DMLS AlSi10Mg Aluminum vs. Silicon

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

DMLS AlSi10Mg Aluminum3D printed metal (DMLS)

SiliconGrown single crystal

Mechanical	DMLS AlSi10Mg Aluminum	Silicon
Yield strength	270MPa1	none (brittle)
Ultimate tensile strength	450MPa1	modulus of rupture130MPa2
Flexural strength	not sourced	modulus of rupture130MPa2
Elongation at break	10.2%1	none (brittle)
Young's modulus (stiffness)	72GPa3	131GPa21.82x stiffer
Density	2,670kg/m³4	2,329kg/m³215% lighter
Strength to weight	101kN·m/kg1.81x higher	55.8kN·m/kg
Stiffness to weight	27MN·m/kg	56.2MN·m/kg2.09x higher
Poisson's ratio	base material0.335	0.2212
Shear modulus	27.1GPa	53.6GPa1.98x stiffer in shear
Bulk modulus	70.6GPa	78.3GPa11% higher
Speed of sound	5,193m/s	7,500m/s44% faster

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	DMLS AlSi10Mg Aluminum	Silicon
Thermal conductivity	110W/m·K1	163W/m·K248% more heat through a fin
Thermal expansion	mean 25-100 °C20µm/m·K1	2.62µm/m·K27.63x less
100 mm part over a 50 °C swing	100µm growth	13.1µm growth7.63x less
Specific heat	base material963J/kg·K5	732J/kg·K2
Heats up and cools (diffusivity)	42.8mm²/s	95.6mm²/s2.24x faster
Thermal shock resistance	13,819W/m	48,095W/m3.48x more resistant
Melting point	not sourced	1,412°C2
Max service temperature	not sourced	300°C2

Thermal conductivity against densityHigher and further left: spreads more heat for its weight

Thermal expansion against thermal conductivityLower and further right: warps less when heated

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Sources5 documents: EOS GmbH, Korth Kristalle, Renishaw, U.S. Department of Defense

DMLS AlSi10Mg Aluminum: 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
Silicon: Synthetic single-crystal silicon (cubic, diamond structure), Korth Kristalle (crystal grower) material data; Korth usually supplies Floating Zone (FZ) material, Czochralski (Cz) also offered. Silicon is elastically anisotropic; the producer quotes one modulus and the solver is isotropic.

1
EOS Aluminium AlSi10Mg Material Data SheetEOS GmbHarchived copyDMLS AlSi10Mg Aluminum · Yield strength: typical, as manufactured, horizontalDMLS AlSi10Mg Aluminum · Ultimate tensile strength: typical, as manufactured, horizontalDMLS AlSi10Mg Aluminum · Elongation at break: typical at break, as manufactured, horizontalDMLS AlSi10Mg Aluminum · Thermal conductivity: typical, as manufactured, horizontal (ISO 22007-2)DMLS AlSi10Mg Aluminum · Thermal expansion: mean 25-100 °C, ASTM E228
2
Si: SiliconKorth Kristallearchived copySilicon · Ultimate tensile strength: modulus of rupture (bending fracture stress); brittle, no yield pointSilicon · Flexural strength: modulus of ruptureSilicon · Young's modulus (stiffness): typical (single quoted value of an anisotropic crystal)Silicon · Density: typicalSilicon · Poisson's ratio: typicalSilicon · Thermal conductivity: typical at 313 K (40 °C)Silicon · Thermal expansion: typical at 300 KSilicon · Specific heat: typicalSilicon · Melting point: typicalSilicon · Max service temperature: producer's maximum application temperature (optical components)
3
RenAM 500 Series Aluminium AlSi10Mg Material Data SheetRenishawDMLS AlSi10Mg Aluminum · Young's modulus (stiffness): same material and process, different machine maker: Renishaw RenAM 500, 30 µm, as built, horizontal (XY)
4
EOS Aluminium AlSi10Mg Material Data Sheet, FlexLine, M 290 (2018)EOS GmbHarchived copyDMLS AlSi10Mg Aluminum · Density: typical part density (ISO 3369), EOS M 290, AlSi10Mg_030_FlexM291 (30 µm)
5
MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseDMLS AlSi10Mg Aluminum · Poisson's ratio: base material: cast Al-Si-Mg alloy 359.0 (Al-9Si-0.6Mg, closest MIL-HDBK-5J alloy to AlSi10Mg / EN AC-43000)DMLS AlSi10Mg Aluminum · Specific heat: base material: cast Al-Si-Mg alloy 359.0 (MIL-HDBK-5J), at 100 °C

Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "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

Mechanical

Is DMLS AlSi10Mg Aluminum stronger than Silicon?

DMLS AlSi10Mg Aluminum is stronger: its yield strength is 270 MPa against tensile strength 130 MPa for Silicon (2.08x).

Which is lighter, DMLS AlSi10Mg Aluminum or Silicon?

Silicon is lighter: 2,329 kg/m³ against 2,670 kg/m³ for DMLS AlSi10Mg Aluminum.

Which is stiffer, DMLS AlSi10Mg Aluminum or Silicon?

Silicon is stiffer: Young's modulus 131 GPa against 72 GPa for DMLS AlSi10Mg Aluminum, so the same part in Silicon deflects less under the same load.

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

For the same stiffness or strength: DMLS AlSi10Mg Aluminum is lighter for a strong rod or tie, strong beam, strong panel or plate; Silicon is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate.

Part that must be	DMLS AlSi10Mg Aluminum	Silicon
Stiff rod or tie (tension)	2.09x heavier	lighter
Stiff beam (bending)	1.55x heavier	lighter
Stiff panel or plate	40% heavier	lighter
Strong rod or tie	lighter	1.81x heavier
Strong beam	lighter	42% heavier
Strong panel or plate	lighter	26% 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).

Thermal

Which conducts heat better, DMLS AlSi10Mg Aluminum or Silicon?

Silicon conducts heat better: 163 W/m·K against 110 W/m·K for DMLS AlSi10Mg Aluminum.

Which expands less with temperature?

Silicon expands less: 2.62 µm/m·K against 20 µm/m·K for DMLS AlSi10Mg Aluminum.