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