AZ81A Magnesium vs. 5251 Aluminum
AZ81A magnesium belongs to the magnesium alloys classification, while 5251 aluminum belongs to the aluminum alloys. There are 31 material properties with values for both materials. Properties with values for just one material (2, in this case) are not shown.
For each property being compared, the top bar is AZ81A magnesium and the bottom bar is 5251 aluminum.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 55 | |
| 44 to 79 |
| Elastic (Young's, Tensile) Modulus, GPa | 46 | |
| 68 |
| Elongation at Break, % | 3.0 to 8.8 | |
| 2.0 to 19 |
| Fatigue Strength, MPa | 78 to 80 | |
| 59 to 110 |
| Poisson's Ratio | 0.29 | |
| 0.33 |
| Shear Modulus, GPa | 18 | |
| 26 |
| Shear Strength, MPa | 91 to 130 | |
| 110 to 160 |
| Tensile Strength: Ultimate (UTS), MPa | 160 to 240 | |
| 180 to 280 |
| Tensile Strength: Yield (Proof), MPa | 84 | |
| 67 to 250 |
Thermal Properties
| Latent Heat of Fusion, J/g | 350 | |
| 400 |
| Maximum Temperature: Mechanical, °C | 130 | |
| 180 |
| Melting Completion (Liquidus), °C | 600 | |
| 650 |
| Melting Onset (Solidus), °C | 500 | |
| 610 |
| Specific Heat Capacity, J/kg-K | 990 | |
| 900 |
| Thermal Conductivity, W/m-K | 84 | |
| 150 |
| Thermal Expansion, µm/m-K | 27 | |
| 24 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 12 | |
| 37 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 65 | |
| 120 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 12 | |
| 9.5 |
| Density, g/cm3 | 1.7 | |
| 2.7 |
| Embodied Carbon, kg CO2/kg material | 23 | |
| 8.5 |
| Embodied Energy, MJ/kg | 160 | |
| 150 |
| Embodied Water, L/kg | 990 | |
| 1180 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 4.0 to 17 | |
| 5.4 to 27 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 77 to 78 | |
| 33 to 450 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 70 | |
| 50 |
| Strength to Weight: Axial, points | 26 to 39 | |
| 18 to 29 |
| Strength to Weight: Bending, points | 38 to 50 | |
| 26 to 35 |
| Thermal Diffusivity, mm2/s | 50 | |
| 61 |
| Thermal Shock Resistance, points | 9.1 to 14 | |
| 7.9 to 13 |
Alloy Composition
| Aluminum (Al), % | 7.0 to 8.1 | |
| 95.5 to 98.2 |
| Chromium (Cr), % | 0 | |
| 0 to 0.15 |
| Copper (Cu), % | 0 to 0.1 | |
| 0 to 0.15 |
| Iron (Fe), % | 0 | |
| 0 to 0.5 |
| Magnesium (Mg), % | 89.8 to 92.5 | |
| 1.7 to 2.4 |
| Manganese (Mn), % | 0.13 to 0.35 | |
| 0.1 to 0.5 |
| Nickel (Ni), % | 0 to 0.010 | |
| 0 |
| Silicon (Si), % | 0 to 0.3 | |
| 0 to 0.4 |
| Titanium (Ti), % | 0 | |
| 0 to 0.15 |
| Zinc (Zn), % | 0.4 to 1.0 | |
| 0 to 0.15 |
| Residuals, % | 0 | |
| 0 to 0.15 |