6Al-2Sn-4Zr-2Mo

6Al-2Sn-4Zr-2Mo

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

 AlSnZrMoCNHOSiFeYOthers,
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