research engineer daido steel co. ltd....dat5(6al-4v) dat54(6al-4sn-4zr-3mo-1nb-04si-0 06c)...

Yoshihiko Koyanagi Research Engineer

Daido Steel Co. Ltd.

Development of new gamma TiAl for turbocharger application

Gamma TiAl has a great potential for use in aircraft engine and automobile engine components. Since we demonstrated the potential of gamma TiAl as a turbocharger turbine wheel in 1987, a great effort has been paid in

order to put the gamma TiAl turbine wheel to practical use. Through successful development of gamma TiAl alloy and of processes of casting and joining between the turbine wheel and an alloy steel shaft, we got into mass production of TiAl turbine rotors of turbocharger for passenger car application in 2003. Currently, heat resistance required for turbine wheels has become severe, because of the rise of exhaust gas along with development of fuel

saving technologies to reduce CO2 emission. Therefore, the new gamma TiAl was developed based on a conventional gamma TiAl under mass production. The new gamma TiAl showed high creep and oxidation resistant than the conventional gamma TiAl. In addition, it was confirmed that the new gamma TiAl has equal manufacturability to the conventional gamma TiAl.

Development of new gamma TiAl for turbocharger applicationfor turbocharger application

Y. Koyanagiy gAdvanced Material Research Department

Daido Corporate Research & Development CenterDaido Steel Co Ltd

TITANIUM 2008 2008.9 page 1

Daido Steel Co., Ltd.

Daido’s titanium alloys

Alloy developed by DaidoSportsDAT5(6Al-4V)DAT51(22V-4Al)

CorrosionDT2(CP Ti)

DAT51(22V 4Al)DAT15G(15-3-3-3) DAT55G(15V-6Cr-4Al)DAT56M(CA Ti, 13Cr-1F 3Al)

MedicalDT2, DT4(CP-Ti) DAT5E(6-4 ELI) DAT67(6Al 7Nb)

PPC furnace

DT2(CP-Ti)DT7(0.15Pd)

1Fe-3Al)DAT57M(VLTi, 6Al-1Fe)

DAT67(6Al-7Nb)Ni-Ti

PPC furnace GFM forging machineLEVICAST*LEVI atomization

AutomobileDAT52F(3Al-2V-REM-S)DAT5M(6Al-4V-Fe)DAT62M(6Al 2S 4ZA DAT62M(6Al-2Sn-4Zr-2Mo-0.1Si)DAT54DAT57M(VLTi, 6Al-1Fe)

AerospaceDAT5(6Al-4V)DAT54(6Al-4Sn-4Zr-3Mo-1Nb-0 4Si-0 06C)

*:Levitation melting and casting


( , )DAT-TA1(TiAl)

3Mo-1Nb-0.4Si-0.06C)

History of development of TiAl T/W in Daido

Production total : 120,000PProduction total : 120,000P: Original alloy or technology of Daido : Original alloy or technology of Daido

CastingCasting

AlloyAlloy

LEVICASTLEVICASTCLV** in CaO crucibleCLV** in CaO crucible

TiTi--36Al36Al TiTi--33.5Al33.5Al DATDAT--TA1TA1RNT004*RNT004*DATDAT--TA2TA2* : Ti* : Ti--33.5Al33.5Al--1.0Nb1.0Nb--0.5Cr0.5Cr--0.5Si0.5Si

gg

JoiningJoining

LEVICASTLEVICASTCLV in CaO crucibleCLV in CaO crucible

Vacuum Brazing(Silver braze)Vacuum Brazing(Silver braze) Pressured induction brazing (PIB)Pressured induction brazing (PIB)

** : Counter gravity Low pressure Vacuum melt** : Counter gravity Low pressure Vacuum melt

ManufacturingManufacturing Mass productionMass productionExperimental productionExperimental production 1998 : Auto racing1998 : Auto racing1999~ : Passenger car1999~ : Passenger car

Y

The first publication concerning TiAl turbochargers

1990 2005 20101987 1995 20001985 20081998

Practical useof TiAl T/W


Year

Feature of turbocharger

Feature of turbocharger Feature of turbocharger 1. Power up1. Power up

t t it t i

Turbine wheelTurbine wheel

-- output increaseoutput increase2. Compactification2. Compactification-- downsizing downsizing -- weight savingweight saving

3 Fuel saving3 Fuel savingCompressor wheelCompressor wheel

3. Fuel saving3. Fuel saving-- combustion efficiency optimizationcombustion efficiency optimization-- reduction of CO2 emissionreduction of CO2 emission

4. Exhaust gas purification4. Exhaust gas purification-- clean making exhaust gasclean making exhaust gas

by fuelby fuel--air ratio optimizationair ratio optimization

-- Good technology Good technology for the environmentfor the environment-- IncreasingIncreasing of total number of turbochargersof total number of turbochargers


Fig. Illustration of turbocharger.

Materials for turbine wheelha

ust

g. C

) 1050

1000

TiAlMar-M247

ervi

ce E

xhra

ture

(deg 1000

950

DAT-TA2

solin

e

stim

ated

SG

as T

empe

r

900

850DAT-TA1

GMR235

Inconel713C

Die

sel G

as

DAT-TA1 : Ti-33 5Al-4 8Nb-1 0Cr-0 2Si(Under Production) [wt%]

Price High

Es G

800

D

DAT-TA1 : Ti-33.5Al-4.8Nb-1.0Cr-0.2Si(Under Production)DAT-TA2 : Ti-31.5Al-7.5Nb-1.0Cr-Si-CMar-M247 : Ni-0.15C-5.5Al-1Ti-10Co-8.3Cr-0.7Mo-3Ta-10W-1.5Hf-0.05Zr-0.015BInconel713C : Ni-0.12C-6Al-0.7Ti-12.5Cr-4Mo-1.8Nb-0.1Zr-0.012B

[wt%]


GMR235 : Ni-0.15C-3.5Al-2Ti-10Fe-15.5Cr-5Mo-0.05B

Alloy design

DAT-TA1(Ti-33.5Al-4.8Nb-1.0Cr-0.2Si)

TiAl under production

High temperature strengthOxidation resistanceOxidation resistance

Al and Nb optimizationC addition

Nb and Si increase

Manufacturability

Lamellar phase stabilizationCreep property

Si increase

DAT TA2(Ti 31 5Al 7 5Nb 1 0Cr Si C)

Si increaseC addition

Nb and C limitationDeveloped TiAl


DAT-TA2(Ti-31.5Al-7.5Nb-1.0Cr-Si-C)

Microstructure

DATDAT TA2TA2 DATDAT TA1TA1DATDAT--TA2TA2 DATDAT--TA1TA1

50μm 50μm50μm 50μm


Density

9.0 8.597 91

6.0

7.0

8.0cmcm

33 ))

Down byDown by 50%50%

7.91

4.0

5.0

nsity

(g/c

nsity

(g/c

4.01 3.94

1 0

2.0

3.0Den

Den

0.0

1.0

DAT-TA2 DAT-TA1(Under Production)

Inconel713C Mar-M247


Tensile & creep rupture properties

Strength (Tension)Strength (Tension) Creep Rupture StrengthCreep Rupture Strength

1000 * : INCO ALLOYS INTERNATIONAL’S DATA450

T t T 750 1050 d C

* : INCO ALLOYS INTERNATIONAL’S DATA4501000 * : INCO ALLOYS INTERNATIONAL’S DATA450

T t T 750 1050 d C

* : INCO ALLOYS INTERNATIONAL’S DATA450

700

800

900300

400 Test Temp. : 750-1050 deg. C

700

800

900300

400 Test Temp. : 750-1050 deg. C

400

500

600

700

engt

h (M

Pa)

DAT-TA2

ress

(MPa

) 200

DAT-TA1

DAT-TA2 +40+40deg. Cdeg. C

400

500

600

700

engt

h (M

Pa)

DAT-TA2

ress

(MPa

) 200

DAT-TA1

DAT-TA2 +40+40deg. Cdeg. C

200300

400

Stre

DAT-TA1DAT-TA2DAT-TA1

(Under Production)

100Str

7080

10090

60

DAT-TA2DAT-TA1

(Under Production)200300

400

Stre

DAT-TA1DAT-TA2DAT-TA1

(Under Production)

DAT-TA2DAT-TA1

(Under Production)

100Str

7080

10090

60

DAT-TA2DAT-TA1

(Under Production)

DAT-TA2DAT-TA1

(Under Production)

0

100

0 200 400 600 800 1000 1200Temperature (deg C)

Open:0.2% Proof StressSolid:Tensile Strength

Inconel713C(as-cast)*Mar-M247(as-cast)

4021 22 23 24 25 26 27 28 29 30

Larson-Miller Parameter

50

40


21 22 23 24 25 26 27 28 29 300

100

0 200 400 600 800 1000 1200Temperature (deg C)


Inconel713C(as-cast)*Mar-M247(as-cast)Inconel713C(as-cast)*Mar-M247(as-cast)

4021 22 23 24 25 26 27 28 29 30

Larson-Miller Parameter

50

40

Inconel713C(as-cast)*Mar-M247(as-cast)Inconel713C(as-cast)*Mar-M247(as-cast)

21 22 23 24 25 26 27 28 29 30


Temperature (deg. C) ( 273+T)x(log|tr|+20)/1000Temperature (deg. C) ( 273+T)x(log|tr|+20)/1000

Specific tensile & creep rupture properties

Specific Strength (Tension)Specific Strength (Tension) Specific Creep Rupture StrengthSpecific Creep Rupture Strength

160 * : INCO ALLOYS INTERNATIONAL’S DATA100

* : INCO ALLOYS INTERNATIONAL’S DATA160 * : INCO ALLOYS INTERNATIONAL’S DATA100

* : INCO ALLOYS INTERNATIONAL’S DATA

120

140

160 100

g/cm

3 ))

60708090

100

cm3 ))

Temp. : 750-1050 deg. C

DAT-TA1

DAT-TA2

DAT-TA2

120

140

160 100

g/cm

3 ))

60708090

100

cm3 ))

Temp. : 750-1050 deg. C

DAT-TA1

DAT-TA2

DAT-TA2

80

100

ngth

(MPa

/(g

30

40

50

ss (M

Pa/(g

/c

+40+40deg. Cdeg. C

80

100

ngth

(MPa

/(g

30

40

50

ss (M

Pa/(g

/c

+40+40deg. Cdeg. C

40

60

peci

fic S

tren

20

Spec

ific

StreDAT-TA1


DAT-TA2DAT-TA1

(Under Production)

DAT-TA2DAT-TA1

(Under Production)

40

60

peci

fic S

tren

20

Spec

ific

StreDAT-TA1


DAT-TA2DAT-TA1

(Under Production)

DAT-TA2DAT-TA1

(Under Production)

DAT-TA2DAT-TA1

(Under Production)

0

20

0 200 400 600 800 1000 120010

22 23 24 25 26 27 28 29 30

Sp

10

S(Under Production)Inconel713C(as-cast)*Mar-M247(as-cast)

T t (d C) Larson-Miller Parameter

(Under Production)Inconel713C(as-cast)*Mar-M247(as-cast)

21 22 23 24 25 26 27 28 29 300

20

0 200 400 600 800 1000 120010

22 23 24 25 26 27 28 29 30

Sp

10

S(Under Production)Inconel713C(as-cast)*Mar-M247(as-cast)

T t (d C) Larson-Miller Parameter



21 22 23 24 25 26 27 28 29 30


Temperature (deg. C) Larson Miller Parameter( 273+T)x(log|tr|+20)/1000Temperature (deg. C) Larson Miller Parameter( 273+T)x(log|tr|+20)/1000

Rotating bending fatigue strength

500

Pa) Rotation speed : 3,500rpmRotation speed : 3,500rpm

500

Pa) Rotation speed : 3,500rpmRotation speed : 3,500rpm

350

400

450e

Lim

it (M

P DAT-TA2

350

400

450e

Lim

it (M

P DAT-TA2

250

300

350

Endu

ranc

e

DAT TA1250

300

350

Endu

ranc

e

DAT TA1

150

200

250

07 C

ycle

s E DAT-TA1

DAT-TA2DAT-TA1

(Under Production)Inconel713C(as-cast)150

200

250

07 C

ycle

s E DAT-TA1

DAT-TA2DAT-TA1

(Under Production)Inconel713C(as-cast)

1000 100 200 300 400 500 600 700 800 900

1 ( )Mar-M247(as-cast)

Temperature (deg. C)

1000 100 200 300 400 500 600 700 800 900

1 ( )Mar-M247(as-cast)



Cyclic oxidation resistance

400DAT TA1

400DAT TA1

Test ConditionTest ConditionAtmosphere : airDew point : 30deg. C 300

350

cm2 )

DAT-TA2

DAT-TA1(Under Production)


Binary Binary TiAlTiAl

Bi TiAl ll

300

350

cm2 )

DAT-TA2

DAT-TA1(Under Production)


Binary Binary TiAlTiAl

Bi TiAl ll

Test Temp. x30min

150

200

250

Gai

n (m

g/c

After 200 cyclesAfter 200 cycles

Binary TiAl alloy

150

200

250

Gai

n (m

g/c

After 200 cyclesAfter 200 cycles

Binary TiAl alloy

RT. x30min

50

100

150W

eigh

t

DATDAT--TA1TA1

DATDAT--TA2TA250

100

150W

eigh

t

DATDAT--TA1TA1

DATDAT--TA2TA2

0750 800 850 900 950 1000 1050 1100 1150


0750 800 850 900 950 1000 1050 1100 1150



Various specific properties

Tensile Strength(900deg. C)Tensile Strength(900deg. C)

160

Unit Axis:MPa/(g/cm3)

DAT-TA2(4.01[g/cm3])DAT-TA1(3.94[g/cm3])

(Under production)

160

Unit Axis:MPa/(g/cm3)

DAT-TA2(4.01[g/cm3])DAT-TA1(3.94[g/cm3])

(Under production)

2040Creep Rupture Strength

(1000deg. C/100hr)

Unit Axis:MPa/(g/cm )

Rotating BendingFatigue Strength

(700deg C/107cycles)2040

Creep Rupture Strength(1000deg. C/100hr)

Unit Axis:MPa/(g/cm )

Rotating BendingFatigue Strength

(700deg C/107cycles) ( 000deg C/ 00 )(700deg. C/107cycles)

Inconel713C(7 91[g/cm3])Mar M247(8 59[g/cm3])

The data of Mar-M247 is calculated fromthe data of 600deg.C and the data of 800deg. C.

( 000deg C/ 00 )(700deg. C/107cycles)

Inconel713C(7 91[g/cm3])Mar M247(8 59[g/cm3])

The data of Mar-M247 is calculated fromthe data of 600deg.C and the data of 800deg. C.

120

Inconel713C(7.91[g/cm3])Mar-M247(8.59[g/cm3])

Tensile Strength(RT)120

Inconel713C(7.91[g/cm3])Mar-M247(8.59[g/cm3])

Tensile Strength(RT)


LEVICAST process

1 Contamination free melting and casting

<Advantage of LEVICAST>1. Contamination free melting and casting- Oxygen content of TiAl cast is around 500ppm

2. Thin-wall castings - Minimum blade tip thickness of TiAl turbineMinimum blade tip thickness of TiAl turbine

wheel is 0.50mm

3. High productivity as compared withconventional processes

- Short cycle of meting and casting

Outer view of molten metal


Experiment production of TiAl T/W

AlloyAlloyConditionConditionprocessprocess

: DAT: DAT--TA2TA2: as: as--castcast: LEVICAST: LEVICASTprocessprocess : LEVICAST: LEVICAST

3 13cmPhoto. DAT-TA2 turbine wheels manufactured by LEVICAST Photo. Macrostructure of DAT-TA2

turbine wheel by LEVICAST

1cm


Conclusion

In order to provide the excellent performance at higher In order to provide the excellent performance at higher exhaust gas temperatures, new gamma TiAl alloy DATexhaust gas temperatures, new gamma TiAl alloy DAT--TA2TA2was developed based on DATwas developed based on DAT--TA1 which is in production. TA1 which is in production.

DATDAT--TA2 has excellent mechanical properties for turbine wheels TA2 has excellent mechanical properties for turbine wheels

DATDAT--TA2 is available to turbine wheels of turbochargers for TA2 is available to turbine wheels of turbochargers for

as compared with conventional turbine wheel materials.as compared with conventional turbine wheel materials.

gasoline engine at high exhaust gas temperatures. gasoline engine at high exhaust gas temperatures.


Thank you for your attention


research engineer daido steel co. ltd....dat5(6al-4v) dat54(6al-4sn-4zr-3mo-1nb-04si-0 06c)...

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