Grade 21 Titanium vs. Ductile Cast Iron
Grade 21 titanium belongs to the titanium alloys classification, while ductile cast iron belongs to the iron alloys. There are 27 material properties with values for both materials. Properties with values for just one material (6, in this case) are not shown.
For each property being compared, the top bar is grade 21 titanium and the bottom bar is ductile cast iron.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 140 | |
| 170 to 180 |
| Elongation at Break, % | 9.0 to 17 | |
| 2.1 to 20 |
| Poisson's Ratio | 0.32 | |
| 0.28 to 0.31 |
| Shear Modulus, GPa | 51 | |
| 64 to 70 |
| Shear Strength, MPa | 550 to 790 | |
| 420 to 800 |
| Tensile Strength: Ultimate (UTS), MPa | 890 to 1340 | |
| 460 to 920 |
| Tensile Strength: Yield (Proof), MPa | 870 to 1170 | |
| 310 to 670 |
Thermal Properties
| Latent Heat of Fusion, J/g | 410 | |
| 270 |
| Maximum Temperature: Mechanical, °C | 310 | |
| 290 |
| Melting Completion (Liquidus), °C | 1740 | |
| 1160 |
| Melting Onset (Solidus), °C | 1690 | |
| 1120 |
| Specific Heat Capacity, J/kg-K | 500 | |
| 490 |
| Thermal Conductivity, W/m-K | 7.5 | |
| 31 to 36 |
| Thermal Expansion, µm/m-K | 7.1 | |
| 11 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 60 | |
| 1.9 |
| Density, g/cm3 | 5.4 | |
| 7.1 to 7.5 |
| Embodied Carbon, kg CO2/kg material | 32 | |
| 1.5 |
| Embodied Energy, MJ/kg | 490 | |
| 21 |
| Embodied Water, L/kg | 180 | |
| 43 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 110 to 180 | |
| 17 to 80 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 2760 to 5010 | |
| 280 to 1330 |
| Stiffness to Weight: Axial, points | 14 | |
| 12 to 14 |
| Stiffness to Weight: Bending, points | 32 | |
| 24 to 26 |
| Strength to Weight: Axial, points | 46 to 69 | |
| 17 to 35 |
| Strength to Weight: Bending, points | 38 to 50 | |
| 18 to 29 |
| Thermal Diffusivity, mm2/s | 2.8 | |
| 8.9 to 10 |
| Thermal Shock Resistance, points | 66 to 100 | |
| 17 to 35 |
Alloy Composition
| Aluminum (Al), % | 2.5 to 3.5 | |
| 0 |
| Carbon (C), % | 0 to 0.050 | |
| 3.0 to 3.5 |
| Hydrogen (H), % | 0 to 0.015 | |
| 0 |
| Iron (Fe), % | 0 to 0.4 | |
| 93.7 to 95.5 |
| Molybdenum (Mo), % | 14 to 16 | |
| 0 |
| Niobium (Nb), % | 2.2 to 3.2 | |
| 0 |
| Nitrogen (N), % | 0 to 0.030 | |
| 0 |
| Oxygen (O), % | 0 to 0.17 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.080 |
| Silicon (Si), % | 0.15 to 0.25 | |
| 1.5 to 2.8 |
| Titanium (Ti), % | 76 to 81.2 | |
| 0 |
| Residuals, % | 0 to 0.4 | |
| 0 |