Materials / Compare
Aluminum 7075-T6 vs. Plastic HDPE
Compare Aluminum 7075-T6 vs. Plastic HDPE strength, stiffness, weight and thermal properties.
| Try it on a partA bracket to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | 503MPasourcetypical, 0.2% offset, .500 in dia specimen | 24MPasourcetypical, tensile stress at yield 23 °C, 50 mm/min ISO 527 |
| Ultimate tensile strength | 572MPasourcetypical | not sourced |
| Elongation at break | 11%sourcetypical, in 4D | not sourced |
| Young's modulus (stiffness) | 71GPasourcetypical | 0.9GPasourcetypical, tensile modulus 23 °C ISO 527 |
| Density | 2,800kg/m³sourcenominal | 950kg/m³sourcetypical, ISO 1183 |
| Strength to weight | 180kN·m/kg7.11x higher | 25.3kN·m/kg |
| Stiffness to weight | 25.4MN·m/kg26.8x higher | 0.947MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.4–0.45sourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) |
| Shear modulus | 26.7GPa84.5x stiffer in shear | 0.316GPa |
| Bulk modulus | 69.6GPa | 2GPa |
| Speed of sound | 5,036m/s | 973m/s |
| Thermal | ||
| Thermal conductivity | 130W/m·Ksourcetypical, 20 °C, T651 | 0.4–0.49W/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) |
| Thermal expansion | 23.4µm/m·Ksourcetypical, mean 20-100 °C | 120µm/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) |
| 100 mm part over a 50 °C swing | 117µm growth5.13x less | 600µm growth |
| Specific heat | 960J/kg·Ksourcetypical, at 100 °C | 2,250J/kg·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) |
| Heats up and cools (diffusivity) | 48.4mm²/s232x faster | 0.208mm²/s |
| Thermal shock resistance | 26,370W/m464x more resistant | 56.9W/m |
| Melting point | 532–635°Csourcemelting range | not sourced |
| Values for | 7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J | LyondellBasell Hostalen 23050 B high density polyethylene, typical ISO values |
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Is Aluminum 7075-T6 stronger than Plastic HDPE?
Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 24 MPa for Plastic HDPE (21x).
Which is lighter, Aluminum 7075-T6 or Plastic HDPE?
Plastic HDPE is lighter: 950 kg/m³ against 2,800 kg/m³ for Aluminum 7075-T6.
Which is stiffer, Aluminum 7075-T6 or Plastic HDPE?
Aluminum 7075-T6 is stiffer: Young's modulus 71 GPa against 0.9 GPa for Plastic HDPE, so the same part in Aluminum 7075-T6 deflects less under the same load.
Which is lighter for the same job, Aluminum 7075-T6 or Plastic HDPE?
For the same stiffness or strength: Aluminum 7075-T6 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Aluminum 7075-T6 | Plastic HDPE |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 26.8x heavier |
| Stiff beam (bending) | lighter | 3.01x heavier |
| Stiff panel or plate | lighter | 46% heavier |
| Strong rod or tie | lighter | 7.11x heavier |
| Strong beam | lighter | 2.58x heavier |
| Strong panel or plate | lighter | 1.55x heavier |
For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).
Which conducts heat better, Aluminum 7075-T6 or Plastic HDPE?
Aluminum 7075-T6 conducts heat better: 130 W/m·K against 0.445 W/m·K for Plastic HDPE.
Which expands less with temperature?
Aluminum 7075-T6 expands less: 23.4 µm/m·K against 120 µm/m·K for Plastic HDPE.