TZM molybdenum alloy TZM

spore: profile
id: tzm
spore_version: 0.2
family: refractory-metals
name: TZM molybdenum alloy
abbreviation: TZM
role: high-temperature molybdenum alloy for furnace and hot-tool parts
category: metals
type: refractory-metals
summary: |
  TZM is a molybdenum alloy (Mo-0.5Ti-0.08Zr-0.02C, titanium-zirconium-molybdenum) with about 0.5 % titanium, 0.08 % zirconium and a small carbon addition that forms fine carbides. Wieland's datasheet gives a density of 10.2 g/cm3, a thermal conductivity of about 130 W/(m·K) at 20 °C and a modulus of elasticity of 300 GPa. Its reference tensile strength is 800 to 1000 MPa with a yield strength of 750 to 900 MPa, and the recrystallisation temperature is 1400 °C against 1100 °C for pure molybdenum (Plansee). The weak point is oxygen: exposed TZM loses ductility at 500 ppm of oxygen, and at 1150 °C it became brittle within 5 to 24 hours in an oxygen study by Oak Ridge National Laboratory.
best_for: 'High-temperature strength in vacuum and inert furnaces: recrystallisation at 1400 °C and a reference yield strength of 750 to 900 MPa, against 1100 °C for pure molybdenum'
weakest_at: Oxygen and water vapour. TZM loses ductility at 500 ppm oxygen and is embrittled within hours at 1150 °C in low-pressure oxygen (ORNL-5431), so it is kept below 825 °C in oxidising service
identity:
  formula: Mo balance, Ti 0.5, Zr 0.08, C 0.03 (reference values, weight %); titanium-zirconium-molybdenum alloy with carbide-forming carbon
  source: wieland-tzm
  where: 'Chemical Composition table, reference values in %: Ti 0.5, Zr 0.08, C 0.03, Mo balance. The Plansee alloys page gives C as 0.01 to 0.04 %'
  designations:
    - system: ASTM
      code: '363'
      note: Molybdenum Alloy 363, vacuum arc-cast TZM, plate, sheet, strip, foil and ribbon
      source: astm-b386
      where: Scope section 1.1.3, Molybdenum Alloy 363 vacuum arc-cast molybdenum-0.5 % titanium-0.1 % zirconium (TZM) alloy
    - system: ASTM
      code: '364'
      note: Molybdenum Alloy 364, powder-metallurgy TZM, plate, sheet, strip, foil and ribbon
      source: astm-b386
      where: Scope section 1.1.4, Molybdenum Alloy 364 powder metallurgy molybdenum-0.5 % titanium-0.1 % zirconium (TZM) alloy
    - system: ASTM
      code: B386
      note: plate, sheet, strip, foil and ribbon; unalloyed and alloy molybdenum
      source: astm-b386
      where: Scope section 1.1
    - system: Trade name
      code: TZM
      note: short name, from Titan-Zirkon-Molybdän
      source: wieland-tzm
      where: Header table, row Short-Name
tags:
  applications:
    - thermal-control
    - structures
    - propulsion-and-tanks
properties:
  - benchmark: density
    label: Density of TZM
    value: 10.2
    unit: g/cm3
    scope: material
    conditions:
      form: reference value, grade and temper not stated
      temperature: not stated in the row
      unit_in_source: g/cm³
    method: Reference value printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Physical Properties table, row Density
  - benchmark: thermal_conductivity
    label: Thermal conductivity of TZM at 20 °C
    value: 130
    unit: W/(m·K)
    scope: material
    conditions:
      temperature: 20 °C (293 K)
      qualifier: printed as ca. 130
      form: not stated
    method: Value printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Physical Properties table, row Thermal conductivity, 20 °C (293 K)
  - benchmark: cte
    label: Coefficient of thermal expansion of TZM, 0 to 300 °C
    value: 5.3
    value_high: 5.7
    bound: range
    unit: ppm/K
    scope: material
    conditions:
      temperature: 0 to 300 °C (273 to 573 K)
      unit_in_source: 5.3 – 5.7 × 10-6 1/K
    method: Range printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Physical Properties table, row Coefficient of thermal expansion, 0 to 300 °C
  - benchmark: specific_heat
    label: Specific heat of TZM
    value: 0.25
    unit: J/(g·K)
    scope: material
    conditions:
      temperature: not stated in the row
      unit_in_source: 0.25 J/(g·K)
    method: Value printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Physical Properties table, row Specific heat
  - benchmark: electrical_conductivity
    label: Electrical conductivity of TZM at 20 °C
    value: 15
    unit: MS/m
    scope: material
    conditions:
      temperature: 20 °C (293 K)
      qualifier: printed as ca. 15
    method: Value printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Physical Properties table, row Electrical conductivity, 20 °C (293 K)
  - benchmark: electrical_resistivity
    label: Electrical resistance of TZM at 20 °C
    value: 0.06
    unit: Ω·mm²/m
    scope: material
    conditions:
      temperature: 20 °C (293 K)
      qualifier: printed as ca. 0.06
    method: Value printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Physical Properties table, row Electrical resistance, 20 °C (293 K)
  - benchmark: elastic_modulus
    label: Modulus of elasticity of TZM at 20 °C
    value: 300
    unit: GPa
    scope: material
    conditions:
      temperature: 20 °C (293 K)
      unit_in_source: 300 kN/mm²
    method: Reference value printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Mechanical Properties (Reference values) table, row Modulus of elasticity
  - benchmark: hardness_vickers
    label: Hardness of TZM (Vickers)
    value: 200
    value_high: 250
    bound: range
    unit: HV
    scope: material
    conditions:
      form: reference value, temper not stated
    method: Reference range printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Mechanical Properties (Reference values) table, row Hardness HV
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of TZM, reference range
    value: 800
    value_high: 1000
    bound: range
    unit: MPa
    scope: material
    conditions:
      form: reference value, temper not stated
      unit_in_source: 800–1.000 N/mm²
      note: the datasheet says tensile strength depends on cross-section and design
    method: Reference range printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Mechanical Properties (Reference values) table, row Tensile strength
  - benchmark: yield_strength
    label: Yield strength of TZM, reference range
    value: 750
    value_high: 900
    bound: range
    unit: MPa
    scope: material
    conditions:
      form: reference value, temper not stated
      unit_in_source: 750–900 N/mm²
    method: Reference range printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Mechanical Properties (Reference values) table, row Yield strength
  - benchmark: elongation
    label: Elongation of TZM, L = 5D, reference range
    value: 6
    value_high: 10
    bound: range
    unit: '%'
    scope: material
    conditions:
      gauge_length: L = 5D
      form: reference value, temper not stated
    method: Reference range printed in a manufacturer technical datasheet
    status: ground
    source: wieland-tzm
    where: Mechanical Properties (Reference values) table, row Elongation L = 5 D
  - benchmark: recrystallization_temperature
    label: Temperature for 100 % recrystallisation of TZM, 90 % deformation
    value: 1400
    unit: °C
    scope: material
    conditions:
      annealing_time: 1 hour
      deformation: 90 %
      definition: temperature for 100 % recrystallisation
      form: not stated
    method: Value in a table of recrystallisation temperatures printed on the Plansee molybdenum properties page
    status: ground
    note: The same table gives 1100 for pure molybdenum at 90 % deformation, and TZM at 99.99 % deformation is shown as a dash
    source: plansee-mo-properties
    where: 'Table Temperature [°C] for 100% recrystallization (annealing time: 1 hour), row TZM, column Level of deformation = 90%'
  - benchmark: operating_temperature
    label: Recommended operating temperature range of TZM
    value: 700
    value_high: 1400
    bound: range
    unit: °C
    scope: material
    conditions:
      basis: recommended operating temperature printed for TZM
    method: Range printed on the Plansee molybdenum alloys page
    status: ground
    source: plansee-tzm-alloys
    where: Overview of possible molybdenum alloys, Recommended operating temperature
  - benchmark: oxygen_embrittlement_level
    label: Oxygen content at which exposed TZM loses ductility
    value: 500
    unit: wt ppm O
    scope: material
    conditions:
      exposure: oxidising gas (oxygen, water vapour or CO) at 825 to 1150 °C
      independent_of: exposure temperature
      material: TZM sheet, 0.51 mm, ORNL study
    method: Ductility result from tensile tests of oxygen-exposed TZM sheet, Oak Ridge National Laboratory report ORNL-5431
    status: ground
    source: ornl-5431
    where: Abstract, and Summary (Exposed TZM loses its ductility at a level of 500 ppm O)
  - benchmark: max_service_temp
    label: Operating limit for TZM in oxidising gases
    value: 825
    bound: upper
    unit: °C
    scope: material
    conditions:
      environment: oxidising gases, oxygen, water vapour or CO
      basis: ORNL recommendation for closed-cycle energy systems
    method: Recommendation printed in the conclusions of an Oak Ridge National Laboratory report
    status: ground
    source: ornl-5431
    where: 'Summary, final paragraph: operation temperature should be kept below 825 °C if TZM must be used in certain cases'
corrosion:
  - environment: Low-pressure oxygen at 1150 °C
    headline: Oxygen dissolves into TZM and it loses its ductility within hours.
    effect: TZM picks up oxygen at about 20 ppm/h at 1150 °C in 1.3 mPa oxygen and loses carbon, from 177 to 43 ppm after 100 hours. Tensile ductility falls in 5 to 24 hours. Oxide zones and precipitates harden the alloy and promote cleavage and grain-boundary fracture.
    rating: severe
    conditions:
      pressure: 1.3 mPa oxygen
      temperature: 1150 °C
      specimen: 0.51 mm TZM sheet, ORNL study composition Ti 0.51 wt%, Zr 0.054 wt%
    source: ornl-5431
    where: Abstract; Change in Interstitial Composition, Table 2 row TZM; Conclusions
  - environment: Oxygen, water vapour or CO at 825 to 1000 °C
    headline: At 1000 °C TZM is embrittled after 100 hours in oxygen or 1500 hours in CO.
    effect: The ORNL study says TZM is embrittled after 100 hours exposure in 1.3 mPa oxygen at 1000 °C, or after 1500 hours in 1.3 mPa CO at 1000 °C. Below 825 °C oxygen uptake is by bulk diffusion, and the study predicts ductility below 5 % after 20,000 hours at 825 °C for 0.51 mm sheet.
    rating: moderate
    conditions:
      pressure: 1.3 mPa
      temperature: 825 to 1000 °C
      thickness: 0.51 mm sheet, predicted case
    source: ornl-5431
    where: Summary, paragraph on kinetics of oxygen absorption in TZM
  - environment: Molten fluoride salt (FLiBe) above 1300 °C
    headline: TZM resists molten fluoride salts above 1300 °C with little measurable corrosion.
    effect: Wikipedia reports that TZM resists molten fluoride salts above 1,300 °C and lasted 1100 hours with so little corrosion that it was difficult to measure, in a test with FLiBe salt and its vapour.
    rating: low
    conditions:
      salt: FLiBe and salt vapour
      duration: 1100 hours
      temperature: above 1300 °C
    source: wikipedia-mo
    where: Alloys section, TZM paragraph
risks:
  hazards:
    - text: PubChem aggregates ECHA C&L notifications for molybdenum (EC 231-107-2, 1523 company reports). H228 flammable solid is given for 30 % of notifications that gave codes, H361 suspected of damaging fertility or the unborn child for 29.5 %, and H225 for 11.6 %. Signal word Danger. 57.4 % of reports do not meet GHS criteria. The notifications are for the element and are not specific to a solid alloy part.
      ghs:
        - H228
        - H361
        - H225
      source: pubchem-mo
      where: GHS Classification section, ECHA C&L Inventory, Source 1
    - text: A second notifier, NITE-CMC (FY2015 revised classification), lists H315 skin irritation, H319 serious eye irritation and H335 respiratory irritation for molybdenum, with signal word Warning. A FY2006 entry lists H335 only.
      ghs:
        - H315
        - H319
        - H335
      source: pubchem-mo
      where: GHS Classification section, NITE-CMC entries (references 52 and 53)
  failure_risks:
    - mode: Oxygen embrittlement
      trigger: Exposure to oxygen, water vapour or CO at 825 to 1150 °C
      consequence: Exposed TZM loses its ductility at 500 ppm oxygen, and in the ORNL study it lost ductility in 5 to 24 hours at 1150 °C in 1.3 mPa oxygen. The study concludes it is generally not suitable for closed-cycle energy systems.
      severity: critical
      source: ornl-5431
      where: Abstract; Summary
    - mode: Recrystallisation of cold-worked structure
      trigger: Annealing or service above about 1400 °C after 90 % deformation (1 hour)
      consequence: The recrystallised structure replaces the deformed one. Plansee gives 1400 °C for TZM and 1100 for pure molybdenum in the same table; the page gives no strength figure for the change.
      severity: moderate
      source: plansee-mo-properties
      where: Table Temperature [°C] for 100% recrystallization, rows TZM and Mo (pure)
  side_effects:
    - text: Molybdenum is dense at 10.2 g/cm3 (Wieland reference value for TZM), so mass is a concern in lightweight hardware. Wieland's datasheet lists TZM for trays, sinter boats, heating elements and hot-runner tips, all of them furnace or mould parts rather than structures.
      affects: Mass of hot-zone hardware
      source: wieland-tzm
      where: Physical Properties table, row Density; Applications list
  handling:
    - text: Keep TZM below 825 °C in oxidising gases, since the ORNL study finds oxygen embrittlement follows exposure in oxygen, water vapour or CO.
      source: ornl-5431
      where: Summary, final paragraph
    - text: Wieland notes that tensile strength depends on cross-section and design, so reference strengths are not a guarantee for a given part.
      source: wieland-tzm
      where: Mechanical Properties table, footnote text
  mitigations: []
uses:
  - application: thermal-control
    device: Vacuum furnace heating elements, trays in continuous heating furnaces, sinter boats
    example: Wieland lists TZM for vacuum furnace heating elements, trays in continuous heating furnaces and sinter boats, with hot-runner tips in plastic injection nozzles.
    source: wieland-tzm
    where: Applications list
  - application: structures
    device: Forging tools
    example: Plansee gives typical uses as forging tools and rotating anodes in X-ray tubes, and says TZM is stronger than pure molybdenum.
    source: plansee-tzm-alloys
    where: Overview of possible molybdenum alloys, typical uses
  - application: propulsion-and-tanks
    device: Rocket nozzles and engine valve bodies
    example: Wikipedia lists torpedo engine valve bodies, rocket nozzles and gas pipelines among TZM uses, and radiation shields in nuclear applications.
    source: wikipedia-mo
    where: Alloys section, TZM paragraph
supply:
  - subject: Molybdenum (mine production, molybdenum content, 2025 estimate)
    producers:
      - country: China
        share_percent: 37.3
        year: 2025
      - country: Chile
        share_percent: 16.2
        year: 2025
      - country: Peru
        share_percent: 15
        year: 2025
      - country: United States
        share_percent: 15.4
        year: 2025
    recycling: 'USGS: molybdenum recycled as part of new and old steel and other scrap may be as much as 30 % of the apparent supply. There is no separate recovery process for secondary molybdenum from its alloys.'
    substitutes:
      - 'USGS: little substitution for molybdenum in steels and cast irons. Potential substitutes in refractory materials for high-temperature electric furnaces are graphite, tantalum and tungsten.'
    source: usgs-mcs2026-mo
    where: Mine production table, 2025e, world total (rounded) 260,000 t; shares are calculated from China 97,000, Chile 42,000, Peru 39,000 and United States 40,000 t. Recycling and Substitutes paragraphs; Events, Trends, and Issues
documents:
  - title: Wieland Duro TZM technical datasheet
    type: datasheet
    url: https://www.wieland.com/da/content/download/12678/file/TZM_EX_EN.pdf
  - title: 'Plansee: Molybdenum alloys (TZM composition and overview)'
    type: database
    url: https://www.plansee.com/en/materials/molybdenum/alloys.html
  - title: 'Plansee: Molybdenum properties (recrystallisation temperature table)'
    type: database
    url: https://www.plansee.com/en/materials/molybdenum/Properties.html
  - title: ASTM B386/B386M, Standard Specification for Molybdenum and Molybdenum Alloy Plate, Sheet, Strip, Foil, and Ribbon (catalogue page)
    type: standard
    url: https://catalogue.normdocs.ru/catalog/com.normdocs.astm.card.b386.b386m-25/Standard-ASTM-B386-B386M-25
  - title: ASTM B387-18, Standard Specification for Molybdenum and Molybdenum Alloy Bar, Rod, and Wire (catalogue page, superseded)
    type: standard
    url: https://catalogue.normdocs.ru/catalog/com.normdocs.astm.card.b387-18/Standard-ASTM-B387-18
  - title: 'Wikipedia: Molybdenum (alloys section)'
    type: database
    url: https://en.wikipedia.org/wiki/Molybdenum
  - title: Liu, Anderson, Inouye, Effect of Oxidizing Environment on Mechanical Properties of Molybdenum and TZM, ORNL-5431 (1978)
    type: report
    url: https://info.ornl.gov/sites/publications/Files/Pub188434.pdf
    year: 1978
  - title: 'USGS Mineral Commodity Summaries 2026: Molybdenum'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    year: 2026
  - title: 'PubChem compound record: Molybdenum (CID 23932), GHS Classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Molybdenum
gaps:
  - No melting point, boiling point figure for TZM itself was found in a fetched source. Pure-molybdenum figures seen in search snippets were not used.
  - The Plansee TZM product data sheet (PSE-030-PDS-018) was linked but returned compressed PDF text, so its values were not read. Wieland's datasheet is the only fetched datasheet with strength and physical values.
  - No UNS number (R03620 is not printed in any fetched source), no W.Nr. or EN material number, and no DIN or JIS code for TZM was found in a fetched source.
  - The Samaterials TZM datasheet returned a titanium pipe PDF, and the Admat TZM page returned HTTP 403, so neither was used.
  - Strength figures from Wieland are reference values with no temper, form or temperature stated. The ORNL tensile table is for a specific 0.51 mm sheet and was not entered, to avoid mixing conditions.
  - No strength curve values at 1200 °C or in stress-relieved versus recrystallised condition could be read; Wieland plots them only as graphs.
  - No critical-mineral list entry for molybdenum was found in the USGS 2026 summary, so the critical_lists field is empty.
  - The 2025 Chinese export control on molybdenum powders is named in the USGS summary, but no tonnage effect is recorded.
  - The PubChem GHS entries are for the element molybdenum, not for TZM parts. The two notifiers disagree on the hazard classes.
  - No radiation effect, outgassing, atomic-oxygen or cold-welding data for TZM was found in a fetched source, so the space-environment section is empty.
  - The Wang et al. 2024 Materials Letters paper on rolled TZM sheet recrystallisation was seen only in a search result and was not opened.
  - Electrical resistance temperature coefficient (ca. 0.0046 per K, Wieland) is not entered because its temperature range is not stated.
sources:
  wieland-tzm:
    title: TZM Technical Datasheet, Wieland Duro GmbH (Short-Name TZM, Titan-Zirkon-Molybdän)
    url: https://www.wieland.com/da/content/download/12678/file/TZM_EX_EN.pdf
    kind: datasheet
    license: Manufacturer datasheet, general information only (cited, not reproduced)
  plansee-tzm-alloys:
    title: 'Plansee: Molybdenum alloys, overview and TZM composition'
    url: https://www.plansee.com/en/materials/molybdenum/alloys.html
    kind: web
    license: Manufacturer web page (cited, not reproduced)
  plansee-mo-properties:
    title: 'Plansee: Molybdenum properties, recrystallisation temperature table'
    url: https://www.plansee.com/en/materials/molybdenum/Properties.html
    kind: web
    license: Manufacturer web page (cited, not reproduced)
  astm-b386:
    title: ASTM B386/B386M-25, Standard Specification for Molybdenum and Molybdenum Alloy Plate, Sheet, Strip, Foil, and Ribbon
    url: https://catalogue.normdocs.ru/catalog/com.normdocs.astm.card.b386.b386m-25/Standard-ASTM-B386-B386M-25
    kind: standard
    license: Standards catalogue page (cited, not reproduced)
  astm-b387:
    title: ASTM B387-18, Standard Specification for Molybdenum and Molybdenum Alloy Bar, Rod, and Wire (superseded by B387/B387M-23)
    url: https://catalogue.normdocs.ru/catalog/com.normdocs.astm.card.b387-18/Standard-ASTM-B387-18
    kind: standard
    license: Standards catalogue page (cited, not reproduced)
  wikipedia-mo:
    title: 'Wikipedia: Molybdenum, alloys section'
    url: https://en.wikipedia.org/wiki/Molybdenum
    kind: web
    license: CC BY-SA (cited, not reproduced)
  ornl-5431:
    title: Liu, Anderson, Inouye, Effect of Oxidizing Environment on Mechanical Properties of Molybdenum and TZM, ORNL-5431 (Oak Ridge National Laboratory, October 1978)
    url: https://info.ornl.gov/sites/publications/Files/Pub188434.pdf
    kind: report
    license: US government report (public domain)
  usgs-mcs2026-mo:
    title: USGS Mineral Commodity Summaries 2026, Molybdenum
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    kind: report
    license: Public domain (USGS)
  pubchem-mo:
    title: 'PubChem compound record: Molybdenum (CID 23932), GHS Classification'
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Molybdenum
    kind: database
    license: PubChem (NCBI), public domain; ECHA and NITE-CMC notifications
license: CC-BY-4.0
updated: '2026-10-25'
review:
  status: draft
  method: assistant
  checked_values: 15
  unreachable: 3
  caveats: 5
  note: 'Values were read by an AI assistant on 2026-10-25 from the pages named in each entry. Unreachable: the Plansee TZM datasheet PDF (compressed text), the Admat TZM page (HTTP 403) and the PubChem GHS page (browser check, read through the JSON view). Caveats: the Wieland strength values are reference ranges with no temper stated; the recrystallisation and operating range come from Plansee''s web pages; the 825 °C limit and the oxygen figures come from a 1978 ORNL study on a specific 0.51 mm sheet; the supply shares are calculated from the USGS production table.'
story:
  risk_groups:
    - title: For people
      lead: The hazard notifications for molybdenum disagree, and none of the opened sources describes a health effect of a TZM part.
      level: 1
      verdict: Mixed notifications
      points:
        - label: Molybdenum as a substance
          line: Notifications to the European chemicals agency for molybdenum give H228 flammable solid for 30 % of codes and H361 for 29.5 %, but 57.4 % of reports do not meet the criteria. The NITE-CMC entries list only irritation, H315, H319 and H335.
    - title: If it fails
      lead: The failure route in the sources is oxygen, not mechanical overload.
      points:
        - label: Oxygen
          line: At 1150 °C in 1.3 mPa oxygen, TZM lost ductility in 5 to 24 hours in the ORNL study, and exposed TZM loses ductility at 500 ppm oxygen.
        - label: Recrystallisation
          line: Plansee gives 1400 °C as the temperature for full recrystallisation of TZM after 90 % deformation, against 1100 for pure molybdenum.
    - title: Handling and storage
      points:
        - label: Oxidising gas
          line: Keep TZM below 825 °C in oxygen, water vapour or CO, the ORNL recommendation.
        - label: Specify the datasheet values
          line: Wieland's strengths are reference ranges with no temper stated, so test the real part.
  why: 'TZM is a molybdenum alloy with about 0.5 % titanium and 0.08 % zirconium. It is chosen for high-temperature work in vacuum or inert gas, where it keeps more strength than pure molybdenum. Plansee says it has a recrystallisation temperature of 1400 °C, against 1100 for pure molybdenum, and Wieland gives a reference yield strength of 750 to 900 MPa. Oxygen is the weak point: the ORNL study found it loses ductility at 500 ppm oxygen.'
  uses:
    - where: Furnace parts
      line: Wieland lists vacuum furnace heating elements, trays in continuous furnaces, sinter boats and hot-runner tips for plastic injection nozzles.
    - where: Forging and tools
      line: Plansee lists forging tools and rotating anodes in X-ray tubes as typical uses of TZM.
    - where: Military and nuclear hardware
      line: Wikipedia lists torpedo engine valve bodies, rocket nozzles and radiation shields in nuclear applications.
  can_do:
    - label: Carry heat
      value: 130 W/(m·K)
      benchmark: thermal_conductivity
      line: Thermal conductivity is about 130 W/(m·K) at 20 °C (Wieland, printed as ca. 130).
    - label: Hold strength when hot
      value: 1400 °C
      benchmark: recrystallization_temperature
      line: Plansee gives 1400 °C as the temperature for 100 % recrystallisation after 90 % deformation and one hour, which is above the 1100 for pure molybdenum.
    - label: Weight
      value: 10.2 g/cm3
      benchmark: density
      line: Density is 10.2 g/cm3 in the Wieland datasheet.
    - label: Stiffness
      value: 300 GPa
      benchmark: elastic_modulus
      line: The modulus of elasticity at 20 °C is 300 GPa.
    - label: Strength
      value: 750 to 900 MPa yield
      benchmark: yield_strength
      line: Reference yield strength is 750 to 900 MPa and reference tensile strength 800 to 1000 MPa, with 6 to 10 % elongation at L = 5D.
  compare: Plansee states TZM is stronger than pure molybdenum and recrystallises at 1400 °C against 1100 for pure molybdenum. No pure-molybdenum density was taken from a fetched page for this profile, so the density row shows TZM only. The rows show these as examples, since the sources use different grades and conditions.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Recrystallisation temperature
      benchmark: recrystallization_temperature
  handling:
    - Keep TZM below 825 °C when oxygen, water vapour or CO is present.
    - Specify the form and temper, because Wieland's strength values are reference ranges with no temper stated.
    - Use the Plansee and Wieland ranges as a starting point, and test the actual part.
  good_for:
    - 'High-temperature furnace and hot-tool parts in vacuum or inert gas: recrystallisation at 1400 °C.'
    - 'Heat flow: about 130 W/(m·K) at 20 °C.'
    - 'Stiffness: 300 GPa modulus with a 750 to 900 MPa reference yield strength.'
  watch_out:
    - 'Oxygen: TZM loses ductility at 500 ppm oxygen and was embrittled within 5 to 24 hours at 1150 °C in the ORNL study.'
    - 'Oxidising gas: keep below 825 °C if the part must be used in oxygen, water vapour or CO.'
    - 'Supply: China, Chile, Peru and the United States produced most of the 260,000 t of molybdenum mined in 2025, and China imposed powder export controls in February 2025.'
    - Some values, including the melting point, are missing for TZM itself.
  verdict: TZM is a molybdenum alloy with about 0.5 % titanium and 0.08 % zirconium, chosen for strength and high recrystallisation temperature at high temperature. Wieland gives a reference density of 10.2 g/cm3, a thermal conductivity of about 130 W/(m·K) and a yield strength of 750 to 900 MPa. Its main weakness is oxygen, which embrittles it at 500 ppm and within hours at 1150 °C. This profile lacks a TZM melting point, a UNS number and any space-environment test data.
  recipe:
    line: 'TZM is a molybdenum-base alloy. Plansee gives 0.5 % titanium, 0.08 % zirconium and 0.01 to 0.04 % carbon, which forms fine carbides. ASTM B386 names two forms with 0.5 % titanium and 0.1 % zirconium: Alloy 363, vacuum arc-cast, and Alloy 364, powder metallurgy. Wikipedia gives roughly 99 % molybdenum, 0.5 % titanium, 0.08 % zirconium and some carbon.'
    parts:
      - name: Molybdenum
        symbol: Mo
        share_note: balance (the rest)
        role: The matrix of the alloy, with a body-centred cubic structure.
      - name: Titanium
        symbol: Ti
        share_percent: 0.5
        role: Forms fine carbides and oxide zones; the oxygen study shows titanium and zirconium react with oxygen.
      - name: Zirconium
        symbol: Zr
        share_percent: 0.08
        role: Forms carbides with carbon, and reacts with oxygen in service.
      - name: Carbon
        symbol: C
        share_percent: 0.01
        share_high: 0.04
        role: Forms fine carbides that raise strength and recrystallisation temperature (Plansee).