Materials / Compare
FDM Polycarbonate vs. Silicon
Compare FDM Polycarbonate 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 | 53.3MPasourcetypical | not given (tensile used) |
| Ultimate tensile strength | 53.3MPasourcetypical, peak stress (= stress at yield) | 130MPasourcemodulus of rupture (bending fracture stress); brittle, no yield point |
| Flexural strength | 89.4MPasourcetypical | 130MPasourcemodulus of rupture |
| Elongation at break | 9.2%sourcetypical | not sourced |
| Young's modulus (stiffness) | 2.39GPasourcetypical | 131GPasourcetypical (single quoted value of an anisotropic crystal) |
| Density | 1,180–1,200kg/m³sourcerange | 2,329kg/m³sourcetypical |
| Strength to weight | 44.8kN·m/kg | 55.8kN·m/kg25% higher |
| Stiffness to weight | 2.01MN·m/kg | 56.2MN·m/kg28x higher |
| Poisson's ratio | 0.38sourcebase material: polycarbonate family typical (Covestro Part and Mold Design guide, Table 3-1) | 0.221sourcetypical |
| Shear modulus | 0.867GPa | 53.6GPa61.8x stiffer in shear |
| Bulk modulus | 3.33GPa | 78.3GPa |
| Speed of sound | 1,418m/s | 7,500m/s |
| Thermal | ||
| Thermal conductivity | 0.2W/m·Ksourcebase material: Covestro Makrolon 2405 injection-molding PC, typical, through-plane, 23 °C | 163W/m·Ksourcetypical at 313 K (40 °C) |
| Thermal expansion | 65µm/m·Ksourcebase material: Covestro Makrolon 2405 injection-molding PC, typical, 23-55 °C, parallel | 2.62µm/m·Ksourcetypical at 300 K |
| 100 mm part over a 50 °C swing | 325µm growth | 13.1µm growth24.8x less |
| Specific heat | not sourced | 732J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | not sourced | 95.6mm²/s |
| Thermal shock resistance | 42.5W/m | 48,095W/m1,132x more resistant |
| Melting point | not sourced | 1,412°Csourcetypical |
| Glass transition | 108°Csourcetypical | not sourced |
| Max service temperature | 105°CsourceHDT 0.455 MPa (printed specimens) | 300°Csourceproducer's maximum application temperature (optical components) |
| 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. | 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.
FDM Polycarbonate is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is FDM Polycarbonate stronger than Silicon?
Silicon is stronger: its tensile strength is 130 MPa against yield strength 53.3 MPa for FDM Polycarbonate (2.44x).
Which is lighter, FDM Polycarbonate or Silicon?
FDM Polycarbonate is lighter: 1,190 kg/m³ against 2,329 kg/m³ for Silicon.
Which is stiffer, FDM Polycarbonate or Silicon?
Silicon is stiffer: Young's modulus 131 GPa against 2.39 GPa for FDM Polycarbonate, so the same part in Silicon deflects less under the same load.
Which is lighter for the same job, FDM Polycarbonate or Silicon?
For the same stiffness or strength: FDM Polycarbonate is lighter for a strong beam, strong panel or plate; Silicon is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie.
| Part that must be | FDM Polycarbonate | Silicon |
|---|---|---|
| Stiff rod or tie (tension) | 28x heavier | lighter |
| Stiff beam (bending) | 3.78x heavier | lighter |
| Stiff panel or plate | 1.94x heavier | lighter |
| Strong rod or tie | 25% heavier | lighter |
| Strong beam | lighter | 8% heavier |
| Strong panel or plate | lighter | 25% 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 Silicon?
Silicon conducts heat better: 163 W/m·K against 0.2 W/m·K for FDM Polycarbonate.
Which expands less with temperature?
Silicon expands less: 2.62 µm/m·K against 65 µm/m·K for FDM Polycarbonate.