Grade 18 Titanium vs. Grade 21 Titanium
Both grade 18 titanium and grade 21 titanium are titanium alloys. They have 82% of their average alloy composition in common. There are 28 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.
For each property being compared, the top bar is grade 18 titanium and the bottom bar is grade 21 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 110 | |
| 140 |
| Elongation at Break, % | 11 to 17 | |
| 9.0 to 17 |
| Fatigue Strength, MPa | 330 to 480 | |
| 550 to 660 |
| Poisson's Ratio | 0.32 | |
| 0.32 |
| Reduction in Area, % | 23 | |
| 22 |
| Shear Modulus, GPa | 40 | |
| 51 |
| Shear Strength, MPa | 420 to 590 | |
| 550 to 790 |
| Tensile Strength: Ultimate (UTS), MPa | 690 to 980 | |
| 890 to 1340 |
| Tensile Strength: Yield (Proof), MPa | 540 to 810 | |
| 870 to 1170 |
Thermal Properties
| Latent Heat of Fusion, J/g | 410 | |
| 410 |
| Maximum Temperature: Mechanical, °C | 330 | |
| 310 |
| Melting Completion (Liquidus), °C | 1640 | |
| 1740 |
| Melting Onset (Solidus), °C | 1590 | |
| 1690 |
| Specific Heat Capacity, J/kg-K | 550 | |
| 500 |
| Thermal Conductivity, W/m-K | 8.3 | |
| 7.5 |
| Thermal Expansion, µm/m-K | 9.9 | |
| 7.1 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.5 | |
| 5.4 |
| Embodied Carbon, kg CO2/kg material | 41 | |
| 32 |
| Embodied Energy, MJ/kg | 670 | |
| 490 |
| Embodied Water, L/kg | 270 | |
| 180 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 87 to 110 | |
| 110 to 180 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1380 to 3110 | |
| 2760 to 5010 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 35 | |
| 32 |
| Strength to Weight: Axial, points | 43 to 61 | |
| 46 to 69 |
| Strength to Weight: Bending, points | 39 to 49 | |
| 38 to 50 |
| Thermal Diffusivity, mm2/s | 3.4 | |
| 2.8 |
| Thermal Shock Resistance, points | 47 to 67 | |
| 66 to 100 |
Alloy Composition
| Aluminum (Al), % | 2.5 to 3.5 | |
| 2.5 to 3.5 |
| Carbon (C), % | 0 to 0.080 | |
| 0 to 0.050 |
| Hydrogen (H), % | 0 to 0.015 | |
| 0 to 0.015 |
| Iron (Fe), % | 0 to 0.25 | |
| 0 to 0.4 |
| Molybdenum (Mo), % | 0 | |
| 14 to 16 |
| Niobium (Nb), % | 0 | |
| 2.2 to 3.2 |
| Nitrogen (N), % | 0 to 0.030 | |
| 0 to 0.030 |
| Oxygen (O), % | 0 to 0.15 | |
| 0 to 0.17 |
| Palladium (Pd), % | 0.040 to 0.080 | |
| 0 |
| Silicon (Si), % | 0 | |
| 0.15 to 0.25 |
| Titanium (Ti), % | 92.5 to 95.5 | |
| 76 to 81.2 |
| Vanadium (V), % | 2.0 to 3.0 | |
| 0 |
| Residuals, % | 0 | |
| 0 to 0.4 |