Aluminum 6063-T6 vs. Nickel Inconel 718

Compare Aluminum 6063-T6 vs. Nickel Inconel 718 strength, stiffness, weight and thermal properties.

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Mechanical
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Yield strength	215MPasourcetypical, T6, 0.0625 in specimen	1,207MPasourcetypical, 1.0 in. hot-rolled bar, 0.2% offset
Ultimate tensile strength	240MPasourcetypical, T6	1,389MPasourcetypical, 1.0 in. bar
Elongation at break	12%sourcetypical, T6, in 4D	20%sourcetypical, 1.0 in. bar
Young's modulus (stiffness)	69GPasourcetypical	200GPasourcetypical, 21 °C, annealed + aged
Density	2,700kg/m³sourcenominal, 20 °C	8,221kg/m³sourcenominal, annealed and aged
Strength to weight	79.6kN·m/kg	147kN·m/kg1.84x higher
Stiffness to weight	25.6MN·m/kg5% higher	24.3MN·m/kg
Poisson's ratio	not sourced	0.294sourcetypical, 21 °C, annealed + aged
Shear modulus	not sourced	77.3GPa
Bulk modulus	not sourced	162GPa
Speed of sound	5,055m/s	4,932m/s
Thermal
Thermal conductivity	201W/m·Ksourcetypical, T6, 20 °C	11.4W/m·Ksourcetypical, 21 °C, annealed + aged (calculated from resistivity per footnote a)
Thermal expansion	23.4µm/m·Ksourcetypical, mean 20-100 °C	13.2µm/m·Ksourcetypical, mean 21-93 °C, annealed + aged
100 mm part over a 50 °C swing	117µm growth	66µm growth1.77x less
Specific heat	901J/kg·Ksourcetypical, 20 °C (Hydro EN AW-6063)	435J/kg·Ksourcetypical, 21 °C
Heats up and cools (diffusivity)	82.6mm²/s25.9x faster	3.19mm²/s
Thermal shock resistance	not sourced	3,680W/m
Melting point	615–655°Csourcemelting range	1,260–1,336°Csourcemelting range
Max service temperature	not sourced	704°Csourceupper use temperature stated by producer
Values for	6063-T6 extruded tube, Kaiser Aluminum Tube & Pipe Alloy 6063 Technical Data (Rev. 05/06), typical properties; specific heat from Hydro EN AW-6063 extruded-products datasheet (Rev.4, 03/2023).	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 6063-T6 stronger than Nickel Inconel 718?

Nickel Inconel 718 is stronger: its yield strength is 1,207 MPa against 215 MPa for Aluminum 6063-T6 (5.61x).

Which is lighter, Aluminum 6063-T6 or Nickel Inconel 718?

Aluminum 6063-T6 is lighter: 2,700 kg/m³ against 8,221 kg/m³ for Nickel Inconel 718.

Which is stiffer, Aluminum 6063-T6 or Nickel Inconel 718?

Nickel Inconel 718 is stiffer: Young's modulus 200 GPa against 69 GPa for Aluminum 6063-T6, so the same part in Nickel Inconel 718 deflects less under the same load.

Which is lighter for the same job, Aluminum 6063-T6 or Nickel Inconel 718?

For the same stiffness or strength: Aluminum 6063-T6 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong panel or plate; Nickel Inconel 718 is lighter for a strong rod or tie, strong beam.

Part that must be	Aluminum 6063-T6	Nickel Inconel 718
Stiff rod or tie (tension)	lighter	5% heavier
Stiff beam (bending)	lighter	1.79x heavier
Stiff panel or plate	lighter	2.14x heavier
Strong rod or tie	1.84x heavier	lighter
Strong beam	4% heavier	lighter
Strong panel or plate	lighter	29% 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 6063-T6 or Nickel Inconel 718?

Aluminum 6063-T6 conducts heat better: 201 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 23.4 µm/m·K for Aluminum 6063-T6.

Among 72 materials

Stiffness against density

Strength against density