Grade 18 Titanium vs. SAE-AISI O2 Steel
Grade 18 titanium belongs to the titanium alloys classification, while SAE-AISI O2 steel belongs to the iron alloys. There are 22 material properties with values for both materials. Properties with values for just one material (9, in this case) are not shown.
For each property being compared, the top bar is grade 18 titanium and the bottom bar is SAE-AISI O2 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 110 | |
| 190 |
| Poisson's Ratio | 0.32 | |
| 0.29 |
| Shear Modulus, GPa | 40 | |
| 72 |
| Tensile Strength: Ultimate (UTS), MPa | 690 to 980 | |
| 640 to 2050 |
Thermal Properties
| Latent Heat of Fusion, J/g | 410 | |
| 250 |
| Melting Completion (Liquidus), °C | 1640 | |
| 1450 |
| Melting Onset (Solidus), °C | 1590 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 550 | |
| 470 |
| Thermal Conductivity, W/m-K | 8.3 | |
| 43 |
| Thermal Expansion, µm/m-K | 9.9 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 1.3 | |
| 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.7 | |
| 8.6 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 41 | |
| 1.8 |
| Embodied Energy, MJ/kg | 670 | |
| 26 |
| Embodied Water, L/kg | 270 | |
| 50 |
Common Calculations
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 35 | |
| 24 |
| Strength to Weight: Axial, points | 43 to 61 | |
| 23 to 73 |
| Strength to Weight: Bending, points | 39 to 49 | |
| 21 to 46 |
| Thermal Diffusivity, mm2/s | 3.4 | |
| 12 |
| Thermal Shock Resistance, points | 47 to 67 | |
| 22 to 70 |
Alloy Composition
| Aluminum (Al), % | 2.5 to 3.5 | |
| 0 |
| Carbon (C), % | 0 to 0.080 | |
| 0.85 to 1.0 |
| Chromium (Cr), % | 0 | |
| 0 to 0.5 |
| Copper (Cu), % | 0 | |
| 0 to 0.25 |
| Hydrogen (H), % | 0 to 0.015 | |
| 0 |
| Iron (Fe), % | 0 to 0.25 | |
| 95 to 97.8 |
| Manganese (Mn), % | 0 | |
| 1.4 to 1.8 |
| Molybdenum (Mo), % | 0 | |
| 0 to 0.3 |
| Nickel (Ni), % | 0 | |
| 0 to 0.3 |
| Nitrogen (N), % | 0 to 0.030 | |
| 0 |
| Oxygen (O), % | 0 to 0.15 | |
| 0 |
| Palladium (Pd), % | 0.040 to 0.080 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.030 |
| Silicon (Si), % | 0 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Titanium (Ti), % | 92.5 to 95.5 | |
| 0 |
| Vanadium (V), % | 2.0 to 3.0 | |
| 0 to 0.3 |
| Residuals, % | 0 to 0.4 | |
| 0 |