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Aluminum 2A70-T652

Temper

GB 2A70

T652 = t6, stress relieved by compression

Choose for large forgings that must be heavily machined — residual stress is removed so parts stay dimensionally stable.

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Values for the T652 condition

Other 2A70 tempers and conditions

2A70 is listed in 5 conditions; see the grade overview at 2A70.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Annealed
Softest condition for deep forming, straightening or intermediate machining before heat treatment.1202301865 HB48 % IACS
As fabricated
Raw hot-worked forging or extrusion before solution treatment; used only as a semi-finished supply state.1602801580 HB42 % IACS
Solution heat treated and naturally aged
Intermediate state for parts that must be formed or straightened after quenching and then artificially aged.2053501895 HB33 % IACS
T652This page
T6, stress relieved by compression
Choose for large forgings that must be heavily machined — residual stress is removed so parts stay dimensionally stable.3454209118 HB38 % IACS
T6Default
Solution heat treated and artificially aged
Standard supply condition for pistons, impellers and hot-running forgings — peak strength plus stable elevated-temperature properties.35043010120 HB38 % IACS

What is 2A70-T652?

2A70-T652 is 2A70 in the T652 temper — choose for large forgings that must be heavily machined — residual stress is removed so parts stay dimensionally stable. 2A70-T652 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 83% of aluminum grades. Elongation at break is 9% and the elastic modulus is 73 GPa (10.6 Msi). 2A70-T652 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 505°C (941 °F). T6 is the default condition FabDigit quotes; T652 is available on request or by drawing note.

Advantages

  • High service temperature — 200°C (392 °F), better than 90% of aluminum grades
  • High strength — 345 MPa (50 ksi), better than 83% of aluminum grades
  • Easy to machine — 72/100, better than 80% of aluminum grades

Limitations

  • Needs corrosion protection — 34/100, worse than 89% of aluminum grades
  • Difficult to weld — 22/100, worse than 83% of aluminum grades

2A70-T652 properties

Typical room-temperature values for 2A70-T652; 21 are specific to this condition. Other listed values are 2A70 reference data and may not represent this condition. Bars are the position among aluminum grades.

Physical3

2A70-T652 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 505°C (941 °F).

Density2.8 g/cm³0.1 lb/in³
Melting Point (Solidus)505°C941 °F
Liquidus Temperature638°C1,180 °F

Mechanical15

2A70-T652 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 83% of aluminum grades. Elongation at break is 9% and the elastic modulus is 73 GPa (10.6 Msi).

Elastic (Young's) Modulus73 GPa10.6 Msi
Shear Modulus27.5 GPa4 Msi
Bulk Modulus71 GPa10.3 Msi
Poisson's Ratio0.33
Tensile Strength (Ultimate)420 MPa60.9 ksi
Yield Strength (0.2% offset)345 MPa50 ksi
Elongation at Break9%
Reduction in Area20%
Compressive Strength350 MPa50.8 ksi
Shear Strength255 MPa37 ksi
Fatigue Strength (Endurance Limit)125 MPa18.1 ksi
Fracture Toughness (K_IC)26 MPa·√m23.7 ksi·√in
Charpy V-Notch Impact (RT)11 J8.1 ft·lbf
Hardness, Brinell118 HB
Hardness, Vickers128 HV

Thermal6

2A70-T652 is rated for continuous service to 200°C (392 °F). It conducts heat at 146 W/m·K (84.4 BTU/hr·ft·°F), better than 55% of aluminum grades. Thermal expansion is 22.3 µm/m·K (12.4 µin/in·°F).

Thermal Conductivity146 W/m·K84.4 BTU/hr·ft·°F
Specific Heat Capacity875 J/kg·K0.21 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)22.3 µm/m·K12.4 µin/in·°F
Latent Heat of Fusion390 J/g168 BTU/lb
Max Service Temperature (continuous)200°C392 °F
Min Service Temperature-196°C-321 °F

Electrical3

2A70-T652 conducts electricity at 38 % IACS, better than 61% of aluminum grades.

Electrical Conductivity38 % IACS
Electrical Resistivity4.5×10⁻⁸ Ω·m1.77 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is poor (34/100), worse than 89% of aluminum grades.

Galvanic Potential (seawater, vs SCE)-0.68 V
Corrosion ResistancePoor34/100
Chemical Resistance SummaryPoor in chloride and marine environments; susceptible to pitting, intergranular and exfoliation attack because of Cu/Ni-rich phases; attacked by strong acids and alkalis; needs cladding, anodizing or coating for outdoor use.

Sustainability4

Producing a kilogram of 2A70-T652 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 10%.

Embodied Energy (primary production)200 MJ/kg85,985 BTU/lb
Embodied Carbon (primary production)12.5 kg CO₂/kg
Embodied Water1,150 L/kg138 gal/lb
Typical Recycled Content10%

Manufacturability8

2A70-T652's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (22/100); formability poor (22/100).

MachinabilityVery good72/100
Machinability Rating (AISI 1212 = 100 %)60%
WeldabilityPoor22/100
Formability (cold)Poor22/100
CastabilityFair35/100
Brazeability / SolderabilityPoor15/100
PolishabilityGood55/100
Anodizing Responsefair — protective sulfuric/hard anodic films form, but Cu-Ni-Fe intermetallics give dark, mottled and less corrosion-tight coatings; chromic or hard anodize preferred over decorative anodizing

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with 2A70-T652

Is 2A70 easy to machine?

Machines well in T6 with sharp carbide tools and flood coolant, but the hard Al9FeNi/Al7Cu2Fe particles are abrasive — expect faster tool wear than 6061 and use PCD for high-volume piston turning.

Can 2A70 be welded?

Fusion welding is not recommended (hot-cracking, loss of aged strength); join by bolting, riveting, shrink fit or friction/inertia welding with post-weld re-ageing.

Can 2A70 be formed, bent or molded?

Designed for hot die forging and extrusion at roughly 380–460 °C; cold forming in T6 is very limited, form in O or T4 and age afterwards.

What surface finishes work on 2A70?

Use hard or chromic anodizing, chemical conversion coating or Ni/Sn plating for pistons; decorative sulfuric anodizing gives dark uneven color due to Cu-Ni phases.

2A70 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.

ElementSpec limit (wt %)Nominal
Cu1.9 – 2.52.2
Mg1.4 – 1.81.6
Fedeliberate addition, forms Al9FeNi0.9 – 1.51.2
Niheat-resistance phase former0.9 – 1.51.2
Tigrain refiner0.02 – 0.10.05
Si≤ 0.35—
Mn≤ 0.2—
Zn≤ 0.3—
Others (each)total ≤ 0.15≤ 0.05—
Albalance—

2A70-T652 — frequently asked

What is 2A70-T652 used for?

2A70-T652 is typically used for forged engine pistons, high-temperature forged structural parts, engine accessory brackets and links, extruded sections for elevated-temperature service, hot-section machined fittings and compressor and engine housings. In short: service to 200 °C; 2618-class piston alloy; abrasive Fe-Ni phases.

What is the yield strength of 2A70-T652?

2A70-T652 has a typical yield strength of 345 MPa (50 ksi) and a tensile strength of 420 MPa (60.9 ksi) — stronger than 83% of aluminum grades. Strength varies by condition: see the 5 listed tempers.

Is 2A70-T652 easy to machine?

Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines well in T6 with sharp carbide tools and flood coolant, but the hard Al9FeNi/Al7Cu2Fe particles are abrasive — expect faster tool wear than 6061 and use PCD for high-volume piston turning.

Can 2A70-T652 be welded?

Not readily — weldability is rated poor (22/100). Fusion welding is not recommended (hot-cracking, loss of aged strength); join by bolting, riveting, shrink fit or friction/inertia welding with post-weld re-ageing.

What surface finishes work on 2A70-T652?

Use hard or chromic anodizing, chemical conversion coating or Ni/Sn plating for pistons; decorative sulfuric anodizing gives dark uneven color due to Cu-Ni phases.

Can 2A70-T652 be formed, bent or molded?

Designed for hot die forging and extrusion at roughly 380–460 °C; cold forming in T6 is very limited, form in O or T4 and age afterwards.

What is the maximum service temperature of 2A70-T652?

2A70-T652 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 2A70-T6 and 2A70-O?

T6 is the default condition — standard supply condition for pistons, impellers and hot-running forgings — peak strength plus stable elevated-temperature properties. O: softest condition for deep forming, straightening or intermediate machining before heat treatment. Yield strength is 350 MPa in T6 versus 120 MPa in O.

Sources

  1. ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys (2618 data) — ASM International (1990)
  2. Aluminum Association Teal Sheets — alloy/temper designations — 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.