MakeItFrom.com
Menu (ESC)

Titanium 6-6-2 (3.7175, R56620)

Titanium 6-6-2 is a titanium alloy formulated for primary forming into wrought products. 3.7175 is the EN numeric designation for this material. R56620 is the UNS number. And Titanium 6-6-2 is the common industry name.

It has the lowest embodied energy among wrought titaniums. In addition, it can have a fairly high tensile strength and has a moderately low thermal conductivity.

The properties of titanium 6-6-2 include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare titanium 6-6-2 to: wrought titaniums (top), all titanium alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Mechanical Properties

Elastic (Young's, Tensile) Modulus

120 GPa 17 x 106 psi

Elongation at Break

6.7 to 9.0 %

Fatigue Strength

590 to 670 MPa 85 to 97 x 103 psi

Poisson's Ratio

0.32

Reduction in Area

17 to 23 %

Shear Modulus

44 GPa 6.3 x 106 psi

Shear Strength

670 to 800 MPa 98 to 120 x 103 psi

Tensile Strength: Ultimate (UTS)

1140 to 1370 MPa 170 to 200 x 103 psi

Tensile Strength: Yield (Proof)

1040 to 1230 MPa 150 to 180 x 103 psi

Thermal Properties

Latent Heat of Fusion

400 J/g

Maximum Temperature: Mechanical

310 °C 580 °F

Melting Completion (Liquidus)

1610 °C 2920 °F

Melting Onset (Solidus)

1560 °C 2830 °F

Specific Heat Capacity

540 J/kg-K 0.13 BTU/lb-°F

Thermal Conductivity

5.5 W/m-K 3.2 BTU/h-ft-°F

Thermal Expansion

9.4 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

1.1 % IACS

Electrical Conductivity: Equal Weight (Specific)

2.1 % IACS

Otherwise Unclassified Properties

Base Metal Price

40 % relative

Density

4.8 g/cm3 300 lb/ft3

Embodied Carbon

29 kg CO2/kg material

Embodied Energy

470 MJ/kg 200 x 103 BTU/lb

Embodied Water

200 L/kg 24 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

89 to 99 MJ/m3

Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

34 points

Strength to Weight: Axial

66 to 79 points

Strength to Weight: Bending

50 to 57 points

Thermal Diffusivity

2.1 mm2/s

Thermal Shock Resistance

75 to 90 points

Alloy Composition

Titanium (Ti) 82.8 to 87.8
Molybdenum (Mo) 5.0 to 6.0
Aluminum (Al) 5.0 to 6.0
Tin (Sn) 1.5 to 2.5
Iron (Fe) 0.35 to 1.0
Copper (Cu) 0.35 to 1.0
Oxygen (O) 0 to 0.2
Carbon (C) 0 to 0.050
Nitrogen (N) 0 to 0.040
Hydrogen (H) 0 to 0.015
Residuals 0 to 0.4

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

Titanium and Titanium Alloys: Fundamentals and Applications, Christoph Leyens and Manfred Peters (editors), 2003

Titanium, 2nd ed., G. Lutjering and J. C. Williams, 2007

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015