A near-alpha alloy, primarily used for high strength and toughness, with good creep resistance up to 1000°F. Forging and machining characteristics similar to those of Ti 6Al-4V. Applications include compressor components, hot airframe skin, and engine afterburner structures. The weldability of Ti 6-2-4-2 is fair, using AMS 4952 weld wire. Several different treatments are available.
Sheet & Strip under 0.1875" thickness: Duplex anneal: 1650 ± 25°F), 30± 3 minutes, air cool, followed by 1450± 25°F 15± 2 minutes, air cool.
Triplex anneal: 1650°F ½ hour, air cool, followed by 1450°F ¼ hour, air cool, 1100°F 2 hours air cool.
Plate 0.1875 inch thickness and over: Duplex anneal: 650± 25°F 60± 5 minutes, air cool, followed by 1100±25°F 8 hours ± 15 minutes, air cool. Triplex anneal: 1650°F ½ hour, air cool, followed by 1450°F ¼, air cool, 1100°F 2 hours air cool.
Bar and Forgings: Duplex anneal: Solution anneal 25 - 50°F below. Beta transus 1 hour, air cool or faster, 1100°F 8 hours air cool.
Chemistry
|
|
Al
|
Sn
|
Zr
|
Mo
|
C
|
N
|
H
|
O
|
Si
|
Fe
|
Y
|
Others,
Each
|
Others,
Total
|
Ti
|
|
MIN
|
5.5
|
1.8
|
3.6
|
1.8
|
--
|
--
|
--
|
--
|
0.06
|
|
|
--
|
--
|
--
|
|
MAX
|
6.5
|
2.2
|
4.4
|
2.2
|
0.05
|
0.05
|
0.015
|
0.12
|
0.1
|
0.25
|
0.005
|
0.1
|
0.3
|
Balance
|
Specifications
AMS 4919, AMS 4975, AMS 4976, AMS 4979, AMS T-9047
EN 3.71450
MIL-F-81556
MIL-F-82142, MIL-T-9046
MIL-T-9047
UNS R54620
Werkstoff 3.7145
Inventory
6Al-2Sn-4Zr-2Mo Forged Billet, 6Al-2Sn-4Zr-2Mo Plate, 6Al-2Sn-4Zr-2Mo Round Bar, 6Al-2Sn-4Zr-2Mo Sheet
Common Trade Names
6-2-4-2 Titanium, 6-2-4-2
Features
• Machinability similar to austenitic stainless steels
• Easily welded if proper precautions are taken to prevent oxygen, nitrogen and hydrogen contaminations
• Long term stability for temperatures up to 800°F
Applications
• Compressor discs, blades
• Airframe structure, skin
• Engine afterburner components
• Hush kits
Physical Properties
Density: 0.160 lb/in3
Beta Transus: 1825±25°F
Thermal Conductivity: 4.00 Btu • hr/ft2 • hr°F
Coefficient of Thermal Expansion: 32-212°F 4.3 x10-6 in/in°F
Modulus of Elasticity: 16.5x106 psi
Mechanical Properties
Minimum Tensile Properties, AMS 4919, Duplex Annealed
|
Thickness, in
|
0.025 ≤ 0.062
|
> 0.062 ≤ 1.000
|
> 1.000 ≤ 3.000
|
|
Tensile Strength, ksi
|
135,000
|
135,000
|
135,000
|
|
0.2% offset Yield Strength, ksi
|
125,000
|
125,000
|
125,000
|
|
Elongation, %
|
8
|
10
|
10
|
Bend Factors, Duplex Annealed, AMS 4919
|
Nominal Thickness, in
|
≤ 0.070
|
> 0.070 < 0.1875
|
|
Factor, 105° Bend
|
9
|
10
|
