AZ81A Magnesium vs. R30003 Cobalt
AZ81A magnesium belongs to the magnesium alloys classification, while R30003 cobalt belongs to the cobalt alloys. There are 27 material properties with values for both materials. Properties with values for just one material (6, 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 AZ81A magnesium and the bottom bar is R30003 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 46 | |
| 210 |
| Elongation at Break, % | 3.0 to 8.8 | |
| 10 to 73 |
| Fatigue Strength, MPa | 78 to 80 | |
| 320 to 560 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 18 | |
| 83 |
| Tensile Strength: Ultimate (UTS), MPa | 160 to 240 | |
| 970 to 1720 |
| Tensile Strength: Yield (Proof), MPa | 84 | |
| 510 to 1090 |
Thermal Properties
| Latent Heat of Fusion, J/g | 350 | |
| 310 |
| Melting Completion (Liquidus), °C | 600 | |
| 1400 |
| Melting Onset (Solidus), °C | 500 | |
| 1440 |
| Specific Heat Capacity, J/kg-K | 990 | |
| 450 |
| Thermal Conductivity, W/m-K | 84 | |
| 13 |
| Thermal Expansion, µm/m-K | 27 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 12 | |
| 2.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 65 | |
| 2.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 12 | |
| 95 |
| Density, g/cm3 | 1.7 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 23 | |
| 8.0 |
| Embodied Energy, MJ/kg | 160 | |
| 110 |
| Embodied Water, L/kg | 990 | |
| 400 |
Common Calculations
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 77 to 78 | |
| 600 to 2790 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 70 | |
| 24 |
| Strength to Weight: Axial, points | 26 to 39 | |
| 32 to 57 |
| Strength to Weight: Bending, points | 38 to 50 | |
| 26 to 38 |
| Thermal Diffusivity, mm2/s | 50 | |
| 3.3 |
| Thermal Shock Resistance, points | 9.1 to 14 | |
| 26 to 45 |
Alloy Composition
| Aluminum (Al), % | 7.0 to 8.1 | |
| 0 |
| Boron (B), % | 0 | |
| 0 to 0.1 |
| Carbon (C), % | 0 | |
| 0 to 0.15 |
| Chromium (Cr), % | 0 | |
| 19 to 21 |
| Cobalt (Co), % | 0 | |
| 39 to 41 |
| Copper (Cu), % | 0 to 0.1 | |
| 0 |
| Iron (Fe), % | 0 | |
| 10 to 20.5 |
| Magnesium (Mg), % | 89.8 to 92.5 | |
| 0 |
| Manganese (Mn), % | 0.13 to 0.35 | |
| 1.5 to 2.5 |
| Molybdenum (Mo), % | 0 | |
| 6.0 to 8.0 |
| Nickel (Ni), % | 0 to 0.010 | |
| 14 to 16 |
| Phosphorus (P), % | 0 | |
| 0 to 0.015 |
| Silicon (Si), % | 0 to 0.3 | |
| 0 to 1.2 |
| Sulfur (S), % | 0 | |
| 0 to 0.015 |
| Zinc (Zn), % | 0.4 to 1.0 | |
| 0 |
| Residuals, % | 0 to 0.3 | |
| 0 |