R30021 Cobalt vs. R30012 Cobalt
Both R30021 cobalt and R30012 cobalt are cobalt alloys. Both are furnished in the annealed condition. They have 88% of their average alloy composition in common.
For each property being compared, the top bar is R30021 cobalt and the bottom bar is R30012 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 1300 | |
| 1770 |
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 220 |
| Elongation at Break, % | 9.0 | |
| 1.0 |
| Fatigue Strength, MPa | 250 | |
| 320 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Rockwell C Hardness | 32 | |
| 48 |
| Shear Modulus, GPa | 86 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 700 | |
| 830 |
| Tensile Strength: Yield (Proof), MPa | 500 | |
| 650 |
Thermal Properties
| Latent Heat of Fusion, J/g | 330 | |
| 320 |
| Melting Completion (Liquidus), °C | 1350 | |
| 1470 |
| Melting Onset (Solidus), °C | 1190 | |
| 1280 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 440 |
| Thermal Conductivity, W/m-K | 15 | |
| 15 |
| Thermal Expansion, µm/m-K | 11 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 1.9 | |
| 1.8 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.1 | |
| 1.8 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 8.8 |
| Embodied Carbon, kg CO2/kg material | 8.0 | |
| 8.3 |
| Embodied Energy, MJ/kg | 110 | |
| 120 |
| Embodied Water, L/kg | 520 | |
| 480 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 57 | |
| 7.7 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 570 | |
| 960 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 23 |
| Strength to Weight: Axial, points | 23 | |
| 26 |
| Strength to Weight: Bending, points | 21 | |
| 22 |
| Thermal Diffusivity, mm2/s | 3.8 | |
| 3.8 |
| Thermal Shock Resistance, points | 21 | |
| 23 |
Alloy Composition
| Carbon (C), % | 0.2 to 0.35 | |
| 1.4 to 2.0 |
| Chromium (Cr), % | 26 to 29 | |
| 27 to 32 |
| Cobalt (Co), % | 61.7 to 67.3 | |
| 47.5 to 64.1 |
| Iron (Fe), % | 0 to 3.0 | |
| 0 to 3.0 |
| Molybdenum (Mo), % | 4.5 to 6.0 | |
| 0 to 1.0 |
| Nickel (Ni), % | 2.0 to 3.0 | |
| 0 to 3.0 |
| Silicon (Si), % | 0 to 1.5 | |
| 0 to 2.0 |
| Tungsten (W), % | 0 | |
| 7.5 to 9.5 |