Grade 7 (3.7235, R52400) Titanium
Grade 7 titanium is a titanium alloy formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 3.7235 is the EN numeric designation for this material. R52400 is the UNS number. Additionally, the ASTM designation is Titanium Grade 7.
It has a moderately high thermal conductivity among wrought titaniums. In addition, it has a fairly high embodied energy and a moderately high ductility.
The graph bars on the material properties cards below compare grade 7 titanium 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
Brinell Hardness
150
Elastic (Young's, Tensile) Modulus
110 GPa 15 x 106 psi
Elongation at Break
24 %
Fatigue Strength
250 MPa 36 x 103 psi
Poisson's Ratio
0.32
Reduction in Area
34 %
Shear Modulus
38 GPa 5.5 x 106 psi
Shear Strength
270 MPa 39 x 103 psi
Tensile Strength: Ultimate (UTS)
420 MPa 61 x 103 psi
Tensile Strength: Yield (Proof)
340 MPa 50 x 103 psi
Thermal Properties
Latent Heat of Fusion
420 J/g
Maximum Temperature: Mechanical
320 °C 600 °F
Melting Completion (Liquidus)
1660 °C 3020 °F
Melting Onset (Solidus)
1610 °C 2930 °F
Specific Heat Capacity
540 J/kg-K 0.13 BTU/lb-°F
Thermal Conductivity
22 W/m-K 13 BTU/h-ft-°F
Thermal Expansion
9.2 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
3.6 % IACS
Electrical Conductivity: Equal Weight (Specific)
7.2 % IACS
Otherwise Unclassified Properties
Density
4.5 g/cm3 280 lb/ft3
Embodied Carbon
47 kg CO2/kg material
Embodied Energy
800 MJ/kg 340 x 103 BTU/lb
Embodied Water
470 L/kg 56 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
95 MJ/m3
Resilience: Unit (Modulus of Resilience)
560 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
35 points
Strength to Weight: Axial
26 points
Strength to Weight: Bending
28 points
Thermal Diffusivity
8.9 mm2/s
Thermal Shock Resistance
31 points
Alloy Composition
| Ti | 98.7 to 99.88 | |
| Pd | 0.12 to 0.25 | |
| Fe | 0 to 0.3 | |
| O | 0 to 0.25 | |
| C | 0 to 0.080 | |
| N | 0 to 0.030 | |
| 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
ASTM B861: Standard Specification for Titanium and Titanium Alloy Seamless Pipe
ASTM B381: Standard Specification for Titanium and Titanium Alloy Forgings
ASTM B265: Standard Specification for Titanium and Titanium Alloy Strip, Sheet, and Plate
ASTM B348: Standard Specification for Titanium and Titanium Alloy Bars and Billets
Titanium and Titanium Alloys: Fundamentals and Applications, Christoph Leyens and Manfred Peters (editors), 2003
Titanium, 2nd ed., G. Lutjering and J. C. Williams, 2007
Aerospace Materials, Brian Cantor et al. (editors), 2001
Environmental Degradation of Advanced and Traditional Engineering Materials, Lloyd H. Hihara et al., 2014.
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015