Materials / Compare
Nickel Inconel 718 vs. Silicon
Compare Nickel Inconel 718 vs. Silicon strength, stiffness, weight and thermal properties.
| Try it on a partA sample part to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | 1,207MPasourcetypical, 1.0 in. hot-rolled bar, 0.2% offset | not given (tensile used) |
| Ultimate tensile strength | 1,389MPasourcetypical, 1.0 in. bar | 130MPasourcemodulus of rupture (bending fracture stress); brittle, no yield point |
| Flexural strength | not sourced | 130MPasourcemodulus of rupture |
| Elongation at break | 20%sourcetypical, 1.0 in. bar | not sourced |
| Young's modulus (stiffness) | 200GPasourcetypical, 21 °C, annealed + aged | 131GPasourcetypical (single quoted value of an anisotropic crystal) |
| Density | 8,221kg/m³sourcenominal, annealed and aged | 2,329kg/m³sourcetypical |
| Strength to weight | 147kN·m/kg2.63x higher | 55.8kN·m/kg |
| Stiffness to weight | 24.3MN·m/kg | 56.2MN·m/kg2.31x higher |
| Poisson's ratio | 0.294sourcetypical, 21 °C, annealed + aged | 0.221sourcetypical |
| Shear modulus | 77.3GPa44% stiffer in shear | 53.6GPa |
| Bulk modulus | 162GPa | 78.3GPa |
| Speed of sound | 4,932m/s | 7,500m/s |
| Thermal | ||
| Thermal conductivity | 11.4W/m·Ksourcetypical, 21 °C, annealed + aged (calculated from resistivity per footnote a) | 163W/m·Ksourcetypical at 313 K (40 °C) |
| Thermal expansion | 13.2µm/m·Ksourcetypical, mean 21-93 °C, annealed + aged | 2.62µm/m·Ksourcetypical at 300 K |
| 100 mm part over a 50 °C swing | 66µm growth | 13.1µm growth5.04x less |
| Specific heat | 435J/kg·Ksourcetypical, 21 °C | 732J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | 3.19mm²/s | 95.6mm²/s30x faster |
| Thermal shock resistance | 3,680W/m | 48,095W/m13.1x more resistant |
| Melting point | 1,260–1,336°Csourcemelting range | 1,412°Csourcetypical |
| Max service temperature | 704°Csourceupper use temperature stated by producer | 300°Csourceproducer's maximum application temperature (optical components) |
| Values for | 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 | Synthetic single-crystal silicon (cubic, diamond structure), Korth Kristalle (crystal grower) material data; Korth usually supplies Floating Zone (FZ) material, Czochralski (Cz) also offered. Silicon is elastically anisotropic; the producer quotes one modulus and the solver is isotropic. |
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 Nickel Inconel 718 stronger than Silicon?
Nickel Inconel 718 is stronger: its yield strength is 1,207 MPa against tensile strength 130 MPa for Silicon (9.28x).
Which is lighter, Nickel Inconel 718 or Silicon?
Silicon is lighter: 2,329 kg/m³ against 8,221 kg/m³ for Nickel Inconel 718.
Which is stiffer, Nickel Inconel 718 or Silicon?
Nickel Inconel 718 is stiffer: Young's modulus 200 GPa against 131 GPa for Silicon, so the same part in Nickel Inconel 718 deflects less under the same load.
Which is lighter for the same job, Nickel Inconel 718 or Silicon?
For the same stiffness or strength: Nickel Inconel 718 is lighter for a strong rod or tie, strong beam; Silicon is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong panel or plate.
| Part that must be | Nickel Inconel 718 | Silicon |
|---|---|---|
| Stiff rod or tie (tension) | 2.31x heavier | lighter |
| Stiff beam (bending) | 2.86x heavier | lighter |
| Stiff panel or plate | 3.07x heavier | lighter |
| Strong rod or tie | lighter | 2.63x heavier |
| Strong beam | lighter | 25% heavier |
| Strong panel or plate | 16% 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, Nickel Inconel 718 or Silicon?
Silicon conducts heat better: 163 W/m·K against 11.4 W/m·K for Nickel Inconel 718.
Which expands less with temperature?
Silicon expands less: 2.62 µm/m·K against 13.2 µm/m·K for Nickel Inconel 718.