2024-T4/T351, Kaiser Aluminum sheet, coil & plate typical datasheet; Poisson from MIL-HDBK-5J
Röhm PLEXIGLAS GS 0F00 cast acrylic sheet, typical values at 23 °C / 50 % RH (Röhm Technical Information Ref. No. 211-1)
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 Aluminum 2024-T351 stronger than Plastic PMMA?
Aluminum 2024-T351 is stronger: its yield strength is 324 MPa against tensile strength 80 MPa for Plastic PMMA (4.05x).
Which is lighter, Aluminum 2024-T351 or Plastic PMMA?
Plastic PMMA is lighter: 1,190 kg/m³ against 2,770 kg/m³ for Aluminum 2024-T351.
Which is stiffer, Aluminum 2024-T351 or Plastic PMMA?
Aluminum 2024-T351 is stiffer: Young's modulus 73.1 GPa against 3.3 GPa for Plastic PMMA, so the same part in Aluminum 2024-T351 deflects less under the same load.
Which is lighter for the same job, Aluminum 2024-T351 or Plastic PMMA?
For the same stiffness or strength: Aluminum 2024-T351 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam; Plastic PMMA is lighter for a strong panel or plate.
Part that must be
Aluminum 2024-T351
Plastic PMMA
Stiff rod or tie (tension)
lighter
9.52x heavier
Stiff beam (bending)
lighter
2.02x heavier
Stiff panel or plate
lighter
21% heavier
Strong rod or tie
lighter
1.74x heavier
Strong beam
lighter
9% 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, Aluminum 2024-T351 or Plastic PMMA?
Aluminum 2024-T351 conducts heat better: 120 W/m·K against 0.19 W/m·K for Plastic PMMA.
Which expands less with temperature?
Aluminum 2024-T351 expands less: 22.9 µm/m·K against 70 µm/m·K for Plastic PMMA.