Aluminum AlSi12
EN AlSi12 · ASTM 413.0
AlSi12 is a near-eutectic Al-12Si powder for laser powder-bed fusion, matching the EN AC-44200 / A413.0 casting chemistry and offered as printed, stress relieved, HIP or T6.
Values for the As Printed condition
AlSi12 tempers and conditions
AlSi12 is supplied in 4 conditions, soft to hard. As Printed is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot isostatic pressed | Closes gas and lack-of-fusion porosity for fatigue-critical or pressure-tight parts; strength drops sharply because the Si network spheroidises. | 130 | 240 | 14 | 63 HB | 36 % IACS |
Solution heat treated and artificially aged | Applied when maximum ductility and stability are wanted; because AlSi12 has essentially no Mg or Cu the age-hardening response is small and strength stays below the as-printed level. | 150 | 265 | 12 | 70 HB | 35 % IACS |
annealed ~250–300 °C / 2 h after printing | Standard choice for dimensionally stable parts: removes build residual stress and raises ductility and conductivity at the cost of ~25 % strength. | 180 | 300 | 9 | 78 HB | 33 % IACS |
As PrintedDefault as-built LPBF/SLM condition | Highest strength and hardness from the ultrafine cellular Si network; use when residual stress and distortion are tolerable. | 250 | 400 | 5 | 105 HB | 27 % IACS |
What is AlSi12?
AlSi12 is a near-eutectic Al-12Si powder for laser powder-bed fusion, matching the EN AC-44200 / A413.0 casting chemistry and offered as printed, stress relieved, HIP or T6. Printed parts reach 250 MPa yield, 400 MPa tensile, 5 % elongation, 105 HB and 72 GPa modulus with 120 W/m·K thermal conductivity, which suits thin-walled, pressure-tight and heat-transfer geometries. The alloy gains less from ageing than AlSi10Mg, service is limited to about 120 °C, and machinability (50) is held back by abrasive eutectic silicon. AlSi12 has a density of 2.67 g/cm³ (0.0965 lb/in³), lighter than 78% of aluminum grades. It melts at 574°C (1,065 °F). AlSi12 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 65% of aluminum grades. Elongation at break is 5% and the elastic modulus is 72 GPa (10.4 Msi).
What is AlSi12 used for?
- Heat sinks and cold plates
- Thin-wall housings and enclosures
- Fluid and air manifolds
- Electronics and RF housings
- Lightweight brackets and mounts
- Jigs, fixtures and tooling inserts
- Replacement parts for obsolete castings
Limitations
- Low electrical conductivity — 27 % IACS, worse than 86% of aluminum grades
- Low fracture toughness — 17 MPa·√m (15.5 ksi·√in), worse than 83% of aluminum grades
- Poor heat conductor — 120 W/m·K (69.3 BTU/hr·ft·°F), worse than 80% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
AlSi12 properties
Typical room-temperature values for AlSi12-As Printed; bars are the position among aluminum grades.
Physical3
AlSi12 has a density of 2.67 g/cm³ (0.0965 lb/in³), lighter than 78% of aluminum grades. It melts at 574°C (1,065 °F).
Mechanical14
AlSi12 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 65% of aluminum grades. Elongation at break is 5% and the elastic modulus is 72 GPa (10.4 Msi).
Thermal6
AlSi12 is rated for continuous service to 120°C (248 °F). It conducts heat at 120 W/m·K (69.3 BTU/hr·ft·°F), worse than 80% of aluminum grades. Thermal expansion is 20.4 µm/m·K (11.3 µin/in·°F).
Electrical3
AlSi12 conducts electricity at 27 % IACS, worse than 86% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 51% of aluminum grades.
Sustainability4
Producing a kilogram of AlSi12 takes about 215 MJ of energy and emits 13 kg of CO₂ — more than 93% of aluminum grades. Typical recycled content is 10%.
Manufacturability7
AlSi12's machinability is fair (50/100, worse than 65% of aluminum grades); weldability very good (80/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. AlSi12 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AlSi12
Is AlSi12 easy to machine?
Machine with polished-flute uncoated or diamond-coated carbide, high speed and copious coolant; the eutectic Si is abrasive and chips are gummy without sharp edges.
Can AlSi12 be welded?
Excellent — the alloy is essentially 4047 filler chemistry, so TIG/laser repair welding of printed parts is straightforward with little hot-cracking risk.
Can AlSi12 be formed, bent or molded?
Not a wrought alloy: parts are built by LPBF (or cast); design for self-supporting angles, keep walls ≥0.4 mm, and stress-relieve before removing from the plate to avoid distortion.
Manufacturability
The process limits FabDigit's quote engine applies to AlSi12. Design inside these and the part quotes instantly; outside them it routes to an engineer.
3D printing
| Technologies | DMLS |
|---|---|
| Layer height | 20 – 60 µmdefault 30 µm |
| Minimum wall / feature | 0.5 / 0.3 mm |
| Build envelope | 250 × 250 × 325 mm |
| Supports | Yes |
| Anisotropy | Mild |
| Mandatory post-processing | heat treatment |
AlSi12 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Sinear-eutectic; AM powders typically 11–13 | 10.5 – 13.5 | 12 |
| Fe | ≤ 0.55 | 0.2 |
| Cu | ≤ 0.1 | 0.02 |
| Mn | ≤ 0.45 | 0.05 |
| Mgmax; no deliberate Mg, hence weak T6 response | ≤ 0.1 | 0.02 |
| Zn | ≤ 0.15 | 0.03 |
| Ti | ≤ 0.15 | 0.03 |
| Ni | ≤ 0.05 | |
| Pb | ≤ 0.05 | |
| Sn | ≤ 0.05 | |
| Others (each / total)0.05 each, 0.15 total | ≤ 0.15 | |
| Al | balance |
What surface finishes work on AlSi12?
Blast, tumble or machine to remove partially melted particles; hard anodising is possible but the high Si gives a dark grey, patchy colour, so paint, powder coat or chemical conversion coating is preferred for cosmetics.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Metal Finish
Equivalent designations
Standards and trade names that resolve to Aluminum AlSi12 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does AlSi12 cost?
AlSi12 is a premium-cost aluminum ($$$), cheaper than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
AlSi12 — frequently asked
What is AlSi12 used for?
AlSi12 is typically used for heat sinks and cold plates, thin-wall housings and enclosures, fluid and air manifolds, electronics and RF housings, lightweight brackets and mounts and jigs, fixtures and tooling inserts. In short: eutectic Al-Si AM powder; excellent castability.
What is the yield strength of AlSi12?
AlSi12 has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 65% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is AlSi12 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 65% of aluminum grades). Machine with polished-flute uncoated or diamond-coated carbide, high speed and copious coolant; the eutectic Si is abrasive and chips are gummy without sharp edges.
Can AlSi12 be welded?
Yes — weldability is rated very good (80/100). Excellent — the alloy is essentially 4047 filler chemistry, so TIG/laser repair welding of printed parts is straightforward with little hot-cracking risk.
What surface finishes work on AlSi12?
Blast, tumble or machine to remove partially melted particles; hard anodising is possible but the high Si gives a dark grey, patchy colour, so paint, powder coat or chemical conversion coating is preferred for cosmetics.
Can AlSi12 be formed, bent or molded?
Not a wrought alloy: parts are built by LPBF (or cast); design for self-supporting angles, keep walls ≥0.4 mm, and stress-relieve before removing from the plate to avoid distortion.
What is the maximum service temperature of AlSi12?
AlSi12 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AlSi12 As Printed and AlSi12-HIP?
As Printed is the default condition — highest strength and hardness from the ultrafine cellular Si network; use when residual stress and distortion are tolerable. HIP: closes gas and lack-of-fusion porosity for fatigue-critical or pressure-tight parts; strength drops sharply because the Si network spheroidises. Yield strength is 250 MPa in As Printed versus 130 MPa in HIP.
How much does AlSi12 cost?
AlSi12 is a premium-cost aluminum ($$$), cheaper than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in AlSi12?
Yes — AlSi12 is available for 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- EN 1706 — Aluminium and aluminium alloys, castings (EN AC-44200) — CEN (2020)
- ASTM B108 / Aluminum Association designation A413.0 — ASTM / Aluminum Association (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- EOS Aluminium AlSi12 material data sheet — EOS GmbH (2022)
- SLM Solutions / Nikon SLM Al-Alloy AlSi12 powder data sheet — SLM Solutions (2021)
- Published LPBF AlSi12 mechanical and thermophysical property studies — peer-reviewed AM literature (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.