Application of Thermo-Calc and DICTRA in an Industrial Settingweb.access.rwth-aachen.de/THERMOCALC/proceedings/proceedings2011/2011... · Areas of Application for Thermo-Calc and

Copyright © Siemens AG 2009. All rights reserved.

Application of Thermo-Calc and

DICTRA in an Industrial SettingSebastian Piegert

Thermo-Calc/DICTRA Users MeetingAachen

2011-09-08/09

Page 2 2011-09-08 Siemens Energy Sector F PR GT EN MT 2 4Copyright © Siemens AG 2009. All rights reserved.

Piegert, S.

Outline

Introduction

MCrAlY Coating DevelopmentBackgroundSet-Up of DICTRA ModelResults of CalculationsExperimental Validation

Summary

Bla

de

1 o

f SG

T5-4

00

0F

mad

e o

f PW

A 1

48

3 S

X s

up

eral

loy


Piegert, S.

Organisational

Background

Base Material

CoatingJoining

sco

pe

of

MT

2 d

epar

tmen

t


Piegert, S.

Areas of Application for Thermo-Calc and DICTRA

Coating-SubstrateInteraction

Estimation ofnon Conformances

and Failure Analysis

Heat Treatment Optimisation

Base MaterialCharacterisation

Braze Alloys andWeld FillersDevelopment

Base AlloyDevelopment

Thermo-Calc Version S with TTNi

7 Database

DICTRA 26 with MobNi1 Database

sco

pe

of

MT

2 d

epar

tmen

t

http://www.thermocalc.com/DICTRA.htm


Piegert, S.

MCrAlY

Protective Coatings

Function:Corrosion and oxidation protectionAl and Cr reservoir for formation of Al2O3 and Cr2O3 protective scalesBond coat function for TBC

Composition (example):Co - 31Ni - 27Cr - 7.5Al - 0.5Y - 0.5Si

Microstructure:Cr and Al trapped in second phases (β (NiAl) or γ’ (Ni3Al)) in γ Ni-matrix

ApplicationThermal spraying (VPS or LPPS)Bonding heat treatment

aged

MC

rAlY

coat

ing

sys

tem

γ-layer

γ

+ β-layer

base material(γ

+ γ’-layer)

γ-layer

oxide layer


Piegert, S.

Problem Statement

Currently used system (baseline):Ni - Co - Cr - Al - 1.5Re - Y

ProblemRe price extremely high

RequestDevelop coating free of Re

Approachvariation of Cr contentslight increase of Al concentration

Base material PWA 1483 SXNi - 9Co - 12.2Cr - 1.9Mo - 3.8W - 5Ta -3.6Al - 4.1Ti

0.76

1.00

1.41

1.101.00 1.05

00.2

0.40.60.8

11.2

1.41.6

Alloy 1 baseline Alloy 4

c X/c

X0

/ -

Cr concentrationAl concentration

rela

tio

n o

f co

nst

itu

ents

ph

ase

dia

gra

m


Piegert, S.

Phase Diagrams of MCrAlY

Alloys

coating composed of β- and γ-phase above 900 °Cnear eutectic systems

simulation of substrate-coating interaction only with single phase systems so far

Alloy 1 (low Cr) Alloy 4 (high Cr)

bas

elin

e al

loy

e

xper

imen

tal a

lloys


Piegert, S.

Results of Ageing Trials at 1100 °C

Baseline materialPrecipitate free zoneHigh γ’-content directly on interface between γ-layer and γ - γ’-layer

Alloy 4 (high Cr)Almost no precipitate free layer in coatingLarge amount of base material transformsKirkendall porosity in Alloy 4 already after short times (« 300 h)

Alloy 1 (low Cr)Similar behaviour to baselineNo porosity

Allo

y4

(h

igh

Cr)

68

4 h

Bas

elin

e4

86

h

γ-layer

γ

+ β-layer

γ

+ γ’-layer

original interface


Piegert, S.

Set-Up

Modelsingle cell problem (9 (8) species)double geometric gridelement distribution via “high step”functioneffective diffusion in dispersed system with γ’ and β:

*

Boundary ConditionsT = 1100 °C, tmax = 500 - 700 hisothermal, i.e. heating and cooling processes are not taken into account

Coating Substrate

200 µm 200 µm

Grid

Element Distribution

γ-matrix with γ’ and β

as dispersed phases

00.10.20.30.40.50.60.70.80.9

1

0 0.2 0.4 0.6 0.8 1

f Vγ / -

Def

f/Dγ

/ -

γ

γ

γ Df

fDupper

eff

⎟⎟⎟⎟

⎠

⎞

⎜⎜⎜⎜

⎝

⎛

−

−+=

310

331

effe

ctiv

ed

iffu

sio

nm

od

el

* D

ahl,

Hal

dan

d H

orse

wel

l: D

efec

t an

d D

iffu

sion

For

um

Vol

s. 2

58

-26

0 (

20

06

)


Piegert, S.

bas

elin

e

e

xper

imen

tal a

lloys

Phase Distribution

Alloy 1 and baseline behave similarprecipitate free zonepileup of γ’ at the interface

Alloy 4no precipitate free zonemoving interface

0.0

0.2

0.4

0.6

0.8

1.0

0.00E+00 1.00E-04 2.00E-04 3.00E-04 4.00E-04

distance / m

Np(

*) /

mol

/mol

GAMMA_Prime 1 hNiAl 1 hGAMMA_Prime 10 hNiAl 10 hNiAl 100 hGAMMA_Prime 100 hNiAl 300 hGamma_Prime 300 h

0.0

0.2

0.4

0.6

0.8

1.0

0.00E+00 1.00E-04 2.00E-04 3.00E-04 4.00E-04

distance / mm

Np(

*) /

mol

/mol

Gamma_Prime 1 hNiAl 1 hGamma_Prime 10 hNiAl 10 hGamma_Prime 100 hNiAl 100 hGamma_Prime 300 hNiAl 300 h

0.0

0.2

0.4

0.6

0.8

1.0

0.00E+00 1.00E-04 2.00E-04 3.00E-04 4.00E-04

distance / m

Np(

*) /

mol

/mol

GAMMA_Prime 1 hNiAl 1 hGAMMA_Prime 10 hNiAl 10 hNiAl 100 hGAMMA_Prime 100 hNiAl 300 hGamma_Prime 300 h

Alloy 1 (low Cr) Alloy 4 (high Cr)

baseline


Piegert, S.

Element Distribution

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.0E+00 1.0E-04 2.0E-04 3.0E-04 4.0E-04

distance / m

x(*)

/ m

ol/m

ol

x(Cr) 1 hx(Ta) 1 hx(Cr) 10 hx(Ta) 10 hx(Cr) 100 hx(Ta) 100 hx(Cr) 300 hx(Ta) 300 h

0.00

0.05

0.10

0.15

0.20

0.25

0.0E+00 1.0E-04 2.0E-04 3.0E-04 4.0E-04

distance / mx(

*) /

mol

/mol

x(Al) 1 hx(Ti) 1 hx(Al) 10 hx(Ti) 10 hx(Al) 100 hx(Ti) 100 hx(Al) 300 hx(Ti) 300 h

0.00

0.05

0.10

0.15

0.20

0.25

0.0E+00 1.0E-04 2.0E-04 3.0E-04 4.0E-04

distance / m

x(*)

/ m

ol/m

ol


0.00

0.05

0.10

0.15

0.20

0.0E+00 1.0E-04 2.0E-04 3.0E-04 4.0E-04

distance / m

x(*)

/ m

ol/m

ol


0.00

0.05

0.10

0.15

0.20

0.25

0.0E+00 1.0E-04 2.0E-04 3.0E-04 4.0E-04

distance / m

x(*)

/ m

ol/m

ol


0.00

0.05

0.10

0.15

0.20

0.25

0.0E+00 1.0E-04 2.0E-04 3.0E-04 4.0E-04

distance / m

x(*)

/ m

ol/m

ol


Alloy 1 (low Cr) Alloy 4 (high Cr)baseline


Piegert, S.

-40

-20

0

20

40

60

80

100

1.6E-04 1.8E-04 2.0E-04 2.2E-04 2.4E-04

distance / m

d(-J

Va)/d

z

Alloy4 0.5 hAlloy4 1 hAlloy4 10 hAlloy4 100 h

Tracking of Kirkendall

Porosity

zJc Va

Va ∂−∂

=Δ)(

∫ ∂−∂

=t

VaVa t

zJy

0

d)(

Change of the local vacancy content at a distinct position

Content of vacancies at a distinct position **

-40

-20

0

20

40

60

80

100

1.6E-04 1.8E-04 2.0E-04 2.2E-04 2.4E-04

distance / m

d(-J

Va)/d

z

baseline 0.5 hbaseline 1 hbaseline 10 hbaseline 100 h

-40

-20

0

20

40

60

80

100

1.6E-04 1.8E-04 2.0E-04 2.2E-04 2.4E-04

distance / m

d(-J

Va)/d

z

Alloy1 0.5 hAlloy1 1 hAlloy1 10 hAlloy1 100 h

Alloy 1 (low Cr) Alloy 4 (high Cr)baseline

** Höglund

and Ågren: Acta

mater 49 (2001) 1311-1317


Piegert, S.

Experimental Validation (Composition Profiles)

Al profile Ti profileCr profile

Allo

y 4

(h

igh

Cr)

b

asel

ine


Piegert, S.

Experimental Validation (Microstructure)

γ−layer PWA1483

GAMMA_PrimeNiAl

Gamma_PrimeNiAl

γ−layer PWA1483

SEM

imag

es v

s. a

mo

un

t o

f p

has

es

Alloy 4 (high Cr)baseline


Piegert, S.

Summary

Thermo-Calc helps identifying MCrAlY coating systems

interdiffusion between MCrAlY and substrate can be handledlabyrinth factors for “diffusion none” phasescomplex material systems (9 species)TCP phases and minor elements not taken into accountqualitative prediction of Kirkendall porosity

experimental validationshape of composition profiles metno general labyrinth factor applicabledistribution of phases qualitatively shown

ROI: significant reduction of experiments ➙ faster time to market (>> 9:1)


Piegert, S.

Thank you for your attention!

Copyright ©

Siemens AG 2009. All rights reserved.


Piegert, S.

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Documents

Application of Thermo-Calc and DICTRA in an Industrial Settingweb.access.rwth-aachen.de/THERMOCALC/proceedings/proceedings2011/2011... · Areas of Application for Thermo-Calc and