ASTM B780 Alloy vs. R30021 Cobalt
ASTM B780 alloy belongs to the otherwise unclassified metals classification, while R30021 cobalt belongs to the cobalt alloys. There are 16 material properties with values for both materials. Properties with values for just one material (14, in this case) are not shown.
For each property being compared, the top bar is ASTM B780 alloy and the bottom bar is R30021 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 83 | |
| 220 |
| Elongation at Break, % | 1.1 to 9.1 | |
| 9.0 |
| Poisson's Ratio | 0.36 | |
| 0.29 |
| Shear Modulus, GPa | 30 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 330 to 590 | |
| 700 |
Thermal Properties
| Latent Heat of Fusion, J/g | 140 | |
| 330 |
| Specific Heat Capacity, J/kg-K | 270 | |
| 450 |
| Thermal Expansion, µm/m-K | 18 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 70 to 76 | |
| 1.9 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 62 to 68 | |
| 2.1 |
Otherwise Unclassified Properties
| Density, g/cm3 | 10 | |
| 8.4 |
Common Calculations
| Stiffness to Weight: Axial, points | 4.5 | |
| 15 |
| Stiffness to Weight: Bending, points | 14 | |
| 24 |
| Strength to Weight: Axial, points | 9.1 to 16 | |
| 23 |
| Strength to Weight: Bending, points | 11 to 15 | |
| 21 |
| Thermal Shock Resistance, points | 16 to 29 | |
| 21 |
Alloy Composition
| Cadmium (Cd), % | 0 to 0.050 | |
| 0 |
| Carbon (C), % | 0 | |
| 0.2 to 0.35 |
| Chromium (Cr), % | 0 | |
| 26 to 29 |
| Cobalt (Co), % | 0 | |
| 61.7 to 67.3 |
| Copper (Cu), % | 23.5 to 25.7 | |
| 0 |
| Iron (Fe), % | 0 to 0.050 | |
| 0 to 3.0 |
| Lead (Pb), % | 0 to 0.030 | |
| 0 |
| Molybdenum (Mo), % | 0 | |
| 4.5 to 6.0 |
| Nickel (Ni), % | 0.35 to 0.65 | |
| 2.0 to 3.0 |
| Silicon (Si), % | 0 | |
| 0 to 1.5 |
| Silver (Ag), % | 74 to 76 | |
| 0 |
| Zinc (Zn), % | 0 to 0.060 | |
| 0 |