7178 Aluminum vs. 7021 Aluminum
Both 7178 aluminum and 7021 aluminum are aluminum alloys. They have a very high 95% of their average alloy composition in common.
For each property being compared, the top bar is 7178 aluminum and the bottom bar is 7021 aluminum.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 71 | |
| 69 |
| Elongation at Break, % | 4.5 to 12 | |
| 9.4 |
| Fatigue Strength, MPa | 120 to 210 | |
| 150 |
| Poisson's Ratio | 0.32 | |
| 0.32 |
| Shear Modulus, GPa | 27 | |
| 26 |
| Shear Strength, MPa | 140 to 380 | |
| 270 |
| Tensile Strength: Ultimate (UTS), MPa | 240 to 640 | |
| 460 |
| Tensile Strength: Yield (Proof), MPa | 120 to 560 | |
| 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 370 | |
| 380 |
| Maximum Temperature: Mechanical, °C | 180 | |
| 200 |
| Melting Completion (Liquidus), °C | 630 | |
| 630 |
| Melting Onset (Solidus), °C | 480 | |
| 510 |
| Specific Heat Capacity, J/kg-K | 860 | |
| 870 |
| Thermal Conductivity, W/m-K | 130 | |
| 150 |
| Thermal Expansion, µm/m-K | 23 | |
| 24 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 31 | |
| 38 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 91 | |
| 120 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 10 | |
| 9.5 |
| Density, g/cm3 | 3.1 | |
| 2.9 |
| Embodied Carbon, kg CO2/kg material | 8.2 | |
| 8.3 |
| Embodied Energy, MJ/kg | 150 | |
| 150 |
| Embodied Water, L/kg | 1110 | |
| 1140 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 24 to 52 | |
| 41 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 110 to 2220 | |
| 1110 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 45 | |
| 47 |
| Strength to Weight: Axial, points | 21 to 58 | |
| 44 |
| Strength to Weight: Bending, points | 28 to 54 | |
| 45 |
| Thermal Diffusivity, mm2/s | 47 | |
| 59 |
| Thermal Shock Resistance, points | 10 to 28 | |
| 20 |
Alloy Composition
| Aluminum (Al), % | 85.4 to 89.5 | |
| 90.7 to 93.7 |
| Chromium (Cr), % | 0.18 to 0.28 | |
| 0 to 0.050 |
| Copper (Cu), % | 1.6 to 2.4 | |
| 0 to 0.25 |
| Iron (Fe), % | 0 to 0.5 | |
| 0 to 0.4 |
| Magnesium (Mg), % | 2.4 to 3.1 | |
| 1.2 to 1.8 |
| Manganese (Mn), % | 0 to 0.3 | |
| 0 to 0.1 |
| Silicon (Si), % | 0 to 0.4 | |
| 0 to 0.25 |
| Titanium (Ti), % | 0 to 0.2 | |
| 0 to 0.1 |
| Zinc (Zn), % | 6.3 to 7.3 | |
| 5.0 to 6.0 |
| Zirconium (Zr), % | 0 | |
| 0.080 to 0.18 |
| Residuals, % | 0 | |
| 0 to 0.15 |