FDM Polycarbonate vs. Nickel Inconel 718

Compare FDM Polycarbonate vs. Nickel Inconel 718 strength, stiffness, weight and thermal properties.

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Mechanical
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Yield strength	53.3MPasourcetypical	1,207MPasourcetypical, 1.0 in. hot-rolled bar, 0.2% offset
Ultimate tensile strength	53.3MPasourcetypical, peak stress (= stress at yield)	1,389MPasourcetypical, 1.0 in. bar
Flexural strength	89.4MPasourcetypical	not sourced
Elongation at break	9.2%sourcetypical	20%sourcetypical, 1.0 in. bar
Young's modulus (stiffness)	2.39GPasourcetypical	200GPasourcetypical, 21 °C, annealed + aged
Density	1,180–1,200kg/m³sourcerange	8,221kg/m³sourcenominal, annealed and aged
Strength to weight	44.8kN·m/kg	147kN·m/kg3.28x higher
Stiffness to weight	2.01MN·m/kg	24.3MN·m/kg12.1x higher
Poisson's ratio	0.38sourcebase material: polycarbonate family typical (Covestro Part and Mold Design guide, Table 3-1)	0.294sourcetypical, 21 °C, annealed + aged
Shear modulus	0.867GPa	77.3GPa89.1x stiffer in shear
Bulk modulus	3.33GPa	162GPa
Speed of sound	1,418m/s	4,932m/s
Thermal
Thermal conductivity	0.2W/m·Ksourcebase material: Covestro Makrolon 2405 injection-molding PC, typical, through-plane, 23 °C	11.4W/m·Ksourcetypical, 21 °C, annealed + aged (calculated from resistivity per footnote a)
Thermal expansion	65µm/m·Ksourcebase material: Covestro Makrolon 2405 injection-molding PC, typical, 23-55 °C, parallel	13.2µm/m·Ksourcetypical, mean 21-93 °C, annealed + aged
100 mm part over a 50 °C swing	325µm growth	66µm growth4.92x less
Specific heat	not sourced	435J/kg·Ksourcetypical, 21 °C
Heats up and cools (diffusivity)	not sourced	3.19mm²/s
Thermal shock resistance	42.5W/m	3,680W/m86.6x more resistant
Melting point	not sourced	1,260–1,336°Csourcemelting range
Glass transition	108°Csourcetypical	not sourced
Max service temperature	105°CsourceHDT 0.455 MPa (printed specimens)	704°Csourceupper use temperature stated by producer
Values for	Ultimaker PC, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS (file v5.00), April 20, 2022.	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.

FDM Polycarbonate is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Is FDM Polycarbonate stronger than Nickel Inconel 718?

Nickel Inconel 718 is stronger: its yield strength is 1,207 MPa against 53.3 MPa for FDM Polycarbonate (22.6x).

Which is lighter, FDM Polycarbonate or Nickel Inconel 718?

FDM Polycarbonate is lighter: 1,190 kg/m³ against 8,221 kg/m³ for Nickel Inconel 718.

Which is stiffer, FDM Polycarbonate or Nickel Inconel 718?

Nickel Inconel 718 is stiffer: Young's modulus 200 GPa against 2.39 GPa for FDM Polycarbonate, so the same part in Nickel Inconel 718 deflects less under the same load.

Which is lighter for the same job, FDM Polycarbonate or Nickel Inconel 718?

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

Part that must be	FDM Polycarbonate	Nickel Inconel 718
Stiff rod or tie (tension)	12.1x heavier	lighter
Stiff beam (bending)	32% heavier	lighter
Stiff panel or plate	lighter	1.58x heavier
Strong rod or tie	3.28x heavier	lighter
Strong beam	16% heavier	lighter
Strong panel or plate	lighter	45% 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, FDM Polycarbonate or Nickel Inconel 718?

Nickel Inconel 718 conducts heat better: 11.4 W/m·K against 0.2 W/m·K for FDM Polycarbonate.

Which expands less with temperature?

Nickel Inconel 718 expands less: 13.2 µm/m·K against 65 µm/m·K for FDM Polycarbonate.

Among 59 materials

Stiffness against density

Strength against density