DMLS AlSi10Mg Aluminum vs. Plastic Polycarbonate

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

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DMLS AlSi10Mg Aluminum3D printed metal (DMLS)

Plastic PolycarbonateBulk polymer (molded or machined)

Mechanical
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Yield strength	270MPasourcetypical, as manufactured, horizontal	65MPasourcetypical, tensile yield
Ultimate tensile strength	450MPasourcetypical, as manufactured, horizontal	65MPasourcetypical, stress at break
Flexural strength	not sourced	97MPasourcetypical, flexural strength
Elongation at break	10.2%sourcetypical at break, as manufactured, horizontal	125%sourcetypical, strain at break
Young's modulus (stiffness)	72GPasourcesame material and process, different machine maker: Renishaw RenAM 500, 30 µm, as built, horizontal (XY)	2.4GPasourcetypical
Density	2,670kg/m³sourcetypical part density (ISO 3369), EOS M 290, AlSi10Mg_030_FlexM291 (30 µm)	1,200kg/m³sourcetypical
Strength to weight	101kN·m/kg1.87x higher	54.2kN·m/kg
Stiffness to weight	27MN·m/kg13.5x higher	2MN·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)	0.38sourcetypical, polycarbonate family (Covestro Part and Mold Design guide, Table 3-1)
Shear modulus	27.1GPa31.1x stiffer in shear	0.87GPa
Bulk modulus	70.6GPa	3.33GPa
Speed of sound	5,193m/s	1,414m/s
Thermal
Thermal conductivity	110W/m·Ksourcetypical, as manufactured, horizontal (ISO 22007-2)	0.2W/m·Ksourcetypical, through-plane, 23 C
Thermal expansion	20µm/m·Ksourcemean 25-100 °C, ASTM E228	65µm/m·Ksourcetypical, 23-55 C, parallel and normal
100 mm part over a 50 °C swing	100µm growth3.25x less	325µm growth
Specific heat	963J/kg·Ksourcebase material: cast Al-Si-Mg alloy 359.0 (MIL-HDBK-5J), at 100 °C	1,172J/kg·Ksourcetypical (guide value), Bayer ASTM datasheet for Makrolon 2405, ASTM D 2766
Heats up and cools (diffusivity)	42.8mm²/s301x faster	0.142mm²/s
Thermal shock resistance	13,819W/m267x more resistant	51.7W/m
Glass transition	not sourced	144°Csourcetypical, DSC 10 C/min
Max service temperature	not sourced	125°CsourceUL 746B RTI, tensile strength, 1.5 mm
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	Covestro Makrolon 2405 general-purpose PC (MVR 19), Covestro technical datasheet version 2026-09-28, typical 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.

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

Questions

Is DMLS AlSi10Mg Aluminum stronger than Plastic Polycarbonate?

DMLS AlSi10Mg Aluminum is stronger: its yield strength is 270 MPa against 65 MPa for Plastic Polycarbonate (4.15x).

Which is lighter, DMLS AlSi10Mg Aluminum or Plastic Polycarbonate?

Plastic Polycarbonate is lighter: 1,200 kg/m³ against 2,670 kg/m³ for DMLS AlSi10Mg Aluminum.

Which is stiffer, DMLS AlSi10Mg Aluminum or Plastic Polycarbonate?

DMLS AlSi10Mg Aluminum is stiffer: Young's modulus 72 GPa against 2.4 GPa for Plastic Polycarbonate, 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 Polycarbonate?

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; Plastic Polycarbonate is lighter for a strong panel or plate.

Part that must be	DMLS AlSi10Mg Aluminum	Plastic Polycarbonate
Stiff rod or tie (tension)	lighter	13.5x heavier
Stiff beam (bending)	lighter	2.46x heavier
Stiff panel or plate	lighter	40% heavier
Strong rod or tie	lighter	1.87x heavier
Strong beam	lighter	16% heavier
Strong panel or plate	9% 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, DMLS AlSi10Mg Aluminum or Plastic Polycarbonate?

DMLS AlSi10Mg Aluminum conducts heat better: 110 W/m·K against 0.2 W/m·K for Plastic Polycarbonate.

Which expands less with temperature?

DMLS AlSi10Mg Aluminum expands less: 20 µm/m·K against 65 µm/m·K for Plastic Polycarbonate.

Among 59 materials

Stiffness against density

Strength against density