spore: profile
id: magnesium-aj62
spore_version: 0.2
family: magnesium-alloys
name: Magnesium alloy AJ62
abbreviation: AJ62
role: die-cast structural alloy
category: metals
type: magnesium
summary: |
  AJ62 is a die-casting magnesium alloy with about 6 wt% aluminium, 2 to 2.5 wt% strontium and about 0.35 wt% manganese. Its strontium gives it creep resistance at temperatures up to about 150 to 175 °C, and the alloy is known for castability and hot-tear resistance. A 2007 rheo-diecasting study measured as-cast tensile strength of 225 to 244 MPa and elongation of 7 to 9 %, and 258 MPa and 12 % after a 2 h anneal at 450 °C. The main gap is corrosion: the only corrosion study read here is qualitative, and no density, melting range or thermal property was read from a page in this run.
best_for: Die-cast engine and power-train parts that run warm, such as crankcases, transmission cases and oil pans, where creep resistance and castability matter more than the highest strength (the sources name these uses)
weakest_at: Corrosion data are qualitative only (no corrosion rate read for AJ62), and the strength figures come from one 2007 study of one melt rather than a supplier datasheet
identity:
  formula: 'Die-casting alloy, Mg-Al-Sr-Mn: Mg balance, Al 6.3, Sr 2.5, Mn 0.36 wt% (composition of the commercial AJ62 supplied by Magnesium Elektron, Wang et al. 2007); a 2007 sand-cast study measured Al 6.1, Mn 0.34, Sr 2.1 wt%; the Wikipedia nominal is Mg-6Al-2Sr'
  designations:
    - system: Name
      code: AJ62
      source: wikipedia-aj-alloys
      where: AJ alloys table, AJ62 row (Mg Balance, Al 6, Sr 2, Mn 0.34)
  source: wang-2007-rdc-aj62
  where: 'Section 2 (Experimental): composition Mg-6.3Al-2.5Sr-0.36Mn; the 2007 sand-cast study (mse-aj62-2007) prints Table 1 with Al 6.1, Mn 0.34, Sr 2.1'
tags:
  environments: []
  applications:
    - structures
properties:
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, HPDC as cast (F condition)
    value: 225.3
    unit: MPa
    scope: material
    conditions:
      temper: F (as cast, high-pressure die cast)
      process: high-pressure die casting (HPDC), same alloy lot as the rheo-diecast samples
      spread: ± 11.3 MPa (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row HPDC (F condition), this work, UTS column
  - benchmark: yield_strength
    label: Yield strength, HPDC as cast (F condition)
    value: 123.5
    unit: MPa
    scope: material
    conditions:
      temper: F (as cast, high-pressure die cast)
      process: high-pressure die casting (HPDC)
      spread: ± 4.0 MPa (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row HPDC (F condition), this work, Yield Strength column
  - benchmark: elongation
    label: Elongation, HPDC as cast (F condition)
    value: 7.43
    unit: '%'
    scope: material
    conditions:
      temper: F (as cast, high-pressure die cast)
      process: high-pressure die casting (HPDC)
      spread: ± 1.49 % (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row HPDC (F condition), this work, Elongation column
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, rheo-diecast as cast (F condition)
    value: 243.9
    unit: MPa
    scope: material
    conditions:
      temper: F (as cast, rheo-diecast)
      process: semisolid rheo-diecasting (RDC), one-step process from the BCAST group
      spread: ± 10.4 MPa (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row RDC (F condition), this work, UTS column
  - benchmark: yield_strength
    label: Yield strength, rheo-diecast as cast (F condition)
    value: 129.8
    unit: MPa
    scope: material
    conditions:
      temper: F (as cast, rheo-diecast)
      process: semisolid rheo-diecasting (RDC)
      spread: ± 3.4 MPa (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row RDC (F condition), this work, Yield Strength column
  - benchmark: elongation
    label: Elongation, rheo-diecast as cast (F condition)
    value: 9.05
    unit: '%'
    scope: material
    conditions:
      temper: F (as cast, rheo-diecast)
      process: semisolid rheo-diecasting (RDC)
      spread: ± 1.01 % (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row RDC (F condition), this work, Elongation column
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, rheo-diecast after heat treatment (2 h at 450 °C)
    value: 257.6
    unit: MPa
    scope: material
    conditions:
      temper: heat treated, 2 h at 450 °C after rheo-diecasting (the paper's row label is "Heat treated")
      process: semisolid rheo-diecasting (RDC)
      spread: ± 7.7 MPa (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row RDC (Heat treated, 2 hrs at 450 °C), UTS column
  - benchmark: yield_strength
    label: Yield strength, rheo-diecast after heat treatment (2 h at 450 °C)
    value: 121.4
    unit: MPa
    scope: material
    conditions:
      temper: heat treated, 2 h at 450 °C after rheo-diecasting
      process: semisolid rheo-diecasting (RDC)
      spread: ± 5.2 MPa (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row RDC (Heat treated, 2 hrs at 450 °C), Yield Strength column
  - benchmark: elongation
    label: Elongation, rheo-diecast after heat treatment (2 h at 450 °C)
    value: 12.01
    unit: '%'
    scope: material
    conditions:
      temper: heat treated, 2 h at 450 °C after rheo-diecasting
      process: semisolid rheo-diecasting (RDC)
      spread: ± 1.06 % (printed as mean ± standard deviation)
      temperature: not stated
    method: Tensile tests on standard test samples in an Instron machine (authors' own runs, this work)
    status: ground
    source: wang-2007-rdc-aj62
    where: Table 1, row RDC (Heat treated, 2 hrs at 450 °C), Elongation column
  - benchmark: fluidity_spiral_length
    label: Fluidity, sand-cast spiral test, pour at 695 °C
    value: 38
    unit: cm
    scope: material
    conditions:
      pour_temperature: 695 °C
      mould: sand (spiral test)
    method: Spiral fluidity test, sand mould, flow length read from the spiral casting (not a standard property; snake_case name used, see gaps)
    status: ground
    source: mse-aj62-2007
    where: 'Fig. 4 caption: Fluidity length is equal 38 cm (pouring from 695 °C)'
    note: Not in spores/property-canon.yaml; the snake_case name fluidity_spiral_length is used.
  - benchmark: fluidity_spiral_length
    label: Fluidity, sand-cast spiral test, pour at 755 °C
    value: 57
    unit: cm
    scope: material
    conditions:
      pour_temperature: 755 °C
      mould: sand (spiral test)
    method: Spiral fluidity test, sand mould, flow length read from the spiral casting (not a standard property; snake_case name used, see gaps)
    status: ground
    source: mse-aj62-2007
    where: 'Fig. 5 caption: Fluidity length is equal 57 cm (pouring from 755 °C); text says flow length rises with pouring temperature'
    note: Not in spores/property-canon.yaml; the snake_case name fluidity_spiral_length is used.
corrosion:
  - environment: Salt solutions and engine coolant, potentiodynamic polarization (permanent-mould cast AJ62, fine- and coarse-grained sections)
    headline: Fine-grained AJ62 resisted corrosion better than coarse-grained AJ62 in the same test.
    effect: The abstract says the permanent-mould cast AJ62 has a fine-grained thin section and a coarse-grained thick section, and that the fine-grained alloy shows enhanced corrosion resistance in the salt solutions and engine coolant tested. The abstract gives no corrosion rate, and the full text was not open, so no number is given here.
    rating: unknown
    conditions:
      method: potentiodynamic polarization (electrochemical), not immersion mass loss
      solutions: salt solutions and engine coolant (named in the abstract; concentrations not in the abstract)
    source: li-aj62-amm-2015
    where: Abstract (Scientific.net record, Applied Mechanics and Materials Vol. 865, pp. 9-14)
risks:
  hazards: []
  failure_risks:
    - mode: Heat-treatment coarsening of the eutectic
      trigger: Annealing at 450 °C (the rheo-diecast study used 2 h at 450 °C, and tested up to 12 h)
      consequence: The Al4Sr eutectic lamellae break up, spheroidise and coarsen; the study reports little change in hardness up to 12 h at 450 °C, while elongation rose to 12.01 %.
      severity: low
      source: wang-2007-rdc-aj62
      where: Abstract; Section 3.3 and Table 1
  side_effects: []
  handling: []
  mitigations: []
uses:
  - application: structures
    device: Automotive engine crankcase and power-train components
    example: The 2007 sand-cast study says AJ62 is typically used in the automotive industry for engine crankcase and power-train components.
    source: mse-aj62-2007
    where: Abstract (Purpose)
  - application: structures
    device: Transmission cases and oil pans (named for AJ62x, the variant the SAE paper describes)
    example: The SAE paper says that AJ62x, which it describes as the most recent formulation with about 6 % Al and 2 % Sr, is positioned for transmission cases and oil pans.
    source: pekguleryuz-saeaj62x-2003
    where: Abstract
  - application: structures
    device: Magnesium-aluminium composite engine block (BMW)
    example: Wikipedia says AJ52 and AJ62 are both used in the BMW magnesium-aluminium composite engine block.
    source: wikipedia-aj-alloys
    where: Last paragraph of the article
supply:
  - subject: Magnesium (the base metal), world primary smelter production
    abundance: 'USGS: resources for magnesium range from large to virtually unlimited and are globally widespread; magnesium-bearing brines are estimated to be a resource in the billions of tons.'
    producers:
      - country: China
        share_percent: 87.7
        year: 2025
      - country: Russia
        share_percent: 5.5
        year: 2025
      - country: Brazil
        share_percent: 1.8
        year: 2025
      - country: Israel
        share_percent: 1.8
        year: 2025
      - country: Turkey
        share_percent: 1.4
        year: 2025
    recycling: 'USGS: in 2025 about 26,000 tons of secondary magnesium was recovered from old scrap and 82,000 tons from new scrap (United States figures).'
    substitutes:
      - 'USGS: aluminium and zinc may substitute for magnesium in castings and wrought products; magnesium''s light weight is an advantage over them in most applications, but its high cost is a disadvantage.'
    source: usgs-mcs2026-magnesium-metal
    where: World Primary Production and Reserves table, 2025 column (shares calculated by Space Mushroom against the 1,083 thousand t sum of the listed countries, as for AZ31B; world total printed as 1,100 rounded); Recycling; Substitutes
documents:
  - title: 'Wang, Liu, Wang and Fan: Microstructural characterisation and thermal stability of an Mg-Al-Sr alloy prepared by rheo-diecasting (Proc. 5th Decennial Int. Conf. on Solidification Processing, Sheffield, 2007)'
    type: paper
    url: https://bura.brunel.ac.uk/bitstream/2438/2682/1/18-sp07-2.pdf
    year: 2007
  - title: 'Archives of Materials Science and Engineering, vol. 28, issue 6 (2007): AJ62 casting temperature, fluidity and structure (Wayback copy of the PDF)'
    type: paper
    url: https://web.archive.org/web/2011/http://www.archivesmse.org/vol28_6/2865.pdf
    year: 2007
  - title: 'Pekguleryuz, Labelle and Argo: Magnesium Die Casting Alloy AJ62x with Superior Creep Resistance, Ductility and Die Castability (SAE 2003-01-0190)'
    type: paper
    url: https://saemobilus.sae.org/content/2003-01-0190/
    year: 2003
  - title: Corrosion Behaviors of Permanent Mold Cast Mg Alloy AJ62 with Varying Grain Structures in Automotive-Related Environments (Applied Mechanics and Materials, vol. 865)
    type: paper
    url: https://www.scientific.net/AMM.865.9
    year: 2015
  - title: 'USGS Mineral Commodity Summaries 2026: Magnesium Metal'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-magnesium-metal.pdf
    year: 2026
gaps:
  - No density, melting range, specific heat, thermal conductivity, thermal expansion or elastic modulus for AJ62 was found in a page read in this run. Search snippets for these were not used.
  - No AJ62 creep numbers were read. The SAE 2003 abstract gives only qualitative creep performance (150 to 175 °C, 50 to 70 MPa). The 2020 Journal of Magnesium and Alloys creep paper on AJ62 (DOI 10.1016/j.jma.2020.03.001) was blocked by a bot check on ScienceDirect.
  - No AJ62 corrosion rate was read. The 2015 Applied Mechanics and Materials abstract is qualitative and the full text needs institutional access. Chloride immersion data for AJ62 were not found.
  - No safety data sheet or PubChem GHS entry for AJ62 or for magnesium was read in this run (PubChem returned a browser check). risks.hazards is therefore empty. Search results on general magnesium and aluminium SDSs were not used as values.
  - No UNS, ASTM, AMS or EN designation for AJ62 was found on a page read in this run. The ASTM B951 codification practice was only seen in search results. Variants AJ62x and AJ62Lx are different grades and are not listed as designations.
  - Strontium and aluminium supply (USGS) were not read in this run, and the magnesium critical-mineral listing was not checked in this run.
  - Failure modes other than heat-treatment coarsening (for example creep failure in service or fatigue) were not found in a source read in this run.
  - Fluidity is a sand-cast spiral test, not a standard property; it is kept under the snake_case name fluidity_spiral_length and is not compared with other alloys.
sources:
  wang-2007-rdc-aj62:
    title: Microstructural characterisation and thermal stability of an Mg-Al-Sr alloy prepared by rheo-diecasting (Wang, Liu, Wang, Fan; BCAST, Brunel University)
    id: Proc. 5th Decennial International Conference on Solidification Processing, Sheffield, July 2007, pp. 603 onward
    url: https://bura.brunel.ac.uk/bitstream/2438/2682/1/18-sp07-2.pdf
    year: 2007
    kind: paper
    license: Brunel University repository copy, cited and not reproduced
  mse-aj62-2007:
    title: 'AJ62 magnesium alloy: influence of pouring temperature on fluidity and structure (Archives of Materials Science and Engineering, vol. 28, issue 6)'
    id: Archives of Materials Science and Engineering 28(6), June 2007
    url: https://web.archive.org/web/2011/http://www.archivesmse.org/vol28_6/2865.pdf
    year: 2007
    kind: paper
    license: Journal copy (Wayback), cited and not reproduced
  pekguleryuz-saeaj62x-2003:
    title: Magnesium Die Casting Alloy AJ62x with Superior Creep Resistance, Ductility and Die Castability (SAE 2003-01-0190)
    id: DOI 10.4271/2003-01-0190; Pekguleryuz, Labelle and Argo, Noranda Inc.
    url: https://saemobilus.sae.org/content/2003-01-0190/
    year: 2003
    kind: paper
    license: SAE abstract page read, cited and not reproduced
  li-aj62-amm-2015:
    title: Corrosion Behaviors of Permanent Mold Cast Mg Alloy AJ62 with Varying Grain Structures in Automotive-Related Environments
    id: Applied Mechanics and Materials Vol. 865 (Trans Tech Publications)
    url: https://www.scientific.net/AMM.865.9
    year: 2015
    kind: paper
    license: Scientific.net abstract page read, cited and not reproduced
  wikipedia-aj-alloys:
    title: 'Wikipedia: AJ alloys (composition table, AJ62 row; BMW engine block)'
    url: https://en.wikipedia.org/wiki/AJ_alloys
    kind: web
    license: CC BY-SA (Wikipedia), cited for composition and uses only
  usgs-mcs2026-magnesium-metal:
    title: 'USGS Mineral Commodity Summaries 2026: Magnesium Metal'
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-magnesium-metal.pdf
    year: 2026
    kind: report
    license: US Government work, public domain
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 11
  unreachable: 4
  caveats: 6
  note: 'Written 2026-10-26 from pages fetched in this run. 11 values are sourced: 9 tensile values from one 2007 table (HPDC and rheo-diecast, as cast and heat treated), 2 fluidity values from one 2007 paper. Four pages were blocked (ScienceDirect, PubChem, a Springer record and a DOI redirect). Density and thermal properties were not found.'
story:
  recipe:
    line: AJ62 is a magnesium alloy with about 6 wt% aluminium, 2 to 2.5 wt% strontium and about 0.35 wt% manganese. The strontium forms Al4Sr eutectic lamellae, and the 2007 study also found other intermetallic particles in the as-cast structure. The commercial alloy studied in 2007 was made by semisolid rheo-diecasting, and it was also cast by high-pressure die casting for comparison.
    parts:
      - name: Magnesium
        symbol: Mg
        share_note: balance (the rest)
        role: The base metal and the balance of the alloy.
        source: wang-2007-rdc-aj62
        where: Section 2 (composition Mg-6.3Al-2.5Sr-0.36Mn)
      - name: Aluminium
        symbol: Al
        share_percent: 6.3
        share_note: 6.1 wt% in the 2007 sand-cast analysis (mse-aj62-2007); about 6 wt% nominal (Wikipedia)
        role: Main alloying addition; forms the Al4Sr and Mg-Al-Sr phases and sets the solid solution.
        source: wang-2007-rdc-aj62
        where: Section 2 (composition)
      - name: Strontium
        symbol: Sr
        share_percent: 2.5
        share_note: 2.1 wt% in the 2007 sand-cast analysis; about 2 wt% nominal (Wikipedia)
        role: Creep-resistance addition. It forms the Al4Sr eutectic, which the study says is extremely stable up to 450 °C.
        source: wang-2007-rdc-aj62
        where: Section 2 (composition); Discussion of heat treatment, before Section 3.3
      - name: Manganese
        symbol: Mn
        share_percent: 0.36
        share_note: 0.34 wt% in the 2007 sand-cast analysis and on Wikipedia
        role: Minor addition. It forms Al8Mn5 particles, found in the as-cast structure.
        source: mse-aj62-2007
        where: Table 1 (chemical composition); Findings in abstract
  risk_groups:
    - title: For people
      lead: No safety data sheet or hazard classification for AJ62 was read in this run, so no hazard statement is given here.
      points: []
    - title: If it fails
      lead: The sources read here give little failure data for AJ62 in service.
      points:
        - label: Heat treatment
          line: Annealing at 450 °C coarsens the Al4Sr eutectic. The study reports little change in hardness up to 12 h at 450 °C, and tensile elongation rose from 9.05 % to 12.01 % after 2 h.
        - label: Corrosion
          line: The one corrosion study read here is qualitative. It reports that a fine-grained AJ62 casting resisted corrosion better than a coarse-grained one in salt solutions and engine coolant.
  why: 'AJ62 is a die-casting magnesium alloy whose strontium gives it creep resistance at engine temperatures and good castability. Its strength is modest: as-cast tensile strength is about 225 to 244 MPa in the 2007 study. What it offers is light weight and creep resistance at 150 to 175 °C, which is the reason the sources name engine and transmission parts as its uses.'
  uses:
    - where: Engine crankcases and power-train parts
      line: The 2007 sand-cast study says AJ62 is typically used in the automotive industry for engine crankcases and power-train components.
    - where: Transmission cases and oil pans
      line: The SAE paper of 2003 positions AJ62x, the variant it describes, for transmission cases and oil pans.
    - where: Engine block (with AJ52)
      line: Wikipedia says that AJ52 and AJ62 are both used in the BMW magnesium-aluminium composite engine block.
  can_do:
    - label: Creep at temperature
      line: The SAE abstract says Mg-Al-Sr alloys show superior creep performance at 150 to 175 °C and stress levels of 50 to 70 MPa. The number is qualitative in the abstract; no creep rate for AJ62 was read.
    - label: Castability
      line: In a sand-cast spiral test the flow length rose from 38 cm at 695 °C to 57 cm at 755 °C (2007 study).
    - label: Heat treatment
      value: 257.6 MPa
      line: After 2 h at 450 °C, the rheo-diecast alloy reached 257.6 MPa tensile strength and 12.01 % elongation, against 243.9 MPa and 9.05 % as cast.
  compare: AJ62 is compared here only with its own process variants. The 2007 study found that rheo-diecasting gave higher strength and much higher ductility than high-pressure die casting of the same alloy (9.05 % against 7.43 % elongation as cast). No other magnesium alloy was compared with AJ62 in a source read in this run.
  compare_rows:
    - label: Tensile strength, as cast
      benchmark: ultimate_tensile_strength
    - label: Yield strength, as cast
      benchmark: yield_strength
    - label: Elongation, as cast
      benchmark: elongation
  handling:
    - Read a supplier safety data sheet before machining. No AJ62 SDS was read in this run, and magnesium alloy chips and fines are flammable.
    - Keep it away from chloride solutions. The one corrosion source read here is qualitative, so no rate is given.
  good_for:
    - Warm engine and power-train castings. The sources name crankcases, transmission cases and oil pans.
    - Thin-walled die castings where castability matters. The 2007 study says AJ62 offers good castability and the SAE paper reports hot-tear resistance.
  watch_out:
    - 'Strength is modest: 225 to 244 MPa as cast in the 2007 study, with a yield strength of 123.5 to 129.8 MPa.'
    - Corrosion data are qualitative only. No AJ62 corrosion rate was read.
    - Creep figures are qualitative in the abstract; no creep rate or stress exponent was read from a page in this run.
  verdict: AJ62 is a creep-resistant die-casting magnesium alloy that the sources name for engine and transmission parts. The strength and elongation figures come from one 2007 study, and the properties a designer needs most (density, thermal and corrosion rates) were not found in a page read in this run.