Materials / Compare
Aluminum vs. Nickel Inconel 718
Compare Aluminum vs. Nickel Inconel 718 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 | 276MPasourcetypical, 0.2% offset, .500 in dia specimen | 1,207MPasourcetypical, 1.0 in. hot-rolled bar, 0.2% offset |
| Ultimate tensile strength | 310MPasourcetypical | 1,389MPasourcetypical, 1.0 in. bar |
| Elongation at break | 17%sourcetypical, in 4D, 0.500 in dia specimen | 20%sourcetypical, 1.0 in. bar |
| Young's modulus (stiffness) | 68.3GPasourcetypical | 200GPasourcetypical, 21 °C, annealed + aged |
| Density | 2,700kg/m³sourcenominal | 8,221kg/m³sourcenominal, annealed and aged |
| Strength to weight | 102kN·m/kg | 147kN·m/kg44% higher |
| Stiffness to weight | 25.3MN·m/kg4% higher | 24.3MN·m/kg |
| Poisson's ratio | 0.33sourcetypical (handbook physical constant) | 0.294sourcetypical, 21 °C, annealed + aged |
| Shear modulus | 25.7GPa | 77.3GPa3.01x stiffer in shear |
| Bulk modulus | 67GPa | 162GPa |
| Speed of sound | 5,030m/s | 4,932m/s |
| Thermal | ||
| Thermal conductivity | 167W/m·Ksourcetypical, 20 °C | 11.4W/m·Ksourcetypical, 21 °C, annealed + aged (calculated from resistivity per footnote a) |
| Thermal expansion | 23.6µm/m·Ksourcetypical, mean 20-100 °C | 13.2µm/m·Ksourcetypical, mean 21-93 °C, annealed + aged |
| 100 mm part over a 50 °C swing | 118µm growth | 66µm growth1.79x less |
| Specific heat | 896J/kg·Ksourcetypical, at 100 °C | 435J/kg·Ksourcetypical, 21 °C |
| Heats up and cools (diffusivity) | 69mm²/s21.7x faster | 3.19mm²/s |
| Thermal shock resistance | 19,159W/m5.21x more resistant | 3,680W/m |
| Melting point | 582–652°Csourcesolidus-liquidus | 1,260–1,336°Csourcemelting range |
| Max service temperature | not sourced | 704°Csourceupper use temperature stated by producer |
| Values for | 6061-T6/T651, Kaiser Aluminum typical properties (sheet, coil & plate datasheet); Poisson from MIL-HDBK-5J | INCONEL alloy 718, standard grade, 1750 °F/1 hr anneal + 1325 °F/8 hr F.C. to 1150 °F aged; Special Metals bulletin SMC-045 typical 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 stronger than Nickel Inconel 718?
Nickel Inconel 718 is stronger: its yield strength is 1,207 MPa against 276 MPa for Aluminum (4.37x).
Which is lighter, Aluminum or Nickel Inconel 718?
Aluminum is lighter: 2,700 kg/m³ against 8,221 kg/m³ for Nickel Inconel 718.
Which is stiffer, Aluminum or Nickel Inconel 718?
Nickel Inconel 718 is stiffer: Young's modulus 200 GPa against 68.3 GPa for Aluminum, so the same part in Nickel Inconel 718 deflects less under the same load.
Which is lighter for the same job, Aluminum or Nickel Inconel 718?
For the same stiffness or strength: Aluminum is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong beam, strong panel or plate; Nickel Inconel 718 is lighter for a strong rod or tie.
| Part that must be | Aluminum | Nickel Inconel 718 |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 4% heavier |
| Stiff beam (bending) | lighter | 1.78x heavier |
| Stiff panel or plate | lighter | 2.13x heavier |
| Strong rod or tie | 44% heavier | lighter |
| Strong beam | lighter | 14% heavier |
| Strong panel or plate | lighter | 46% 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 or Nickel Inconel 718?
Aluminum conducts heat better: 167 W/m·K against 11.4 W/m·K for Nickel Inconel 718.
Which expands less with temperature?
Nickel Inconel 718 expands less: 13.2 µm/m·K against 23.6 µm/m·K for Aluminum.