Mo LINEAR 1e-5 1e-5W LINEAR 1e-5 1e-5Al LINEAR 1e-5 1e-5B LINEAR 4 4
@@Base Material FCCent-compbaseFCC_A1niw-pCr LINEAR 14 14Co LINEAR 9.5 9.5Mo LINEAR 4 4W LINEAR 4 4Al LINEAR 3 3B LINEAR 0.015 0.015@@Simulation Times-sim-time100000 y 200 1E-10 1E-15@@Simulation Conditions (Euler
backwards)s-s-c0 1 2 NO ACTIVITIES YES 99 1 2 NO YES NOsave R80_MBF80_1204_50mu.dic @@Start Simulationsim
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
• Simulation as Moving Boundary Model
• In-situ boride formation not included
• René 80 + MBF 80:
• Max. gap width: 2 x 34.5m
• Isothermal solidification finished after about 18.7h
• Alloy 247 + MBF 80:
• Max. gap width: 2 x 33m
• Isothermal solidification finished after about 8.9h
René 80, MBF 80, 1204°C, W0 = 50 µm, Ti excluded
Modeling: DICTRA 26 – Moving Boundary Model
Alloy 247, MBF 80, 1204°C, W0 = 50 µm, Ti, Hf excluded
Page 13 B. Laux / E F PR GT EN MT 2 4
End of solidification
Max. gap width
End of solidification
Max. gap width
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
B. Laux / E F PR GT EN MT 2 4Page 14
Modeling: DICTRA 26 – Moving Boundary Model
• Simulation as Moving Boundary Model
• In-situ boride formation not included
• René 80 + NiFlex 110:
• Max. gap width: 2 x 25m
• Isothermal solidification finished after about 1.4h
• Alloy 247 + NiFlex 110:
• Max. gap width: 2 x 25m
• Isothermal solidification finished after about 10.2h
René 80, NiFlex110, 1204°C, W0 = 50 µm, Ti excluded
Alloy 247, NiFlex110, 1204°C, W0 = 50 µm, Ti, Hf excluded
End of solidification
End of solidification
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Modeling: DICTRA 26 – Moving Boundary Model
Complete isothermal solidification only predicted for René 80 + NiFlex 110
B. Laux / E F PR GT EN MT 2 4Page 15
1h 2h 5h
T=1204°C
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Comparison to Brazing Experiments
Page 16
Cycle 3 (1204°C, 2h)
René 80
Ni Flex 110 Ni Flex 115
Alloy 247 CC
MBF 50 MBF 80
Alloy 247 DS
B. Laux / E F PR GT EN MT 2 4
Iso. Sol. completed
Iso. Sol. completed
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Page 17 B. Laux / E F PR GT EN MT 2 4
Modeling: DICTRA 26 – Homogenization Model
Composition Elements excluded Phases
René 80 Ni-14Cr-9.5Co-4Mo-4W- 3Al-0.15B
Ti, C, Zr FCC + M3B2_TETR (Mo- and Cr-rich boride)
Alloy 247 Ni-8.1Cr-9.2Co-0.5Mo- 9.5W-3.2Ta-5.6Al-0.01B
Mo, Ti, C, Zr, Hf FCC + M3B2_TETR (W- and Cr-rich boride)
MBF 80 Ni-15.2Cr-4B C LIQUID
NiFlex110 Ni-10Cr-5Co-4W-4Ta-2Al- 1.5B
LIQUID + FCC
Stable Phases at 1204°C (TC, Database TTNi7)
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Page 18 B. Laux / E F PR GT EN MT 2 4
go datsw ttni7def-spec ni cr mo w co al brej ph *rest ph fcc_a1 liquid m3b2_tetr getappend mobni1@@Elementsdef-sys ni cr mo w co al brej ph *rest ph fcc_a1 liquid m3b2_tetr get@@DICTRAgo d-m@@Simulation Temperatureset-con GLOBAL T 0 1477.15; * N@@Geometryent-geo 0@@Regionsent-regsystem@@Grid ent-gridsystem1e-3geo1001.05
@@ Phases Present@@ Rene 80ent-phaseactivesystemmatrixfcc@@ liquid spheroidenter-phaseactivesystemsphliqenter-phaseactivesystemsphmb_orthenter-phaseactivesystemsphm3b2_tetr@@ Composition of Phases@@ FCC Phaseenter-compsystemfccniw_pcr func 15.2 - 1.2*HS(x-25e-6);co func 1e-5 + 9.5*HS(x-25e-6);al func 1e-5 + 3*HS(x-25e-6);
mo func 1e-5 + 4*HS(x-25e-6);b func 4 - 3.985*HS(x-25e-6);w func 1e-5 + 4*HS(x-25e-6);@@ LIQUID composition according to
equilibriumenter-compsystemliqyes@@ M3B2_TETR composition according
to equilibriumenter-compsystemm3b2_tetryes@@ Simulation timeset-sim-time 7200yes100 1e-10 1e-15@@Simulation Conditionss-s-c 0 1 2 NO ACTIVITIES YES 99 1 2 NO
YES NO@@ Application of homogenization modelHomo yes n n y 1000 y n log n n n@@ Hom. Func. (Hashin Shtrikman:
Majority phase as matrix with excluded phases)
en-ho 12 m3b2_tetr nSaveR80_MBF80_1204_50mu_M3B2_hom.dic @@Start Simulationsim
Modeling: Set up in DICTRA 26 (Homogenization Model)
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
B. Laux / E F PR GT EN MT 2 4Page 19
Modeling: DICTRA 26 – Homogenization Model
Alloy 247, Ni-Flex 110, 2h @ 1204°C, W0 = 50 µm, Ti excluded
René 80, MBF 80, 2h @ 1204°C, W0 = 50 µm, Ti excluded
0.1s
520s
1s1s
1000s
3600s
100s
7200s
1s
10s
100s
510s
1s1000s
3600s
100s
7200s
• Simulation as Homogenization Model
• MBF 80: completely liquid at 1204°C
• Ni-Flex 110: not completely liquid
• Position of phase interface cannot be plotted
• René 80 + MBF 80:
• Isothermal solidification finished after about 520s
• Alloy 247 + NiFlex 110:
• Isothermal solidification finished after about 510s
• In-situ boride formation (M3 B2 ) included → Predicted time for isothermal solidification extremely short
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Page 20 B. Laux / E F PR GT EN MT 2 4
go datsw ttni7def-spec ni cr mo w co al brej ph *rest ph fcc_a1 liquid m3b2_tetr getappend mobni1@@Elementsdef-sys ni cr mo w co al brej ph *rest ph fcc_a1 liquid m3b2_tetr get@@DICTRAgo d-m@@Simulation Temperatureset-con GLOBAL T 0 1477.15; * N@@Geometryent-geo 0@@Regionsent-reglotent-regbaselotYES@@Grid Braze Gapent-gridlot25e-6geo300.97
@@Grid Base Materialent-gridbase20e-4geo1001.03@@Liquid Phase in Braze Gapent-phACTIVElotMATRIXLIQUID@@FCC in Base Materialent-phACTIVEbaseMATRIXfcc@@M3B2 in Base Materialent-phACTIVEbasesphm3b2_tetr@@Compositions@@Braze Gap (MBF 80) Liquident-complotLIQUIDniw-p
Cr LINEAR 15.2 15.2Co LINEAR 1e-5 1e-5Mo LINEAR 1e-5 1e-5W LINEAR 1e-5 1e-5Al LINEAR 1e-5 1e-5B LINEAR 4 4@@Base Material FCCent-compbaseFCC_A1niw-pCr LINEAR 14 14Co LINEAR 9.5 9.5Mo LINEAR 4 4W LINEAR 4 4Al LINEAR 3 3B LINEAR 0.015 0.015@@Base Material M3B2ent-compbasem3b2_tetry@@Simulation Times-sim-time3600 y 50 1E-10 1E-15@@Simulation Conditionss-s-c 0 1 2 NO ACTIVITIES YES 99
1 2 NO YES NOSaveR80_MBF80_1204_50mu_M3B2.dic @@Start Simulationsim
Modeling: Set up in DICTRA 27
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Modeling: DICTRA 27
Page 21 B. Laux / E F PR GT EN MT 2 4
• Simulation as Homogenization Model
• Position of phase interface can be tracked in homogenization model
• Combination of boride formation with two regions set-up
• Phases included: FCC (matrix), LIQUID (braze gap), M3 B2 in base material
→ Predicted time for isothermal solidification still very short
René 80, MBF 80, 1204°C, W0 = 50 µm, Ti excluded
Max. gap width
100s
1000s
Plot of position of interface not complete
Phase boundary
1s1s
100s
1000s3600s
3600s
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Summary
• Modeling of TLP bonding of Ni-base superalloys challengingMany elements to be includedResults fit qualitatively to experimental resultsCalculated times w/o boride formation are relatively long Implementation of borides lead to extremely short solidification timesPrediction of exact isothermal solidification time is difficult
Page 22 B. Laux / E F PR GT EN MT 2 4
Summary and Next Steps
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Next Steps
• Identification of borides within Alloy 247 (EBSD, XRD)• Implementation of these boride types in DICTRA models • Modeling of complete brazing cycle 4 (brazing + post-braze heat treatment)Comparison to experimental findings (solidification completed for René 80 + MBF 80)
• Modeling of complete brazing cycle 5, 6 (1232°C, 1243°C)Comparison to experimental findings (incipient melting)
• Inclusion of more elements• Set-up of NiFlex110 as non-homogeneous foil (boron-free core)
Optimization of current brazing cycles
Page 23 B. Laux / E F PR GT EN MT 2 4
Summary and Next Steps
Confidential © Siemens AG 2013 All rights reserved.
Technology Classification: ECCN: EAR99 AL: N US-Content: NoThis document is subject to US Export Administration Regulations, EU Dual-Use Regulations, and or other foreign national export regulations. Diversion contrary to law is prohibited."
Contact
Dr.-Ing. Britta Laux Joining and Repair Siemens AG Energy Sector E F PR GT EN MT 2 4
Huttenstr. 12 10553 Berlin
Phone: +49 (30) 3461-11989 Fax: +49 (30) 3461-2153
E-mail: [email protected]
Page 24 B. Laux / E F PR GT EN MT 2 4