Aluminum 7050-T7451 vs. Nickel Inconel 718

Compare Aluminum 7050-T7451 vs. Nickel Inconel 718 strength, stiffness, weight and thermal properties.

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Mechanical
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Yield strength	469MPasourcetypical, longitudinal, 0.2% offset	1,207MPasourcetypical, 1.0 in. hot-rolled bar, 0.2% offset
Ultimate tensile strength	524MPasourcetypical, longitudinal	1,389MPasourcetypical, 1.0 in. bar
Elongation at break	11%sourcetypical, longitudinal	20%sourcetypical, 1.0 in. bar
Young's modulus (stiffness)	70.3GPasourcetypical	200GPasourcetypical, 21 °C, annealed + aged
Density	2,830kg/m³sourcenominal	8,221kg/m³sourcenominal, annealed and aged
Strength to weight	166kN·m/kg13% higher	147kN·m/kg
Stiffness to weight	24.8MN·m/kg2% higher	24.3MN·m/kg
Poisson's ratio	0.33sourcetypical (handbook physical constant)	0.294sourcetypical, 21 °C, annealed + aged
Shear modulus	26.4GPa	77.3GPa2.92x stiffer in shear
Bulk modulus	68.9GPa	162GPa
Speed of sound	4,984m/s	4,932m/s
Thermal
Thermal conductivity	157W/m·Ksourcetypical, 20 °C	11.4W/m·Ksourcetypical, 21 °C, annealed + aged (calculated from resistivity per footnote a)
Thermal expansion	23.5µm/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 growth1.78x less
Specific heat	860J/kg·Ksourcetypical, at 100 °C	435J/kg·Ksourcetypical, 21 °C
Heats up and cools (diffusivity)	64.5mm²/s20.2x faster	3.19mm²/s
Thermal shock resistance	29,862W/m8.12x more resistant	3,680W/m
Melting point	524–635°Csourcemelting range	1,260–1,336°Csourcemelting range
Max service temperature	not sourced	704°Csourceupper use temperature stated by producer
Values for	7050-T7451 plate, Kaiser Aluminum sheet, coil & plate typical datasheet (longitudinal); 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 7050-T7451 stronger than Nickel Inconel 718?

Nickel Inconel 718 is stronger: its yield strength is 1,207 MPa against 469 MPa for Aluminum 7050-T7451 (2.57x).

Which is lighter, Aluminum 7050-T7451 or Nickel Inconel 718?

Aluminum 7050-T7451 is lighter: 2,830 kg/m³ against 8,221 kg/m³ for Nickel Inconel 718.

Which is stiffer, Aluminum 7050-T7451 or Nickel Inconel 718?

Nickel Inconel 718 is stiffer: Young's modulus 200 GPa against 70.3 GPa for Aluminum 7050-T7451, so the same part in Nickel Inconel 718 deflects less under the same load.

Which is lighter for the same job, Aluminum 7050-T7451 or Nickel Inconel 718?

For the same stiffness or strength: Aluminum 7050-T7451 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 7050-T7451	Nickel Inconel 718
Stiff rod or tie (tension)	lighter	2% heavier
Stiff beam (bending)	lighter	1.72x heavier
Stiff panel or plate	lighter	2.05x heavier
Strong rod or tie	lighter	13% heavier
Strong beam	lighter	1.55x heavier
Strong panel or plate	lighter	1.81x 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 7050-T7451 or Nickel Inconel 718?

Aluminum 7050-T7451 conducts heat better: 157 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 23.5 µm/m·K for Aluminum 7050-T7451.

Among 59 materials

Stiffness against density

Strength against density