BASF Forward AM (BASF 3D Printing Solutions) Ultrafuse HiPS, TDS v2.2 (13.11.2019), printed specimens, XY 'Flat'. Specimen print settings are not stated; recommended processing on the sheet: nozzle 240-260 °C, bed 100-120 °C, 40-80 mm/s. Product is discontinued (Forward AM product page) but the TDS is still served by Forward AM.
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 HIPS is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is FDM HIPS stronger than Magnesium AZ91D?
Magnesium AZ91D is stronger: its yield strength is 150 MPa against tensile strength 18.4 MPa for FDM HIPS (8.15x).
Which is lighter, FDM HIPS or Magnesium AZ91D?
FDM HIPS is lighter: 1,023 kg/m³ against 1,810 kg/m³ for Magnesium AZ91D.
Which is stiffer, FDM HIPS or Magnesium AZ91D?
Magnesium AZ91D is stiffer: Young's modulus 45 GPa against 1.59 GPa for FDM HIPS, so the same part in Magnesium AZ91D deflects less under the same load.
Which is lighter for the same job, FDM HIPS 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 HIPS
Magnesium AZ91D
Stiff rod or tie (tension)
16x heavier
lighter
Stiff beam (bending)
3.01x heavier
lighter
Stiff panel or plate
1.72x heavier
lighter
Strong rod or tie
4.61x heavier
lighter
Strong beam
2.29x heavier
lighter
Strong panel or plate
1.61x 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 HIPS or Magnesium AZ91D?
Magnesium AZ91D conducts heat better: 72 W/m·K against 0.17 W/m·K for FDM HIPS.
Which expands less with temperature?
Magnesium AZ91D expands less: 25 µm/m·K against 80 µm/m·K for FDM HIPS.