spore: profile
id: electroless-nickel
spore_version: 0.2
family: nickel-phosphorus-coatings
name: Electroless nickel-phosphorus plating (AMS 2404 / ASTM B733)
abbreviation: NiP
role: Corrosion- and wear-resistant metal coating on aluminium and other substrates
category: coatings
type: conductive-coatings
summary: |
  Electroless nickel-phosphorus (NiP) is a nickel coating that contains 1 to 13 % phosphorus by weight, with the grade set by the phosphorus content. The medium grade (5 to 9 % P) is the general-purpose wear and corrosion coating in NASA's process specification. As plated, the Kanigen table gives about 580 HV 0.1 for the medium grade, and about 900 HV 0.1 after a 290 degC heat treatment. NASA's JSC specification PRC-5007 requires a minimum thickness of 0.0010 inch on aluminium alloys and a maximum of 0.0030 inch, and it calls for a hydrogen bakeout at 375 F on listed high-strength steels.
best_for: Hard, wear- and corrosion-resistant plating on aluminium connector shells and flight hardware, where a plated finish is specified (NASA recommends it for connector shells)
weakest_at: No space-environment test result (outgassing, atomic oxygen or thermal vacuum) and no measured corrosion rate was found, and the supplier sources disagree on thermal conductivity by about a factor of ten
identity:
  formula: Ni-P alloy deposit, nickel with 1 to 13 % phosphorus by weight (low, medium and high phosphorus grades)
  source: nasa-prc-5007
  where: Section 3.0 Usage, phosphorus callouts (1 - 3 %, 5 - 9 %, 9 - 13 % P)
tags:
  environments: []
  stresses: []
  applications:
    - structures
    - electronics-and-chips
    - mechanisms
properties:
  - benchmark: melting_point
    label: Melting point, KANIGEN MP (medium phosphorus)
    value: 890
    unit: °C
    scope: material
    conditions:
      grade: KANIGEN MP, 5 - 9 % wt. phosphorus
      table_column: MP
    method: Value printed in a manufacturer comparison table (technical information, ISO 4527 comparison)
    status: ground
    source: kanigen-atela
    where: Technical information table, row Melting point, column MP
  - benchmark: melting_point
    label: Melting point, KANIGEN HP (high phosphorus)
    value: 875
    unit: °C
    scope: material
    conditions:
      grade: KANIGEN HP, more than 10 % wt. phosphorus
      table_column: HP
    method: Value printed in a manufacturer comparison table (technical information, ISO 4527 comparison)
    status: ground
    source: kanigen-atela
    where: Technical information table, row Melting point, column HP
  - benchmark: melting_point
    label: Melting point, KANIGEN LP (low phosphorus)
    value: 910
    unit: °C
    scope: material
    conditions:
      grade: KANIGEN LP, 1 - 4 % wt. phosphorus
      table_column: LP
    method: Value printed in a manufacturer comparison table (technical information, ISO 4527 comparison)
    status: ground
    source: kanigen-atela
    where: Technical information table, row Melting point, column LP
  - benchmark: melting_point
    label: Melting range, electroless nickel (supplier technical data panel)
    value: 890
    value_high: 1300
    bound: range
    unit: °C
    scope: material
    conditions:
      basis: generic range in the supplier technical data panel, not tied to one phosphorus grade
    method: Range printed in a supplier technical data panel
    status: ground
    note: Wider than the three Kanigen grade values (875 to 910 °C). The sources disagree and both are recorded.
    source: advplating-specs
    where: Electroless Nickel Plating, Technical Data Panel, melting point
  - benchmark: electrical_resistivity
    label: Electrical resistivity, KANIGEN HP
    value: 110
    unit: µΩ·cm
    scope: material
    conditions:
      grade: KANIGEN HP, more than 10 % wt. phosphorus
      unit_in_source: µOcm (printed)
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Electrical resistivity, column HP
  - benchmark: electrical_resistivity
    label: Electrical resistivity, KANIGEN MP
    value: 72
    unit: µΩ·cm
    scope: material
    conditions:
      grade: KANIGEN MP, 5 - 9 % wt. phosphorus
      unit_in_source: µOcm (printed)
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Electrical resistivity, column MP
  - benchmark: electrical_resistivity
    label: Electrical resistivity, KANIGEN LP
    value: 30
    unit: µΩ·cm
    scope: material
    conditions:
      grade: KANIGEN LP, 1 - 4 % wt. phosphorus
      unit_in_source: µOcm (printed)
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Electrical resistivity, column LP
  - benchmark: electrical_resistivity
    label: Electrical resistivity, electrolytic nickel (comparison column)
    value: 6.8
    unit: µΩ·cm
    scope: material
    conditions:
      material: electrolytic nickel, the comparison column in the Kanigen table
      unit_in_source: µOcm (printed)
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Electrical resistivity, column Electrolytic nickel
  - benchmark: electrical_resistivity
    label: Electrical resistivity, electroless nickel (supplier technical data panel)
    value: 100
    value_high: 1100
    bound: range
    unit: nΩ·m
    scope: material
    conditions:
      basis: generic range in the supplier technical data panel, not tied to one phosphorus grade
    method: Range printed in a supplier technical data panel
    status: ground
    note: Printed in nΩ·m; the Kanigen grades read 30 to 110 µΩ·cm. The sources give different ranges and both are recorded.
    source: advplating-specs
    where: Electroless Nickel Plating, Technical Data Panel, electrical resistivity
  - benchmark: hardness_vickers
    label: Hardness as plated, electrolytic nickel (comparison column)
    value: 200
    unit: HV
    scope: material
    conditions:
      material: electrolytic nickel, the comparison column in the Kanigen table
      load: not printed for this row
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Hardness (without Therm line), column Electrolytic nickel
  - benchmark: cte
    label: Coefficient of thermal expansion, KANIGEN HP, MP and LP (same value printed for each)
    value: 13
    unit: ppm/K
    scope: material
    conditions:
      temperature: room temperature
      unit_in_source: 13 x 10 – 6 / °K (printed)
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Expansion coefficient
  - benchmark: thermal_conductivity
    label: Thermal conductivity, KANIGEN MP
    value: 0.7
    unit: W/(cm·K)
    scope: material
    conditions:
      grade: KANIGEN MP
      note_on_value: printed with a tilde as approximate (~ 0.7)
    method: Approximate value printed in a manufacturer comparison table
    status: ground
    note: About ten times the supplier panel range below (0.042 to 0.067 W/(cm·K)). The sources disagree and both are recorded.
    source: kanigen-atela
    where: Technical information table, row Thermal conductivity (W/cm x K), column MP
  - benchmark: thermal_conductivity
    label: Thermal conductivity, electroless nickel (supplier technical data panel)
    value: 0.042
    value_high: 0.067
    bound: range
    unit: W/(cm·K)
    scope: material
    conditions:
      basis: generic range in the supplier technical data panel, not tied to one phosphorus grade
    method: Range printed in a supplier technical data panel
    status: ground
    source: advplating-specs
    where: Electroless Nickel Plating, Technical Data Panel, thermal conductivity
  - benchmark: density
    label: Density, electroless nickel (supplier technical data panel)
    value: 7.6
    value_high: 8.8
    bound: range
    unit: g/cm3
    scope: material
    conditions:
      basis: generic range in the supplier technical data panel, not tied to one phosphorus grade
    method: Range printed in a supplier technical data panel
    status: ground
    source: advplating-specs
    where: Electroless Nickel Plating, Technical Data Panel, density
  - benchmark: hardness_vickers
    label: Hardness as plated, KANIGEN HP
    value: 520
    unit: HV
    scope: material
    conditions:
      grade: 'KANIGEN HP, as plated (row label: without thermal treatment)'
      load: 0.1 (printed as HV 0.1)
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Hardness (without Therm line), column HP
  - benchmark: hardness_vickers
    label: Hardness as plated, KANIGEN MP
    value: 580
    unit: HV
    scope: material
    conditions:
      grade: 'KANIGEN MP, as plated (row label: without thermal treatment)'
      load: 0.1 (printed as HV 0.1)
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Hardness (without Therm line), column MP
  - benchmark: hardness_vickers
    label: Hardness as plated, KANIGEN LP
    value: 650
    unit: HV
    scope: material
    conditions:
      grade: 'KANIGEN LP, as plated (row label: without thermal treatment)'
      load: not printed for this row
    method: Value printed in a manufacturer comparison table
    status: ground
    note: The LP row prints HV without a test load, so the load is not stated.
    source: kanigen-atela
    where: Technical information table, row Hardness (without Therm line), column LP
  - benchmark: hardness_vickers
    label: Hardness after heat treatment, KANIGEN (medium grade row, same value printed for HP and LP)
    value: 900
    unit: HV
    scope: material
    conditions:
      treatment: 'thermal treatment at 290 °C for 5 hours (row label: with thermal treatment 290 °C 5 h)'
      load: 0.1 (printed as HV 0.1)
    method: Value printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Hardness (with trait. Therm 290°C 5h)
  - benchmark: hardness_vickers
    label: Hardness, non-heat-treated deposit (Kanigen text)
    value: 500
    value_high: 550
    bound: range
    unit: HV
    scope: material
    conditions:
      state: non-heat-treated, as printed in the Hardness section
      load: 0.1 (printed as HV 0.1)
    method: Range printed in a manufacturer product text
    status: ground
    note: The same page's table gives 520 to 650 HV 0.1 as plated. The two statements are recorded side by side.
    source: kanigen-atela
    where: Hardness section of the Kanigen page
  - benchmark: hardness_vickers
    label: Hardness after heat treatment (Kanigen text)
    value: 1100
    unit: HV
    scope: material
    conditions:
      treatment: one hour at 400 C or 5 hours at 290 C (as printed)
      load: 0.1 (printed as HV 0.1)
    method: Value printed in a manufacturer product text
    status: ground
    note: The same page's table gives about 900 HV 0.1 after heat treatment. The two values are recorded side by side.
    source: kanigen-atela
    where: Hardness section of the Kanigen page
  - benchmark: hardness_rockwell_c
    label: Hardness, medium phosphorus (6 to 9 % P, Type IV), as plated
    value: 58
    value_high: 62
    bound: range
    unit: Rc
    scope: material
    conditions:
      grade: medium phosphorus, 6 to 9 % P as printed
      condition: as plated
    method: Range printed in a supplier technical data page
    status: ground
    note: The same page writes the medium grade as 6 to 9 % P, while the NASA text and the ASTM summary on the same page write 5 to 9 % P.
    source: advplating-specs
    where: Electroless Nickel Plating, Deposit Properties, medium phosphorous row
  - benchmark: hardness_rockwell_c
    label: Hardness, medium phosphorus (6 to 9 % P, Type IV), with heat treatment
    value: 66
    value_high: 70
    bound: range
    unit: Rc
    scope: material
    conditions:
      grade: medium phosphorus, 6 to 9 % P as printed
      condition: with heat treatment (temperature and time not printed in this row)
    method: Range printed in a supplier technical data page
    status: ground
    source: advplating-specs
    where: Electroless Nickel Plating, Deposit Properties, medium phosphorous row
  - benchmark: hardness_knoop
    label: Minimum hardness, ASTM B733 Class 2 heat treatment
    value: 850
    bound: lower
    unit: HK100
    scope: material
    conditions:
      standard: ASTM B733 Class 2
      condition: after hardening heat treatment at 260 to 400 °C
    method: Minimum value printed in a supplier summary of ASTM B733
    status: ground
    note: The same page gives 800 HK100 as the AMS 2404 Class 2 minimum. Both are recorded.
    source: advplating-specs
    where: ASTM B733 Class 2 entry, Electroless Nickel Plating page
  - benchmark: hardness_knoop
    label: Minimum hardness, AMS 2404 Class 2 heat treatment
    value: 800
    bound: lower
    unit: HK100
    scope: material
    conditions:
      standard: AMS 2404 Class 2
      condition: after hardening heat treatment
    method: Minimum value printed in a supplier summary of AMS 2404
    status: ground
    source: advplating-specs
    where: AMS 3.4.4 (Class 2 hardness), Electroless Nickel Plating page
  - benchmark: max_service_temp
    label: Service temperature, electroless nickel deposit (AMS 2404C statement)
    value: 538
    unit: °C
    scope: material
    conditions:
      standard: AMS-2404C
      unit_in_source: 1000F (printed as up to 1000F (538C))
    method: Service temperature statement printed on a finishing reference page; not a test result
    status: ground
    source: engineersedge
    where: Introduction (AMS-2404C, AMS-2505B, AMS-2433B)
  - benchmark: coating_thickness
    label: Electroless nickel thickness on aluminium, minimum to maximum
    value: 0.001
    value_high: 0.003
    bound: range
    unit: inch
    scope: material
    conditions:
      substrate: aluminium alloys
      standard: NASA/JSC PRC-5007 Rev. E, Table 1
    method: Requirement printed in NASA's process specification
    status: ground
    note: Pitting and roughness are a process control problem above 0.0030 inch, per the footnote to Table 1.
    source: nasa-prc-5007
    where: Table 1, Thickness Requirements for Electroless Nickel Plate, row Aluminum
  - benchmark: phosphorus_content
    label: Phosphorus content, low phosphorus grade
    value: 1
    value_high: 4
    bound: range
    unit: '% wt'
    scope: material
    conditions:
      grade: KANIGEN LP
    method: Range printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Chemical composition, column LP
  - benchmark: phosphorus_content
    label: Phosphorus content, medium phosphorus grade
    value: 5
    value_high: 9
    bound: range
    unit: '% wt'
    scope: material
    conditions:
      grade: KANIGEN MP
    method: Range printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Chemical composition, column MP
  - benchmark: phosphorus_content
    label: Phosphorus content, high phosphorus grade
    value: 10
    bound: lower
    unit: '% wt'
    scope: material
    conditions:
      grade: KANIGEN HP
      printed_as: '> 10 % wt. Phosphorus'
    method: Lower bound printed in a manufacturer comparison table
    status: ground
    source: kanigen-atela
    where: Technical information table, row Chemical composition, column HP
corrosion:
  - environment: Periodic salt-spray check of a corrosion test panel (ASTM B117)
    headline: The process specification requires a 48-hour salt-spray check of a periodic test panel, but it prints no result.
    effect: NASA/JSC PRC-5007 requires a periodic corrosion test panel to be tested for 48 hours in a continuous salt spray test under ASTM B117. The specification states the test duration only, so no corrosion rate or pass result for this deposit is recorded here.
    rating: unknown
    conditions:
      test: continuous salt spray, ASTM B117, 48 hours
      result: not printed in the source
    source: nasa-prc-5007
    where: Section 7.0 Process qualification
  - environment: Higher phosphorus deposits (9 to 13 % P) in corrosive service
    headline: NASA says the higher-phosphorus deposit gives increased corrosion resistance, and the Kanigen text claims up to five times the corrosion resistance of electrolytic nickel.
    effect: NASA's process specification states that a deposit in the range 9 to 13 % P gives increased corrosion resistance. The Kanigen text states that the coating is up to 5 times more resistant to corrosion than electrolytic nickel, according to the Taber index. The Taber index is a wear index, and the page gives no test conditions, so the five-fold figure is recorded as a claim and not verified.
    rating: low
    conditions:
      basis: qualitative statement in NASA text and a supplier claim; no measured corrosion rate
      comparison: electrolytic nickel
    source: nasa-prc-5007
    where: Section 3.0 Usage, higher phosphorous coating callout; the five-fold claim is in the Kanigen page text, Wear resistance and Corrosion resistance sections
risks:
  hazards:
    - text: PubChem's GHS record for nickel (CID 935) gives H317, May cause an allergic skin reaction, with the signal word Danger in its main entries. Some notifications in the same record also carry H350 and H351 cancer codes. The record is for elemental nickel, not for the phosphorus-containing deposit.
      ghs:
        - H317
      source: pubchem-nickel
      where: GHS Classification section, aggregated company notifications (CID 935)
  failure_risks:
    - mode: Poor adhesion on aluminium alloys
      trigger: Plating aluminium without the adhesion steps and checks in the specification
      consequence: NASA says plating adhesion can be a problem with aluminium alloys. It requires a 180-degree bend test to ASTM B571 over a 4T mandrel, and a Class 3 or Class 4 thermal treatment to improve adhesion.
      severity: moderate
      source: nasa-prc-5007
      where: Section 7.0 Process qualification; Section 3.0 classes
    - mode: Hydrogen embrittlement of high-strength steel
      trigger: Steel at 150 ksi or more, or tempered below 375 F, plated without a hydrogen bakeout
      consequence: NASA requires a hydrogen bakeout within four hours of plating for the steels listed in its Table 2. The ASTM B733 summary gives Class 3 at 180 to 200 °C for 2 to 4 hours for steel adhesion and hydrogen embrittlement relief.
      severity: high
      source: nasa-prc-5007
      where: Table 2 (steels that require a hydrogen bakeout) and the hydrogen bakeout note in Section 3.0
    - mode: Pitting and roughness in thick deposits
      trigger: Deposit thicker than 0.0030 inch
      consequence: NASA notes that pitting and roughness become a process control problem above 0.0030 inch.
      severity: low
      source: nasa-prc-5007
      where: Table 1 footnote
  side_effects:
    - text: A post-plate bake above 500 F can change the deposit from amorphous to crystalline and greatly raise its hardness, according to the APT page on electroless deposition.
      affects: Hardness and internal structure of the coating
      source: advplating-specs
      where: What is Electroless Deposition section
    - text: A US patent on aluminium mirrors argues that a nickel layer on aluminium is theoretically bimetallic and deforms with temperature, which it says degrades optical performance. The patent gives this as the inventors' position and gives no test result for it.
      affects: Optical figure of aluminium mirrors (the patent's claim)
      source: us6350176
      where: Background and summary text of the patent
  handling:
    - text: The specification requires the thickness, the PRC-5007 reference and the AMS 2404 class to be called out on the engineering drawing, and the phosphorus content to be called out when it is outside 5 to 9 %.
      source: nasa-prc-5007
      where: Section 3.0 Usage and the phosphorus callout text
    - text: Bake listed steels at 375 F within four hours of plating, per NASA's hydrogen bakeout note. The duration printed in the extracted text is not recorded here.
      source: nasa-prc-5007
      where: Section 3.0 hydrogen bakeout note and Table 2
    - text: NASA PRC-5007 does not cover titanium or beryllium alloys, but the AMS 2404 and ASTM B733 classes list beryllium alloys for the Class 3 and Class 5 treatments.
      source: nasa-prc-5007
      where: Section 2.0 Applicability; the class list is on the Electroless Nickel Plating specifications page (advplating-specs)
  mitigations:
    - text: 'Match the heat-treatment class to the substrate: AMS 2404 Class 3 at 375 F for nonheat-treatable aluminium and beryllium, and Class 4 at 250 F for heat-treatable aluminium.'
      source: advplating-specs
      where: AMS 2404 classes, Electroless Nickel Plating specifications page
uses:
  - application: electronics-and-chips
    device: Aluminium connector shells for space-flight connectors
    example: NASA recommends electroless nickel or gold plating on connector shells, and Glenair describes that guidance for its space-grade connectors, which list electroless nickel as the shell finish.
    source: glenair-hiper-d
    where: Connector Material and Finish for Space Applications panel
  - application: structures
    device: NASA/JSC flight hardware in steels, aluminium, copper, nickel and cobalt alloys
    example: NASA's example callout is electroless nickel plate to a thickness of 0.0010-0.0012 inch per NASA/JSC PRC-5007, Class 4, for a 6061-T6 or 7075-T73 aluminium alloy.
    source: nasa-prc-5007
    where: Section 3.0 Usage, example callout
  - application: mechanisms
    device: General wear and corrosion parts
    example: NASA states that the medium phosphorus coating (5 - 9 % P) is the most widely used for the general-purpose requirements of wear and corrosion resistance.
    source: nasa-prc-5007
    where: Section 3.0 Usage, phosphorus callout text
supply:
  - subject: Nickel (mine production)
    producers:
      - country: Indonesia
        share_percent: 66.7
        year: 2025
      - country: Philippines
        share_percent: 6.9
        year: 2025
      - country: Russia
        share_percent: 5.1
        year: 2025
      - country: New Caledonia
        share_percent: 3.6
        year: 2025
      - country: Canada
        share_percent: 3.6
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (printed as Nickel, used to make high-strength steel, and rechargeable batteries)
        listed: true
    recycling: 'USGS: most secondary nickel was recovered as the nickel content of stainless-steel scrap; nickel in alloyed form was recovered from processing nickel-containing waste.'
    substitutes:
      - 'USGS: low-nickel, duplex or ultrahigh-chromium stainless steels have been substituted for austenitic grades in construction, and titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments.'
    source: usgs-mcs2026-nickel
    where: World Mine Production and Reserves table, 2025e (world total 3,900,000 t, rounded; shares calculated by Space Mushroom from the country values 2,600,000; 270,000; 200,000; 140,000; 140,000 t); Recycling; Substitutes; critical list from the USGS 2025 list page
media: []
documents:
  - title: NASA/JSC PRC-5007 Rev. E, Process Specification for Electroless Nickel Plating (May 2020)
    type: standard
    url: https://www.nasa.gov/wp-content/uploads/2023/03/prc-5007-current.pdf
    year: 2020
  - title: Glenair HiPer-D space-grade connector information, Connector Material and Finish for Space Applications
    type: datasheet
    url: https://www.glenair.com/hiper-d/pdf/space-grade-hiper-d-information.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: PubChem compound record, Nickel (CID 935), GHS classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Nickel
    year: 2026
  - title: Kanigen technical information table (KANIGEN HP, MP, LP and electrolytic nickel)
    type: datasheet
    url: https://coatings.atela.ch/en/coatings/kanigen-mp/
gaps:
  - No measured corrosion rate, salt-spray pass result or ISO 9227 result for the deposit was found in an opened source; the NASA 48-hour salt-spray requirement is recorded as a requirement only.
  - No space-environment result for the deposit (outgassing, total mass loss, atomic oxygen, thermal vacuum or cold welding) was found in a source we opened. The space link is NASA's connector guidance and its flight-hardware specification.
  - Density values for the Kanigen grades (7.9, 8.2, 8.5 and 8.9) are printed without a unit in the table, so they are not recorded.
  - The Kanigen high-phosphorus thermal conductivity is printed as '0.044 – 00.57' (garbled), so it is not recorded.
  - The Kanigen Taber wear index values (8, 6, 3 and 14) are printed without a unit, and the page's 'up to 5 times' wear claim does not match its own numbers, so they are not recorded.
  - A Knoop microhardness of 500-720 from the APT blog is printed with no unit and no as-plated or heat-treated label, so it is not recorded.
  - The Nickel Institute properties PDF (density by phosphorus content, resistivity, melting point) returned HTTP 403 and could not be read; the density and melting ranges here come from supplier pages.
  - Process chemistry (how the deposit is reduced without electric current) was not read in a fetched page, so the recipe lists the elements and the phosphorus grades only.
  - 'Hydrogen bakeout duration: the NASA text extraction prints ''23 hours'' for the 375 F bake, which looks like a line-break error, so the duration is not recorded.'
  - Hazard data rest on the PubChem record for elemental nickel. No supplier safety data sheet for a nickel-phosphorus deposit or its bath chemicals was read, and the PubChem record mixes notifications for several nickel forms.
  - Phosphorus supply and nickel-bath chemical supply were not looked up. The EU critical raw materials list status for nickel was not checked.
  - 'Optical use: no fetched source gives a test result for electroless nickel on an aluminium optic. The Fraunhofer and ESA optics work seen in search results was not opened, and the patent is recorded only as an inventors'' claim.'
  - Sources disagree on several values (thermal conductivity by about ten times, melting range, phosphorus ranges of 5 to 9 % against 6 to 9 %, heat-treated hardness of about 900 against 1100 HV 0.1). Both values are recorded side by side, and none is chosen.
  - 'Property names not in spores/property-canon.yaml: hardness_vickers, hardness_knoop, hardness_rockwell_c, coating_thickness and phosphorus_content.'
  - 'Beryllium and titanium: NASA PRC-5007 excludes both, while AMS 2404 Class 3 and ASTM B733 cover beryllium. No beryllium deposit value was read.'
sources:
  kanigen-atela:
    title: KANIGEN technical information table (HP, MP, LP and electrolytic nickel, ISO 4527 comparison), coatings.atela.ch
    url: https://coatings.atela.ch/en/coatings/kanigen-mp/
    kind: datasheet
    license: Manufacturer-derived comparison table (cited, not reproduced)
  advplating-blog:
    title: Electroless nickel phosphorus content (Advanced Plating Technologies blog)
    url: https://advancedplatingtech.com/blog/electroless-nickel-phosphorus-content/
    kind: web
    license: Supplier web page (cited, not reproduced)
  advplating-specs:
    title: Electroless Nickel Plating per MIL-C-26074, ASTM B733 and AMS 2404 (Advanced Plating Technologies)
    url: https://advancedplatingtech.com/electroless-nickel/electroless-nickel-plating/
    kind: web
    license: Supplier web page (cited, not reproduced)
  engineersedge:
    title: Electroless nickel plating (EngineersEdge finishing reference)
    url: https://engineersedge.com/finishing/electroless_nickel.htm
    kind: web
    license: Reference web page (cited, not reproduced)
  nasa-prc-5007:
    title: NASA/JSC PRC-5007 Rev. E, Process Specification for Electroless Nickel Plating (Engineering Directorate, May 2020)
    url: https://www.nasa.gov/wp-content/uploads/2023/03/prc-5007-current.pdf
    kind: standard
    license: Public domain (NASA)
  usgs-mcs2026-nickel:
    title: Mineral Commodity Summaries 2026, Nickel
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    kind: report
    license: Public domain (USGS)
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (USGS, final list of 60 minerals)
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    kind: web
    license: Public domain (USGS)
  glenair-hiper-d:
    title: Glenair HiPer-D space-grade connector information, Connector Material and Finish for Space Applications
    url: https://www.glenair.com/hiper-d/pdf/space-grade-hiper-d-information.pdf
    kind: datasheet
    license: Manufacturer document (cited, not reproduced)
  us6350176:
    title: US Patent 6,350,176 B3, High quality optically polished aluminum mirror and process for producing (copy on NTRS 20080005024)
    url: https://ntrs.nasa.gov/api/citations/20080005024/downloads/20080005024.pdf
    kind: report
    license: Patent document (cited, not reproduced)
  pubchem-nickel:
    title: PubChem compound record, Nickel (CID 935), GHS classification
    id: CID 935
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Nickel
    kind: database
    license: PubChem (NCBI), public domain; notifications attributed to ECHA C&L Inventory
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 29
  unreachable: 2
  caveats: 4
  note: 'Values read by an AI assistant on 2026-11-01 from the web pages and PDFs named in each entry. Unreachable: the Nickel Institute properties PDF (HTTP 403) and the PubChem summary page as HTML (browser check); the PubChem JSON record was read through its data API. Caveats: supplier values are not from a standard; the sources disagree on several values; the hazard data are for elemental nickel; the optics use is not supported by a test result.'
story:
  recipe:
    line: Electroless nickel-phosphorus is a nickel coating that contains phosphorus, which sets its grade. The grades are low (1 to 4 % P), medium (5 to 9 % P) and high (more than 10 % P) in the Kanigen table, and NASA gives 9 to 13 % P as the higher-corrosion-resistance range.
    parts:
      - name: Nickel
        symbol: Ni
        share: the balance of the deposit
        role: The main metal. The coating is nickel with phosphorus dissolved or combined in it, and the nickel sets most of the base metal behaviour.
      - name: Phosphorus
        symbol: P
        share: 1 to 4 % by weight (low), 5 to 9 % (medium), more than 10 % (high)
        role: Sets the grade. The phosphorus content changes the hardness, melting point, electrical resistivity and corrosion resistance (see properties).
  risk_groups:
    - title: For people
      lead: The hazard data we could open are for elemental nickel. Nickel is a skin sensitiser, and the deposit's own safety data sheet was not read.
      points:
        - label: The metal
          line: PubChem's GHS record for nickel (CID 935) gives H317, may cause an allergic skin reaction, with the signal word Danger in its main entries. Some notifications also carry H350 and H351, cancer codes.
        - label: Process hazards
          line: The bath chemicals and the bake ovens are not covered by any source we opened, so their hazards are not recorded here.
    - title: If it fails
      lead: These failure routes come from NASA's process specification and the supplier text. None is a flight result.
      points:
        - label: Poor adhesion on aluminium
          line: NASA says adhesion can be a problem on aluminium alloys, and it asks for a 180-degree bend test to ASTM B571 over a 4T mandrel.
        - label: Hydrogen in high-strength steel
          line: NASA requires a hydrogen bakeout at 375 F within four hours of plating for the steels in its Table 2.
        - label: Thick deposits
          line: Above 0.0030 inch, pitting and roughness become a process control problem, according to NASA.
    - title: Handling and storage
      points:
        - label: Callout
          line: NASA requires the thickness, the PRC-5007 reference and the AMS 2404 class on the drawing, and the phosphorus content when it is outside 5 to 9 %.
        - label: Substrate
          line: NASA's PRC-5007 does not cover titanium or beryllium alloys, while the AMS 2404 and ASTM B733 classes list beryllium alloys.
  why: Electroless nickel-phosphorus (NiP) is a nickel coating used on aluminium and other metals to add hardness, wear resistance and corrosion resistance. The phosphorus content sets the grade, and the grade changes the hardness, melting point and electrical resistivity. NASA's JSC process specification PRC-5007, which applies AMS 2404, is the flight-hardware route, and the medium grade (5 to 9 % P) is the one NASA calls the most widely used for general wear and corrosion resistance.
  uses:
    - where: Space connectors
      line: NASA recommends electroless nickel or gold plating on connector shells. Glenair, which makes space-grade connectors, describes that guidance and lists electroless nickel as the shell finish for its aluminium connectors.
    - where: NASA flight hardware
      line: NASA/JSC PRC-5007 governs electroless nickel on steels, stainless steels, aluminium, copper, nickel and cobalt alloys. Its example callout is 0.0010-0.0012 inch on 6061-T6 or 7075-T73 aluminium, Class 4.
    - where: Optical mirrors (not established)
      line: Optical aluminium mirrors are the open question. A US patent argues that the nickel layer makes the mirror bimetallic and degrades its figure, and that bare heat-treated aluminium works better. That is the inventors' claim, and no test result we opened supports or refutes it.
  can_do:
    - label: Hardness
      benchmark: hardness_vickers
      line: As plated, the Kanigen table gives about 520 HV 0.1 for the high-phosphorus grade, about 580 HV 0.1 for the medium grade and about 650 HV for the low grade. After a 290 °C heat treatment for 5 hours it gives about 900 HV 0.1 for the grades.
    - label: Hardness after bake
      benchmark: hardness_rockwell_c
      value: Rc 66 to 70
      line: For the medium grade, the supplier page gives Rc 58 to 62 as plated and Rc 66 to 70 after heat treatment.
    - label: Service temperature
      benchmark: max_service_temp
      value: 538 °C
      line: A finishing reference page states that the AMS 2404C deposit is for service up to 1000F (538 °C).
    - label: Thermal expansion
      benchmark: cte
      value: 13 ppm/K
      line: The Kanigen table gives a coefficient of thermal expansion of 13 ppm/K at room temperature, the same value for all three grades.
  compare: Against electrolytic nickel, the Kanigen table gives a medium-phosphorus deposit with higher electrical resistivity (72 µΩ·cm against 6.8 µΩ·cm for electrolytic nickel) and much higher as-plated hardness (about 580 HV 0.1 against 200 HV). The three electroless grades melt between 875 and 910 °C in the same table. The table compares these grades with electrolytic nickel, and the values are the manufacturer's, not a standard.
  compare_rows:
    - label: Hardness as plated (medium grade)
      benchmark: hardness_vickers
    - label: Electrical resistivity (medium grade)
      benchmark: electrical_resistivity
    - label: Thermal expansion
      benchmark: cte
  handling:
    - Call out the thickness, the PRC-5007 reference and the AMS 2404 class on the drawing.
    - Bake listed high-strength steels at 375 F within four hours of plating.
    - Keep the phosphorus grade on the drawing, because hardness and resistivity change with it.
    - Do not plate titanium or beryllium under PRC-5007 without checking the AMS or ASTM class for beryllium.
  good_for:
    - 'Hard wear and corrosion coatings on aluminium: about 580 HV 0.1 as plated and about 900 HV 0.1 after heat treatment in the medium grade, per the Kanigen table.'
    - Space connector shells, where NASA recommends electroless nickel or gold plating.
  watch_out:
    - Sources disagree on thermal conductivity by about ten times (0.7 W/(cm·K) against 0.042 to 0.067 W/(cm·K)); both are recorded.
    - No measured corrosion rate and no space-environment test result for the deposit were found.
    - Hazard data are for elemental nickel, and the nickel sensitiser code H317 applies to the metal.
    - A heat treatment above 500 F can change the deposit from amorphous to crystalline.
  verdict: Electroless nickel-phosphorus is the standard plated finish that NASA specifies for aluminium flight hardware and connector shells. The medium grade gives about 580 HV 0.1 as plated and about 900 HV 0.1 after heat treatment, and the phosphorus grade changes the properties. This profile lacks a measured corrosion result, a space-environment test and a deposit safety data sheet, and the thermal conductivity sources disagree.