7021 Aluminum vs. AZ31B Magnesium
7021 aluminum belongs to the aluminum alloys classification, while AZ31B magnesium belongs to the magnesium alloys.
For each property being compared, the top bar is 7021 aluminum and the bottom bar is AZ31B magnesium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 69 | |
| 45 |
| Elongation at Break, % | 9.4 | |
| 5.6 to 12 |
| Fatigue Strength, MPa | 150 | |
| 100 to 120 |
| Poisson's Ratio | 0.32 | |
| 0.29 |
| Shear Modulus, GPa | 26 | |
| 17 |
| Shear Strength, MPa | 270 | |
| 130 to 160 |
| Tensile Strength: Ultimate (UTS), MPa | 460 | |
| 240 to 270 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 120 to 180 |
Thermal Properties
| Latent Heat of Fusion, J/g | 380 | |
| 350 |
| Maximum Temperature: Mechanical, °C | 200 | |
| 150 |
| Melting Completion (Liquidus), °C | 630 | |
| 600 |
| Melting Onset (Solidus), °C | 510 | |
| 600 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 990 |
| Thermal Conductivity, W/m-K | 150 | |
| 100 |
| Thermal Expansion, µm/m-K | 24 | |
| 26 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 38 | |
| 18 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 120 | |
| 95 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.5 | |
| 12 |
| Density, g/cm3 | 2.9 | |
| 1.7 |
| Embodied Carbon, kg CO2/kg material | 8.3 | |
| 23 |
| Embodied Energy, MJ/kg | 150 | |
| 160 |
| Embodied Water, L/kg | 1140 | |
| 970 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 41 | |
| 13 to 25 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1110 | |
| 170 to 370 |
| Stiffness to Weight: Axial, points | 13 | |
| 15 |
| Stiffness to Weight: Bending, points | 47 | |
| 70 |
| Strength to Weight: Axial, points | 44 | |
| 39 to 44 |
| Strength to Weight: Bending, points | 45 | |
| 50 to 55 |
| Thermal Diffusivity, mm2/s | 59 | |
| 62 |
| Thermal Shock Resistance, points | 20 | |
| 14 to 16 |
Alloy Composition
| Aluminum (Al), % | 90.7 to 93.7 | |
| 2.4 to 3.6 |
| Calcium (Ca), % | 0 | |
| 0 to 0.040 |
| Chromium (Cr), % | 0 to 0.050 | |
| 0 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.050 |
| Iron (Fe), % | 0 to 0.4 | |
| 0 to 0.050 |
| Magnesium (Mg), % | 1.2 to 1.8 | |
| 93.6 to 97.1 |
| Manganese (Mn), % | 0 to 0.1 | |
| 0.050 to 1.0 |
| Nickel (Ni), % | 0 | |
| 0 to 0.0050 |
| Silicon (Si), % | 0 to 0.25 | |
| 0 to 0.1 |
| Titanium (Ti), % | 0 to 0.1 | |
| 0 |
| Zinc (Zn), % | 5.0 to 6.0 | |
| 0.5 to 1.5 |
| Zirconium (Zr), % | 0.080 to 0.18 | |
| 0 |
| Residuals, % | 0 | |
| 0 to 0.3 |