Aluminum Scalmalloy Stress Relieved
Heat-treated state
EN AlMgSc
Pick when distortion after plate removal is the main risk; partial Sc precipitation already raises strength above as-built.
Values for the Stress Relieved condition
Other Scalmalloy tempers and conditions
Scalmalloy is listed in 5 conditions; see the grade overview at Scalmalloy.
- As Printed
- Stress Relieved
- HIP
- HIP+T6
- T6
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As PrintedDefault as-built L-PBF, no post heat treatment | Baseline condition straight off the machine; already strong from ultrafine solidification grains, chosen when parts are non-critical or will be aged later. | 285 | 400 | 14 | 100 HB | 26 % IACS |
Stress RelievedThis page low-temperature anneal (~300 °C, 2 h) to relax build stresses | Pick when distortion after plate removal is the main risk; partial Sc precipitation already raises strength above as-built. | 390 | 460 | 14 | 123 HB | 25 % IACS |
Hot isostatic pressed | Choose for fatigue-critical or fracture-critical flight hardware where internal gas porosity must be eliminated; HIP temperature must be kept low or Sc dispersoids coarsen. | 390 | 470 | 17 | 123 HB | 26 % IACS |
hot isostatic pressed then peak aged | Best combination for fatigue-loaded aerospace brackets: porosity closed and full precipitation strength restored by the subsequent 325 °C age. | 470 | 515 | 15 | 143 HB | 28 % IACS |
Solution heat treated and artificially aged | Standard delivery condition for structural parts: peak Al3(Sc,Zr) precipitation gives ~500 MPa UTS with double-digit ductility (no solution treatment/quench needed). | 480 | 520 | 13 | 145 HB | 30 % IACS |
What is Scalmalloy Stress Relieved?
Scalmalloy Stress Relieved is Scalmalloy heat treated to Stress Relieved — pick when distortion after plate removal is the main risk; partial Sc precipitation already raises strength above as-built. Scalmalloy Stress Relieved has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 460 MPa (66.7 ksi) — stronger than 87% of aluminum grades. Elongation at break is 14% and the elastic modulus is 70 GPa (10.2 Msi). Scalmalloy Stress Relieved 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). As Printed is the default condition FabDigit quotes; Stress Relieved is available on request or by drawing note.
Advantages
- High strength — 390 MPa (56.6 ksi), better than 87% of aluminum grades
- Tough — resists crack growth — 32 MPa·√m (29.1 ksi·√in), better than 83% of aluminum grades
- Polishes to a fine finish — 65/100, better than 82% of aluminum grades
- Ductile — tolerates forming and impact — 14%, better than 81% of aluminum grades
- Good corrosion resistance — 68/100, better than 75% of aluminum grades
Limitations
- High embodied carbon — 26 kg CO₂/kg, worse than 100% of aluminum grades
- Low electrical conductivity — 25 % IACS, worse than 92% of aluminum grades
- Poor heat conductor — 115 W/m·K (66.4 BTU/hr·ft·°F), worse than 85% of aluminum grades
Scalmalloy Stress Relieved properties
Typical room-temperature values for Scalmalloy Stress Relieved; 22 are specific to this condition. Other listed values are Scalmalloy reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
Scalmalloy Stress Relieved 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).
Mechanical13
Scalmalloy Stress Relieved has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 460 MPa (66.7 ksi) — stronger than 87% of aluminum grades. Elongation at break is 14% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal6
Scalmalloy Stress Relieved is rated for continuous service to 150°C (302 °F). It conducts heat at 115 W/m·K (66.4 BTU/hr·ft·°F), worse than 85% of aluminum grades. Thermal expansion is 23.5 µm/m·K (13.1 µin/in·°F).
Electrical3
Scalmalloy Stress Relieved conducts electricity at 25 % IACS, worse than 92% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 75% of aluminum grades.
Sustainability4
Producing a kilogram of Scalmalloy Stress Relieved takes about 350 MJ of energy and emits 26 kg of CO₂ — more than 100% of aluminum grades. Typical recycled content is 5%.
Manufacturability7
Scalmalloy Stress Relieved's machinability is fair (50/100, worse than 65% of aluminum grades); weldability good (60/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Scalmalloy Stress Relieved
Is Scalmalloy easy to machine?
Machines like 5083 — sharp uncoated or polished-flute carbide, high rake, generous coolant to stop built-up edge; aged material cuts cleaner than as-built.
Can Scalmalloy be welded?
TIG/MIG and friction-stir weldable with 5000-series-type filler, but the HAZ over-ages and can lose 30–40 % of yield strength; re-age at 325 °C where geometry allows.
Can Scalmalloy be formed, bent or molded?
Supplied as gas-atomised powder for L-PBF (typ. 15–53 µm, N₂/Ar atmosphere, ~200–400 W, heated plate ~150–200 °C); not intended for conventional casting or wrought forming.
What surface finishes work on Scalmalloy?
Blast/tumble to remove partly-melted particles, then chemical mill or machine critical faces; anodises well (type II or hard coat) and accepts chromate-free conversion coatings and primers.
Scalmalloy 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 |
|---|---|---|
| Mgsolid-solution strengthening | 4 – 4.9 | 4.5 |
| Scforms Al3(Sc,Zr) nano-precipitates | 0.6 – 0.8 | 0.7 |
| Zrco-precipitates with Sc, thermal stability | 0.2 – 0.5 | 0.3 |
| Mn | 0.3 – 0.8 | 0.5 |
| Siimpurity limit | ≤ 0.4 | 0.1 |
| Feimpurity limit | ≤ 0.4 | 0.15 |
| Ti | ≤ 0.15 | 0.05 |
| Znimpurity limit | ≤ 0.25 | — |
| Cukept low for corrosion resistance | ≤ 0.1 | — |
| Opowder oxygen content | ≤ 0.05 | 0.03 |
| Al | balance | — |
Scalmalloy Stress Relieved — frequently asked
What is Scalmalloy Stress Relieved used for?
Scalmalloy Stress Relieved is typically used for aerospace structural brackets, satellite and launcher fittings, motorsport suspension and upright components, UAV airframe structures, topology-optimised load-carrying brackets and robotic arm structures. In short: high-strength LPBF aluminum.
What is the yield strength of Scalmalloy Stress Relieved?
Scalmalloy Stress Relieved has a typical yield strength of 390 MPa (56.6 ksi) and a tensile strength of 460 MPa (66.7 ksi) — stronger than 87% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is Scalmalloy Stress Relieved easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 65% of aluminum grades). Machines like 5083 — sharp uncoated or polished-flute carbide, high rake, generous coolant to stop built-up edge; aged material cuts cleaner than as-built.
Can Scalmalloy Stress Relieved be welded?
Yes — weldability is rated good (60/100). TIG/MIG and friction-stir weldable with 5000-series-type filler, but the HAZ over-ages and can lose 30–40 % of yield strength; re-age at 325 °C where geometry allows.
What surface finishes work on Scalmalloy Stress Relieved?
Blast/tumble to remove partly-melted particles, then chemical mill or machine critical faces; anodises well (type II or hard coat) and accepts chromate-free conversion coatings and primers.
Can Scalmalloy Stress Relieved be formed, bent or molded?
Supplied as gas-atomised powder for L-PBF (typ. 15–53 µm, N₂/Ar atmosphere, ~200–400 W, heated plate ~150–200 °C); not intended for conventional casting or wrought forming.
What is the maximum service temperature of Scalmalloy Stress Relieved?
Scalmalloy Stress Relieved 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 Scalmalloy As Printed and Scalmalloy-T6?
As Printed is the default condition — baseline condition straight off the machine; already strong from ultrafine solidification grains, chosen when parts are non-critical or will be aged later. T6: standard delivery condition for structural parts: peak Al3(Sc,Zr) precipitation gives ~500 MPa UTS with double-digit ductility (no solution treatment/quench needed). Yield strength is 285 MPa in As Printed versus 480 MPa in T6.
Can FabDigit make parts in Scalmalloy Stress Relieved?
Yes — Scalmalloy Stress Relieved is available for 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Scalmalloy material data sheet — APWorks GmbH (Airbus) (2021)
- Scalmalloy powder for laser powder bed fusion — Toyal / Heraeus AMLOY-class licensed producers (2022)
- ASM Handbook Vol. 2 — Properties of Aluminum Alloys — ASM International (1990)
- Additive manufacturing Al-Mg-Sc mechanical property compilations — peer-reviewed L-PBF literature (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.