Titanium Alloy Ti6Al-4V – Properties, Composition, Heat Treatments and Specifications from Super Alloys

Topics Covered

Background

Titanium Ti6Al-4V

Applications

Composition of Ti6Al-4V

Specifications

Heat Treatments

Physical Properties of Titanium Ti6Al-4V

Thermal Properties of Titanium Ti6Al-4V

Typical Mechanical Properties of Titanium Ti6Al-4V

Typical Range, Room Temperature Bar Tensile Properties

Typical Tensile Strength and Fracture Toughness

Background

The Super Alloys management team are amongst the most experienced professionals in the market. Supported by professional metallurgists and technicians, Super Alloys not only provide access to the largest range of high-tec metals in Europe, but also access to the broadest range of expertise.

The unique combination of access to stock, expertise and rapid delivery reduces lead times and can eliminate costly production delays.

The Super Alloys range of materials includes:

         Titanium Alloys

         Nickel Alloys

         Steels

Titanium Ti6Al-4V

Ti6Al-4V is the most widely used of all the alpha-beta titanium alloys. It may be heat treated for high strength in welded construction at service temperatures through 600°F. Hardenability is limited and sections over about one inch may not develop full properties.

Applications

Typical Applications for the titanium alloy Ti 6Al-4V include:

         Turbine blades, discs and rings

         Aircraft structural components

         Fasteners

         Medical and dental implants

         Hand tools

         Sporting equipment

Composition of Ti6Al-4V

The composition range for Ti6Al-4V is provided in table 1.

Table 1. Composition of titanium alloy Ti6Al-4V.

Chemistry, %

AMS 4967

 

Min

Max

Aluminum

5.50

6.75

Vanadium

3.50

4.50

Carbon

-

0.08

Nitrogen

-

0.05

Oxygen

-

0.20

Hydrogen

-

0.0125

Iron

-

0.30

Yttrium

-

0.005

Others, each

-

0.10

Other, total

-

0.40

Titanium

remainder

 

Specifications

The various forms of Ti6Al-4V are covered by the following standards:

         UNS R56400 W.Nr. 3.7164/5

         AMS 4911 Sheet, strip, and plate, annealed

         AMS 4928 Bars, wire, forgings & rings, annealed, heat treatable

         AMS 4967 Bars, wire, forgings & rings, annealed, heat treatable

         MIL-T-9047 Bars and reforging stock

         MIL-T-81556 Extruded bars and shapes

         MIL-F-83142 Forgings

         ASTM B 265, Strip, sheet and plate Grade 5

         ASME SB-265

         ASTM B 348, Bar, Billet Grade 5

         ASME SB-348

         ASTM B 861, Seamless pipe Grade 5

         ASME SB-861

Heat Treatments

Annealing bar and forgings for maximum ductility is done at 1275-1325°F 2 hours furnace cool. Solution treated and aged condition is:

For sheet, 1675-1725°F 5 to 25 minutes, water quench. Age 975°F 4 to 6 hours, air cool.

For bars and forgings, 1675-1725°F 1 hour, water quench. Age 975-1025°F 3 hours, air cool.

For increased fracture toughness, but lower tensile strength, precipitation treat (overage) 1150-1250°F

4 hours, air cool.

Stress-relief annealing is commonly 1000-1200°F

1/2- 4 hours, air cool.

Physical Properties of Titanium Ti6Al-4V

Density:

0.160 lb/inch3

Melting Range:

2929-3020°F

Beta Transus Nominal:

1825±25°F

Thermal Properties of Titanium Ti6Al-4V

The thermal properties of Ti6Al-4V are summarised in table 2.

Table 2. Thermal properties of titanium alloy Ti6Al-4V.

Temp

Coeffcient of Thermal Exp.

Thermal Conductivity

Modulus

°F

in/in °F x 10-6

Btu. ft/ft2.hr°F

psi x 106

 

 

STA

STA

RT

-

4.0

16.7

200

5.3

4.3

16.0

400

5.4

5.2

15.0

600

5.5

.1

14.0

Typical Mechanical Properties of Titanium Ti6Al-4V

The mechanical properties titanium alloy Ti6Al-4V, specified, AMS 4911, annealed sheet & plate are provided in table 3.

Table 3. Typical mechanical properties of Ti6Al-4V.

Size up to

Tensile Strength

0.2% Yield Strength

Elong in 2”

Inch

ksi

ksi

%

>0.025 ≤ 0.063

134

126

8

>0.063 ≤0.1874

134

126

10

>0.1874 ≤ 4.000

130

120

10

Typical Range, Room Temperature Bar Tensile Properties

Table 4. Range in properties as a function of heat treatment for Ti6Al-4V

Heat Treatment

UTS, ksi

0.2% YS, ksi

% Elong

%RA

Anneal 1300°F Air Cool

138-155

128-147

15-20

38-51

Anneal 1300°F Solution anneal 1750°F Age 1000°F

150-172

137-156

15-17

41-46

Typical Tensile Strength and Fracture Toughness

Table 5. Typical tensile strength and fracture toughness, various heat treatments for flat-rolled products (MCIC-HB-02 1985 reprint) for Ti6Al-4V

Heat Treatment

0.2% YS, ksi

Fracture Toughness kc, ksi √ inch

Annealed (Continuously)

143

178

Rolled Sheet

142 (transversea)

140 (transversea)

Beta Annealed

131

134

Beta STA 1250°Fb

128

150

Beta STA 1000°Fb

143

120

STA 1250°Fc

137

105

STA 1000°Fc

159

80

 

(a) Directional variations
(b) Beta heat treated followed by solution treating and overaging 1250°F, or aging 1000°F
(c) Solution treating and overaging 1250°F, or aging 1000°F

 

Source: Super Alloys

 

For more information on this source please visit Super Alloys.

 

Date Added: Apr 24, 2008 | Updated: Jun 11, 2013
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