2018 Aluminum vs. AZ91D Magnesium
2018 aluminum belongs to the aluminum alloys classification, while AZ91D magnesium belongs to the magnesium alloys. There are 31 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.
For each property being compared, the top bar is 2018 aluminum and the bottom bar is AZ91D magnesium.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 120 | |
| 60 to 80 |
| Elastic (Young's, Tensile) Modulus, GPa | 73 | |
| 46 |
| Elongation at Break, % | 9.6 | |
| 2.3 to 4.5 |
| Fatigue Strength, MPa | 120 | |
| 74 to 85 |
| Poisson's Ratio | 0.33 | |
| 0.29 |
| Shear Modulus, GPa | 27 | |
| 18 |
| Shear Strength, MPa | 270 | |
| 120 to 140 |
| Tensile Strength: Ultimate (UTS), MPa | 420 | |
| 160 to 220 |
| Tensile Strength: Yield (Proof), MPa | 310 | |
| 80 to 130 |
Thermal Properties
| Latent Heat of Fusion, J/g | 390 | |
| 350 |
| Maximum Temperature: Mechanical, °C | 220 | |
| 130 |
| Melting Completion (Liquidus), °C | 640 | |
| 600 |
| Melting Onset (Solidus), °C | 510 | |
| 490 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 990 |
| Thermal Conductivity, W/m-K | 150 | |
| 78 |
| Thermal Expansion, µm/m-K | 22 | |
| 27 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 40 | |
| 11 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 120 | |
| 58 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 11 | |
| 12 |
| Density, g/cm3 | 3.1 | |
| 1.7 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 22 |
| Embodied Energy, MJ/kg | 150 | |
| 160 |
| Embodied Water, L/kg | 1130 | |
| 990 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 37 | |
| 4.2 to 7.7 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 670 | |
| 69 to 170 |
| Stiffness to Weight: Axial, points | 13 | |
| 15 |
| Stiffness to Weight: Bending, points | 45 | |
| 69 |
| Strength to Weight: Axial, points | 38 | |
| 26 to 34 |
| Strength to Weight: Bending, points | 41 | |
| 38 to 46 |
| Thermal Diffusivity, mm2/s | 57 | |
| 45 |
| Thermal Shock Resistance, points | 19 | |
| 9.5 to 13 |
Alloy Composition
| Aluminum (Al), % | 89.7 to 94.4 | |
| 8.3 to 9.7 |
| Chromium (Cr), % | 0 to 0.1 | |
| 0 |
| Copper (Cu), % | 3.5 to 4.5 | |
| 0 to 0.030 |
| Iron (Fe), % | 0 to 1.0 | |
| 0 to 0.0050 |
| Magnesium (Mg), % | 0.45 to 0.9 | |
| 88.7 to 91.2 |
| Manganese (Mn), % | 0 to 0.2 | |
| 0.15 to 0.5 |
| Nickel (Ni), % | 1.7 to 2.3 | |
| 0 to 0.0020 |
| Silicon (Si), % | 0 to 0.9 | |
| 0 to 0.1 |
| Zinc (Zn), % | 0 to 0.25 | |
| 0.35 to 1.0 |
| Residuals, % | 0 to 0.15 | |
| 0 |