R31538 Cobalt vs. Grade 21 Titanium
R31538 cobalt belongs to the cobalt alloys classification, while grade 21 titanium belongs to the titanium alloys. There are 26 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 R31538 cobalt and the bottom bar is grade 21 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 140 |
| Elongation at Break, % | 13 to 23 | |
| 9.0 to 17 |
| Fatigue Strength, MPa | 310 to 480 | |
| 550 to 660 |
| Poisson's Ratio | 0.29 | |
| 0.32 |
| Reduction in Area, % | 13 to 22 | |
| 22 |
| Shear Modulus, GPa | 86 | |
| 51 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 to 1360 | |
| 890 to 1340 |
| Tensile Strength: Yield (Proof), MPa | 580 to 930 | |
| 870 to 1170 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 410 |
| Melting Completion (Liquidus), °C | 1360 | |
| 1740 |
| Melting Onset (Solidus), °C | 1290 | |
| 1690 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 500 |
| Thermal Conductivity, W/m-K | 13 | |
| 7.5 |
| Thermal Expansion, µm/m-K | 13 | |
| 7.1 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 5.4 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 32 |
| Embodied Energy, MJ/kg | 110 | |
| 490 |
| Embodied Water, L/kg | 530 | |
| 180 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 140 to 200 | |
| 110 to 180 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 750 to 1920 | |
| 2760 to 5010 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 32 |
| Strength to Weight: Axial, points | 34 to 45 | |
| 46 to 69 |
| Strength to Weight: Bending, points | 27 to 32 | |
| 38 to 50 |
| Thermal Diffusivity, mm2/s | 3.5 | |
| 2.8 |
| Thermal Shock Resistance, points | 25 to 33 | |
| 66 to 100 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 2.5 to 3.5 |
| Carbon (C), % | 0.15 to 0.35 | |
| 0 to 0.050 |
| Chromium (Cr), % | 26 to 30 | |
| 0 |
| Cobalt (Co), % | 58.7 to 68.9 | |
| 0 |
| Hydrogen (H), % | 0 | |
| 0 to 0.015 |
| Iron (Fe), % | 0 to 0.75 | |
| 0 to 0.4 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 |
| Molybdenum (Mo), % | 5.0 to 7.0 | |
| 14 to 16 |
| Nickel (Ni), % | 0 to 1.0 | |
| 0 |
| Niobium (Nb), % | 0 | |
| 2.2 to 3.2 |
| Nitrogen (N), % | 0 to 0.25 | |
| 0 to 0.030 |
| Oxygen (O), % | 0 | |
| 0 to 0.17 |
| Silicon (Si), % | 0 to 1.0 | |
| 0.15 to 0.25 |
| Titanium (Ti), % | 0 | |
| 76 to 81.2 |
| Residuals, % | 0 | |
| 0 to 0.4 |