2218 Aluminum vs. 5251 Aluminum
Both 2218 aluminum and 5251 aluminum are aluminum alloys. They have a moderately high 94% of their average alloy composition in common.
For each property being compared, the top bar is 2218 aluminum and the bottom bar is 5251 aluminum.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 95 to 110 | |
| 44 to 79 |
| Elastic (Young's, Tensile) Modulus, GPa | 73 | |
| 68 |
| Elongation at Break, % | 6.8 to 10 | |
| 2.0 to 19 |
| Fatigue Strength, MPa | 110 | |
| 59 to 110 |
| Poisson's Ratio | 0.33 | |
| 0.33 |
| Shear Modulus, GPa | 27 | |
| 26 |
| Shear Strength, MPa | 210 to 250 | |
| 110 to 160 |
| Tensile Strength: Ultimate (UTS), MPa | 330 to 430 | |
| 180 to 280 |
| Tensile Strength: Yield (Proof), MPa | 260 to 310 | |
| 67 to 250 |
Thermal Properties
| Latent Heat of Fusion, J/g | 390 | |
| 400 |
| Maximum Temperature: Mechanical, °C | 220 | |
| 180 |
| Melting Completion (Liquidus), °C | 640 | |
| 650 |
| Melting Onset (Solidus), °C | 510 | |
| 610 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 900 |
| Thermal Conductivity, W/m-K | 140 | |
| 150 |
| Thermal Expansion, µm/m-K | 22 | |
| 24 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 37 | |
| 37 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 110 | |
| 120 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 11 | |
| 9.5 |
| Density, g/cm3 | 3.1 | |
| 2.7 |
| Embodied Carbon, kg CO2/kg material | 8.2 | |
| 8.5 |
| Embodied Energy, MJ/kg | 150 | |
| 150 |
| Embodied Water, L/kg | 1130 | |
| 1180 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 27 to 31 | |
| 5.4 to 27 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 450 to 650 | |
| 33 to 450 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 45 | |
| 50 |
| Strength to Weight: Axial, points | 30 to 39 | |
| 18 to 29 |
| Strength to Weight: Bending, points | 34 to 41 | |
| 26 to 35 |
| Thermal Diffusivity, mm2/s | 52 | |
| 61 |
| Thermal Shock Resistance, points | 15 to 19 | |
| 7.9 to 13 |
Alloy Composition
| Aluminum (Al), % | 88.8 to 93.6 | |
| 95.5 to 98.2 |
| Chromium (Cr), % | 0 to 0.1 | |
| 0 to 0.15 |
| Copper (Cu), % | 3.5 to 4.5 | |
| 0 to 0.15 |
| Iron (Fe), % | 0 to 1.0 | |
| 0 to 0.5 |
| Magnesium (Mg), % | 1.2 to 1.8 | |
| 1.7 to 2.4 |
| Manganese (Mn), % | 0 to 0.2 | |
| 0.1 to 0.5 |
| Nickel (Ni), % | 1.7 to 2.3 | |
| 0 |
| Silicon (Si), % | 0 to 0.9 | |
| 0 to 0.4 |
| Titanium (Ti), % | 0 | |
| 0 to 0.15 |
| Zinc (Zn), % | 0 to 0.25 | |
| 0 to 0.15 |
| Residuals, % | 0 | |
| 0 to 0.15 |