Aluminium alloy 7050 AA7050

spore: profile
id: aluminium-7050
spore_version: 0.2
family: aluminium-alloys
name: Aluminium alloy 7050
abbreviation: AA7050
role: aerospace structural alloy
category: metals
type: aluminium
summary: |
  AA7050 (UNS A97050, EN AW-7050) is a zinc-copper-magnesium-zirconium aluminium alloy sold as thick plate and as closed-die forgings for aerospace structure. A manufacturer datasheet gives, for forged stock in the over-aged T74 condition at 100 to 125 mm, a yield strength above 414 MPa and a tensile strength above 483 MPa. The same datasheet gives a thermal conductivity of 154 W/(m·K) at 20 °C in the T76 condition, and a distributor plate page gives a density of 2.83 g/cm3. Its weak point is the weld zone: in a 2003 study, friction-stir welds of 7050-T7451 cracked more readily in a corrosive solution than welds of 7075-T651.
best_for: Thick, high-strength aerospace structure in the over-aged T74 or T7451 conditions, where high yield strength and good exfoliation resistance are needed
weakest_at: 'Weld zones: friction-stir welds of 7050-T7451 showed less cracking resistance than 7075-T651 welds in constant extension rate tests (2003 study)'
identity:
  formula: Al-Zn-Cu-Mg-Zr alloy, typical composition zinc 6.20, copper 2.30, magnesium 2.30 and zirconium 0.12 weight percent, aluminium the balance (Aubert and Duval)
  source: aubertduval-7050
  where: Composition box, typical values, Aubert and Duval 7050 datasheet
  designations:
    - system: UNS
      code: A97050
      source: aubertduval-7050
      where: Specifications box, UNS line
    - system: EN
      code: '3.4144'
      source: aubertduval-7050
      where: Specifications box, WL line
    - system: EN name
      code: EN AW-7050
      source: aubertduval-7050
      where: Specifications box, European Standards line
    - system: EN name
      code: AlZn6CuMgZr
      source: referansmetal-7050
      where: Product heading, AMS 4050 / AlZn6CuMgZr / 7050 / T7451
    - system: AMS
      code: '4050'
      note: plate, T7451
      source: alro-7050
      where: Specifications list, AMS 4050
tags:
  environments: []
  stresses: []
  applications:
    - structures
properties:
  - benchmark: density
    label: Density, AMS 4050 plate (7050-T7451)
    value: 2.83
    unit: g/cm3
    scope: material
    conditions:
      grade: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 (page heading)
      temperature: not stated
      unit_in_source: 2.83 g/cm³
    method: Value in a physical properties table of a distributor data page, with no test conditions stated
    status: ground
    source: referansmetal-7050
    where: Physical Properties table, row Density
  - benchmark: melting_point
    label: Melting point, AMS 4050 plate (7050-T7451)
    value: 490
    unit: °C
    scope: material
    conditions:
      grade: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 (page heading)
      unit_in_source: 490 °C
    method: Value in a physical properties table of a distributor data page
    status: ground
    source: referansmetal-7050
    where: Physical Properties table, row Melting Point
  - benchmark: elastic_modulus
    label: Modulus of elasticity at 20 °C, forged 7050 (typical)
    value: 71.5
    unit: GPa
    scope: material
    conditions:
      temperature: 20 °C
      form: forged product (datasheet covers closed-die forgings and large forged bars)
      unit_in_source: 71.5 x 10^3 N/mm2
    method: Typical value printed in a manufacturer datasheet, which states the values are typical or average rather than guaranteed
    status: ground
    source: aubertduval-7050
    where: Physical properties, Modulus of elasticity in N/mm2 at 20°C
  - benchmark: elastic_modulus
    label: Modulus of elasticity, AMS 4050 plate (7050-T7451)
    value: 71.7
    unit: GPa
    scope: material
    conditions:
      grade: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 (page heading)
      temperature: not stated
      unit_in_source: 71.7 GPa
    method: Value in a physical properties table of a distributor data page, with no test conditions stated
    status: ground
    source: referansmetal-7050
    where: Physical Properties table, row Modulus of Elasticity
  - benchmark: cte
    label: Mean coefficient of expansion, 20 to 100 °C, forged 7050 (typical)
    value: 23.5
    unit: ppm/K
    scope: material
    conditions:
      temperature: 20 to 100 °C (mean)
      form: forged product
      unit_in_source: 23.5 x 10-6 m/m.°C
    method: Typical value printed in a manufacturer datasheet
    status: ground
    source: aubertduval-7050
    where: Physical properties, Mean coefficient of expansion in m/m.°C, between 20°C and 100°C
  - benchmark: cte
    label: Thermal expansion, AMS 4050 plate (7050-T7451)
    value: 22.1
    unit: µm/m.°C
    scope: material
    conditions:
      grade: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 (page heading)
      temperature: not stated
      unit_in_source: 22.1 µm/m.°C
    method: Value in a physical properties table of a distributor data page, with no test conditions stated
    status: ground
    source: referansmetal-7050
    where: Physical Properties table, row Thermal Expansion
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 20 °C, forged 7050 in T76 condition (typical)
    value: 154
    unit: W/(m·K)
    scope: material
    conditions:
      temper: T76
      temperature: 20 °C
      form: forged product
      unit_in_source: W.m/m2.°C
    method: Typical value printed in a manufacturer datasheet
    status: ground
    source: aubertduval-7050
    where: Physical properties, Thermal conductivity at 20°C (T76 conditions)
  - benchmark: thermal_conductivity
    label: Thermal conductivity, AMS 4050 plate (7050-T7451)
    value: 157
    unit: W/(m·K)
    scope: material
    conditions:
      grade: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 (page heading)
      temperature: not stated
      unit_in_source: 157 W/m-K
    method: Value in a physical properties table of a distributor data page, with no test conditions stated
    status: ground
    source: referansmetal-7050
    where: Physical Properties table, row Thermal Conductivity
  - benchmark: specific_heat
    label: Mean specific heat, 0 to 100 °C, forged 7050 (typical)
    value: 0.86
    unit: J/g°C
    scope: material
    conditions:
      temperature: 0 to 100 °C (mean)
      form: forged product
      unit_in_source: J/g°C
    method: Typical value printed in a manufacturer datasheet
    status: ground
    source: aubertduval-7050
    where: Physical properties, Mean specific heat in J/g°C, between 0°C and 100°C
  - benchmark: electrical_conductivity
    label: Electrical conductivity at 20 °C, forged 7050 in T76 condition
    value: 23
    bound: lower
    unit: MS/m
    scope: material
    conditions:
      temper: T76
      temperature: 20 °C
      form: forged product
      unit_in_source: '>23 x 10^6 S/m'
    method: Typical value printed in a manufacturer datasheet, given as a lower bound
    status: ground
    source: aubertduval-7050
    where: Physical properties, Electrical conductivity in S/m at 20°C (T76 condition)
  - benchmark: yield_strength
    label: Yield strength Rp0.2, forged 7050 in T74, 100 to 125 mm, longitudinal
    value: 414
    bound: lower
    unit: MPa
    scope: material
    conditions:
      temper: T74 (over-aged)
      form: closed-die forging
      thickness: 100/125 mm
      direction: longitudinal
      temperature: ambient
      unit_in_source: '>414 N/mm2'
    method: Typical value printed in a manufacturer datasheet, given as a lower bound, not a guaranteed minimum
    status: ground
    source: aubertduval-7050
    where: Typical mechanical properties, closed-die forged T74 condition, 0.2 % yield strength
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, forged 7050 in T74, 100 to 125 mm, longitudinal
    value: 483
    bound: lower
    unit: MPa
    scope: material
    conditions:
      temper: T74 (over-aged)
      form: closed-die forging
      thickness: 100/125 mm
      direction: longitudinal
      temperature: ambient
      unit_in_source: '>483 N/mm2'
    method: Typical value printed in a manufacturer datasheet, given as a lower bound, not a guaranteed minimum
    status: ground
    source: aubertduval-7050
    where: Typical mechanical properties, closed-die forged T74 condition, UTS
  - benchmark: elongation
    label: Elongation (5d), forged 7050 in T74, 100 to 125 mm, longitudinal
    value: 7
    bound: lower
    unit: '%'
    scope: material
    conditions:
      temper: T74 (over-aged)
      form: closed-die forging
      thickness: 100/125 mm
      direction: longitudinal
      gauge_length: 5d
      unit_in_source: '>7 %'
    method: Typical value printed in a manufacturer datasheet, given as a lower bound
    status: ground
    source: aubertduval-7050
    where: Typical mechanical properties, closed-die forged T74 condition, Elongation (5d)
  - benchmark: yield_strength
    label: Yield strength Rp0.2, forged 7050 in T7452, 150 to 175 mm, longitudinal
    value: 400
    bound: lower
    unit: MPa
    scope: material
    conditions:
      temper: T7452 (stress relieved, over-aged)
      form: forged product
      thickness: 150/175 mm
      direction: longitudinal
      temperature: ambient
      unit_in_source: '>400 N/mm2'
    method: Typical value printed in a manufacturer datasheet, given as a lower bound, not a guaranteed minimum
    status: ground
    source: aubertduval-7050
    where: Typical mechanical properties, forged T7452 condition, 0.2 % yield strength
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, forged 7050 in T7452, 150 to 175 mm, longitudinal
    value: 469
    bound: lower
    unit: MPa
    scope: material
    conditions:
      temper: T7452 (stress relieved, over-aged)
      form: forged product
      thickness: 150/175 mm
      direction: longitudinal
      temperature: ambient
      unit_in_source: '>469 N/mm2'
    method: Typical value printed in a manufacturer datasheet, given as a lower bound, not a guaranteed minimum
    status: ground
    source: aubertduval-7050
    where: Typical mechanical properties, forged T7452 condition, UTS
  - benchmark: elongation
    label: Elongation (5d), forged 7050 in T7452, 150 to 175 mm, longitudinal
    value: 9
    bound: lower
    unit: '%'
    scope: material
    conditions:
      temper: T7452 (stress relieved, over-aged)
      form: forged product
      thickness: 150/175 mm
      direction: longitudinal
      gauge_length: 5d
      unit_in_source: '>9 %'
    method: Typical value printed in a manufacturer datasheet, given as a lower bound
    status: ground
    source: aubertduval-7050
    where: Typical mechanical properties, forged T7452 condition, Elongation (5d)
  - benchmark: fracture_toughness_k1c
    label: Fracture toughness K1c, forged 7050 in T74, L-T direction
    value: 27.5
    bound: lower
    unit: MPam
    scope: material
    conditions:
      temper: T74 (over-aged)
      form: closed-die forging
      direction: L-T
      unit_in_source: '>27.5 MPam'
    method: Typical value printed in a manufacturer datasheet, given as a lower bound. Custom property name, not in property-canon
    status: ground
    source: aubertduval-7050
    where: Typical mechanical properties, closed-die forged T74 condition, K1c (L-T direction)
  - benchmark: yield_strength
    label: Yield strength, plate 7050-T7451, 1.000 to 2.000 in, minimum
    value: 64
    bound: lower
    unit: ksi
    scope: material
    conditions:
      temper: T7451
      form: plate
      thickness: 1.000 to 2.000 in
      direction: longitudinal
      unit_in_source: 64.0 ksi (min.)
    method: Minimum value printed in a distributor datasheet, which describes the values as typical industry averages for reference
    status: ground
    source: alro-7050
    where: Typical Mechanical Properties table, row 7050-T7451 1.000 - 2.000, column Yield Strength (ksi)
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, plate 7050-T7451, 1.000 to 2.000 in, minimum
    value: 74
    bound: lower
    unit: ksi
    scope: material
    conditions:
      temper: T7451
      form: plate
      thickness: 1.000 to 2.000 in
      direction: longitudinal
      unit_in_source: 74.0 ksi (min.)
    method: Minimum value printed in a distributor datasheet, which describes the values as typical industry averages for reference
    status: ground
    source: alro-7050
    where: Typical Mechanical Properties table, row 7050-T7451 1.000 - 2.000, column Tensile Strength (ksi)
  - benchmark: elongation
    label: Elongation, plate 7050-T7451, 1.000 to 2.000 in, minimum
    value: 10
    bound: lower
    unit: '%'
    scope: material
    conditions:
      temper: T7451
      form: plate
      thickness: 1.000 to 2.000 in
      direction: longitudinal
      gauge_length: 2 in
      unit_in_source: 10%
    method: Minimum value printed in a distributor datasheet
    status: ground
    source: alro-7050
    where: Typical Mechanical Properties table, row 7050-T7451 1.000 - 2.000, column Elongation (% in 2 in)
  - benchmark: yield_strength
    label: Yield strength, plate 7050-T7451, 5.001 to 6.000 in, minimum
    value: 60
    bound: lower
    unit: ksi
    scope: material
    conditions:
      temper: T7451
      form: plate
      thickness: 5.001 to 6.000 in
      direction: longitudinal
      unit_in_source: 60.0 ksi (min.)
    method: Minimum value printed in a distributor datasheet, which describes the values as typical industry averages for reference
    status: ground
    source: alro-7050
    where: Typical Mechanical Properties table, row 7050-T7451 5.001 - 6.000, column Yield Strength (ksi)
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, plate 7050-T7451, 5.001 to 6.000 in, minimum
    value: 70
    bound: lower
    unit: ksi
    scope: material
    conditions:
      temper: T7451
      form: plate
      thickness: 5.001 to 6.000 in
      direction: longitudinal
      unit_in_source: 70.0 ksi (min.)
    method: Minimum value printed in a distributor datasheet, which describes the values as typical industry averages for reference
    status: ground
    source: alro-7050
    where: Typical Mechanical Properties table, row 7050-T7451 5.001 - 6.000, column Tensile Strength (ksi)
  - benchmark: elongation
    label: Elongation, plate 7050-T7451, 5.001 to 6.000 in, minimum
    value: 8
    bound: lower
    unit: '%'
    scope: material
    conditions:
      temper: T7451
      form: plate
      thickness: 5.001 to 6.000 in
      direction: longitudinal
      gauge_length: 2 in
      unit_in_source: 8%
    method: Minimum value printed in a distributor datasheet
    status: ground
    source: alro-7050
    where: Typical Mechanical Properties table, row 7050-T7451 5.001 - 6.000, column Elongation (% in 2 in)
  - benchmark: yield_strength
    label: Yield strength, AMS 4050 plate (7050-T7451)
    value: 479
    unit: MPa
    scope: material
    conditions:
      grade: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 (page heading)
      temperature: not stated
      thickness: not stated
      unit_in_source: 479 MPa
    method: Value in a mechanical properties table of a distributor data page, with no thickness, direction or test conditions stated
    status: ground
    source: referansmetal-7050
    where: Mechanical Properties table, row Yield Strength
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, AMS 4050 plate (7050-T7451)
    value: 540
    unit: MPa
    scope: material
    conditions:
      grade: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 (page heading)
      temperature: not stated
      thickness: not stated
      unit_in_source: 540 MPa
    method: Value in a mechanical properties table of a distributor data page, labelled Ultimate Strength, with no test conditions stated
    status: ground
    source: referansmetal-7050
    where: Mechanical Properties table, row Ultimate Strength
  - benchmark: elongation
    label: Elongation A50 mm, AMS 4050 plate (7050-T7451)
    value: 11
    unit: '%'
    scope: material
    conditions:
      grade: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 (page heading)
      gauge_length: A50 mm
      unit_in_source: 11%
    method: Value in a mechanical properties table of a distributor data page, with no thickness or direction stated
    status: ground
    source: referansmetal-7050
    where: Mechanical Properties table, row Elongation A50 mm
corrosion:
  - environment: Exfoliation (layered corrosion) of over-aged plate and forgings
    headline: Aubert and Duval name the over-aged T76 temper as particularly resistant to exfoliation corrosion.
    effect: Aubert and Duval say the over-aged T76 condition is particularly resistant to exfoliation corrosion. Alro says the T7451 plate temper has better exfoliation resistance than standard high-strength alloys. Neither gives a rating or test result.
    rating: low
    conditions:
      basis: manufacturer and distributor claims, no test data
      temper: T76 and T7451
    source: aubertduval-7050
    where: Characteristics section
  - environment: 3.5 % NaCl solution, stress corrosion cracking
    headline: In 3.5 % NaCl, 7050-T7451 was slightly more sensitive to stress corrosion cracking than 7475-T7351, and the difference was not significant.
    effect: A 2018 Korean study found 7475-T7351 slightly less sensitive to stress corrosion cracking than 7050-T7451 and 7140-T7451. The difference was not significant in either anodic dissolution or hydrogen embrittlement conditions. No threshold stress or time to failure is given in the abstract.
    rating: moderate
    conditions:
      solution: 3.5 % NaCl
      basis: laboratory SCC study, abstract only read
    source: kjmm2018
    where: Abstract
  - environment: Friction-stir welded joints in a chloride environment
    headline: Friction-stir welds of 7050-T7451 cracked more readily than welds of 7075-T651, although the parent 7050-T7451 metal was the more resistant of the two.
    effect: In a 2003 constant extension rate test, 7075-T651 friction-stir welds showed better cracking resistance than 7050-T7451 welds. The 7075-T651 parent metal was less resistant than 7050-T7451 parent metal, so the ranking reverses at the weld. In 7050-T7451 the TMAZ-nugget boundary was the most susceptible zone to corrosion.
    rating: moderate
    conditions:
      process: friction stir welding
      test: constant extension rate test (CERT)
      environment: chloride solution (as in the study)
    source: buchheit2003
    where: Abstract
risks:
  hazards:
    - text: 'Russel Metals safety data sheet for aluminium alloys (dated 15 April 2019, a generic sheet that is not written for 7050): the solid alloy is treated as an article and is not hazardous in solid form, but cutting, milling, grinding, melting and welding can emit hazardous dust and fume. The sheet classifies emitted products as flammable solid category 1 (chips or powder), carcinogenicity category 2, respiratory sensitiser category 1, toxic to reproduction category 1B, specific target organ toxicity repeated exposure category 1 and skin sensitiser category 1, with signal word Warning.'
      ghs: []
      source: russel-sds-2019
      where: Section 2, Hazardous ingredients, classification table
    - text: Dust from grinding can burn if ignited, and aluminium chips, dust and fines in contact with water can generate flammable hydrogen gas. The sheet names Class D extinguishing agents or sand for dust and chip fires.
      ghs: []
      source: russel-sds-2019
      where: Fire-fighting section, specific hazards arising from the material, and reactivity section, conditions to avoid
  failure_risks:
    - mode: Stress corrosion cracking of friction-stir welds
      trigger: Friction stir welding of 7050-T7451 followed by exposure to a chloride environment
      consequence: In a 2003 constant extension rate test, weld zones cracked more readily than 7075-T651 welds, and the TMAZ-nugget boundary was the most susceptible zone in 7050-T7451. The study does not give a time to failure or a design allowance.
      severity: moderate
      source: buchheit2003
      where: Abstract
    - mode: Lower minimum strength in thicker plate
      trigger: Plate of 7050-T7451 above 1 in thick, in the longitudinal direction
      consequence: The distributor minimum yield strength falls from 64.0 ksi for 1.000 to 2.000 in plate to 60.0 ksi for 5.001 to 6.000 in plate, and the minimum elongation falls from 10 % to 8 %. Designs should use the minimum for the actual thickness.
      severity: low
      source: alro-7050
      where: Typical Mechanical Properties table, rows 7050-T7451 1.000 - 2.000 and 5.001 - 6.000
  side_effects: []
  handling:
    - text: Where local ventilation and vacuum systems collect aluminium dust and fines, use explosion-proof systems, and do not let dust accumulate. Avoid generating dust when cutting or grinding.
      source: russel-sds-2019
      where: Handling and storage section, and exposure controls section (engineering controls)
    - text: The ACGIH threshold limit value for aluminium dust is 1 mg/m3 as a respirable TWA, and the sheet advises a respirator (dust and fume) when grinding or welding if limits are exceeded.
      source: russel-sds-2019
      where: Exposure controls section, control parameters table, row Aluminum, and respirator entry
  mitigations: []
uses:
  - application: structures
    device: Aircraft fuselage frames, bulkheads and wing skins
    example: Alro lists aerospace fuselage frames, wing skins and bulkheads among the typical applications of 7050 plate. Aubert and Duval sell closed-die forgings and large forged bars for the aerospace industry, designed for structural parts under high fatigue stress and corrosion risk.
    source: alro-7050
    where: Typical Applications list; Aubert and Duval datasheet, Applications box
  - application: structures
    device: Spacecraft structural plate
    example: Alro lists spacecraft among the typical applications of 7050-T7451 plate and says the plate is ideal for military, space and mobile equipment markets. This is a distributor statement. No flight record for a specific spacecraft was found in this run.
    source: alro-7050
    where: Typical Applications list and product introduction text
  - application: structures
    device: Commercial aerospace structure
    example: Wikipedia describes 7050 as a commercial aerospace alloy, with applications listed as aircraft structures, fuselage frames, bulkheads, wing skins and military aircraft. Wikipedia is used here for the application list only.
    source: wikipedia-7050
    where: Lead paragraph and Applications section
supply:
  - subject: Aluminium metal, primary smelter production (2025 estimate, all 7050 alloying elements not covered)
    producers:
      - country: China
        share_percent: 60.8
        year: 2025
      - country: India
        share_percent: 5.7
        year: 2025
      - country: Russia
        share_percent: 5.3
        year: 2025
      - country: Canada
        share_percent: 4.5
        year: 2025
      - country: United Arab Emirates
        share_percent: 3.6
        year: 2025
    critical_lists: []
    recycling: 'USGS: in 2025 aluminium recovered from purchased scrap in the United States was about 3.6 million tons, of which about 56 % came from new scrap and 44 % from old scrap. Aluminium recovered from old scrap equalled about 28 % of apparent consumption.'
    substitutes:
      - 'USGS: composites can substitute for aluminium in aircraft fuselages and wings, and composites, magnesium, steel and titanium can substitute for aluminium in ground transportation.'
    source: usgs-mcs2026-aluminum
    where: World Smelter Production and Capacity table, column 2025e (shares calculated by Space Mushroom from the world total of 74,000 thousand t, for China 45,000, India 4,200, Russia 3,900, Canada 3,300 and United Arab Emirates 2,700); Domestic Production and Use and Recycling paragraphs; Substitutes paragraph
documents:
  - title: 'Aubert and Duval datasheet: aluminium alloy 7050 (Al Zn6CuMgZr)'
    type: datasheet
    url: https://aubertduval.com/wp-content/uploads/2024/12/7050_GB.pdf
  - title: 'Alro Steel datasheet: 7050 aluminum plate, AMS 4050, T7451'
    type: datasheet
    url: https://www.alro.com/Resources/WebResources/AlroCom/Literature/PDFs/356%20-%207050-Aluminum-Plate.pdf
    year: 2025
  - title: 'Referansmetal data page: AMS 4050 / AlZn6CuMgZr / 7050 / T7451 plate'
    type: datasheet
    url: https://www.referansmetal.com/alasimli-aluminyum/product/58/uzay-havacilik-savunma/levha-plaka/ams-4050-alzn6cumgzr-7050-t7451?lang=en
  - title: 'SA Materials: Description of Aluminum Alloy 7050 (UNS A97050) Plate/Sheet'
    type: datasheet
    url: https://samaterials.com/aluminum/2147-aluminum-alloy-7050-plate-sheet.html
  - title: 'Wikipedia: 7050 aluminium alloy'
    type: database
    url: https://en.wikipedia.org/wiki/7050_aluminium_alloy
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Aluminum'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf
    year: 2026
  - title: 'Russel Metals safety data sheet: Aluminum alloys (dated 15 April 2019)'
    type: sds
    url: https://www.russelmetals.com/wp-content/uploads/sds-aluminum-alloys.pdf
    year: 2019
  - title: Buchheit and Paglia, Localized corrosion and stress corrosion cracking of friction stir welded 7075 and 7050, Corrosion and Protection of Light Metal Alloys, pp. 94-103
    type: paper
    url: https://scholars.uky.edu/en/publications/localized-corrosion-and-stress-corrosion-cracking-of-friction-sti/
    year: 2003
  - title: Lee et al., Resistance to Stress Corrosion Cracking of High-Strength 7xxx Series Aluminum Alloys in 3.5% NaCl Solution, KJMM 56(10), 708-717
    type: paper
    url: https://kjmm.org/kjmm/ArticleDetail/RD_R/445858
    year: 2018
gaps:
  - No flight record for a specific spacecraft or rocket using 7050 was found in this run. The spacecraft use rests on a distributor list (Alro) and is recorded as such.
  - 'The AMS 4050 specification itself was not read: the SAE page returned HTTP 403. AMS 4050 is named only on the Alro and Referansmetal pages, so the code is recorded from those.'
  - The AMS 4201, BMS 7-323 and DMS-2233 designations appeared only in search snippets and were not printed on a page read in this run, so they are not recorded.
  - Plate values from the Alro page are minimums printed as typical industry averages. The Referansmetal plate values (density, modulus, thermal conductivity, yield, tensile, elongation) have no thickness, direction or test condition printed, so they are marked as such.
  - No property value for a specific temper gives electrical resistivity. Referansmetal prints 35 % IACS with no conditions, and Aubert and Duval prints an electrical resistivity whose unit is garbled in the PDF text, so neither is entered.
  - Fracture toughness K1c is not in property-canon, so it is recorded under a custom name, fracture_toughness_k1c.
  - No 7050-specific safety data sheet was read. The Central Steel aluminium alloy SDS returned HTTP 403, so the hazard entries come from the generic Russel Metals aluminium alloy sheet and are not 7050 classifications.
  - The USGS Aluminum summary read in this run has no critical-minerals list, so critical_lists is left empty. Supply of zinc, magnesium, copper and zirconium, the other main alloying elements, was not looked up.
  - Atmospheric corrosion rates, EXCO or ASTM G34 exfoliation ratings, and SCC threshold stresses for 7050 were not found in any page read. The exfoliation claims are manufacturer and distributor statements.
  - 'The two composition limit tables disagree on titanium: SA Materials gives a maximum, and Referansmetal gives a range (0.08 to 0.21 %). Both are kept in the recipe text, and the Aubert and Duval datasheet gives no titanium value.'
  - Weldability other than the friction-stir weld data, formability and machinability were not established from a fetched page, so they are not recorded.
  - Wikipedia values for density (2.6 to 2.8 g/cm3), melting point (494 C), tensile (515 MPa), yield (455 MPa), elongation (11 %), modulus (70 to 80 GPa) and thermal conductivity (180 W/mK) have no conditions and are not used as property values.
  - No environment tag is recorded, since no source describes 7050 in low Earth orbit, lunar or launch environments.
sources:
  aubertduval-7050:
    title: Aubert and Duval, Aluminium alloy 7050 (Al Zn6CuMgZr), product datasheet
    id: UNS A97050; EN AW-7050 (Al Zn6CuMgZr); WL 3.4144
    url: https://aubertduval.com/wp-content/uploads/2024/12/7050_GB.pdf
    kind: datasheet
    license: Manufacturer datasheet, typical values (cited, not reproduced)
  alro-7050:
    title: Alro Steel, 7050 Aluminum Plate datasheet, August 2025
    id: AMS 4050; ASTM B594; AMS 2154
    url: https://www.alro.com/Resources/WebResources/AlroCom/Literature/PDFs/356%20-%207050-Aluminum-Plate.pdf
    year: 2025
    kind: datasheet
    license: Distributor datasheet (cited, not reproduced)
  referansmetal-7050:
    title: Referansmetal data page, AMS 4050 / AlZn6CuMgZr / 7050 / T7451 plate
    url: https://www.referansmetal.com/alasimli-aluminyum/product/58/uzay-havacilik-savunma/levha-plaka/ams-4050-alzn6cumgzr-7050-t7451?lang=en
    kind: web
    license: Distributor web page (cited, not reproduced)
  samaterials-7050:
    title: SA Materials, Description of Aluminum Alloy 7050 (UNS A97050) Plate/Sheet
    id: UNS A97050
    url: https://samaterials.com/aluminum/2147-aluminum-alloy-7050-plate-sheet.html
    kind: web
    license: Supplier web page (cited, not reproduced)
  wikipedia-7050:
    title: Wikipedia, 7050 aluminium alloy
    url: https://en.wikipedia.org/wiki/7050_aluminium_alloy
    year: 2026
    kind: web
    license: CC BY-SA (cited, not reproduced)
  usgs-mcs2026-aluminum:
    title: Mineral Commodity Summaries 2026, Aluminum (USGS)
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf
    year: 2026
    kind: report
    license: Public domain (USGS)
  russel-sds-2019:
    title: 'Russel Metals, Safety Data Sheet: Aluminum alloys (generic), dated 15 April 2019'
    url: https://www.russelmetals.com/wp-content/uploads/sds-aluminum-alloys.pdf
    year: 2019
    kind: datasheet
    license: Supplier safety data sheet (cited, not reproduced)
  buchheit2003:
    title: Buchheit and Paglia, Localized corrosion and stress corrosion cracking of friction stir welded 7075 and 7050, Corrosion and Protection of Light Metal Alloys
    id: Proceedings, Orlando FL, 12-17 October 2003, pp. 94-103
    url: https://scholars.uky.edu/en/publications/localized-corrosion-and-stress-corrosion-cracking-of-friction-sti/
    year: 2003
    kind: paper
    license: Conference abstract (cited, not reproduced)
  kjmm2018:
    title: Lee, Choi, Ahn, Lee and Kim, Resistance to Stress Corrosion Cracking of High-Strength 7xxx Series Aluminum Alloys in 3.5% NaCl Solution, KJMM 56(10), 708-717
    url: https://kjmm.org/kjmm/ArticleDetail/RD_R/445858
    year: 2018
    kind: paper
    license: Journal abstract (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 26
  unreachable: 2
  caveats: 5
  note: 'Values were read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry. Unreachable: the SAE AMS 4050 page and the Central Steel SDS (both HTTP 403). Caveats: the Aubert and Duval values are typical, not guaranteed; the Alro plate values are minimums printed as typical industry averages; the Referansmetal values have no conditions printed; the hazard entries come from a generic aluminium alloy sheet, not 7050; the SCC and weld results come from a 2003 conference abstract and a 2018 abstract.'
story:
  risk_groups:
    - title: For people
      lead: The solid alloy is an article and is not hazardous as a bar or plate. The hazard comes from dust and fume made while the metal is machined, ground, melted or welded.
      level: 1
      verdict: Hazard in processing, not in solid form
      points:
        - label: The solid alloy
          line: The Russel Metals sheet treats aluminium alloy as an article and not hazardous in solid form. Its GHS classes apply to the fume and dust produced in processing, not to the bar or plate.
        - label: Dust and fume
          line: Grinding and welding produce dust and fume that can irritate the eyes, skin and airways, and heated aluminium can cause metal fume fever. The sheet gives an ACGIH threshold limit value of 1 mg/m3 for aluminium dust.
    - title: If it fails
      lead: The failure routes found in the sources concern the weld zone and thick sections. The exfoliation claims are manufacturer statements, and no test data were found.
      points:
        - label: Weld zones
          line: In a 2003 constant extension rate test, friction-stir welds of 7050-T7451 cracked more readily than welds of 7075-T651, and the TMAZ-nugget boundary was the most susceptible zone.
        - label: Thick plate
          line: The distributor minimum yield strength falls from 64.0 ksi for 1 to 2 in plate to 60.0 ksi for 5 to 6 in plate.
        - label: Dust fire
          line: Dust from grinding can burn if ignited, and fines in contact with water release hydrogen.
    - title: Handling and storage
      points:
        - label: Keep dust down
          line: Use explosion-proof dust extraction where dust is collected, and avoid letting dust build up.
        - label: Temper choice
          line: Name the temper on every order. The over-aged T74, T76 and T7451 tempers are the ones the sources tie to exfoliation resistance.
  why: AA7050 is chosen for thick, high-strength aerospace structure. Its typical forged T74 properties are above 414 MPa yield and above 483 MPa tensile, and its over-aged tempers are named as resistant to exfoliation corrosion. Aerospace suppliers list it for fuselage frames, wing skins and bulkheads, and the Alro datasheet also lists spacecraft as a typical application. The alloy's main weakness is in the weld zone.
  uses:
    - where: Aircraft structure
      line: Fuselage frames, bulkheads and wing skins are the typical aerospace applications listed by Alro. Aubert and Duval sell closed-die forgings and large forged bars for aerospace structure.
    - where: Spacecraft
      line: Alro lists spacecraft among the typical applications of 7050-T7451 plate. No specific spacecraft flight record was found in this run, so this is a supplier claim.
    - where: Commercial aerospace
      line: Wikipedia describes 7050 as a commercial aerospace alloy and lists aircraft structures, fuselage frames, bulkheads and wing skins, and military aircraft among its applications.
  can_do:
    - label: Carry load
      value: 414 MPa yield (forged T74)
      benchmark: yield_strength
      line: In the T74 condition, forged stock at 100 to 125 mm has a typical yield strength above 414 MPa and a tensile strength above 483 MPa, with 7 % elongation. The plate minimum in T7451 is 64.0 ksi yield for 1 to 2 in thickness.
    - label: Light for its strength
      value: 2.83 g/cm3
      benchmark: density
      line: The AMS 4050 plate density is 2.83 g/cm3 on the Referansmetal page, with no conditions printed.
    - label: Stiffness
      value: 71.5 GPa
      benchmark: elastic_modulus
      line: The modulus of elasticity at 20 °C is 71.5 GPa in the Aubert and Duval datasheet. Referansmetal gives 71.7 GPa for the plate.
    - label: Heat conduction
      value: 154 W/(m·K)
      benchmark: thermal_conductivity
      line: Thermal conductivity at 20 °C is 154 W/(m·K) in the T76 forged condition, and 157 W/(m·K) on the Referansmetal plate page.
    - label: Fracture toughness
      value: above 27.5 MPam
      benchmark: fracture_toughness_k1c
      line: The typical K1c for forged T74 in the L-T direction is above 27.5 MPam in the Aubert and Duval datasheet.
  compare: The USGS summary lists composites as a substitute for aluminium in aircraft fuselages and wings, and composites, magnesium, steel and titanium in ground transport. The rows below give AA7050 plate and forging values from the sources read here. They are examples, not a ranking, because the sources use different tempers, forms and conditions.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Modulus of elasticity
      benchmark: elastic_modulus
    - label: Yield strength
      benchmark: yield_strength
  recipe:
    line: AA7050 is an aluminium alloy of zinc, copper and magnesium with a small addition of zirconium. The typical composition from Aubert and Duval is zinc 6.20, copper 2.30, magnesium 2.30 and zirconium 0.12 weight percent, with aluminium the balance. The composition limit tables from SA Materials and Referansmetal are cited in the sources, and they differ on titanium.It is solution heat treated at 475 °C, water quenched, and aged between 100 and 180 °C, with the over-aged T74 and T76 conditions the most common (Aubert and Duval).
    parts:
      - name: Aluminium
        symbol: Al
        role: The base metal. The balance by weight after the alloying elements, per the typical composition (Aubert and Duval).
      - name: Zinc
        symbol: Zn
        share_percent: 6.2
        role: Alloying element. Typical value from Aubert and Duval; limits in the SA Materials table.
      - name: Copper
        symbol: Cu
        share_percent: 2.3
        role: Alloying element. Typical value from Aubert and Duval; limits in the SA Materials table.
      - name: Magnesium
        symbol: Mg
        share_percent: 2.3
        role: Alloying element. Typical value from Aubert and Duval; limits in the SA Materials table.
      - name: Zirconium
        symbol: Zr
        share_percent: 0.12
        role: Alloying element. Typical value from Aubert and Duval; limits in the SA Materials table.
  handling:
    - Name the temper on every order, since the strength values belong to a specific temper and form.
    - Cut and grind with dust extraction, and keep chips and fines away from water.
    - 'Weld with care: in the 2003 study the TMAZ-nugget boundary of 7050-T7451 friction-stir welds was the most corrosion-susceptible zone.'
  good_for:
    - 'High strength in thick aerospace structure: typical forged T74 yield above 414 MPa and tensile above 483 MPa (Aubert and Duval).'
    - Exfoliation resistance in the over-aged tempers, as the manufacturer and distributor say.
    - 'Recycling: about 3.6 million tons of aluminium was recovered from purchased scrap in the United States in 2025 (USGS).'
  watch_out:
    - Friction-stir welds of 7050-T7451 cracked more readily than 7075-T651 welds in one 2003 study.
    - 'Strength falls with thickness in plate: the minimum yield strength is 64.0 ksi at 1 to 2 in and 60.0 ksi at 5 to 6 in (Alro).'
    - Most of the strength values come from datasheets and distributor pages, not from a standard. Check AMS 4050 for design values.
    - No spacecraft flight record was found for this alloy in this run.
    - China produced about 60.8 % of world primary aluminium in 2025 by the USGS estimate, so supply is concentrated.
  verdict: AA7050 is a high-strength aerospace aluminium for thick structure, with typical forged T74 yield above 414 MPa and plate minimum yield of 64.0 ksi in T7451. Its exfoliation resistance rests on manufacturer and distributor claims, and its friction-stir welds are its weak point in a 2003 corrosion study. The spacecraft use is a supplier claim, and the values need checking against AMS 4050 before design.