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Transcript of Thermodynamic, kinetic and phase transformation web. ... Folie 1 Thermodynamic, kinetic and phase...

  • © Folie 1

    Thermodynamic, kinetic and phase transformation

    calculations in the field of single crystal nickel based

    superalloys

    R. Rettig, M.M. Franke, R.F. Singer

    Institute of Science and Technology of Metals (WTM)

    Department of Materials Science and Engineering

    University of Erlangen-Nürnberg

    Germany

    ThermoCalc User Meeting - Aachen

    5th September 2013

  • © Folie 2

    Agenda

    o Nickel-based alloys as a key for energy production

    o Thermodynamic and kinetic databases for alloy development

    o Heat treatment modelling

    o Simulation of microstructure evolution

    o Summary

  • © Folie 3

    Keppel, Alstom, Cooretec Workshop, 2006

    heat recovery

    steam generator gas turbine

    generator

    steam turbine

    condensor

    plant control

    Siemens AG

    1st stage blade

    250 mm, 4,3 kg

    1 MW

    50 Hz

    10 t

    1000 °C

    3 yrs

    10.000,- $

    Efficiency (2007): ca. 58% (330 g CO2 / kWh)

    Aim 2020: ca. 63% (300 g CO2 / kWh)

    Siemens AG

    Combined cycle power plant

  • © Folie 4

    Efficiency of fossile power plants

    500 1000 1500 2000 0

    20

    40

    60

    e ff

    ic ie

    n c

    y i

    n c

    re a

    s e

    material improvement

    turbine outlet temperature is 500 °C

    C a rn

    o t-

    e ff

    ic ie

    n c

    y / %

    process temperature / °C

    data according to Siemens AG and DPG (2005)

    Development of efficiency Relation of efficiency and

    process temperature

     efficiency increase is always

    related to higher material temperatures

    1965 1980 1995 2010 2025 20

    30

    40

    50

    60

    70

    brown coal

    gas (CC)

    planse ff

    ic ie

    n c y / %

    year of entry into service

  • © Folie 5

    Harada et al. (2003) IGTC2003

    temperature capability of nickel-

    based superalloys

    single crystalline

    directionally solidified

    polycrystalline

    wrought alloys

    Year of development

    S e

    rv ic

    e t

    e m

    p e

    ra tu

    re

    Development of nickel-based superalloys

  • © Folie 6

    Tc

    Tg Tm

    Turbine blades

    1st stage, SGT5-4000F, Siemens AG polycrystalline directionally solidified single crystalline

  • © Folie 7

    Tc

    Tg Tm

    Turbine blades

    1st stage, SGT5-4000F, Siemens AG polycrystalline directionally solidified single crystalline

    1 mm

  • © Folie 8

    1st 2nd 3rd 4th 5th 0

    2

    4

    6

    8

    10

    12

    14

    c o

    n te

    n t

    / w

    t- %

    generation

    Rhenium

    Ruthenium

    PWA1483

    René N2

    CMSX-2

    René N5

    CMSX-4

    René N6

    CMSX-10

    Single crystal nickel-based superalloys

    g‘

    g

    composition of single crystal superalloys

    γ + γ‘-microstructure gives unique creep properties

    typical alloying elements (ca. 8 – 10):

    Ni-Al-Co-Cr-Mo-Re-Ru-Ta-Ti-W-B-Zr-Y

    5 µm

  • © Folie 9

    Material / process simulation at Institute WTM

    thermodynamics

    ThermoCalc

    diffusion

    DICTRA phase transformations

    TC-PRISMA

    microstructure

    MICRESS

    computer-aided alloy

    development

    inhouse software

    (MultOPT)

    process simulation

    (temperature-, fluid flow)

    - Flow3D

    - ProCAST

    - inhouse Lattice

    Boltzmann code

    Institute WTM /

    NMF

    mechanics (finite elements)

    ABAQUS

  • © Folie 10

    Agenda

    o Nickel-based alloys as a key for energy production

    o Thermodynamic and kinetic databases for alloy development

    o Heat treatment modelling

    o Simulation of microstructure evolution

    o Summary

  • © Folie 11

    Fields of application

    o prediction of:

     liquidus (melting) temperature

     γ‘-phase fraction

     γ‘-solvus temperature

     TCP-phase solvus temperatures

    o limitations:

     „exotic“ alloying elements are not available

     most commercial databases are not changable and the exact parameters are often not

    accessible

     calculations for untypical compositions may be critical

     calculations are only valid for stable equilibrium

    600 800 1000 1200 1400 0

    20

    40

    60

    80

    100

    g'

    L

    P 

    g

    p h

    a s e

    f ra

    c ti

    o n

    s / m

    o l-

    %

    temperature / °C

    CMSX-4, database TTNi8

  • © Folie 12

    Verification of commercial database TTNi7

    R. Rettig et al. Defect and Diffusion Forum 289 – 292 (2009) 101-108

    liquidus g‘-solvus

    1300 1350 1400 1450 1300

    1350

    1400

    1450 with Ru with Re no Re and Ru

    Shao05

    Fuchs02

    Sponseller96

    Copland01

    Dharwadkar92

    this workm e lt

    in g

    t e m

    p . m

    e a s . / °C

    melting temp. sim. / °C

    800 1000 1200 1400 800

    1000

    1200

    1400

    with Ru with Re no Re and Ru

    Shao05

    Fuchs02

    Sponseller96

    Copland01

    Dharwadkar92

    this work

    Caron00

    g' s

    o lv

    u s m

    e a s . / °C

    g' solvus sim. / °C

  • © Folie 13

    800 900 1000 1100 1200 1300

    0,1

    1

    10

    Ta

    Co Al

    Ti

    Cr

    c o

    m p

    o s it

    io n

    g / a

    t- %

    temperature / °C

    800 900 1000 1100 1200 1300

    0,1

    1

    10 Ru

    Re

    Mo

    c o

    m p

    o s it

    io n

    g / a

    t- %

    temperature / °C

    800 900 1000 1100 1200 1300

    0,1

    1

    10

    Al

    Co

    Ti

    Cr

    c o

    m p

    o s it

    io n

    g ' / a t-

    %

    temperature / °C

    800 900 1000 1100 1200 1300

    0,1

    1

    10

    Ru

    Ta

    Re

    Mo c o

    m p

    o s it

    io n

    g ' / a t-

    %

    temperature / °C

    good agreement bad agreement

    Phase compositions calculated with TTNi7

    R. Rettig et al.

    Defect and

    Diffusion

    Forum (2009)

  • © Folie 14

    6.5x10 -4

    6.7x10 -4

    7.0x10 -4

    7.2x10 -4

    10 -14

    10 -13

    10 -12

    René N5

    PWA1483

    NiGe1

    NiGe8

    d if

    fu s io

    n c

    o e ff

    ic ie

    n t

    D / m

    ²s -1

    1/T / 1/K

    Diffusion database development for Ni-Ge

    0 2 4 6 8 10 12 10

    -14

    10 -13

    10 -12

    10 -11

    1250 °C 1200 °C

    1150 °C

    d if

    fu s io

    n c

    o e ff

    ic ie

    n t

    D G

    e / m

    ²s -1

    Ge / at-%

    R. Rettig et al. Journal of Phase Equilibria

    and Diffusion 32 (2011) 198-205

    interdiffusion

    DICTRA-database from diffusion couple measurements

    impurity diffusion

    6.5x10 -4

    6.7x10 -4

    7.0x10 -4

    7.2x10 -4

    10 -14

    10 -13

    10 -12

    self diffusion

    Rettig et al. (2011)

    Hirano et al. (1962)

    Mantl et al. (1983)

    Ge impurity

    d if

    fu s io

    n c

    o e ff

    ic ie

    n t

    D / m

    ²s -1

    1/T / 1/K

  • © Folie 15

    Agenda

    o Nickel-based alloys as a key for energy production

    o Thermodynamic and kinetic databases for alloy development

    o Heat treatment modelling

    o Simulation of microstructure evolution

    o Summary

  • © Folie 16

    Agenda

    o Nickel-based alloys as a key for energy production

    oThermodynamic and kinetic databases for alloy development

    o Heat treatment modelling

    o Simulation of microstructure evolution

    o Summary

  • © Folie 17

    A multicomponent, multiphase precipitation model

    Idea of model Loop for all timesteps

    timestep 1

    Loop for all precipitate

    types

    New nucleation

    Growth of all existing

    particles

    Total removal of solute

    from matrix

    Driving force from

    CALPHAD

    Nucleation rate

    Loop for all particles

    Growth rate using

    CALPHAD

    Volume change

    Solute removal from

    matrix

    numerical Kampmann-Wagner model (1984), T. Sourmail (2002)

    red: new multicomponent model