80°Csourcerecommended max constant operating temperature
Values for
6061-T6/T651, Kaiser Aluminum typical properties (sheet, coil & plate datasheet); Poisson from MIL-HDBK-5J
Celanese GUR 4120 (avg. molecular weight 4.7x10^6 g/mol), typical values on compression-molded specimens; CTE and thermal conductivity from Celanese's generic UHMWPE guide (grade not named)
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 stronger than Plastic UHMWPE?
Aluminum is stronger: its yield strength is 276 MPa against 20 MPa for Plastic UHMWPE (13.8x).
Which is lighter, Aluminum or Plastic UHMWPE?
Plastic UHMWPE is lighter: 930 kg/m³ against 2,700 kg/m³ for Aluminum.
Which is stiffer, Aluminum or Plastic UHMWPE?
Aluminum is stiffer: Young's modulus 68.3 GPa against 0.66 GPa for Plastic UHMWPE, so the same part in Aluminum deflects less under the same load.
Which is lighter for the same job, Aluminum or Plastic UHMWPE?
For the same stiffness or strength: Aluminum is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
Part that must be
Aluminum
Plastic UHMWPE
Stiff rod or tie (tension)
lighter
35.6x heavier
Stiff beam (bending)
lighter
3.5x heavier
Stiff panel or plate
lighter
1.62x heavier
Strong rod or tie
lighter
4.75x heavier
Strong beam
lighter
1.98x heavier
Strong panel or plate
lighter
28% 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, Aluminum or Plastic UHMWPE?
Aluminum conducts heat better: 167 W/m·K against 0.4 W/m·K for Plastic UHMWPE.
Which expands less with temperature?
Aluminum expands less: 23.6 µm/m·K against 200 µm/m·K for Plastic UHMWPE.