spore: profile
id: platinum-tungsten-copper
spore_version: 0.2
family: precious-metals
name: Platinum-tungsten and platinum-copper alloys
abbreviation: Pt-W, Pt-Cu
role: resistance wire, probes and spark-plug electrodes (Pt-W); catalysts (Pt-Cu)
category: metals
type: precious-metals
summary: |
  Platinum-tungsten is a ductile precious-metal alloy. The grade read here is Pt-8W, 92 % platinum and 8 % tungsten by mass, sold by Heraeus as PtW8 (Hera 158) and by Goodfellow as Pt92/W8 wire. The Heraeus datasheet gives a density of 21.26 g/cm3 and a melting range of 1865 to 1885 °C, and lists PtW8 for spark plug electrodes, resistance wire and medical wire. Goodfellow lists the same composition for high-temperature furnace wiring, precision heater coils and sensor assemblies. Platinum-copper appears in the sources read here as a catalyst: a 2021 open-access study of carbon-supported PtCu nanoparticles reports a lattice parameter of 3.815 Å and a peak methanol-oxidation current of 1236 A/g(Pt). No bulk density, melting point or hardness for Pt-Cu was read in this run.
best_for: Fine resistance wire, probes and electrodes that must resist oxidation in air at high temperature (Pt-W), and dealloyed PtCu catalysts in acid electrolyte (Pt-Cu, laboratory).
weakest_at: Density (21.26 g/cm3) and conductivity (2.58 to 2.77 % IACS, a poor conductor). The PtCu catalyst loses much of its copper in acid.
identity:
  formula: 'Pt-8W: platinum with 8 % tungsten by mass (Pt92/W8). Pt-Cu: carbon-supported PtCux nanoparticles, x = 1.3 by XRF before activation'
  source: goodfellow-ptw
  where: Composition line, Pt 92/W 8 (Goodfellow). Heraeus designation PtW8 on the datasheet title line.
  designations:
    - system: Trade name
      code: PtW8
      source: hera158
      where: Title line, product name
    - system: Trade name
      code: Hera 158
      source: hera158
      where: Title line, product name
tags:
  environments: []
  stresses: []
  applications:
    - propulsion-and-tanks
    - thermal-control
    - electronics-and-chips
    - batteries
properties:
  - benchmark: density
    label: Density, PtW8 wire (Heraeus Hera 158)
    value: 21.26
    unit: g/cm3
    scope: material
    conditions:
      form: PtW8 wire
      temperature: not stated in the datasheet
    method: Value printed in a manufacturer datasheet
    status: ground
    source: hera158
    where: General information table, row Density, g/cm3
  - benchmark: density
    label: Density, Pt92/W8 wire (Goodfellow)
    value: 21.3
    unit: g/cm3
    scope: material
    conditions:
      form: Pt92/W8 spooled wire
      temperature: not stated on the page
    method: Value printed on a reseller product page
    status: ground
    source: goodfellow-ptw
    where: Physical properties list, Density
  - benchmark: melting_point
    label: Melting range, PtW8 (Heraeus Hera 158)
    value: 1865
    value_high: 1885
    bound: range
    unit: °C
    scope: material
    conditions:
      form: PtW8 wire
      pressure: not stated
    method: Range printed in a manufacturer datasheet
    status: ground
    source: hera158
    where: General information table, row Melting Range, °C
  - benchmark: melting_point
    label: Melting range, Pt92/W8 (Goodfellow)
    value: 1870
    value_high: 1910
    bound: range
    unit: °C
    scope: material
    conditions:
      form: Pt92/W8 wire
      pressure: not stated
    method: Range printed on a reseller product page
    status: ground
    source: goodfellow-ptw
    where: Physical properties list, Melting point
  - benchmark: vickers_hardness
    label: Hardness HV, PtW8 (Heraeus Hera 158)
    value: 200
    value_high: 300
    bound: range
    unit: HV
    scope: material
    conditions:
      form: PtW8 wire
      temper: not stated; the datasheet gives one property range
    method: Range printed in a manufacturer datasheet
    status: ground
    source: hera158
    where: Property Range table, row Hardness HV
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, PtW8 (Heraeus Hera 158)
    value: 800
    value_high: 1100
    bound: range
    unit: MPa
    scope: material
    conditions:
      form: PtW8 wire
      temper: not stated; one property range printed
    method: Range printed in a manufacturer datasheet
    status: ground
    source: hera158
    where: Property Range table, row Tensile Strength MPa
  - benchmark: yield_strength
    label: Yield strength, PtW8 (Heraeus Hera 158)
    value: 400
    value_high: 1000
    bound: range
    unit: MPa
    scope: material
    conditions:
      form: PtW8 wire
      temper: not stated; one property range printed
    method: Range printed in a manufacturer datasheet
    status: ground
    source: hera158
    where: Property Range table, row Yield Strength MPa
  - benchmark: elongation
    label: Elongation, PtW8 (Heraeus Hera 158)
    value: 2
    value_high: 20
    bound: range
    unit: '%'
    scope: material
    conditions:
      form: PtW8 wire
      gauge_length: not stated
    method: Range printed in a manufacturer datasheet
    status: ground
    source: hera158
    where: Property Range table, row Elongation %
  - benchmark: electrical_conductivity
    label: Electrical conductivity range, PtW8 (Heraeus Hera 158)
    value: 2.58
    value_high: 2.77
    bound: range
    unit: '% IACS'
    scope: material
    conditions:
      form: PtW8 wire
      temperature: not stated in the datasheet
    method: Minimum and maximum printed in a manufacturer datasheet. The datasheet prints the minimum (2.77) above the maximum (2.58), so the range is entered low to high. Check the datasheet before using either end.
    status: ground
    source: hera158
    where: Physical properties table, rows Conductivity min % IACS and Conductivity max % IACS
  - benchmark: electrical_resistivity
    label: Electrical resistivity, Pt92/W8 (Goodfellow)
    value: 62
    value_high: 68
    bound: range
    unit: µOhm cm
    scope: material
    conditions:
      form: Pt92/W8 wire
      temperature: not stated on the page
    method: Range printed on a reseller product page
    status: ground
    source: goodfellow-ptw
    where: Physical properties list, Electrical resistivity
  - benchmark: elastic_modulus
    label: Modulus of elasticity, Pt92/W8 (Goodfellow)
    value: 230
    unit: GPa
    scope: material
    conditions:
      form: Pt92/W8 wire
      temperature: not stated on the page
    method: Value printed on a reseller product page
    status: ground
    source: goodfellow-ptw
    where: Physical properties list, Modulus of elasticity
  - benchmark: temperature_coefficient_of_resistance
    label: Temperature coefficient of resistance, Pt92/W8 (Goodfellow)
    value: 0.00025
    unit: K-1
    scope: material
    conditions:
      form: Pt92/W8 wire
      temperature_range: not stated on the page
    method: Value printed on a reseller product page
    status: ground
    note: Non-canonical name; add to property-canon if kept.
    source: goodfellow-ptw
    where: Physical properties list, Temperature coefficient
  - benchmark: electrochemically_active_surface_area
    label: Electrochemically active surface area, PtCu/C activated 0.04 to 1.20 V
    value: 41
    unit: m2/g(Pt)
    scope: material
    conditions:
      form: carbon-supported PtCu/C catalyst, nominal PtCu1.3 before activation
      electrolyte: 0.1 M HClO4
      activation: 100 voltammetric cycles, 0.04 to 1.20 V vs RHE, 200 mV/s
    method: Value printed in a 2021 open-access paper, Table 1
    status: ground
    note: Non-canonical name.
    source: pavlets2021
    where: Table 1, row PtCu/C with activation range 0.04 to 1.20 V, column ESA
  - benchmark: electrochemically_active_surface_area
    label: Electrochemically active surface area, PtCu/C activated 0.04 to 1.00 V
    value: 43
    unit: m2/g(Pt)
    scope: material
    conditions:
      form: carbon-supported PtCu/C catalyst, nominal PtCu1.3 before activation
      electrolyte: 0.1 M HClO4
      activation: 100 voltammetric cycles, 0.04 to 1.00 V vs RHE, 200 mV/s
    method: Value printed in a 2021 open-access paper, Table 1
    status: ground
    note: Non-canonical name.
    source: pavlets2021
    where: Table 1, row PtCu/C with activation range 0.04 to 1.00 V, column ESA
  - benchmark: methanol_oxidation_peak_current
    label: Peak methanol oxidation current, PtCu/C activated 0.04 to 1.00 V
    value: 1236
    unit: A/g(Pt)
    scope: material
    conditions:
      electrolyte: 0.1 M HClO4 with 0.5 M CH3OH, argon
      scan: 20 mV/s, 0.04 to 1.3 V vs RHE
    method: Value printed in a 2021 open-access paper, Table 2
    status: ground
    note: Non-canonical name. Normalised to platinum mass by the authors.
    source: pavlets2021
    where: Table 2, row PtCu/C 0.04 to 1.00 V, column Imax
  - benchmark: methanol_oxidation_peak_current
    label: Peak methanol oxidation current, commercial Pt/C reference (JM20)
    value: 350
    unit: A/g(Pt)
    scope: material
    conditions:
      electrolyte: 0.1 M HClO4 with 0.5 M CH3OH, argon
      scan: 20 mV/s, 0.04 to 1.3 V vs RHE
    method: Value printed in a 2021 open-access paper, Table 2
    status: ground
    note: Non-canonical name. Reference catalyst for the comparison above.
    source: pavlets2021
    where: Table 2, row JM20 0.04 to 1.20 V, column Imax
  - benchmark: lattice_parameter
    label: Lattice parameter a, PtCu/C from XRD
    value: 3.815
    unit: Å
    scope: material
    conditions:
      form: PtCu/C catalyst, Pt-Cu solid solution
      method: XRD with Vegard's law
    method: Value calculated and printed in a 2021 open-access paper
    status: ground
    note: Non-canonical name. The same sentence gives the composition PtCu0.54 by Vegard's law.
    source: pavlets2021
    where: Section 2 (XRD results), sentence beginning For the obtained PtCu/C catalyst
  - benchmark: crystallite_size
    label: XRD crystallite size, PtCu/C (Scherrer)
    value: 2.7
    unit: nm
    scope: material
    conditions:
      form: PtCu/C catalyst
      method: Scherrer equation from XRD
    method: Value printed in a 2021 open-access paper; plus or minus 0.1 nm printed
    status: ground
    note: Non-canonical name. TEM gives a nanoparticle size of about 5 nm, which the authors say is larger than the XRD crystallite size.
    source: pavlets2021
    where: Section 2 (XRD results), sentence with the Scherrer calculation
corrosion:
  - environment: Air at high temperature (PtW8 wire)
    headline: Heraeus lists PtW8 as oxidation resistant to 1000 °C.
    effect: The datasheet gives this as a chemical-property comment with no test method, atmosphere, exposure time or oxidation rate.
    rating: low
    conditions:
      basis: qualitative datasheet statement only
      limit: 1000 °C as printed
    source: hera158
    where: Chemical Properties section, Comment row
  - environment: Acid electrolyte with electrochemical cycling (PtCu/C catalyst)
    headline: Copper leaves the PtCu/C surface during activation in acid, and the copper content falls.
    effect: After 100 voltammetric cycles in 0.1 M HClO4, the Cu to Pt ratio fell from PtCu1.3 to PtCu0.25 after activation to 1.20 V, and to PtCu0.24 after activation to 1.00 V. The authors call this de-alloying. The text read here does not report Pt or Cu dissolved into the electrolyte.
    rating: moderate
    conditions:
      electrolyte: 0.1 M HClO4
      cycling: 100 cycles at 200 mV/s, 0.04 to 1.20 V or 0.04 to 1.00 V vs RHE
      composition_basis: after the activation stage, as printed in Table 1
    source: pavlets2021
    where: Section 2 (activation procedure) and Table 1, column Composition after the Activation Stage
risks:
  hazards:
    - text: 'PubChem tungsten record (CID 23964): 26.5 % of company reports (196 of 741) do not meet GHS criteria. Notified codes are H228 (73.4 %, flammable solid), H252 (47.8 %, self-heating in large quantities), H320 (eye irritation) and H335 (respiratory irritation).'
      ghs:
        - H228
        - H252
        - H320
        - H335
      source: pubchem-w
      where: Safety and Hazards, GHS Classification (CID 23964)
    - text: 'PubChem platinum record (CID 23939): 81.3 % of company reports (410 of 504) do not meet GHS criteria. H228 (10.7 %, flammable solid) is shown, and H315 (skin irritation) and H334 (sensitisation, respiratory) come from the notifications.'
      ghs:
        - H228
        - H315
        - H334
      source: pubchem-pt
      where: Safety and Hazards, GHS Classification (CID 23939)
    - text: 'PubChem copper record (CID 23978): 52.5 % of company reports (1818 of 3463) do not meet GHS criteria. Notified codes include H302 (21.7 %), H400 (43.1 %), H410 (18.8 %), H411 (22.5 %), H317, H335, H370 and H372.'
      ghs:
        - H302
        - H317
        - H335
        - H370
        - H372
        - H400
        - H410
        - H411
      source: pubchem-cu
      where: Safety and Hazards, GHS Classification (CID 23978)
  failure_risks:
    - mode: Copper loss from the PtCu catalyst surface in acid
      trigger: Electrochemical activation cycling in 0.1 M HClO4
      consequence: Copper falls to a Cu to Pt ratio of about 0.25 after activation in both windows, while the activation window changes the kinetic current (417 and 878 A/g(Pt) in Table 1). The authors attribute the activity difference to surface structure, not composition.
      severity: moderate
      source: pavlets2021
      where: Table 1, columns Composition after the Activation Stage and Ik A g-1 (Pt); Section 2
  side_effects:
    - text: PtW8 density is 21.26 g/cm3, so parts are heavy for their size.
      affects: Mass of electrodes, probes and wire assemblies
      source: hera158
      where: General information table, row Density
  handling:
    - text: Heraeus lists PtW8 as ductile, formable and machinable, but hardly formable, and as not age hardenable.
      source: hera158
      where: Forming Processes table, rows Age Hardenable, Material Behaviour and Forming Process
  mitigations: []
uses:
  - application: propulsion-and-tanks
    device: Spark plug electrodes
    example: Heraeus lists PtW8 for spark plug electrodes, supplied as wire.
    source: hera158
    where: General information table, row Applications
  - application: thermal-control
    device: Resistance and heater wire in high-temperature furnaces
    example: Goodfellow lists Pt92/W8 wire for specialised resistance wiring in high-temperature furnaces and for precision heater coils.
    source: goodfellow-ptw
    where: Uses and applications description
  - application: electronics-and-chips
    device: Sensor assemblies, microfabricated probe tips and electrical feedthroughs
    example: Goodfellow lists Pt92/W8 for advanced sensor assemblies, microfabricated probe tips and high-vacuum electrical feedthroughs.
    source: goodfellow-ptw
    where: Uses and applications description
  - application: batteries
    device: Acid fuel-cell electrode catalyst (laboratory study, not a battery)
    example: A 2021 study reports a peak methanol oxidation current of 1236 A/g(Pt) for dealloyed PtCu/C, against 350 A/g(Pt) for a commercial Pt/C reference, in 0.1 M HClO4 with methanol.
    source: pavlets2021
    where: Introduction and Table 2
supply:
  - subject: Platinum (world mine production, used for the platinum content)
    producers:
      - country: South Africa
        share_percent: 70.6
        year: 2025
      - country: Russia
        share_percent: 11.8
        year: 2025
      - country: Zimbabwe
        share_percent: 10.6
        year: 2025
      - country: Canada
        share_percent: 2.9
        year: 2025
      - country: United States
        share_percent: 1.1
        year: 2025
    critical_lists: []
    recycling: 'USGS: about 140,000 kg of palladium and platinum were recovered globally from new and old scrap in 2025.'
    substitutes: []
    source: usgs-mcs2026-pgm
    where: World Mine Production and Reserves table, platinum 2025e (South Africa 120,000 kg, Russia 20,000, Zimbabwe 18,000, Canada 5,000, United States 1,800, world total 170,000 kg). Shares calculated by Space Mushroom from those kilogram values. Recycling paragraph, PGM chapter.
  - subject: Tungsten
    producers:
      - country: China
        share_percent: 78.8
        year: 2025
      - country: Vietnam
        share_percent: 3.5
        year: 2025
      - country: Kazakhstan
        share_percent: 2.8
        year: 2025
      - country: Russia
        share_percent: 2.4
        year: 2025
      - country: Korea, North
        share_percent: 2.4
        year: 2025
    critical_lists: []
    recycling: 'USGS: the quantity of secondary tungsten produced and consumed in 2025 was withheld to avoid disclosing company data.'
    substitutes:
      - 'USGS: molybdenum can replace tungsten in some mill products, and depleted uranium or lead can replace tungsten alloys where high density or radiation shielding is needed.'
    source: usgs-mcs2026-tungsten
    where: World Mine Production table, mine production 2025e (China 67,000 t, Kazakhstan 2,400, Vietnam 3,000, Russia 2,000, Korea North 2,000, world total 85,000 t of tungsten content). Shares calculated by Space Mushroom. Recycling and Substitutes paragraphs.
  - subject: Copper
    producers:
      - country: Chile
        share_percent: 23
        year: 2025
      - country: Congo (Kinshasa)
        share_percent: 13.9
        year: 2025
      - country: Peru
        share_percent: 11.7
        year: 2025
      - country: China
        share_percent: 7.8
        year: 2025
      - country: Russia
        share_percent: 5.7
        year: 2025
    critical_lists:
      - list: USGS Final 2025 List of Critical Minerals (the copper chapter says copper was added in 2025)
        listed: true
    recycling: 'USGS: old scrap gave an estimated 160,000 tons of copper in the United States in 2025.'
    substitutes:
      - 'USGS: aluminum substitutes for copper in several electrical and cooling uses, and optical fiber substitutes for copper in telecommunications.'
    source: usgs-mcs2026-copper
    where: World Mine and Refinery Production table, mine production 2025e (world total 23,000 thousand t of copper content; Chile 5,300; Congo (Kinshasa) 3,200; Peru 2,700; China 1,800; Russia 1,300). Shares calculated by Space Mushroom. Critical list statement and Recycling and Substitutes paragraphs.
documents:
  - title: Heraeus Precious Metals, PtW8 (Hera 158) datasheet, status 11/2021
    type: datasheet
    url: https://pim.heraeus.com/datasheets/HPM/FM/Contact%20Materials/Hera_158_Datasheet_EN_(Heraeus_Precious_Metals).pdf
    year: 2021
  - title: Goodfellow, Platinum/Tungsten Alloy Spooled Wire (Pt92/W8) product page
    type: datasheet
    url: https://www.goodfellow.com/usa/platinum-tungsten-alloy-spooled-wire-pt92-w8-group
    year: 2026
  - title: PubChem compound record, Tungsten (CID 23964), GHS classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23964
    year: 2026
  - title: PubChem compound record, Platinum (CID 23939), GHS classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23939
    year: 2026
  - title: PubChem compound record, Copper (CID 23978), GHS classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23978
    year: 2026
  - title: Mineral Commodity Summaries 2026, full report (platinum-group metals chapter)
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026.pdf
    year: 2026
  - title: Mineral Commodity Summaries 2026, Tungsten
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tungsten.pdf
    year: 2026
  - title: Mineral Commodity Summaries 2026, Copper
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
  - title: Pavlets et al., Influence of Electrochemical Pretreatment Conditions of PtCu/C Alloy Electrocatalyst on Its Activity, Nanomaterials 11, 1499 (open access)
    type: paper
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC8229528/
    year: 2021
gaps:
  - No bulk density, melting range or hardness for Pt-Cu was read in a page this run. The 2014 PtCu3 ordering paper (RSC Phys. Chem. Chem. Phys.) and the 2021 Nanoscale de-alloyed PtCu/C paper returned HTTP 403, so their numbers are not used.
  - No Pt-Cu datasheet, handbook or phase-diagram page was read. ASM Handbook and Hansen or Massalski phase-diagram sources were not reached in this run.
  - No Young's modulus, thermal conductivity, expansion coefficient or specific heat for PtW8 appears in the Heraeus datasheet, and no other page read gives them with a condition.
  - The Heraeus datasheet gives no temperature or test method for any PtW8 property. Goodfellow gives no test conditions for its values.
  - The 8 % tungsten composition is from the Goodfellow product name (Pt92/W8) and the Calfine product name (Platinum 8% Tungsten), not from the Heraeus datasheet, which prints no composition.
  - No UNS, EN, DIN, JIS or ASTM designation for PtW8 was printed in a page read this run. Only the Heraeus names PtW8 and Hera 158 are recorded.
  - The Calfine Pt-8W page gives a thermal EMF against copper of -0.014 with no unit or temperature, and a resistivity printed with a mixed unit. Neither is used.
  - No critical-mineral status for platinum or tungsten was confirmed from the chapters read in this run. Copper is recorded as listed, from its own chapter.
  - Hazard records are for the platinum, tungsten and copper elements, not for the alloys. No Pt-W or Pt-Cu safety data sheet was read.
  - Pt-Cu supply and corrosion entries describe the metals or the laboratory catalyst, not the bulk alloy. No bulk Pt-Cu corrosion or service test was found.
  - The fuel-cell catalyst use has no fixed application in the list. It is filed under batteries and labelled as a laboratory fuel-cell catalyst, not a battery.
  - Non-canonical benchmark names are used for vickers_hardness, electrical_conductivity, temperature_coefficient_of_resistance, electrochemically_active_surface_area, methanol_oxidation_peak_current, lattice_parameter and crystallite_size. Add them to spores/property-canon.yaml if they are kept.
  - The Heraeus conductivity minimum and maximum are printed in reverse order (2.77 above 2.58). The range is entered low to high with a note in the method field.
  - No space-electrode, vacuum outgassing or flight source for Pt-W or Pt-Cu was found in this run.
  - Medical wire is listed for PtW8 in the datasheet and is mentioned in the story only. No fixed application in the list fits medical implants.
sources:
  hera158:
    title: Hera 158, PtW8, Heraeus Precious Metals datasheet (status 11/2021)
    url: https://pim.heraeus.com/datasheets/HPM/FM/Contact%20Materials/Hera_158_Datasheet_EN_(Heraeus_Precious_Metals).pdf
    year: 2021
    kind: datasheet
    license: Manufacturer datasheet (cited, not reproduced)
  goodfellow-ptw:
    title: Goodfellow, Platinum/Tungsten Alloy Spooled Wire (Pt92/W8) product page
    url: https://www.goodfellow.com/usa/platinum-tungsten-alloy-spooled-wire-pt92-w8-group
    year: 2026
    kind: web
    license: Supplier product page (cited, not reproduced)
  pubchem-w:
    title: PubChem compound record, Tungsten (CID 23964), GHS classification
    id: CID 23964
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23964
    year: 2026
    kind: database
    license: PubChem (NCBI); sections attributed to ECHA and NITE-CMC
  pubchem-pt:
    title: PubChem compound record, Platinum (CID 23939), GHS classification
    id: CID 23939
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23939
    year: 2026
    kind: database
    license: PubChem (NCBI); sections attributed to ECHA and NITE-CMC
  pubchem-cu:
    title: PubChem compound record, Copper (CID 23978), GHS classification
    id: CID 23978
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23978
    year: 2026
    kind: database
    license: PubChem (NCBI); sections attributed to ECHA and others
  usgs-mcs2026-pgm:
    title: Mineral Commodity Summaries 2026, Platinum-Group Metals chapter (U.S. Geological Survey, February 2026)
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-tungsten:
    title: Mineral Commodity Summaries 2026, Tungsten (U.S. Geological Survey, February 2026)
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tungsten.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-copper:
    title: Mineral Commodity Summaries 2026, Copper (U.S. Geological Survey, February 2026)
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  pavlets2021:
    title: Influence of Electrochemical Pretreatment Conditions of PtCu/C Alloy Electrocatalyst on Its Activity (Nanomaterials 11, 1499)
    id: doi:10.3390/nano11061499 (PMC8229528)
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC8229528/
    year: 2021
    kind: paper
    license: CC BY 4.0
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 18
  unreachable: 2
  caveats: 5
  note: 'Read by an AI assistant on 2026-10-26 from the Heraeus Hera 158 datasheet, the Goodfellow Pt92/W8 page, PubChem records for W, Pt and Cu, the USGS MCS 2026 chapters for platinum, tungsten and copper, and one 2021 open-access paper on PtCu/C. Unreachable: two RSC articles on Pt-Cu (403). Caveats: the datasheets give no temperatures; the Pt-Cu values are for a carbon-supported catalyst, not bulk alloy; the platinum and tungsten shares and the copper shares are calculated from production values; the hazard records are for the elements; no bulk Pt-Cu property was found.'
story:
  recipe:
    line: Pt-8W is a binary alloy of platinum and tungsten, 92 % platinum and 8 % tungsten by mass. The Heraeus datasheet calls the same grade PtW8 and gives no composition; the 8 % figure comes from the Goodfellow and Calfine product names. Platinum-copper has no fixed bulk composition in these sources. The catalyst studied has a Cu to Pt ratio of 1.3 by XRF before activation, and its lattice parameter gives a Vegard composition of PtCu0.54.
    parts:
      - name: Platinum
        symbol: Pt
        share_percent: 92
        role: The matrix metal, about 92 % by mass. The Heraeus datasheet gives a density of 21.26 g/cm3 for the alloy.
      - name: Tungsten
        symbol: W
        share_percent: 8
        role: The minor element, about 8 % by mass. The datasheet gives tensile strength of 800 to 1100 MPa for the alloy, but does not say what tungsten contributes.
  risk_groups:
    - title: For people
      level: 1
      verdict: Mixed element records
      lead: The platinum, tungsten and copper element records carry flammable, irritant or aquatic codes in some company reports. The alloys have no record of their own.
      points:
        - label: Platinum element
          line: Of 504 company reports, 410 said platinum does not meet GHS criteria. H228 (flammable solid, 10.7 %) is shown, and H334 (respiratory sensitisation) comes from the notifications.
        - label: Tungsten element
          line: Of 741 company reports, 196 said tungsten does not meet GHS criteria. H228 (73.4 %) and H252 (47.8 %, self-heating in large quantities) are shown, with H320 and H335.
        - label: Copper element
          line: Of 3463 company reports, 1818 said copper does not meet GHS criteria. Notified codes include H400 (43.1 %) and H410 (18.8 %), which concern aquatic life, and H302 (21.7 %).
    - title: If it fails
      lead: The only failure route in a read source is copper loss from the catalyst in acid, found in a laboratory study.
      points:
        - label: Catalyst activation
          line: In the 2021 study, 100 cycles in 0.1 M HClO4 took the Cu to Pt ratio from 1.3 to about 0.25. The two activation windows gave the same composition but different kinetic currents, so the surface state matters as well as the composition.
    - title: Handling and storage
      points:
        - label: Forming
          line: Heraeus lists PtW8 as ductile and formable, but hardly formable, and as not age hardenable. It is machinable.
        - label: Heat
          line: The datasheet lists oxidation resistance to 1000 °C. It gives no test conditions.
  why: Platinum-tungsten is chosen where a dense, heat-resistant precious metal is needed in wire form. Heraeus lists PtW8 for spark plug electrodes, resistance wire and medical wire, and Goodfellow lists the same composition for furnace heater wire, sensor assemblies and probe tips. Platinum-copper appears in the sources as a laboratory catalyst for acid fuel-cell reactions. The bulk alloy's properties are not in the sources read here.
  uses:
    - where: Spark plug electrodes
      line: Heraeus lists PtW8 for spark plug electrodes, supplied as wire.
    - where: Furnace and heater wire
      line: Goodfellow lists Pt92/W8 for specialised resistance wiring in high-temperature furnaces and for precision heater coils.
    - where: Sensors and probe tips
      line: Goodfellow lists Pt92/W8 for advanced sensor assemblies, microfabricated probe tips and high-vacuum electrical feedthroughs.
    - where: Fuel-cell catalyst (laboratory)
      line: A 2021 study reports a peak methanol oxidation current of 1236 A/g(Pt) for dealloyed PtCu/C, against 350 A/g(Pt) for a commercial Pt/C reference, in 0.1 M HClO4 with methanol.
  can_do:
    - label: Density
      value: 21.26 g/cm3
      benchmark: density
      line: The PtW8 wire has a density of 21.26 g/cm3 in the Heraeus datasheet. Goodfellow gives 21.3 g/cm3 for Pt92/W8.
    - label: Melting
      value: 1865 to 1885 °C
      benchmark: melting_point
      line: Heraeus gives a melting range of 1865 to 1885 °C for PtW8. Goodfellow gives 1870 to 1910 °C for Pt92/W8.
    - label: Hardness
      value: 200 to 300 HV
      benchmark: vickers_hardness
      line: The Heraeus datasheet gives 200 to 300 HV for PtW8, with tensile strength of 800 to 1100 MPa.
    - label: Catalyst activity
      value: 1236 A/g(Pt)
      benchmark: methanol_oxidation_peak_current
      line: The dealloyed PtCu/C catalyst gave a peak methanol oxidation current of 1236 A/g(Pt), against 350 A/g(Pt) for the commercial reference, in one laboratory study.
  compare: Platinum-tungsten is a heavy, high-melting wire metal with low electrical conductivity (2.58 to 2.77 % IACS in the Heraeus datasheet). The Heraeus datasheet gives its melting range as 1865 to 1885 °C. The rows below show the bulk alloy's density, melting range and modulus where a source gives them; no comparison with other materials was read in this run.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Melting point
      benchmark: melting_point
    - label: Modulus of elasticity
      benchmark: elastic_modulus
  handling:
    - Heraeus lists PtW8 as hardly formable, so plan forming steps with that in mind.
    - Keep fine forms away from heat and ignition sources, since PubChem gives H228 for the platinum and tungsten element records.
    - Use the temper and form with every strength value. The datasheet gives only ranges, with no temper stated.
  good_for:
    - Heat-resistant wire where density is acceptable. Heraeus lists PtW8 for resistance wire and spark plug electrodes.
    - Sensor and probe wire. Goodfellow lists Pt92/W8 for sensor assemblies and microfabricated probe tips.
    - Laboratory fuel-cell catalyst research on dealloyed PtCu/C, in acid electrolyte.
  watch_out:
    - Heavy for its size at 21.26 g/cm3.
    - Low conductivity, 2.58 to 2.77 % IACS in the datasheet.
    - The PtCu catalyst loses copper in acid during activation. The composition moves from PtCu1.3 to about PtCu0.25.
    - No bulk Pt-Cu density, melting point or hardness was read in this run.
  verdict: Platinum-tungsten is a dense, oxidation-resistant wire metal with datasheet values for density, melting range and mechanical strength. Platinum-copper is only covered here as a catalyst, and the bulk alloy needs a handbook source before it is used.