Titanium 4-4-2 (3.7185)
Titanium 4-4-2 is a titanium alloy formulated for primary forming into wrought products. 3.7185 is the EN numeric designation for this material. Titanium 4-4-2 is the common industry name.
It has a fairly low embodied energy among wrought titaniums. In addition, it has a moderately low melting temperature and a moderately low thermal conductivity.
The properties of titanium 4-4-2 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 4-4-2 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
110 GPa 16 x 106 psi
Elongation at Break
10 %
Fatigue Strength
590 to 620 MPa 86 to 89 x 103 psi
Poisson's Ratio
0.32
Reduction in Area
20 %
Shear Modulus
42 GPa 6.1 x 106 psi
Shear Strength
690 to 750 MPa 100 to 110 x 103 psi
Tensile Strength: Ultimate (UTS)
1150 to 1250 MPa 170 to 180 x 103 psi
Tensile Strength: Yield (Proof)
1030 to 1080 MPa 150 to 160 x 103 psi
Thermal Properties
Latent Heat of Fusion
410 J/g
Maximum Temperature: Mechanical
310 °C 590 °F
Melting Completion (Liquidus)
1610 °C 2930 °F
Melting Onset (Solidus)
1560 °C 2840 °F
Specific Heat Capacity
540 J/kg-K 0.13 BTU/lb-°F
Thermal Conductivity
6.7 W/m-K 3.9 BTU/h-ft-°F
Thermal Expansion
8.6 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
39 % relative
Density
4.7 g/cm3 290 lb/ft3
Embodied Carbon
30 kg CO2/kg material
Embodied Energy
480 MJ/kg 200 x 103 BTU/lb
Embodied Water
180 L/kg 22 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
110 to 120 MJ/m3
Resilience: Unit (Modulus of Resilience)
4700 to 5160 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
34 points
Strength to Weight: Axial
68 to 74 points
Strength to Weight: Bending
52 to 55 points
Thermal Diffusivity
2.6 mm2/s
Thermal Shock Resistance
86 to 93 points
Alloy Composition
| Ti | 85.8 to 92.2 | |
| Mo | 3.0 to 5.0 | |
| Al | 3.0 to 5.0 | |
| Sn | 1.5 to 2.5 | |
| Si | 0.3 to 0.7 | |
| O | 0 to 0.25 | |
| Fe | 0 to 0.2 | |
| C | 0 to 0.080 | |
| N | 0 to 0.050 | |
| H | 0 to 0.015 | |
| res. | 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