7021 Aluminum vs. Nuclear Grade Hafnium
7021 aluminum belongs to the aluminum alloys classification, while nuclear grade hafnium belongs to the otherwise unclassified metals. There are 17 material properties with values for both materials. Properties with values for just one material (13, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is 7021 aluminum and the bottom bar is nuclear grade hafnium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 69 | |
| 78 |
| Elongation at Break, % | 9.4 | |
| 25 |
| Poisson's Ratio | 0.32 | |
| 0.26 |
| Shear Modulus, GPa | 26 | |
| 31 |
| Tensile Strength: Ultimate (UTS), MPa | 460 | |
| 350 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 170 |
Thermal Properties
| Latent Heat of Fusion, J/g | 380 | |
| 130 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 140 |
| Thermal Expansion, µm/m-K | 24 | |
| 5.9 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.9 | |
| 13 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 41 | |
| 73 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1110 | |
| 180 |
| Stiffness to Weight: Axial, points | 13 | |
| 3.3 |
| Stiffness to Weight: Bending, points | 47 | |
| 11 |
| Strength to Weight: Axial, points | 44 | |
| 7.4 |
| Strength to Weight: Bending, points | 45 | |
| 8.4 |
| Thermal Shock Resistance, points | 20 | |
| 55 |
Alloy Composition
| Aluminum (Al), % | 90.7 to 93.7 | |
| 0 |
| Chromium (Cr), % | 0 to 0.050 | |
| 0 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 |
| Hafnium (Hf), % | 0 | |
| 99.8 to 100 |
| Iron (Fe), % | 0 to 0.4 | |
| 0 |
| Magnesium (Mg), % | 1.2 to 1.8 | |
| 0 |
| 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 | |
| 0 |
| Zirconium (Zr), % | 0.080 to 0.18 | |
| 0 |
| Residuals, % | 0 | |
| 0 to 0.23 |