Solution-Treated and Aged (Moderate Strength) Grade 21 Titanium
Moderate strength grade 21 titanium is grade 21 titanium in the annealed and aged condition. The graph bars on the material properties cards below compare moderate strength grade 21 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
Elastic (Young's, Tensile) Modulus
140 GPa 20 x 106 psi
Elongation at Break
17 %
Fatigue Strength
620 MPa 91 x 103 psi
Poisson's Ratio
0.32
Reduction in Area
22 %
Shear Modulus
51 GPa 7.5 x 106 psi
Shear Strength
680 MPa 98 x 103 psi
Tensile Strength: Ultimate (UTS)
1100 MPa 160 x 103 psi
Tensile Strength: Yield (Proof)
970 MPa 140 x 103 psi
Thermal Properties
Latent Heat of Fusion
410 J/g
Maximum Temperature: Mechanical
310 °C 590 °F
Melting Completion (Liquidus)
1740 °C 3170 °F
Melting Onset (Solidus)
1690 °C 3070 °F
Specific Heat Capacity
500 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
7.5 W/m-K 4.3 BTU/h-ft-°F
Thermal Expansion
7.1 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
60 % relative
Density
5.4 g/cm3 340 lb/ft3
Embodied Carbon
32 kg CO2/kg material
Embodied Energy
490 MJ/kg 210 x 103 BTU/lb
Embodied Water
180 L/kg 21 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
180 MJ/m3
Resilience: Unit (Modulus of Resilience)
3490 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
32 points
Strength to Weight: Axial
57 points
Strength to Weight: Bending
44 points
Thermal Diffusivity
2.8 mm2/s
Thermal Shock Resistance
82 points
Alloy Composition
Ti | 76 to 81.2 | |
Mo | 14 to 16 | |
Al | 2.5 to 3.5 | |
Nb | 2.2 to 3.2 | |
Si | 0.15 to 0.25 | |
Fe | 0 to 0.4 | |
O | 0 to 0.17 | |
C | 0 to 0.050 | |
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
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