Aluminum AlMgSc-O (Annealed)
Temper
EN AlMgSc
Only for maximum ductility, straightening or secondary forming — Al3(Sc,Zr) coarsens and most of the strength is lost irrecoverably.
Values for the O condition
Other AlMgSc tempers and conditions
AlMgSc is listed in 5 conditions; see the grade overview at AlMgSc.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OThis page Annealed | Only for maximum ductility, straightening or secondary forming — Al3(Sc,Zr) coarsens and most of the strength is lost irrecoverably. | 200 | 330 | 21 | 80 HB | 33 % IACS |
As built (as printed) | Pick for maximum ductility, thin lattices or when parts are aged later in an assembly; strength is only about 60 % of aged. | 285 | 420 | 16 | 100 HB | 21 % IACS |
Stress relieved | Use when distortion control on the build plate matters more than peak strength; partially ages the Al3(Sc,Zr) dispersoids. | 400 | 470 | 14 | 126 HB | 26 % IACS |
hot isostatic pressing (~300–350 °C class cycle) followed by direct ageing | Choose for fatigue- or fracture-critical aerospace parts where closing residual LPBF porosity is worth the extra cost. | 435 | 480 | 16 | 136 HB | 29 % IACS |
T5Default Cooled from hot working and artificially aged | Standard delivery condition: peak Al3(Sc,Zr) precipitation strength with useful ductility, no solution treatment or quench distortion. | 460 | 500 | 12 | 140 HB | 28 % IACS |
What is AlMgSc-O?
AlMgSc-O is AlMgSc in the O temper — only for maximum ductility, straightening or secondary forming — Al3(Sc,Zr) coarsens and most of the strength is lost irrecoverably. AlMgSc-O has a yield strength of 200 MPa (29 ksi) and a tensile strength of 330 MPa (47.9 ksi) — stronger than 53% of aluminum grades. Elongation at break is 21% and the elastic modulus is 69 GPa (10 Msi). AlMgSc-O has a density of 2.67 g/cm³ (0.0965 lb/in³), lighter than 78% of aluminum grades. It melts at 585°C (1,085 °F). T5 is the default condition FabDigit quotes; O is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 40 MPa·√m (36.4 ksi·√in), better than 98% of aluminum grades
- Ductile — tolerates forming and impact — 21%, better than 91% of aluminum grades
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
- Readily welded — 88/100, better than 85% of aluminum grades
- Forms and bends easily — 70/100, better than 83% of aluminum grades
Limitations
- High embodied carbon — 24 kg CO₂/kg, worse than 100% of aluminum grades
AlMgSc-O properties
Typical room-temperature values for AlMgSc-O; 22 are specific to this condition. Other listed values are AlMgSc reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
AlMgSc-O has a density of 2.67 g/cm³ (0.0965 lb/in³), lighter than 78% of aluminum grades. It melts at 585°C (1,085 °F).
Mechanical14
AlMgSc-O has a yield strength of 200 MPa (29 ksi) and a tensile strength of 330 MPa (47.9 ksi) — stronger than 53% of aluminum grades. Elongation at break is 21% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
AlMgSc-O is rated for continuous service to 200°C (392 °F). It conducts heat at 130 W/m·K (75.1 BTU/hr·ft·°F), worse than 65% of aluminum grades. Thermal expansion is 23.5 µm/m·K (13.1 µin/in·°F).
Electrical3
AlMgSc-O conducts electricity at 33 % IACS, worse than 57% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (63/100), better than 69% of aluminum grades.
Sustainability4
Producing a kilogram of AlMgSc-O takes about 260 MJ of energy and emits 24 kg of CO₂ — more than 99% of aluminum grades. Typical recycled content is 5%.
Manufacturability8
AlMgSc-O's machinability is fair (50/100, worse than 65% of aluminum grades); weldability excellent (88/100); formability very good (70/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AlMgSc-O
Is AlMgSc easy to machine?
Machines like a hard 5083: sharp polished-flute carbide, high rake, high speed and flood coolant to avoid built-up edge; aged parts cut cleaner than as-built.
Can AlMgSc be welded?
Very good for an aluminium AM alloy — Sc/Zr grain refinement suppresses solidification cracking; TIG/FSW with 5356 or matching Al-Mg-Sc filler, then re-age at ~325 °C to restore weld strength.
Can AlMgSc be formed, bent or molded?
Net-shape by LPBF (typ. 20–60 µm layers, preheated plate); powder is highly reactive and moisture-sensitive, so inert handling, sieving and oxygen control below ~0.05 % are essential; little post-print cold forming.
What surface finishes work on AlMgSc?
Support removal, then blast/tumble or machine critical faces; anodises uniformly (clear or hard coat), chromate-free conversion coatings and paint adhere well; polishing requires prior porosity closure.
AlMgSc 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, as in 5000 series | 3.8 – 5 | 4.5 |
| Scforms Al3(Sc,Zr); main cost driver | 0.4 – 0.9 | 0.7 |
| Zrco-precipitates with Sc, coarsening resistance | 0.2 – 0.5 | 0.35 |
| Mnsupplier dependent; some variants Mn-free | 0 – 0.6 | 0.4 |
| Siimpurity limit | ≤ 0.25 | 0.1 |
| Feimpurity limit | ≤ 0.25 | 0.1 |
| Ti | ≤ 0.15 | 0.05 |
| Zn | ≤ 0.1 | — |
| Cukept low for corrosion resistance | ≤ 0.1 | — |
| Opowder oxygen limit (gas atomised) | ≤ 0.05 | 0.03 |
| Al | balance | — |
AlMgSc-O — frequently asked
What is AlMgSc-O used for?
AlMgSc-O is typically used for aerospace lightweight parts, high-performance brackets and fatigue-critical AM components. In short: strongest weldable AM aluminum; scalmalloy-class alternative; high elongation for LPBF.
What is the yield strength of AlMgSc-O?
AlMgSc-O has a typical yield strength of 200 MPa (29 ksi) and a tensile strength of 330 MPa (47.9 ksi) — stronger than 53% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is AlMgSc-O easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 65% of aluminum grades). Machines like a hard 5083: sharp polished-flute carbide, high rake, high speed and flood coolant to avoid built-up edge; aged parts cut cleaner than as-built.
Can AlMgSc-O be welded?
Yes — weldability is rated excellent (88/100). Very good for an aluminium AM alloy — Sc/Zr grain refinement suppresses solidification cracking; TIG/FSW with 5356 or matching Al-Mg-Sc filler, then re-age at ~325 °C to restore weld strength.
What surface finishes work on AlMgSc-O?
Support removal, then blast/tumble or machine critical faces; anodises uniformly (clear or hard coat), chromate-free conversion coatings and paint adhere well; polishing requires prior porosity closure.
Can AlMgSc-O be formed, bent or molded?
Net-shape by LPBF (typ. 20–60 µm layers, preheated plate); powder is highly reactive and moisture-sensitive, so inert handling, sieving and oxygen control below ~0.05 % are essential; little post-print cold forming.
What is the maximum service temperature of AlMgSc-O?
AlMgSc-O is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AlMgSc-T5 and AlMgSc-O?
T5 is the default condition — standard delivery condition: peak Al3(Sc,Zr) precipitation strength with useful ductility, no solution treatment or quench distortion. O: only for maximum ductility, straightening or secondary forming — Al3(Sc,Zr) coarsens and most of the strength is lost irrecoverably. Yield strength is 460 MPa in T5 versus 200 MPa in O.
Sources
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- Al-Mg-Sc (AlMgScZr) LPBF powder datasheets — AM powder producers (composite of several) (2023)
- Aluminum Association Teal Sheets — 5000-series registrations (base-alloy reference) — The Aluminum Association (2018)
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.