An Update on Properties and Applications for Ti-5Al-5Mo-5V-3Cr · International Titanium...

International Titanium AssociationInternational Titanium AssociationScottsdale 2005Scottsdale 2005

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An Update on Properties and Applications for Ti-5Al-5Mo-5V-3Cr


TiTi--55535553• Evolved from Russian alloy, VT-22

– Commonly used for airframe structural forgings– Applications in Ilyushin, Tupolev, Antonov, Yakovlev aircraft

• 1995/1996 – VSMPO began work with Boeing– Goal: Higher strength / lower cost than 10V-2Fe-3Al– Candidate alloy for forged, landing gear components– Led to development of VST-5553 (Ti-5553)

• Selected for applications on 787– Landing gear components– Airframe structural components

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TiTi--55535553Advantages Over Ti-10V-2Fe-3Al

• Less prone to segregation• Higher strength; ~15%• Better hardenability in thick sections

– Up to 6” section thickness vs. 3” for 10V-2Fe-3Al– Potentially lower machining costs

• Air cool vs. water quench– Potentially less distortion

• Able to use higher % level of revert

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Chemical Composition

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Chemical CompositionChemical Composition

1.5

0.5

Fe

1.55.55.55.7Basemax

0.54.04.04.4Basemin

CrVMoAlTiVT22

0.50

0.30

Fe

3.55.55.55.7Basemax

2.54.04.04.4Basemin

CrVMoAlTiTi-

5553

Higher Cr

Lower Fe

VT22 vs. TiVT22 vs. Ti--55535553

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Heat Treat Conditions

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TiTi--55535553Heat Treat Conditions

• Solution treat and age (STA)– Typical cycle: βt-60F, 2 Hrs, A.C.; Age @ 1100F,

8 Hrs, A.C.– High strength applications (180 KSI)– Landing Gear Applications

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Ti-5Al-5Mo-5V-3CrHeat Treat Conditions

• β anneal, slow cool and age (BASCA)– Typical cycle: βt+50F, 1 Hr, F.C. @ 5F/min; Age

@ 1050F, 8 Hrs, A.C.– Lower strength (160 KSI) but much better fatigue– Used on airframe structural components

• Enables design with thinner cross-sections = weight reduction

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Ti 5Al-5Mo-5V-3CrHeat Treat Conditions

• Beta-forged, solution treat and age– Forge above beta-transus– Standard STA heat treat cycle– Similar properties to BASCA with the advantage

of closer-to-net forging design

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Mechanical Properties

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TiTi--5553 Forging Properties5553 Forging Properties

Ti 6Al4VTi 6Al4V Ti 5553Ti 5553Ti 10V2Fe3AlTi 10V2Fe3Al

YS, MPa (KSI)YS, MPa (KSI)

UTS, MPa (KSI)UTS, MPa (KSI)

El, %El, %

KK1C1C, MPa Vm (KSI Vin), MPa Vm (KSI Vin)

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MECHANICAL PROPERTIESMECHANICAL PROPERTIESTiTi--6Al6Al--4V vs. Ti4V vs. Ti--5Al5Al--5Mo5Mo--5V5V--3Cr3Cr

160 KSI Condition160 KSI Condition

0

50

100

150

200

KSI

VST 5553 STA 165 145 6 60 37VST 5553 BASCA 160 140 6 70 40Ti-6Al-4V AMS 4928 130 120 10 60 35.4

Ftu Fty %El K1c da/dN

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Dynamic Property EvaluationsDynamic Property EvaluationsTi-5553 LCF Behavior

0

0.2

0.4

0.6

0.8

1

1.2

1.E+03 1.E+04 1.E+05 1.E+06

Cycles to Failure

Max

Str

ain,

%

r = 0.1

Cast Ti-5553

Cast Ti-64

Source: The Boeing Company

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Machining

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Ti 5553 MachiningTi 5553 Machining• Machining parameters still being

developed– Trials being performed by various end-users– No parts have been machined in production– Cutting tools still being optimized– So, much is yet to be defined

• But in general we can say…– 180 KSI material machines comparably to Ti 10-2-3– 160 KSI material machines much better than 180 KSI

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Ti 5553 MachiningTi 5553 Machining• Machine performance vs. Ti-6Al-4V

– ~ 20% - 30% lower metal removal rates than Ti-6Al-4V

– Tool life 10% - 20% shorter than for Ti 6Al-4V– Carbide inserts do not perform well– Solid cobalt cutters seem to be the best choice

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Current Applications

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Ti 5553 ForgingsTi 5553 Forgings• ~20% of 787 primary structure is

titanium– Ti-5553 makes up a significant portion of this

volume, mostly in forgings

• ~75 configurations – landing gear & airframe structural– Forging weights range from 23kg (50 lbs) to 2600 kg

(5700 lbs)– Sizes range from 400mm (16”) to 5700mm (225”)

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787 Forgings FromTi787 Forgings FromTi--55535553

Size: 2448 x 622 x 550 mmWeight: 1145 kg

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Overall size: 5688 х 555 х 376 mmWeight: 2610 kg (β – die forging)

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Overall size: 1170 x 663 x 254 mmWeight: 276 kg (β – die forging)

Overall size: 1807 x 426 x 273 mmWeight: 158 kg (β – die forging)

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Other Applications

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TiTi--5553 Applications5553 Applications

• Investment casting– Comparable to Ti-6242 and Ti-15-3-3-3 in

castability– Higher strength and better fatigue than Ti 6-4

• Plate product– Demonstrated good strength and K1C

properties

• Extrusions – 787 applications

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Ti 5AlTi 5Al--5Mo5Mo--5V5V--3Cr3CrSummary

• Alloy entering into full production• Two heat treat conditions developed – 180 KSI

and 160 KSI• Widely used in forgings throughout the 787

airplane• Potential use in castings, plate and extrusions

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An Update on Properties and Applications for Ti-5Al-5Mo-5V-3Cr · International Titanium...

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