7021 Aluminum vs. ZK40A Magnesium
7021 aluminum belongs to the aluminum alloys classification, while ZK40A magnesium belongs to the magnesium alloys.
For each property being compared, the top bar is 7021 aluminum and the bottom bar is ZK40A magnesium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 69 | |
| 45 |
| Elongation at Break, % | 9.4 | |
| 4.2 |
| Fatigue Strength, MPa | 150 | |
| 190 |
| Poisson's Ratio | 0.32 | |
| 0.29 |
| Shear Modulus, GPa | 26 | |
| 17 |
| Shear Strength, MPa | 270 | |
| 160 |
| Tensile Strength: Ultimate (UTS), MPa | 460 | |
| 280 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 260 |
Thermal Properties
| Latent Heat of Fusion, J/g | 380 | |
| 340 |
| Maximum Temperature: Mechanical, °C | 200 | |
| 120 |
| Melting Completion (Liquidus), °C | 630 | |
| 600 |
| Melting Onset (Solidus), °C | 510 | |
| 540 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 970 |
| Thermal Conductivity, W/m-K | 150 | |
| 110 |
| Thermal Expansion, µm/m-K | 24 | |
| 26 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 38 | |
| 27 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 120 | |
| 130 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.5 | |
| 13 |
| Density, g/cm3 | 2.9 | |
| 1.8 |
| Embodied Carbon, kg CO2/kg material | 8.3 | |
| 24 |
| Embodied Energy, MJ/kg | 150 | |
| 160 |
| Embodied Water, L/kg | 1140 | |
| 950 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 41 | |
| 12 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1110 | |
| 740 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 47 | |
| 65 |
| Strength to Weight: Axial, points | 44 | |
| 43 |
| Strength to Weight: Bending, points | 45 | |
| 53 |
| Thermal Diffusivity, mm2/s | 59 | |
| 62 |
| Thermal Shock Resistance, points | 20 | |
| 17 |
Alloy Composition
| Aluminum (Al), % | 90.7 to 93.7 | |
| 0 |
| Chromium (Cr), % | 0 to 0.050 | |
| 0 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 |
| Iron (Fe), % | 0 to 0.4 | |
| 0 |
| Magnesium (Mg), % | 1.2 to 1.8 | |
| 94.2 to 96.1 |
| Manganese (Mn), % | 0 to 0.1 | |
| 0 |
| Silicon (Si), % | 0 to 0.25 | |
| 0 |
| Titanium (Ti), % | 0 to 0.1 | |
| 0 |
| Zinc (Zn), % | 5.0 to 6.0 | |
| 3.5 to 4.5 |
| Zirconium (Zr), % | 0.080 to 0.18 | |
| 0.45 to 1.0 |
| Residuals, % | 0 | |
| 0 to 0.3 |