A380 aluminium high-pressure die-casting alloy, typical properties; Rheocast Company (aluminium die caster, Germantown WI) A380 alloy data page.
LyondellBasell Moplen HP501H polypropylene homopolymer (general purpose), typical ISO values
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 A380 stronger than Plastic Polypropylene?
Aluminum A380 is stronger: its yield strength is 160 MPa against 33 MPa for Plastic Polypropylene (4.85x).
Which is lighter, Aluminum A380 or Plastic Polypropylene?
Plastic Polypropylene is lighter: 900 kg/m³ against 2,713 kg/m³ for Aluminum A380.
Which is stiffer, Aluminum A380 or Plastic Polypropylene?
Aluminum A380 is stiffer: Young's modulus 71 GPa against 1.45 GPa for Plastic Polypropylene, so the same part in Aluminum A380 deflects less under the same load.
Which is lighter for the same job, Aluminum A380 or Plastic Polypropylene?
For the same stiffness or strength: Aluminum A380 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie; Plastic Polypropylene is lighter for a strong beam, strong panel or plate.
Part that must be
Aluminum A380
Plastic Polypropylene
Stiff rod or tie (tension)
lighter
16.2x heavier
Stiff beam (bending)
lighter
2.32x heavier
Stiff panel or plate
lighter
21% heavier
Strong rod or tie
lighter
1.61x heavier
Strong beam
5% heavier
lighter
Strong panel or plate
37% 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 A380 or Plastic Polypropylene?
Aluminum A380 conducts heat better: 96.2 W/m·K against 0.195 W/m·K for Plastic Polypropylene.
Which expands less with temperature?
Aluminum A380 expands less: 21.8 µm/m·K against 90 µm/m·K for Plastic Polypropylene.