Ceramic Alumina 96% vs. Nickel Inconel 718

Compare Ceramic Alumina 96% vs. Nickel Inconel 718 strength, stiffness, weight and thermal properties.

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Ceramic Alumina 96%Sintered ceramic (pressed and fired)

Mechanical
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Yield strength	not given (tensile used)	1,207MPasourcetypical, 1.0 in. hot-rolled bar, 0.2% offset
Ultimate tensile strength	221MPasourcetypical tensile strength, 25 °C (ACMA Test #4)	1,389MPasourcetypical, 1.0 in. bar
Compressive strength	2,068MPasourcetypical, 20 °C (ASTM-C773)	not sourced
Flexural strength	358MPasourceflexural strength (MOR), 20 °C (ASTM-F417)	not sourced
Elongation at break	not sourced	20%sourcetypical, 1.0 in. bar
Young's modulus (stiffness)	303GPasourcetypical, 20 °C (ASTM-C848)	200GPasourcetypical, 21 °C, annealed + aged
Density	3,720kg/m³sourcetypical (ASTM-C20)	8,221kg/m³sourcenominal, annealed and aged
Strength to weight	59.4kN·m/kg	147kN·m/kg2.47x higher
Stiffness to weight	81.5MN·m/kg3.35x higher	24.3MN·m/kg
Poisson's ratio	0.21sourcetypical, 20 °C (ASTM-C848)	0.294sourcetypical, 21 °C, annealed + aged
Shear modulus	125GPa1.62x stiffer in shear	77.3GPa
Bulk modulus	174GPa	162GPa
Speed of sound	9,025m/s	4,932m/s
Thermal
Thermal conductivity	24.7W/m·Ksourcetypical, 20 °C (ASTM-C408)	11.4W/m·Ksourcetypical, 21 °C, annealed + aged (calculated from resistivity per footnote a)
Thermal expansion	8.2µm/m·Ksourcemean, 25-1000 °C (ASTM-C372)	13.2µm/m·Ksourcetypical, mean 21-93 °C, annealed + aged
100 mm part over a 50 °C swing	41µm growth1.61x less	66µm growth
Specific heat	880J/kg·Ksourcetypical, 100 °C (ASTM-E1269)	435J/kg·Ksourcetypical, 21 °C
Heats up and cools (diffusivity)	7.55mm²/s2.37x faster	3.19mm²/s
Thermal shock resistance	1,736W/m	3,680W/m2.12x more resistant
Melting point	not sourced	1,260–1,336°Csourcemelting range
Max service temperature	not sourced	704°Csourceupper use temperature stated by producer
Values for	CoorsTek AD-96, nominal 96% Al2O3 sintered alumina, typical values; CoorsTek "Ceramic Seal Material Properties" (© 2018, 01899 F). AD-96 is the general 96% grade, not the ADS-96R substrate grade.	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 Ceramic Alumina 96% stronger than Nickel Inconel 718?

Nickel Inconel 718 is stronger: its yield strength is 1,207 MPa against tensile strength 221 MPa for Ceramic Alumina 96% (5.46x).

Which is lighter, Ceramic Alumina 96% or Nickel Inconel 718?

Ceramic Alumina 96% is lighter: 3,720 kg/m³ against 8,221 kg/m³ for Nickel Inconel 718.

Which is stiffer, Ceramic Alumina 96% or Nickel Inconel 718?

Ceramic Alumina 96% is stiffer: Young's modulus 303 GPa against 200 GPa for Nickel Inconel 718, so the same part in Ceramic Alumina 96% deflects less under the same load.

Which is lighter for the same job, Ceramic Alumina 96% or Nickel Inconel 718?

For the same stiffness or strength: Ceramic Alumina 96% is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate; Nickel Inconel 718 is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must be	Ceramic Alumina 96%	Nickel Inconel 718
Stiff rod or tie (tension)	lighter	3.35x heavier
Stiff beam (bending)	lighter	2.72x heavier
Stiff panel or plate	lighter	2.54x heavier
Strong rod or tie	2.47x heavier	lighter
Strong beam	40% heavier	lighter
Strong panel or plate	6% heavier	lighter

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, Ceramic Alumina 96% or Nickel Inconel 718?

Ceramic Alumina 96% conducts heat better: 24.7 W/m·K against 11.4 W/m·K for Nickel Inconel 718.

Which expands less with temperature?

Ceramic Alumina 96% expands less: 8.2 µm/m·K against 13.2 µm/m·K for Nickel Inconel 718.

Among 72 materials

Stiffness against density

Strength against density