DMLS AlSi10Mg Aluminum vs. Plastic PETG

Compare DMLS AlSi10Mg Aluminum vs. Plastic PETG strength, stiffness, weight and thermal properties.

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DMLS AlSi10Mg Aluminum3D printed metal (DMLS)

Mechanical
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Yield strength	270MPasourcetypical, as manufactured, horizontal	46.2MPasourcetypical
Ultimate tensile strength	450MPasourcetypical, as manufactured, horizontal	46.2MPasourcetypical, peak stress (= stress at yield)
Flexural strength	not sourced	78.9MPasourcetypical
Elongation at break	10.2%sourcetypical at break, as manufactured, horizontal	7.6%sourcetypical
Young's modulus (stiffness)	72GPasourcesame material and process, different machine maker: Renishaw RenAM 500, 30 µm, as built, horizontal (XY)	1.94GPasourcetypical
Density	2,670kg/m³sourcetypical part density (ISO 3369), EOS M 290, AlSi10Mg_030_FlexM291 (30 µm)	1,270kg/m³sourcetypical
Strength to weight	101kN·m/kg2.78x higher	36.4kN·m/kg
Stiffness to weight	27MN·m/kg17.7x higher	1.53MN·m/kg
Poisson's ratio	0.33sourcebase material: cast Al-Si-Mg alloy 359.0 (Al-9Si-0.6Mg, closest MIL-HDBK-5J alloy to AlSi10Mg / EN AC-43000)	not sourced
Shear modulus	27.1GPa	not sourced
Bulk modulus	70.6GPa	not sourced
Speed of sound	5,193m/s	1,236m/s
Thermal
Thermal conductivity	110W/m·Ksourcetypical, as manufactured, horizontal (ISO 22007-2)	0.21W/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical
Thermal expansion	20µm/m·Ksourcemean 25-100 °C, ASTM E228	51µm/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical
100 mm part over a 50 °C swing	100µm growth2.55x less	255µm growth
Specific heat	963J/kg·Ksourcebase material: cast Al-Si-Mg alloy 359.0 (MIL-HDBK-5J), at 100 °C	1,300J/kg·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), DSC at 60 °C (lowest temperature listed)
Heats up and cools (diffusivity)	42.8mm²/s336x faster	0.127mm²/s
Thermal shock resistance	13,819W/m	not sourced
Glass transition	not sourced	77.4°Csourcetypical
Max service temperature	not sourced	76.2°CsourceHDT 0.455 MPa (printed specimens)
Values for	EOS Aluminium AlSi10Mg (powder 9011-0024), EOS M 290 \| 30 µm process (AlSi10Mg_FlexM291 2.01), as manufactured, horizontal; machined (turned) specimens, ISO 6892-1 B10	Ultimaker PETG, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS v1.00, April 29, 2022.

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.

DMLS AlSi10Mg Aluminum and Plastic PETG are 3D printed: their properties depend on build direction and print settings; these are typical values.

Questions

Is DMLS AlSi10Mg Aluminum stronger than Plastic PETG?

DMLS AlSi10Mg Aluminum is stronger: its yield strength is 270 MPa against 46.2 MPa for Plastic PETG (5.84x).

Which is lighter, DMLS AlSi10Mg Aluminum or Plastic PETG?

Plastic PETG is lighter: 1,270 kg/m³ against 2,670 kg/m³ for DMLS AlSi10Mg Aluminum.

Which is stiffer, DMLS AlSi10Mg Aluminum or Plastic PETG?

DMLS AlSi10Mg Aluminum is stiffer: Young's modulus 72 GPa against 1.94 GPa for Plastic PETG, so the same part in DMLS AlSi10Mg Aluminum deflects less under the same load.

Which is lighter for the same job, DMLS AlSi10Mg Aluminum or Plastic PETG?

For the same stiffness or strength: DMLS AlSi10Mg 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	DMLS AlSi10Mg Aluminum	Plastic PETG
Stiff rod or tie (tension)	lighter	17.7x heavier
Stiff beam (bending)	lighter	2.9x heavier
Stiff panel or plate	lighter	1.59x heavier
Strong rod or tie	lighter	2.78x heavier
Strong beam	lighter	1.54x heavier
Strong panel or plate	lighter	15% 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, DMLS AlSi10Mg Aluminum or Plastic PETG?

DMLS AlSi10Mg Aluminum conducts heat better: 110 W/m·K against 0.21 W/m·K for Plastic PETG.

Which expands less with temperature?

DMLS AlSi10Mg Aluminum expands less: 20 µm/m·K against 51 µm/m·K for Plastic PETG.

Among 59 materials

Stiffness against density

Strength against density