Nickel 684 vs. R30075 Cobalt
Nickel 684 belongs to the nickel alloys classification, while R30075 cobalt belongs to the cobalt alloys. They have a modest 40% of their average alloy composition in common, which, by itself, doesn't mean much. There are 24 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.
For each property being compared, the top bar is nickel 684 and the bottom bar is R30075 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 210 to 250 |
| Elongation at Break, % | 11 | |
| 12 |
| Fatigue Strength, MPa | 390 | |
| 250 to 840 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Reduction in Area, % | 17 | |
| 20 |
| Shear Modulus, GPa | 76 | |
| 82 to 98 |
| Tensile Strength: Ultimate (UTS), MPa | 1190 | |
| 780 to 1280 |
| Tensile Strength: Yield (Proof), MPa | 800 | |
| 480 to 840 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 320 |
| Melting Completion (Liquidus), °C | 1370 | |
| 1360 |
| Melting Onset (Solidus), °C | 1320 | |
| 1290 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 450 |
| Thermal Expansion, µm/m-K | 13 | |
| 12 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.3 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 10 | |
| 8.1 |
| Embodied Energy, MJ/kg | 140 | |
| 110 |
| Embodied Water, L/kg | 360 | |
| 530 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 84 to 140 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1610 | |
| 560 to 1410 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 to 17 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 to 25 |
| Strength to Weight: Axial, points | 40 | |
| 26 to 42 |
| Strength to Weight: Bending, points | 30 | |
| 22 to 31 |
| Thermal Shock Resistance, points | 34 | |
| 21 to 29 |
Alloy Composition
| Aluminum (Al), % | 2.5 to 3.3 | |
| 0 to 0.1 |
| Boron (B), % | 0.0030 to 0.010 | |
| 0 to 0.010 |
| Carbon (C), % | 0 to 0.15 | |
| 0 to 0.35 |
| Chromium (Cr), % | 15 to 20 | |
| 27 to 30 |
| Cobalt (Co), % | 13 to 20 | |
| 58.7 to 68 |
| Copper (Cu), % | 0 to 0.15 | |
| 0 |
| Iron (Fe), % | 0 to 4.0 | |
| 0 to 0.75 |
| Manganese (Mn), % | 0 to 0.75 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 3.0 to 5.0 | |
| 5.0 to 7.0 |
| Nickel (Ni), % | 42.7 to 64 | |
| 0 to 0.5 |
| Nitrogen (N), % | 0 | |
| 0 to 0.25 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.020 |
| Silicon (Si), % | 0 to 0.75 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.010 |
| Titanium (Ti), % | 2.5 to 3.3 | |
| 0 to 0.1 |
| Tungsten (W), % | 0 | |
| 0 to 0.2 |