Bambu Lab ASA, TDS V3.0, printed specimens X-Y; nozzle 260 °C, bed 80 °C, 200 mm/s, 100% infill; annealed and dried 80 °C for 12 h before testing.
ELEKTRON AZ91D magnesium die-casting alloy, as cast; Magnesium Elektron datasheet 475 (7/01), typical properties; Poisson from MIL-HDBK-5J for AZ91C castings.
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 ASA is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is FDM ASA stronger than Magnesium AZ91D?
Magnesium AZ91D is stronger: its yield strength is 150 MPa against tensile strength 37 MPa for FDM ASA (4.05x).
Which is lighter, FDM ASA or Magnesium AZ91D?
FDM ASA is lighter: 1,050 kg/m³ against 1,810 kg/m³ for Magnesium AZ91D.
Which is stiffer, FDM ASA or Magnesium AZ91D?
Magnesium AZ91D is stiffer: Young's modulus 45 GPa against 2.45 GPa for FDM ASA, so the same part in Magnesium AZ91D deflects less under the same load.
Which is lighter for the same job, FDM ASA or Magnesium AZ91D?
For the same stiffness or strength: Magnesium AZ91D 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
FDM ASA
Magnesium AZ91D
Stiff rod or tie (tension)
10.7x heavier
lighter
Stiff beam (bending)
2.49x heavier
lighter
Stiff panel or plate
1.53x heavier
lighter
Strong rod or tie
2.35x heavier
lighter
Strong beam
47% heavier
lighter
Strong panel or plate
17% 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, FDM ASA or Magnesium AZ91D?
Magnesium AZ91D conducts heat better: 72 W/m·K against 0.17 W/m·K for FDM ASA.
Which expands less with temperature?
Magnesium AZ91D expands less: 25 µm/m·K against 95 µm/m·K for FDM ASA.