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.
Cleveland-Cliffs 17-4 PH, Condition H 900, sheet/strip, transverse (Product Data Bulletin, May 2021)
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 Silicon stronger than Stainless Steel 17-4PH?
Stainless Steel 17-4PH is stronger: its yield strength is 1,275 MPa against tensile strength 130 MPa for Silicon (9.81x).
Which is lighter, Silicon or Stainless Steel 17-4PH?
Silicon is lighter: 2,329 kg/m³ against 7,800 kg/m³ for Stainless Steel 17-4PH.
Which is stiffer, Silicon or Stainless Steel 17-4PH?
Stainless Steel 17-4PH is stiffer: Young's modulus 197 GPa against 131 GPa for Silicon, so the same part in Stainless Steel 17-4PH deflects less under the same load.
Which is lighter for the same job, Silicon or Stainless Steel 17-4PH?
For the same stiffness or strength: Silicon is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong panel or plate; Stainless Steel 17-4PH is lighter for a strong rod or tie, strong beam.
Part that must be
Silicon
Stainless Steel 17-4PH
Stiff rod or tie (tension)
lighter
2.23x heavier
Stiff beam (bending)
lighter
2.73x heavier
Stiff panel or plate
lighter
2.92x heavier
Strong rod or tie
2.93x heavier
lighter
Strong beam
37% heavier
lighter
Strong panel or plate
lighter
7% 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, Silicon or Stainless Steel 17-4PH?
Silicon conducts heat better: 163 W/m·K against 17.9 W/m·K for Stainless Steel 17-4PH.
Which expands less with temperature?
Silicon expands less: 2.62 µm/m·K against 10.8 µm/m·K for Stainless Steel 17-4PH.