Cold Worked and Stress Relieved Grade 18 Titanium
Cold worked and stress relieved grade 18 titanium is grade 18 titanium in the cold worked and stress relieved condition. It has the highest strength and lowest ductility compared to the other variants of grade 18 titanium.
The graph bars on the material properties cards below compare cold worked and stress relieved grade 18 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
110 GPa 15 x 106 psi
Elongation at Break
11 %
Fatigue Strength
480 MPa 69 x 103 psi
Poisson's Ratio
0.32
Reduction in Area
23 %
Shear Modulus
40 GPa 5.8 x 106 psi
Shear Strength
590 MPa 85 x 103 psi
Tensile Strength: Ultimate (UTS)
980 MPa 140 x 103 psi
Tensile Strength: Yield (Proof)
810 MPa 120 x 103 psi
Thermal Properties
Latent Heat of Fusion
410 J/g
Maximum Temperature: Mechanical
330 °C 630 °F
Melting Completion (Liquidus)
1640 °C 2980 °F
Melting Onset (Solidus)
1590 °C 2890 °F
Specific Heat Capacity
550 J/kg-K 0.13 BTU/lb-°F
Thermal Conductivity
8.3 W/m-K 4.8 BTU/h-ft-°F
Thermal Expansion
9.9 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
1.3 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.7 % IACS
Otherwise Unclassified Properties
Density
4.5 g/cm3 280 lb/ft3
Embodied Carbon
41 kg CO2/kg material
Embodied Energy
670 MJ/kg 290 x 103 BTU/lb
Embodied Water
270 L/kg 33 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
110 MJ/m3
Resilience: Unit (Modulus of Resilience)
3110 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
35 points
Strength to Weight: Axial
61 points
Strength to Weight: Bending
49 points
Thermal Diffusivity
3.4 mm2/s
Thermal Shock Resistance
67 points
Alloy Composition
| Ti | 92.5 to 95.5 | |
| Al | 2.5 to 3.5 | |
| V | 2.0 to 3.0 | |
| Fe | 0 to 0.25 | |
| O | 0 to 0.15 | |
| Pd | 0.040 to 0.080 | |
| 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
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.