Aluminum A20X Stress Relieved
Heat-treated state
Pick when residual stress and distortion control matter more than peak strength (e.g. thin-wall or large frames before machining).
Values for the Stress Relieved condition
Other A20X tempers and conditions
A20X is listed in 6 conditions; see the grade overview at A20X.
- HIP
- Stress Relieved
- As Printed
- T6
- T7
- HIP+T7
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot isostatic pressed | Choose to close gas/lack-of-fusion porosity and maximise fatigue life and ductility; normally followed by T6/T7 ageing. | 200 | 355 | 18 | 87 HB | 37 % IACS |
Stress RelievedThis page low-temperature anneal of as-built parts | Pick when residual stress and distortion control matter more than peak strength (e.g. thin-wall or large frames before machining). | 220 | 350 | 14 | 90 HB | 34 % IACS |
As PrintedDefault as-built L-PBF, no heat treatment | Baseline condition straight off the machine; use only for form/fit parts or before downstream HIP/heat treatment. | 240 | 380 | 12 | 95 HB | 28 % IACS |
Solution heat treated and artificially aged | Default structural condition when maximum strength and hardness are required and corrosion exposure is controlled by coatings. | 425 | 495 | 9 | 140 HB | 31 % IACS |
Solution heat treated and overaged (stabilized) | Preferred aerospace condition: near-T6 strength with better ductility, dimensional stability and resistance to intergranular/stress-corrosion attack. | 435 | 505 | 12 | 138 HB | 35 % IACS |
hot isostatic pressed, solution treated and over-aged | Highest-integrity route for fatigue- and fracture-critical flight hardware: porosity closed plus stabilised precipitation strengthening. | 440 | 510 | 14 | 140 HB | 36 % IACS |
What is A20X Stress Relieved?
A20X Stress Relieved is A20X heat treated to Stress Relieved — pick when residual stress and distortion control matter more than peak strength (e.g. thin-wall or large frames before machining). A20X Stress Relieved has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 350 MPa (50.8 ksi) — stronger than 59% of aluminum grades. Elongation at break is 14% and the elastic modulus is 77 GPa (11.2 Msi). A20X Stress Relieved has a density of 2.83 g/cm³ (0.102 lb/in³), heavier than 91% of aluminum grades. It melts at 545°C (1,013 °F). As Printed is the default condition FabDigit quotes; Stress Relieved is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 14%, better than 81% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
- Tough — resists crack growth — 30 MPa·√m (27.3 ksi·√in), better than 76% of aluminum grades
Limitations
- High embodied carbon — 15 kg CO₂/kg, worse than 97% of aluminum grades
- Needs corrosion protection — 35/100, worse than 85% of aluminum grades
A20X Stress Relieved properties
Typical room-temperature values for A20X Stress Relieved; 22 are specific to this condition. Other listed values are A20X reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
A20X Stress Relieved has a density of 2.83 g/cm³ (0.102 lb/in³), heavier than 91% of aluminum grades. It melts at 545°C (1,013 °F).
Mechanical16
A20X Stress Relieved has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 350 MPa (50.8 ksi) — stronger than 59% of aluminum grades. Elongation at break is 14% and the elastic modulus is 77 GPa (11.2 Msi).
Thermal6
A20X Stress Relieved is rated for continuous service to 150°C (302 °F). It conducts heat at 125 W/m·K (72.2 BTU/hr·ft·°F), worse than 72% of aluminum grades. Thermal expansion is 22.3 µm/m·K (12.4 µin/in·°F).
Electrical3
A20X Stress Relieved conducts electricity at 34 % IACS, worse than 52% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (35/100), worse than 85% of aluminum grades.
Sustainability4
Producing a kilogram of A20X Stress Relieved takes about 240 MJ of energy and emits 15 kg of CO₂ — more than 98% of aluminum grades. Typical recycled content is 5%.
Manufacturability8
A20X Stress Relieved's machinability is very good (72/100, better than 80% of aluminum grades); weldability fair (50/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A20X Stress Relieved
Is A20X easy to machine?
Machines much like 2014/2219-T6 with sharp carbide and generous coolant, but the hard TiB₂ particles are abrasive and shorten tool life — prefer polycrystalline-diamond or coated carbide for finishing.
Can A20X be welded?
TiB₂ grain refinement gives far better hot-cracking resistance than conventional 2000 series; TIG/laser and friction-stir joining are feasible, though post-weld solution + ageing is needed to restore strength.
Can A20X be formed, bent or molded?
Supplied as AM powder or premium castings, not as wrought stock; L-PBF requires tight oxygen/moisture control, pre-heated plates and 180–200 °C stress-relief before plate removal.
What surface finishes work on A20X?
Shot peening or chemical smoothing improves fatigue; use hard or sulphuric anodise plus chromate-free primer for corrosion protection — decorative anodising is unreliable due to Cu and TiB₂.
A20X 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 |
|---|---|---|
| Cumain strengthening addition | 4.2 – 5 | 4.5 |
| Agrefines Ω/θ' precipitation, raises elevated-temperature strength | 0.4 – 1 | 0.7 |
| Mgco-additive with Ag | 0.15 – 0.35 | 0.25 |
| Tipresent largely as in-situ TiB₂ grain refiner | 1 – 2 | 1.5 |
| Bforms TiB₂ particles | 0.2 – 0.6 | 0.4 |
| Feimpurity limit | ≤ 0.15 | — |
| Siimpurity limit | ≤ 0.1 | — |
| Al | balance | — |
A20X Stress Relieved — frequently asked
What is A20X Stress Relieved used for?
A20X Stress Relieved is typically used for aerospace casting replacement parts, aluminium tooling and mould inserts, hot-running engine and powertrain brackets, motorsport structural components, defence hardware and mounts and pressure-tight housings. In short: castable high-strength LPBF.
What is the yield strength of A20X Stress Relieved?
A20X Stress Relieved has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 350 MPa (50.8 ksi) — stronger than 59% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is A20X Stress Relieved easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines much like 2014/2219-T6 with sharp carbide and generous coolant, but the hard TiB₂ particles are abrasive and shorten tool life — prefer polycrystalline-diamond or coated carbide for finishing.
Can A20X Stress Relieved be welded?
With care — weldability is rated fair (50/100). TiB₂ grain refinement gives far better hot-cracking resistance than conventional 2000 series; TIG/laser and friction-stir joining are feasible, though post-weld solution + ageing is needed to restore strength.
What surface finishes work on A20X Stress Relieved?
Shot peening or chemical smoothing improves fatigue; use hard or sulphuric anodise plus chromate-free primer for corrosion protection — decorative anodising is unreliable due to Cu and TiB₂.
Can A20X Stress Relieved be formed, bent or molded?
Supplied as AM powder or premium castings, not as wrought stock; L-PBF requires tight oxygen/moisture control, pre-heated plates and 180–200 °C stress-relief before plate removal.
What is the maximum service temperature of A20X Stress Relieved?
A20X 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 A20X As Printed and A20X-T7?
As Printed is the default condition — baseline condition straight off the machine; use only for form/fit parts or before downstream HIP/heat treatment. T7: preferred aerospace condition: near-T6 strength with better ductility, dimensional stability and resistance to intergranular/stress-corrosion attack. Yield strength is 240 MPa in As Printed versus 435 MPa in T7.
Can FabDigit make parts in A20X Stress Relieved?
Yes — A20X Stress Relieved is available for 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- A20X™ Aluminium Alloy Powder / Casting Alloy Technical Data — Aeromet International (A20X Ltd) (2023)
- Registration Record of Aluminum Association Alloy Designations (A205.0 casting alloy) — The Aluminum Association (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Additive-manufactured Al-Cu-Ag-TiB₂ mechanical property compilations (L-PBF) — peer-reviewed AM 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.