Aluminum AlSi9Cu3
EN AlSi9Cu3
AlSi9Cu3 is an Al-Si-Cu casting chemistry (EN AC-46000, DIN 1725) that is occasionally atomised and processed by laser powder bed fusion for cost-sensitive, moderately strong parts.
Reference datasheet — AlSi9Cu3 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the F condition
AlSi9Cu3 tempers and conditions
AlSi9Cu3 is supplied in 5 conditions, soft to hard. F is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
F | Choose for larger, thicker gravity-cast parts where die casting is impractical; coarser structure, lower strength. | 110 | 200 | 1.5 | 80 HB | 25 % IACS |
FDefault As fabricated | Standard supply condition: high-pressure die castings used as-cast, best strength/cost balance. | 165 | 300 | 2 | 85 HB | 24 % IACS |
Solution heat treated and overaged (stabilized) | Pick when dimensional stability and elevated-temperature service matter more than peak strength. | 200 | 280 | 2.5 | 95 HB | 30 % IACS |
Cooled from hot working and artificially aged | Low-cost ageing (~200-230 °C) of die castings to raise yield strength and dimensional stability without blistering risk. | 210 | 320 | 1.5 | 95 HB | 26 % IACS |
Solution heat treated and artificially aged | Maximum strength for gravity/vacuum-assist castings only — conventional HPDC parts blister during the ~490 °C solution soak. | 250 | 330 | 1.5 | 110 HB | 25 % IACS |
Supply forms, finishes and certifications
Ways AlSi9Cu3 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
LPBF-AB | LPBF as-built | Printing process |
LPBF-SR | LPBF stress relieved | Surface finish |
LPBF-T6 | LPBF T6 | Surface finish |
What is AlSi9Cu3?
AlSi9Cu3 is an Al-Si-Cu casting chemistry (EN AC-46000, DIN 1725) that is occasionally atomised and processed by laser powder bed fusion for cost-sensitive, moderately strong parts. Engineers choose it where the 2-4 % copper aids machinability (machinability score 62) and where die casting, permanent-mould casting or LPBF can deliver near-net housings; conditions on file include F, F-SC, T5, T6, T7 and LPBF-AB/SR/T6. Default properties are 165 MPa yield, 300 MPa tensile, 2 % elongation, 85 HB, 110 W/m·K and 24 % IACS, with a 150 °C service ceiling. Fusion weldability is poor (weldability score 20) and it is less common in LPBF than AlSi10Mg, which is the usual alternative. AlSi9Cu3 has a density of 2.75 g/cm³ (0.0994 lb/in³), heavier than 67% of aluminum grades. It melts at 515°C (959 °F). AlSi9Cu3 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 58% of aluminum grades. Elongation at break is 2% and the elastic modulus is 75 GPa (10.9 Msi).
What is AlSi9Cu3 used for?
- housings
- low-cost prototypes
- automotive components
- general industrial brackets
Limitations
- Low electrical conductivity — 24 % IACS, worse than 95% of aluminum grades
- Hard to polish — 40/100, worse than 91% of aluminum grades
- Low fracture toughness — 16 MPa·√m (14.6 ksi·√in), worse than 89% of aluminum grades
- Difficult to weld — 20/100, worse than 89% of aluminum grades
- Poor heat conductor — 110 W/m·K (63.6 BTU/hr·ft·°F), worse than 88% of aluminum grades
AlSi9Cu3 properties
Typical room-temperature values for AlSi9Cu3-F; bars are the position among aluminum grades.
Physical3
AlSi9Cu3 has a density of 2.75 g/cm³ (0.0994 lb/in³), heavier than 67% of aluminum grades. It melts at 515°C (959 °F).
Mechanical13
AlSi9Cu3 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 58% of aluminum grades. Elongation at break is 2% and the elastic modulus is 75 GPa (10.9 Msi).
Thermal6
AlSi9Cu3 is rated for continuous service to 150°C (302 °F). It conducts heat at 110 W/m·K (63.6 BTU/hr·ft·°F), worse than 88% of aluminum grades. Thermal expansion is 21 µm/m·K (11.7 µin/in·°F).
Electrical3
AlSi9Cu3 conducts electricity at 24 % IACS, worse than 95% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (38/100), worse than 79% of aluminum grades.
Sustainability4
Producing a kilogram of AlSi9Cu3 takes about 190 MJ of energy and emits 12.5 kg of CO₂ — less than 89% of aluminum grades. Typical recycled content is 85%.
Manufacturability8
AlSi9Cu3's machinability is good (62/100, better than 55% of aluminum grades); weldability poor (20/100); formability not recommended (8/100).
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. AlSi9Cu3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AlSi9Cu3
Is AlSi9Cu3 easy to machine?
Machines well for a casting alloy — Cu gives short chips, but primary/eutectic Si is abrasive, so use PCD or polished-flute carbide, high speed, low feed and flood or MQL cooling.
Can AlSi9Cu3 be welded?
Poor fusion weldability: 2-4 % Cu promotes hot cracking and die-cast gas porosity blisters; join by mechanical fastening, adhesive or self-pierce riveting, or use friction stir/laser welding on vacuum-cast and LPBF material with 4047 filler.
Can AlSi9Cu3 be formed, bent or molded?
Outstanding die-casting fluidity, low shrinkage and low die soldering with 0.8-1.1 % Fe; in LPBF it prints readily at ~350-400 W with 60-80 µm layers but needs preheated plate (150-200 °C) and reflective-powder-tolerant optics.
AlSi9Cu3 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 |
|---|---|---|
| SiEN AC-46000 AlSi9Cu3(Fe) | 8 – 11 | 9.5 |
| Cu | 2 – 4 | 3 |
| Fe0.6-1.1 % preferred for die-soldering control | ≤ 1.3 | 0.9 |
| Mn | ≤ 0.55 | 0.25 |
| Mg | 0.05 – 0.55 | 0.25 |
| Zn | ≤ 1.2 | 0.6 |
| Ni | ≤ 0.55 | 0.1 |
| Cr | ≤ 0.15 | |
| Ti | ≤ 0.25 | 0.1 |
| Pb0.25 max in ELV/RoHS-compliant variants | ≤ 0.35 | |
| Sn | ≤ 0.25 | |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.25 | |
| Al | balance |
What surface finishes work on AlSi9Cu3?
Do not decorative-anodize (dark, patchy film from Si+Cu); use chromate-free conversion coating, powder coat, e-coat or hard anodize for wear; shot blasting and vibratory finishing work well, mirror polishing is limited by Si particles.
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
Equivalent designations
Standards and trade names that resolve to Aluminum AlSi9Cu3 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- AC-46000
- Similar grades
- 1725
How much does AlSi9Cu3 cost?
AlSi9Cu3 is a standard-cost aluminum ($$), cheaper than about 71% 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.
AlSi9Cu3 — frequently asked
What is AlSi9Cu3 used for?
AlSi9Cu3 is typically used for housings, low-cost prototypes, automotive components and general industrial brackets. In short: best-machining Al-Si casting alloy; low-cost LPBF aluminum; poor fusion weldability.
What is the yield strength of AlSi9Cu3?
AlSi9Cu3 has a typical yield strength of 165 MPa (23.9 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 58% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is AlSi9Cu3 easy to machine?
Reasonably — machinability is rated good (62/100, better than 55% of aluminum grades). Machines well for a casting alloy — Cu gives short chips, but primary/eutectic Si is abrasive, so use PCD or polished-flute carbide, high speed, low feed and flood or MQL cooling.
Can AlSi9Cu3 be welded?
Not readily — weldability is rated poor (20/100). Poor fusion weldability: 2-4 % Cu promotes hot cracking and die-cast gas porosity blisters; join by mechanical fastening, adhesive or self-pierce riveting, or use friction stir/laser welding on vacuum-cast and LPBF material with 4047 filler.
What surface finishes work on AlSi9Cu3?
Do not decorative-anodize (dark, patchy film from Si+Cu); use chromate-free conversion coating, powder coat, e-coat or hard anodize for wear; shot blasting and vibratory finishing work well, mirror polishing is limited by Si particles.
Can AlSi9Cu3 be formed, bent or molded?
Outstanding die-casting fluidity, low shrinkage and low die soldering with 0.8-1.1 % Fe; in LPBF it prints readily at ~350-400 W with 60-80 µm layers but needs preheated plate (150-200 °C) and reflective-powder-tolerant optics.
What is the maximum service temperature of AlSi9Cu3?
AlSi9Cu3 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AlSi9Cu3-F and AlSi9Cu3-T6?
F is the default condition — standard supply condition: high-pressure die castings used as-cast, best strength/cost balance. T6: maximum strength for gravity/vacuum-assist castings only — conventional HPDC parts blister during the ~490 °C solution soak. Yield strength is 165 MPa in F versus 250 MPa in T6.
How much does AlSi9Cu3 cost?
AlSi9Cu3 is a standard-cost aluminum ($$), cheaper than about 71% 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.
Sources
- EN 1706 — Aluminium and aluminium alloys: Castings, chemical composition and mechanical properties (EN AC-46000) — CEN (2020)
- EN 1676 — Aluminium alloy ingots for remelting — CEN (2020)
- JIS H 5302 (ADC12) / ASTM B85 (A380.0) equivalents — JSA / ASTM (2021)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.15 — Casting — ASM International (2008)
- Al-Si-Cu die-casting and LPBF powder datasheets — Rheinfelden Alloys / ECKA Granules / SLM producers (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.