ASTM B817 Type II vs. R31538 Cobalt
ASTM B817 type II belongs to the titanium alloys classification, while R31538 cobalt belongs to the cobalt alloys. There are 24 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.
For each property being compared, the top bar is ASTM B817 type II and the bottom bar is R31538 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 100 | |
| 220 |
| Elongation at Break, % | 3.0 to 13 | |
| 13 to 23 |
| Fatigue Strength, MPa | 390 to 530 | |
| 310 to 480 |
| Poisson's Ratio | 0.32 | |
| 0.29 |
| Reduction in Area, % | 4.0 to 13 | |
| 13 to 22 |
| Shear Modulus, GPa | 40 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 900 to 960 | |
| 1020 to 1360 |
| Tensile Strength: Yield (Proof), MPa | 780 to 900 | |
| 580 to 930 |
Thermal Properties
| Latent Heat of Fusion, J/g | 400 | |
| 320 |
| Melting Completion (Liquidus), °C | 1580 | |
| 1360 |
| Melting Onset (Solidus), °C | 1530 | |
| 1290 |
| Specific Heat Capacity, J/kg-K | 550 | |
| 450 |
| Thermal Expansion, µm/m-K | 9.9 | |
| 13 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.6 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 40 | |
| 8.1 |
| Embodied Energy, MJ/kg | 650 | |
| 110 |
| Embodied Water, L/kg | 220 | |
| 530 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 26 to 120 | |
| 140 to 200 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 2890 to 3890 | |
| 750 to 1920 |
| Stiffness to Weight: Axial, points | 13 | |
| 15 |
| Stiffness to Weight: Bending, points | 34 | |
| 24 |
| Strength to Weight: Axial, points | 55 to 58 | |
| 34 to 45 |
| Strength to Weight: Bending, points | 45 to 47 | |
| 27 to 32 |
| Thermal Shock Resistance, points | 62 to 66 | |
| 25 to 33 |
Alloy Composition
| Aluminum (Al), % | 5.0 to 6.0 | |
| 0 |
| Carbon (C), % | 0 to 0.1 | |
| 0.15 to 0.35 |
| Chlorine (Cl), % | 0 to 0.2 | |
| 0 |
| Chromium (Cr), % | 0 | |
| 26 to 30 |
| Cobalt (Co), % | 0 | |
| 58.7 to 68.9 |
| Copper (Cu), % | 0.35 to 1.0 | |
| 0 |
| Hydrogen (H), % | 0 to 0.015 | |
| 0 |
| Iron (Fe), % | 0.35 to 1.0 | |
| 0 to 0.75 |
| Manganese (Mn), % | 0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 | |
| 5.0 to 7.0 |
| Nickel (Ni), % | 0 | |
| 0 to 1.0 |
| Nitrogen (N), % | 0 to 0.040 | |
| 0 to 0.25 |
| Oxygen (O), % | 0 to 0.3 | |
| 0 |
| Silicon (Si), % | 0 to 0.1 | |
| 0 to 1.0 |
| Sodium (Na), % | 0 to 0.2 | |
| 0 |
| Tin (Sn), % | 1.5 to 2.5 | |
| 0 |
| Titanium (Ti), % | 82.1 to 87.8 | |
| 0 |
| Vanadium (V), % | 5.0 to 6.0 | |
| 0 |
| Residuals, % | 0 to 0.4 | |
| 0 |