Nickel 684 vs. G-CoCr28 Cobalt
Nickel 684 belongs to the nickel alloys classification, while G-CoCr28 cobalt belongs to the cobalt alloys. They have a modest 39% of their average alloy composition in common, which, by itself, doesn't mean much. There are 25 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is nickel 684 and the bottom bar is G-CoCr28 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 210 |
| Elongation at Break, % | 11 | |
| 6.7 |
| Fatigue Strength, MPa | 390 | |
| 130 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 76 | |
| 83 |
| Tensile Strength: Ultimate (UTS), MPa | 1190 | |
| 560 |
| Tensile Strength: Yield (Proof), MPa | 800 | |
| 260 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 320 |
| Maximum Temperature: Mechanical, °C | 1000 | |
| 1200 |
| Melting Completion (Liquidus), °C | 1370 | |
| 1330 |
| Melting Onset (Solidus), °C | 1320 | |
| 1270 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Expansion, µm/m-K | 13 | |
| 14 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 75 | |
| 100 |
| Density, g/cm3 | 8.3 | |
| 8.1 |
| Embodied Carbon, kg CO2/kg material | 10 | |
| 6.2 |
| Embodied Energy, MJ/kg | 140 | |
| 84 |
| Embodied Water, L/kg | 360 | |
| 440 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 31 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1610 | |
| 160 |
| Stiffness to Weight: Axial, points | 13 | |
| 15 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 40 | |
| 19 |
| Strength to Weight: Bending, points | 30 | |
| 19 |
| Thermal Shock Resistance, points | 34 | |
| 14 |
Alloy Composition
| Aluminum (Al), % | 2.5 to 3.3 | |
| 0 |
| Boron (B), % | 0.0030 to 0.010 | |
| 0 |
| Carbon (C), % | 0 to 0.15 | |
| 0.050 to 0.25 |
| Chromium (Cr), % | 15 to 20 | |
| 27 to 30 |
| Cobalt (Co), % | 13 to 20 | |
| 48 to 52 |
| Copper (Cu), % | 0 to 0.15 | |
| 0 |
| Iron (Fe), % | 0 to 4.0 | |
| 9.7 to 24.5 |
| Manganese (Mn), % | 0 to 0.75 | |
| 0 to 1.5 |
| Molybdenum (Mo), % | 3.0 to 5.0 | |
| 0 to 0.5 |
| Nickel (Ni), % | 42.7 to 64 | |
| 0 to 4.0 |
| Niobium (Nb), % | 0 | |
| 0 to 0.5 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 0.75 | |
| 0.5 to 1.5 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.030 |
| Titanium (Ti), % | 2.5 to 3.3 | |
| 0 |