Aluminum AlSi9Cu3 vs Scalmalloy
Aluminum · grade comparison
Aluminum AlSi9Cu3 and Scalmalloy are both aluminum grades. Scalmalloy is the stronger of the two: yield strength 285 MPa (41.3 ksi) against 165 MPa (23.9 ksi) for AlSi9Cu3, about 73% more; tensile strength follows at 400 MPa (58 ksi) vs 300 MPa (43.5 ksi). Scalmalloy is the more ductile: elongation 14% versus 2% for AlSi9Cu3, and Scalmalloy is harder (100 HB vs 85 HB). AlSi9Cu3 is stiffer (75 GPa vs 70 GPa) and AlSi9Cu3 runs hotter in service (150°C vs 120°C continuous). On the shop floor, Scalmalloy welds better (good vs poor) and AlSi9Cu3 sits in a lower cost tier (standard, $$) than Scalmalloy (specialty, $$$$$).
AlSi9Cu3Choose it when the part sees heat, or when cost is the deciding factor.
ScalmalloyChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
AlSi9Cu3 vs Scalmalloy: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Compressive Strength
Same in both: Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 110 W/m·K63.6 BTU/hr·ft·°F · Latent Heat of Fusion 390 J/g168 BTU/lb
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 1,200 L/kg144 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Strength versus weight
Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | AlSi9Cu3 | Scalmalloy |
|---|---|---|
| 3D printing | — | Yes |
| Default condition | — | As Printed |
| Relative cost | $$ Standard | $$$$$ Specialty |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Anodized (Aluminum AM) | — | Yes |
| Plated (Metal AM) | — | Yes |
They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.
AlSi9Cu3 vs Scalmalloy — frequently asked
Is Scalmalloy stronger than AlSi9Cu3?
Yes. Scalmalloy has a typical yield strength of 285 MPa (41.3 ksi) against 165 MPa (23.9 ksi) for AlSi9Cu3 — about 73% more. Tensile strength is 400 MPa (58 ksi) vs 300 MPa (43.5 ksi).
Which is cheaper, AlSi9Cu3 or Scalmalloy?
AlSi9Cu3 is the lower-cost material: it sits in the standard tier ($$) while Scalmalloy is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, AlSi9Cu3 or Scalmalloy?
AlSi9Cu3, by a small margin. Both rate good for machinability — 62/100 against 55/100 for Scalmalloy; for welding the order is Scalmalloy first (good, 60/100) then AlSi9Cu3 (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in AlSi9Cu3 and Scalmalloy side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.