Ti-6Al-2Sn-4Zr-2Mo (Ti-6242) Ti-6242

spore: profile
id: titanium-6al-2sn-4zr-2mo
spore_version: 0.2
family: titanium-alloys
name: Ti-6Al-2Sn-4Zr-2Mo (Ti-6242)
abbreviation: Ti-6242
role: creep-resistant near-alpha structural alloy for hot forged parts
category: metals
type: titanium
summary: Ti-6Al-2Sn-4Zr-2Mo, also called Ti-6242 and listed under UNS R54620, is a near-alpha titanium alloy for hot forged parts. Rickard Metals prints a density of 0.164 lbs/cubic inch and a minimum yield strength of 827 MPa at 0.2% offset, based on AMS 4975. Its printed weak point is hot salt stress corrosion cracking, which the supplier says proper processing can minimize.
best_for: Hot forged parts that must resist creep, such as turbine engine discs, blades and impellers (Rickard Metals)
weakest_at: Hot salt stress corrosion cracking, which the supplier says the alloy is sometimes susceptible to; no test numbers are printed
identity:
  formula: 'Ti-6Al-2Sn-4Zr-2Mo: titanium with aluminium 5.5 to 6.5 %, tin 1.8 to 2.2 %, zirconium 3.6 to 4.4 % and molybdenum 1.8 to 2.2 % (Titanium Industries, Table 1)'
  source: titanium-com
  where: Table 1, Chemical Composition. Rickard Metals prints the same ranges without units. Oxygen is printed as 0.15 % maximum by Titanium Industries and as 0.12 max by Rickard Metals; the two are not reconciled here.
  designations:
    - system: UNS
      code: R54620
      source: rickard
      where: Standard Specifications list, UNS column
    - system: AMS
      code: '4975'
      source: rickard
      where: Standard Specifications list; also the basis of the Mechanical Properties table
    - system: AMS
      code: '4919'
      source: rickard
      where: Standard Specifications list
    - system: EN
      code: '3.7145'
      source: rickard
      where: Standard Specifications list, Werkstoff 3.7145
    - system: EN
      code: '3.71450'
      source: rickard
      where: Standard Specifications list, EN 3.71450
    - system: Trade name
      code: TIMETAL 6242
      source: timet-plate
      where: 'Products text: higher-performance alloys like TIMETAL 6242'
tags:
  environments: []
  stresses:
    - extreme-heat
  applications:
    - propulsion-and-tanks
    - structures
    - mechanisms
properties:
  - benchmark: density
    label: Density of Ti-6Al-2Sn-4Zr-2Mo, as printed by Rickard Metals
    value: 0.164
    unit: lb/in3
    scope: material
    conditions:
      grade: Ti-6Al-2Sn-4Zr-2Mo (UNS R54620)
      temperature: not stated
      unit_in_source: 0.164 lbs/cubic inch
    method: Value printed on a supplier product page under Additional Information, Physical Properties. The page gives no test temperature. The same number appears in the Titanium Industries table with no unit, so that copy is not recorded.
    status: ground
    source: rickard
    where: 'Additional Information, Physical Properties: Density row'
  - benchmark: melting_point
    label: Melting point, Ti-6Al-2Sn-4Zr-2Mo
    value: 3101
    unit: °F
    scope: material
    conditions:
      grade: Ti-6Al-2Sn-4Zr-2Mo (R54620)
      pressure: not stated
      unit_in_source: 3101 °F
    method: Single value printed in the physical properties table of a supplier alloy page; no test method is stated
    status: ground
    source: titanium-com
    where: Physical properties table, row Melting Point (°F)
  - benchmark: thermal_conductivity
    label: Thermal conductivity, Ti-6Al-2Sn-4Zr-2Mo
    value: 48.6
    unit: BTU-in/hr-ft²-°F
    scope: material
    conditions:
      grade: Ti-6Al-2Sn-4Zr-2Mo (R54620)
      temperature: not stated
      unit_in_source: 48.6 BTU-in/hr-ft²-°F
    method: Value printed in the physical properties table of a supplier alloy page; no temperature is printed
    status: ground
    source: titanium-com
    where: Physical properties table, row Thermal conductivity (BTU-in/hr-ft²-°F)
  - benchmark: cte
    label: Coefficient of thermal expansion, room temperature to 600 F
    value: 5.2
    unit: in/in-F x 10-6
    scope: material
    conditions:
      temperature_range: 'room temperature to 600F (as printed: RT to 600F)'
      unit_in_source: 5.2 microinch/inch/degree F
    method: Printed on a supplier product page under Additional Information, Physical Properties. The printed unit microinch/inch/degree F is written here as in/in-F x 10-6, which is the same unit.
    status: ground
    note: Titanium Industries prints a different thermal expansion figure for the same property, in 1/°F. It is not recorded here because the site unit table does not convert that unit correctly yet.
    source: rickard
    where: 'Additional Information, Physical Properties: Coefficient of Expansion row'
  - benchmark: elastic_modulus
    label: Modulus of elasticity, Ti-6Al-2Sn-4Zr-2Mo (Titanium Industries)
    value: 17100
    unit: ksi
    scope: material
    conditions:
      grade: Ti-6Al-2Sn-4Zr-2Mo (R54620)
      temperature: not stated
      unit_in_source: 17100 ksi
    method: Value printed in the mechanical properties table of a supplier alloy page, under a header giving ksi; no test temperature is stated
    status: ground
    note: Rickard Metals prints 16 msi for the same property. The two suppliers do not agree, and neither value is averaged here.
    source: titanium-com
    where: Table 3, Mechanical Properties, row Modulus of Elasticity (ksi) (E)
  - benchmark: elastic_modulus
    label: Modulus of elasticity, Ti-6Al-2Sn-4Zr-2Mo (Rickard Metals)
    value: 16
    unit: msi
    scope: material
    conditions:
      grade: Ti-6Al-2Sn-4Zr-2Mo
      temperature: not stated
      unit_in_source: 16 msi
    method: 'Printed on a supplier product page as Modulus of Elasticity: 16 msi, with no test temperature'
    status: ground
    note: Titanium Industries prints 17100 ksi for the same property; see the other modulus row.
    source: rickard
    where: 'Additional Information, Physical Properties: Modulus of Elasticity row'
  - benchmark: yield_strength
    label: Minimum yield strength Rp0.2, based on AMS 4975
    value: 827
    bound: lower
    unit: MPa
    scope: material
    conditions:
      basis: minimum tensile property, based on AMS 4975
      offset: 0.2%
      unit_in_source: 120 ksi (827 MPa)
      product_form: not stated in the table
    method: Minimum value printed on a supplier product page under Mechanical Properties (Based on AMS 4975), Minimum Tensile Properties
    status: ground
    source: rickard
    where: 'Mechanical Properties (Based on AMS 4975), Minimum Tensile Properties: Yield Strength at 0.2% Offset'
  - benchmark: ultimate_tensile_strength
    label: Minimum ultimate tensile strength, based on AMS 4975
    value: 896
    bound: lower
    unit: MPa
    scope: material
    conditions:
      basis: minimum tensile property, based on AMS 4975
      unit_in_source: 130 ksi (896 MPa)
      product_form: not stated in the table
    method: Minimum value printed on a supplier product page under Mechanical Properties (Based on AMS 4975), Minimum Tensile Properties
    status: ground
    source: rickard
    where: 'Mechanical Properties (Based on AMS 4975), Minimum Tensile Properties: Tensile Strength'
  - benchmark: elongation
    label: Minimum elongation in 4D, based on AMS 4975
    value: 10
    bound: lower
    unit: '%'
    scope: material
    conditions:
      basis: minimum tensile property, based on AMS 4975
      gauge: 4D
      unit_in_source: 10%
    method: Minimum value printed on a supplier product page under Mechanical Properties (Based on AMS 4975), Minimum Tensile Properties
    status: ground
    source: rickard
    where: 'Mechanical Properties (Based on AMS 4975), Minimum Tensile Properties: Elongation in 4D'
  - benchmark: reduction_of_area
    label: Minimum reduction of area, based on AMS 4975
    value: 25
    bound: lower
    unit: '%'
    scope: material
    conditions:
      basis: minimum tensile property, based on AMS 4975
      unit_in_source: 25%
    method: Minimum value printed on a supplier product page under Mechanical Properties (Based on AMS 4975), Minimum Tensile Properties. Not a canonical property name; snake_case used, see gaps.
    status: ground
    source: rickard
    where: 'Mechanical Properties (Based on AMS 4975), Minimum Tensile Properties: Reduction of Area'
  - benchmark: elongation
    label: Maximum elongation, gauge AL=5 x D (Titanium Industries)
    value: 13
    bound: upper
    unit: '%'
    scope: material
    conditions:
      gauge: AL=5 x D (printed AL=5 x Ø)
      basis: Maximum column of the table
      temperature: not stated
    method: Maximum value printed in the mechanical properties table of a supplier alloy page; no test condition is printed. Different gauge from the Rickard 4D minimum.
    status: ground
    source: titanium-com
    where: Table 3, Mechanical Properties, row Elongation (AL=5 x Ø), Maximum column
  - benchmark: yield_strength
    label: Maximum yield strength range Rp 0.2 offset (Titanium Industries)
    value: 152
    bound: upper
    unit: ksi
    scope: material
    conditions:
      basis: Maximum column of the table
      offset: 0.2%
      temperature: not stated
    method: Maximum value printed in the mechanical properties table of a supplier alloy page; no product form or test condition is printed
    status: ground
    source: titanium-com
    where: Table 3, Mechanical Properties, row Yield Strength Range (Rp 0.2 Offset) (ksi), Maximum column
  - benchmark: ultimate_tensile_strength
    label: Maximum tensile strength range Rm (Titanium Industries)
    value: 161
    bound: upper
    unit: ksi
    scope: material
    conditions:
      basis: Maximum column of the table
      temperature: not stated
    method: Maximum value printed in the mechanical properties table of a supplier alloy page; no product form or test condition is printed
    status: ground
    source: titanium-com
    where: Table 3, Mechanical Properties, row Tensile Strength Range (Rm) (ksi), Maximum column
  - benchmark: beta_transus
    label: Beta transus (approximate, as printed)
    value: 1770
    value_high: 1790
    bound: range
    unit: °F
    scope: material
    conditions:
      basis: printed as approximately 1770F to 1790F with a tilde
      use: reference temperature for solution annealing bar and forgings
    method: Range printed on a supplier product page in the Heat Treatment section. Not a canonical property name; snake_case used, see gaps.
    status: ground
    source: rickard
    where: Heat Treatment section, first paragraph (bar and forgings)
corrosion:
  - environment: General corrosion in service
    headline: Corrosion resistance is printed as generally excellent.
    effect: The supplier describes corrosion resistance of Ti-6Al-2Sn-4Zr-2Mo as generally excellent. No corrosion rate or test data are printed on the page.
    rating: low
    conditions:
      basis: supplier qualitative statement; no test data
      form: not stated
    source: rickard
    where: Corrosion Resistance section
  - environment: Hot salt at elevated temperature
    headline: Hot salt stress corrosion cracking is the printed weak point of this alloy.
    effect: The supplier says the alloy is sometimes susceptible to hot salt stress corrosion cracking and that the risk can be minimized with proper processing. No test temperature, salt chemistry or stress level is printed.
    rating: moderate
    conditions:
      basis: supplier qualitative statement
      test: not stated
    source: rickard
    where: Corrosion Resistance section
risks:
  hazards:
    - text: PubChem's record for titanium metal (the element, not this alloy) lists the GHS hazard statement as 'Not Classified' in its ECHA C&L summary, and notes that the record may vary with impurities and form. Its DOT entry for titanium powder wetted with water lists 'UN1352' and 'Div 4.1 Flammable solid'.
      ghs: []
      source: pubchem-ti
      where: GHS Classification section; 12.1.3 DOT Hazard Classification
    - text: PubChem says titanium powder 'can be easily ignited and burns with an intense flame', and lists titanium as 'Pyrophoric in dust form' in its air and water reactions notes. Treat fine titanium powder and dust as a fire hazard. These statements are about the element and its powder, not the forged alloy.
      ghs: []
      source: pubchem-ti
      where: Physical Description; 12.8.1 Air and Water Reactions
    - text: NASA White Sands tests on commercially pure titanium Grade 2 rods found that the burning rate rose as rod diameter fell and as pressure and oxygen concentration rose. Ti-6242 was not tested in this paper.
      ghs: []
      source: ntrs-ti-burn
      where: Abstract
  failure_risks:
    - mode: Hot salt stress corrosion cracking
      trigger: Exposure to hot salt in service, as named by the supplier
      consequence: The supplier says the alloy is sometimes susceptible; it says the risk can be minimized with proper processing. No test numbers are printed.
      severity: moderate
      source: rickard
      where: Corrosion Resistance section
    - mode: Oxygen enriched layer (alpha case) on forgings
      trigger: Surface of forgings before use
      consequence: The supplier says all alpha cases, which it describes as a hard, brittle, oxygen enriched layer, must be removed before use.
      severity: moderate
      source: rickard
      where: Forgings text, Heat Treatment section
    - mode: Burning in an oxygen enriched gas
      trigger: Ignition of titanium in an oxygen enriched atmosphere; tested on commercially pure Grade 2 rods
      consequence: NASA's tests found the burning rate rises as diameter decreases and as pressure and oxygen concentration increase. This was not measured for Ti-6242.
      severity: high
      source: ntrs-ti-burn
      where: Abstract
  side_effects: []
  handling:
    - text: Weldability is printed as moderate. The supplier recommends a filler metal for fusion welding, complete inert gas shielding, and post weld thermal processing.
      source: rickard
      where: Welding section
    - text: Forming is printed as difficult. For severe forming the supplier recommends forming at elevated temperatures.
      source: rickard
      where: Forming section
    - text: 'Heat treatment as printed for bar and forgings: alpha beta solution annealed at ''25F-50F below the beta transus (~1770F – 1790F) for 1 hour'', then air cooled, then a precipitation heat treat at ''1100 F for 8 hours''. Sheet, strip and plate follow other times and temperatures.'
      source: rickard
      where: Heat Treatment section
    - text: The supplier says alloy data on its page is for reference only, not for design.
      source: titanium-com
      where: Text below the Table 3 mechanical properties
  mitigations:
    - text: The supplier says the hot salt stress corrosion cracking risk can be minimized with proper processing; the page does not say which processing.
      source: rickard
      where: Corrosion Resistance section
uses:
  - application: propulsion-and-tanks
    device: Turbine engine discs, blades and impellers
    example: Rickard Metals says the alloy is most commonly used in the engineering of 'aircraft and turbine engines (discs, blades, and impellers)'.
    source: rickard
    where: Introduction paragraph
  - application: structures
    device: Airframe parts and hot airframe sections
    example: Titanium Industries lists sheet metal parts in afterburners and hot airframe sections among typical uses, and says the alloy is normally used in the intermediate compressor stages of turbine engines for disks, blades, seals and other airframe parts.
    source: titanium-com
    where: Forms, specifications and uses paragraph
  - application: mechanisms
    device: High-performance automotive valves
    example: Both Rickard Metals and Titanium Industries list high performance automotive valves among typical uses.
    source: rickard
    where: Introduction paragraph
supply:
  - subject: Titanium sponge metal, world production
    abundance: not stated in the USGS summary read for this profile
    producers:
      - country: China
        share_percent: 70.3
        year: 2025
      - country: Japan
        share_percent: 14.3
        year: 2025
      - country: Russia
        share_percent: 6.8
        year: 2025
      - country: Kazakhstan
        share_percent: 4.3
        year: 2025
      - country: Saudi Arabia
        share_percent: 3.2
        year: 2025
    critical_lists: []
    recycling: 'USGS: U.S. imports of titanium waste and scrap were an estimated 32,000 tons in 2025. A company in Virginia began commercial production of titanium powder from titanium scrap metal in late 2024.'
    substitutes:
      - 'USGS: few materials possess titanium metal''s strength-to-weight ratio and corrosion resistance; in high-strength applications titanium competes with aluminum, composites, intermetallics, steel and superalloys.'
    source: usgs-mcs2026-titanium
    where: World Sponge Metal Production table, 2025e column (world total 370,000 tons; China 260,000, Japan 53,000, Russia 25,000, Kazakhstan 16,000, Saudi Arabia 12,000). Shares calculated by Space Mushroom from those tonnages. Events, Trends, and Issues; Substitutes.
  - subject: Titanium sponge metal imports to the United States
    abundance: U.S. net import reliance printed as 100 for 2025e, apparent consumption basis
    producers:
      - country: Japan
        share_percent: 73
        year: 2025
      - country: Kazakhstan
        share_percent: 13
        year: 2025
      - country: Saudi Arabia
        share_percent: 13
        year: 2025
    critical_lists: []
    recycling: The USGS says the United States did not produce titanium sponge metal in 2025, and its last domestic sponge plant closed in 2024.
    substitutes: []
    source: usgs-mcs2026-titanium
    where: Events, Trends, and Issues (import sources through July 2025); Import Sources (2021 to 2024); Salient Statistics, net import reliance row
documents:
  - title: 'Titanium Industries alloy page: Titanium 6Al-2SN-4ZR-2MO (R54620)'
    type: datasheet
    url: https://titanium.com/alloys/titanium-and-titanium-alloys/ti-6al-2sn-4zr-2mo/
  - title: 'Rickard Metals: Ti-6Al-2Sn-4Zr-2Mo titanium alloy (Ti 6-2-4-2) product page'
    type: datasheet
    url: https://rickardmetals.com/product/ti-6al-2sn-4zr-2mo-titanium-alloy/
  - title: TIMET plate products page (lists TIMETAL 6242)
    type: datasheet
    url: https://www.timet.com/products/plate.html
  - title: 'USGS Mineral Commodity Summaries 2026: Titanium and Titanium Dioxide'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
    year: 2026
  - title: 'PubChem compound record: Titanium (CID 23963)'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Titanium
    year: 2026
  - title: 'Stoltzfus, Jeffers and Gallus: Burning of CP Titanium (Grade 2) in Oxygen-Enriched Atmospheres (NASA NTRS 20120002982)'
    type: paper
    url: https://ntrs.nasa.gov/citations/20120002982
    year: 2012
  - title: 'Wikipedia: Titanium alloy (near-alpha class and examples)'
    type: database
    url: https://en.wikipedia.org/wiki/Titanium_alloy
    year: 2026
  - title: 'Wikipedia: Titanium (extraction, Kroll process)'
    type: database
    url: https://en.wikipedia.org/wiki/Titanium
    year: 2026
gaps:
  - No AMS 4975 or AMS 4919 specification text was opened. The AMS numbers are recorded only as the Rickard Metals page prints them; the minimum tensile values are that page's figures based on AMS 4975.
  - Rickard Metals also prints DIN 3.7164 for this grade. It is not recorded because no page read in this run confirms that number for Ti-6242.
  - Room temperature tensile data by product form (bar, forgings, sheet, plate) were not found. The strengths here are minimums with no product form printed, and they are not reconciled with the Titanium Industries maxima.
  - No elevated temperature tensile, creep or stress rupture numbers for Ti-6242 were found on any page opened. The creep statements rest on supplier wording only. The planning brief's service limit of about 540 C was not confirmed by any page opened, so it is not stated.
  - Fatigue, fracture toughness, hot salt test results, and corrosion rates in salt water or moist air were not found on any page opened.
  - Brinell hardness (318, printed on Titanium Industries with no unit) is not recorded because its unit is not printed. Rockwell C values from Rickard Metals (HRC 39 max, typical HRC 34 to 36) are not recorded as properties because the property list has no hardness row for that scale.
  - The Titanium Industries thermal expansion figure (printed in 1/°F) is not recorded. The site unit table does not convert that unit correctly at present, so the Rickard figure is the only one recorded.
  - Oxygen content differs between suppliers (0.15 % maximum from Titanium Industries, 0.12 max from Rickard Metals). Both are printed; neither is reconciled.
  - Reduction of area and beta transus are recorded under snake_case names (reduction_of_area, beta_transus) because the canonical property list has no entry for them.
  - No flight, space environment, outgassing, atomic oxygen, radiation or cryogenic data for Ti-6242 were found. The sources cover terrestrial turbine, airframe and automotive use, so no space mission use is stated.
  - 'Feedstock: titanium ore and its concentrate route were not read; the USGS titanium mineral concentrates chapter was not opened. The recipe covers sponge and alloying only.'
  - The USGS summary read for this profile does not state the critical minerals status of titanium, so critical_lists is left empty.
  - PubChem data for pure titanium (density, melting point, autoignition) describe the element, not this alloy, so none are recorded as Ti-6242 values. No Ti-6242 safety data sheet was found.
  - Wikipedia was used only for the near-alpha class, the list of example alloys, and the Kroll process. No numbers were taken from it.
sources:
  titanium-com:
    title: Titanium 6Al-2SN-4ZR-2MO (R54620), Titanium Industries alloy page
    id: UNS R54620 (printed in the page title)
    url: https://titanium.com/alloys/titanium-and-titanium-alloys/ti-6al-2sn-4zr-2mo/
    kind: datasheet
    license: Supplier web page; alloy data stated as for reference only (cited, not reproduced)
  rickard:
    title: Ti-6Al-2Sn-4Zr-2Mo titanium alloy (Ti 6-2-4-2), Rickard Metals product page
    id: UNS R54620; AMS 4919, AMS 4975, AMS 4976, AMS 4979, AMS T 9047
    url: https://rickardmetals.com/product/ti-6al-2sn-4zr-2mo-titanium-alloy/
    kind: datasheet
    license: Supplier web page (cited, not reproduced)
  timet-plate:
    title: TIMET plate products page
    url: https://www.timet.com/products/plate.html
    kind: web
    license: Supplier web page (cited, not reproduced)
  usgs-mcs2026-titanium:
    title: 'Mineral Commodity Summaries 2026: Titanium and Titanium Dioxide'
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  pubchem-ti:
    title: 'PubChem compound record: Titanium (CID 23963), including ECHA C&L and DOT entries'
    id: CID 23963
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Titanium
    year: 2026
    kind: database
    license: public domain (NCBI); sections attributed to ECHA, CAMEO, CRC and others
  ntrs-ti-burn:
    title: Burning of CP Titanium (Grade 2) in Oxygen-Enriched Atmospheres, Stoltzfus, Jeffers and Gallus, NASA White Sands Test Facility (JSC-CN-25709)
    id: NTRS 20120002982
    url: https://ntrs.nasa.gov/citations/20120002982
    year: 2012
    kind: paper
    license: public domain (NASA)
  wikipedia-titanium-alloy:
    title: Titanium alloy, Wikipedia
    url: https://en.wikipedia.org/wiki/Titanium_alloy
    year: 2026
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  wikipedia-titanium:
    title: Titanium, Wikipedia
    url: https://en.wikipedia.org/wiki/Titanium
    year: 2026
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 14
  unreachable: 0
  caveats: 4
  note: 'Values were read by an AI assistant on 2026-11-01 from the supplier pages named in each row (raw page text confirmed for both supplier pages; USGS text extracted from the PDF; PubChem read in the browser). Caveats: the minimum strengths are one supplier''s figures based on AMS 4975 with no product form printed; the two modulus values disagree; the two thermal expansion figures disagree and only one is recorded; the reduction of area and beta transus rows use snake_case names.'
story:
  why: Ti-6Al-2Sn-4Zr-2Mo, also called Ti-6242 and listed under UNS R54620, is a near-alpha titanium alloy that suppliers sell for hot forged parts. Creep is slow deformation under steady load at high temperature, and Rickard Metals says this alloy has exceptional creep resistance. Its density is printed as 0.164 lbs/cubic inch, and its minimum yield strength is 827 MPa at 0.2% offset, based on AMS 4975. Rickard Metals says it is most commonly used for discs, blades and impellers in aircraft and turbine engines. Titanium Industries also lists airframe parts and high performance automotive valves.
  uses:
    - where: Turbine engines
      line: Rickard Metals says the alloy is most commonly used for discs, blades and impellers in aircraft and turbine engines.
    - where: Airframe and hot sections
      line: Titanium Industries lists sheet metal parts in afterburners and hot airframe sections among typical uses.
    - where: Automotive valves
      line: Both suppliers list high performance automotive valves as a use.
  can_do:
    - label: Strength
      line: The minimum tensile strength is printed as 896 MPa, and the minimum yield strength at 0.2% offset as 827 MPa, both based on AMS 4975 (Rickard Metals).
      benchmark: yield_strength
      value: 827 MPa
    - label: Stiffness
      line: The modulus of elasticity is printed as 17100 ksi by Titanium Industries and as 16 msi by Rickard Metals. The two suppliers do not agree.
      benchmark: elastic_modulus
      value: 17100 ksi and 16 msi
    - label: Heat
      line: The melting point is printed as 3101 °F by Titanium Industries.
      benchmark: melting_point
      value: 3101 °F
    - label: Weight
      line: Density is printed as 0.164 lbs/cubic inch by Rickard Metals.
      benchmark: density
      value: 0.164 lbs/cubic inch
  compare: Titanium Industries says Ti-6242 can be heat treated to higher strengths in larger section sizes than Ti-6Al-4V Grade 5, and that forged material shows greater strength, ductility and a good combination of low-cycle fatigue and fatigue-crack growth resistance. No Ti-6Al-4V figure from the same source was opened for this profile, so the table rows below are each alloy's own printed values and are not a ranking. Wikipedia lists Ti-6Al-2Sn-4Zr-2Mo among near-alpha alloys.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Minimum yield strength
      benchmark: yield_strength
    - label: Modulus of elasticity
      benchmark: elastic_modulus
  handling:
    - Specify the product form and heat treatment, because the supplier prints different routes for bar and forgings, sheet and strip, and plate.
    - Remove the alpha case from forgings before use, as the supplier advises.
    - Use filler metal and complete inert gas shielding for fusion welding, and plan post weld thermal processing.
    - Control hot salt exposure through processing, since hot salt stress corrosion cracking is the printed weak point.
  good_for:
    - Hot forged parts where creep resistance matters, such as turbine engine discs, blades and impellers (Rickard Metals).
    - Forged parts, where Titanium Industries says forged material shows greater strength, ductility and a good combination of low-cycle fatigue and fatigue-crack growth resistance.
    - Larger sections that need higher strength after heat treatment than Ti-6Al-4V (Titanium Industries).
  watch_out:
    - 'Stiffness data disagree between suppliers: 17100 ksi on one page and 16 msi on the other.'
    - 'Thermal expansion: Rickard Metals prints 5.2 microinch/inch/degree F from room temperature to 600F; the other supplier''s figure is not recorded here.'
    - Hot salt stress corrosion cracking is the printed weak point, and no test numbers are printed for it.
    - No flight, outgassing, atomic oxygen or radiation data for this alloy were found.
  verdict: Ti-6242 is a creep-resistant near-alpha titanium alloy for hot forged parts, with a printed minimum yield strength of 827 MPa. Its named weak points are hot salt stress corrosion cracking and the need for careful forging and welding. This profile holds no space flight data for it.
  risk_groups:
    - title: For people
      lead: The sources describe the metal as not classified under GHS, and describe fire risk for titanium powder and dust. None of these statements is a test of the forged alloy.
      level: 1
      verdict: Fine powder burns; alloy not GHS-classed
      points:
        - label: Metal as supplied
          line: PubChem lists the GHS hazard statement for titanium metal as Not Classified in its ECHA summary. That is for the element, not this alloy.
        - label: Powder and dust
          line: PubChem says titanium powder can be easily ignited and burns with an intense flame, and that it is pyrophoric in dust form.
    - title: If it fails
      lead: These are failure routes the sources describe. Most are qualitative supplier statements, not test results for this alloy.
      level: 2
      verdict: Hot salt cracking is the named weak point
      points:
        - label: Hot salt
          line: The supplier says the alloy is sometimes susceptible to hot salt stress corrosion cracking, and that proper processing can minimize the risk. No test numbers are printed.
        - label: Oxygen enriched gas
          line: NASA tests on commercially pure Grade 2 titanium rods found that burning speeds up as rod diameter falls and as pressure and oxygen concentration rise. Ti-6242 was not tested in that paper.
        - label: Forging surface
          line: The supplier says the hard, brittle, oxygen enriched layer on forgings must be removed before use.
    - title: Handling and storage
      points:
        - label: Heat treatment
          line: 'The supplier prints a bar and forgings route: solution annealing at ''25F-50F below the beta transus'', then a precipitation heat treat at ''1100 F for 8 hours''.'
        - label: Welding and forming
          line: Welding is printed as moderate, with filler metal and inert gas shielding. Forming is printed as difficult, and the supplier recommends elevated temperature forming for severe shapes.
  recipe:
    line: Ti-6Al-2Sn-4Zr-2Mo is titanium alloyed with aluminium, tin, zirconium and molybdenum, in the near-alpha class (Wikipedia). Titanium metal is extracted by reducing titanium tetrachloride with molten magnesium in an argon atmosphere, the Kroll process, which gives a porous titanium sponge (Wikipedia). Rickard Metals prints the product forms it supplies, including bar, forgings, sheet, plate, extrusion, billet and ingot, and gives the heat treatment routes for each form.
    parts:
      - name: Titanium
        symbol: Ti
        role: Base metal; the balance of the alloy
        share_note: balance (the rest), as the composition table implies
        source: titanium-com
        where: Table 1, Chemical Composition, row Ti
      - name: Aluminium
        symbol: Al
        role: Alpha stabilizer (Wikipedia)
        share_percent: 5.5
        share_high: 6.5
        source: titanium-com
        where: Table 1, Chemical Composition, row Al
      - name: Tin
        symbol: Sn
        role: Alloying addition named in the composition table
        share_percent: 1.8
        share_high: 2.2
        source: titanium-com
        where: Table 1, Chemical Composition, row Sn
      - name: Zirconium
        symbol: Zr
        role: Alloying addition named in the composition table
        share_percent: 3.6
        share_high: 4.4
        source: titanium-com
        where: Table 1, Chemical Composition, row Zr
      - name: Molybdenum
        symbol: Mo
        role: Beta stabilizer (Wikipedia names molybdenum as a beta stabilizer in near-alpha alloys)
        share_percent: 1.8
        share_high: 2.2
        source: titanium-com
        where: Table 1, Chemical Composition, row Mo