Grade 18 Titanium vs. SAE-AISI D7 Steel
Grade 18 titanium belongs to the titanium alloys classification, while SAE-AISI D7 steel belongs to the iron alloys. There are 20 material properties with values for both materials. Properties with values for just one material (12, 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 D7 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 110 | |
| 190 |
| Poisson's Ratio | 0.32 | |
| 0.28 |
| Shear Modulus, GPa | 40 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 690 to 980 | |
| 800 to 2120 |
Thermal Properties
| Latent Heat of Fusion, J/g | 410 | |
| 270 |
| Melting Completion (Liquidus), °C | 1640 | |
| 1440 |
| Melting Onset (Solidus), °C | 1590 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 550 | |
| 480 |
| Thermal Conductivity, W/m-K | 8.3 | |
| 27 |
| Thermal Expansion, µm/m-K | 9.9 | |
| 11 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.5 | |
| 7.6 |
| Embodied Carbon, kg CO2/kg material | 41 | |
| 11 |
| Embodied Energy, MJ/kg | 670 | |
| 180 |
| Embodied Water, L/kg | 270 | |
| 130 |
Common Calculations
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 35 | |
| 25 |
| Strength to Weight: Axial, points | 43 to 61 | |
| 29 to 78 |
| Strength to Weight: Bending, points | 39 to 49 | |
| 25 to 48 |
| Thermal Diffusivity, mm2/s | 3.4 | |
| 7.4 |
| Thermal Shock Resistance, points | 47 to 67 | |
| 27 to 72 |
Alloy Composition
| Aluminum (Al), % | 2.5 to 3.5 | |
| 0 |
| Carbon (C), % | 0 to 0.080 | |
| 2.2 to 2.5 |
| Chromium (Cr), % | 0 | |
| 11.5 to 13.5 |
| Copper (Cu), % | 0 | |
| 0 to 0.25 |
| Hydrogen (H), % | 0 to 0.015 | |
| 0 |
| Iron (Fe), % | 0 to 0.25 | |
| 76.6 to 81.9 |
| Manganese (Mn), % | 0 | |
| 0 to 0.6 |
| Molybdenum (Mo), % | 0 | |
| 0.7 to 1.2 |
| 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 0.6 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Titanium (Ti), % | 92.5 to 95.5 | |
| 0 |
| Vanadium (V), % | 2.0 to 3.0 | |
| 3.8 to 4.4 |
| Residuals, % | 0 to 0.4 | |
| 0 |