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.
|
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.
|
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.
|
>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
|
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
|
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
|