R05255 Alloy vs. R31538 Cobalt
R05255 alloy belongs to the otherwise unclassified metals classification, while R31538 cobalt belongs to the cobalt alloys. There are 20 material properties with values for both materials. Properties with values for just one material (9, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is R05255 alloy and the bottom bar is R31538 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 220 |
| Elongation at Break, % | 20 | |
| 13 to 23 |
| Poisson's Ratio | 0.34 | |
| 0.29 |
| Shear Modulus, GPa | 70 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 540 | |
| 1020 to 1360 |
| Tensile Strength: Yield (Proof), MPa | 450 | |
| 580 to 930 |
Thermal Properties
| Latent Heat of Fusion, J/g | 140 | |
| 320 |
| Specific Heat Capacity, J/kg-K | 140 | |
| 450 |
| Thermal Conductivity, W/m-K | 59 | |
| 13 |
| Thermal Expansion, µm/m-K | 6.6 | |
| 13 |
Otherwise Unclassified Properties
| Density, g/cm3 | 17 | |
| 8.4 |
| Embodied Water, L/kg | 630 | |
| 530 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 100 | |
| 140 to 200 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 530 | |
| 750 to 1920 |
| Stiffness to Weight: Axial, points | 6.3 | |
| 15 |
| Stiffness to Weight: Bending, points | 11 | |
| 24 |
| Strength to Weight: Axial, points | 9.1 | |
| 34 to 45 |
| Strength to Weight: Bending, points | 8.9 | |
| 27 to 32 |
| Thermal Diffusivity, mm2/s | 25 | |
| 3.5 |
| Thermal Shock Resistance, points | 31 | |
| 25 to 33 |
Alloy Composition
| Carbon (C), % | 0 to 0.010 | |
| 0.15 to 0.35 |
| Chromium (Cr), % | 0 | |
| 26 to 30 |
| Cobalt (Co), % | 0 | |
| 58.7 to 68.9 |
| Hydrogen (H), % | 0 to 0.0015 | |
| 0 |
| Iron (Fe), % | 0 to 0.010 | |
| 0 to 0.75 |
| Manganese (Mn), % | 0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 to 0.020 | |
| 5.0 to 7.0 |
| Nickel (Ni), % | 0 to 0.010 | |
| 0 to 1.0 |
| Niobium (Nb), % | 0 to 0.5 | |
| 0 |
| Nitrogen (N), % | 0 to 0.010 | |
| 0 to 0.25 |
| Oxygen (O), % | 0 to 0.015 | |
| 0 |
| Silicon (Si), % | 0 to 0.0050 | |
| 0 to 1.0 |
| Tantalum (Ta), % | 95.9 to 98 | |
| 0 |
| Titanium (Ti), % | 0 to 0.010 | |
| 0 |
| Tungsten (W), % | 2.0 to 3.5 | |
| 0 |