{
  "spore": "profile",
  "id": "nickel",
  "spore_version": "0.2",
  "family": "nickel-alloys",
  "name": "Nickel",
  "abbreviation": "Ni",
  "role": "structural metal and protective plating",
  "category": "metals",
  "type": "nickel-superalloys",
  "summary": "Nickel is a silvery, ferromagnetic metal. Commercially pure Nickel 200 has a density of 8.89 g/cm3, melts at 1435 to 1446 degC, has a Curie temperature of 360 degC, and is used as a bulk metal and as an electroplated or electroless coating on parts. A 2023 recycling study found a nickel layer 10 micrometres thick on aluminium hard-drive platters, and a magnet-coating supplier describes nickel plating as a barrier coating on NdFeB magnets. Nickel is a skin sensitiser (H317), and metallic nickel is listed by the US National Toxicology Program as reasonably anticipated to be a human carcinogen.\n",
  "best_for": "A tough, corrosion-resistant, magnetic metal that conducts heat and electricity and can be applied as a plated barrier coating",
  "weakest_at": "Skin sensitisation and cancer-hazard concerns for people, and no space-environment test data found in this record (no outgassing, atomic-oxygen or flight results)",
  "identity": {
    "formula": "Ni",
    "cas": "7440-02-0",
    "designations": [],
    "source": "pubchem-nickel",
    "where": "Names and Identifiers > CAS (7440-02-0); the NTP Report on Carcinogens also lists CAS 7440-02-0 for metallic nickel"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "extreme-cold"
    ],
    "applications": [
      "electronics-and-chips",
      "mechanisms"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, Nickel 200",
      "value": 8.89,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "Nickel 200 (UNS N02200), 99.0 % min nickel plus cobalt",
        "temperature": "not stated"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "source": "sm-nickel200",
      "where": "Table 2, Physical Constants (0.321 lb/in3)",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, nickel metal (handbook values compiled by PubChem)",
      "value": 8.908,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "material": "elemental nickel metal",
        "temperature": "not stated",
        "note": "other entries in the same PubChem section read 8.9 and 8.90; one gives 8.9 at 25 degC"
      },
      "method": "Value compiled by PubChem from the NTP Chemical Repository (1992) and Hawley's Condensed Chemical Dictionary (13th ed., 1997)",
      "status": "ground",
      "source": "pubchem-nickel",
      "where": "Experimental Properties > Density",
      "source_detail": {
        "title": "PubChem compound summary for Nickel (CID 935), data from CRC Handbook, NTP, NIOSH, ILO ICSC, OSHA, ACGIH, IARC and the ECHA C&L Inventory",
        "id": "PubChem CID 935; CAS 7440-02-0",
        "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Nickel",
        "year": 2026,
        "kind": "database",
        "license": "public domain (NCBI)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point of nickel",
      "value": 1455,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "material": "elemental nickel",
        "pressure": "not stated"
      },
      "method": "Value compiled by PubChem from the CRC Handbook of Chemistry and Physics, 68th ed. (Weast, 1987-1988)",
      "status": "ground",
      "note": "The same PubChem section lists 2651 °F (NTP, 1992) and 2831 °F (NIOSH, 2024); 2831 °F equals 1555 °C by calculation, which disagrees with 1455 °C, so the Fahrenheit entries were not used.",
      "source": "pubchem-nickel",
      "where": "Experimental Properties > Melting Point",
      "source_detail": {
        "title": "PubChem compound summary for Nickel (CID 935), data from CRC Handbook, NTP, NIOSH, ILO ICSC, OSHA, ACGIH, IARC and the ECHA C&L Inventory",
        "id": "PubChem CID 935; CAS 7440-02-0",
        "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Nickel",
        "year": 2026,
        "kind": "database",
        "license": "public domain (NCBI)"
      }
    },
    {
      "benchmark": "melting_range",
      "label": "Melting range, Nickel 200",
      "value": 1435,
      "value_high": 1446,
      "bound": "range",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "Nickel 200",
        "note": "the commercial grade melts over a range, below the pure-element value"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201) (2615 to 2635 °F)",
      "status": "ground",
      "note": "Upper end of the range is 1446 °C.",
      "source": "sm-nickel200",
      "where": "Table 2, Physical Constants",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "boiling_point",
      "label": "Boiling point of nickel",
      "value": 2730,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "material": "elemental nickel",
        "pressure": "not stated"
      },
      "method": "Value compiled by PubChem from the CRC Handbook of Chemistry and Physics, 68th ed. (Weast, 1987-1988)",
      "status": "ground",
      "note": "Another PubChem entry gives 2913 °C at 760 mmHg without naming the source, so the value is not settled in this record.",
      "source": "pubchem-nickel",
      "where": "Experimental Properties > Boiling Point",
      "source_detail": {
        "title": "PubChem compound summary for Nickel (CID 935), data from CRC Handbook, NTP, NIOSH, ILO ICSC, OSHA, ACGIH, IARC and the ECHA C&L Inventory",
        "id": "PubChem CID 935; CAS 7440-02-0",
        "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Nickel",
        "year": 2026,
        "kind": "database",
        "license": "public domain (NCBI)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, Nickel 200 at 20 °C",
      "value": 70.3,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "grade": "Nickel 200",
        "unit_in_source": "W/m·°C"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "note": "The same table gives 75.5 at -100 °C, 66.5 at 100 °C and 55.4 at 400 °C, so conduction falls as the metal warms to 400 °C.",
      "source": "sm-nickel200",
      "where": "Table 3, thermal properties, row 20 °C",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, Nickel 200 at 20 °C",
      "value": 0.096,
      "bound": "exact",
      "unit": "µΩ·m",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "grade": "Nickel 200",
        "unit_in_source": "μΩ·m"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "note": "Equal to 9.6 µΩ·cm. The same table gives 0.050 at -100 °C and 0.130 at 100 °C.",
      "source": "sm-nickel200",
      "where": "Table 3, electrical resistivity, row 20 °C",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of linear thermal expansion, 21 to 100 °C",
      "value": 13.3,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature_range": "21 to 100 °C (mean from 70 °F)",
        "grade": "Nickel 200",
        "unit_in_source": "μm/m·°C, equal to ppm/K"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "source": "sm-nickel200",
      "where": "Table 3, row 100 °C and its footnote",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, Nickel 200",
      "value": 360,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "Nickel 200",
        "note": "above this temperature the metal loses its ferromagnetism"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201) (680 °F)",
      "status": "ground",
      "source": "sm-nickel200",
      "where": "Table 2, Physical Constants",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat, Nickel 200",
      "value": 456,
      "bound": "exact",
      "unit": "J/(kg·K)",
      "scope": "material",
      "conditions": {
        "grade": "Nickel 200",
        "temperature": "not stated",
        "unit_in_source": "J/kg·°C"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201) (0.109 Btu/lb·°F)",
      "status": "ground",
      "source": "sm-nickel200",
      "where": "Table 2, Physical Constants",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Young's modulus, annealed Nickel 200 at 26 °C",
      "value": 205,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "26 °C",
        "condition": "annealed, determined dynamically",
        "grade": "Nickel 200"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "note": "Shear modulus 79.6 GPa and Poisson's ratio 0.29 in the same row; Young's modulus falls to 177 GPa at 500 °C.",
      "source": "sm-nickel200",
      "where": "Table 4, Modulus of Elasticity",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, annealed rod and bar",
      "value": 380,
      "value_high": 520,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "cold-drawn annealed or hot-finished annealed rod and bar",
        "temperature": "room temperature (not stated)",
        "basis": "nominal range, not a specification minimum"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "note": "Hot-finished rod and bar: 415 to 585 MPa. Spring-temper strip: 620 to 895 MPa.",
      "source": "sm-nickel200",
      "where": "Table 5, Nominal Mechanical Properties",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength (0.2 % offset), annealed rod and bar",
      "value": 105,
      "value_high": 210,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "cold-drawn annealed or hot-finished annealed rod and bar",
        "temperature": "room temperature (not stated)",
        "basis": "nominal range"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "note": "Cold-drawn (not annealed) rod and bar: 275 to 690 MPa, so working raises strength sharply.",
      "source": "sm-nickel200",
      "where": "Table 5, Nominal Mechanical Properties",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation in 2 in. (51 mm), annealed rod and bar",
      "value": 40,
      "value_high": 55,
      "bound": "range",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "cold-drawn annealed or hot-finished annealed rod and bar",
        "gauge_length": "2 in. (51 mm)",
        "temperature": "room temperature (not stated)"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "source": "sm-nickel200",
      "where": "Table 5, Nominal Mechanical Properties",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "hardness_brinell",
      "label": "Brinell hardness, annealed rod and bar",
      "value": 90,
      "value_high": 120,
      "bound": "range",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "load": "3000 kg",
        "form": "annealed rod and bar",
        "temperature": "room temperature (not stated)"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "note": "Rockwell B 45 to 70 for the same product. Cold-drawn rod and bar: 140 to 230 HB.",
      "source": "sm-nickel200",
      "where": "Table 5, Nominal Mechanical Properties",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "cryo_tensile_strength",
      "label": "Tensile strength at -185 °C, annealed 0.750 in. bar",
      "value": 621,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "-185 °C (-300 °F)",
        "condition": "annealed bar, 0.750 in. (19.0 mm) diameter",
        "grade": "Nickel 200"
      },
      "method": "Value printed in the manufacturer's technical bulletin (Special Metals, Nickel 200 and 201)",
      "status": "ground",
      "note": "Same bar at 21 °C: 441 MPa. At -255 °C: 758 MPa. Elongation at -185 °C was 61 %, against 48 % at room temperature, so the metal did not become brittle in this test.",
      "source": "sm-nickel200",
      "where": "Table 13, Low-Temperature Tensile Properties of Annealed Nickel 200 Bar",
      "source_detail": {
        "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
        "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
        "kind": "datasheet",
        "license": "Special Metals bulletin, linked not reproduced"
      }
    },
    {
      "benchmark": "plated_hardness_electroless",
      "label": "Hardness of electroless nickel-phosphorus, before heat treatment",
      "value": 300,
      "value_high": 600,
      "bound": "range",
      "unit": "kg/mm2",
      "scope": "material",
      "conditions": {
        "process": "electroless NiP, 3 to 16 wt% phosphorus",
        "state": "before heat treatment",
        "scale": "kg/mm2 as printed (hardness scale not named)"
      },
      "method": "Range stated in a magnet-coating supplier's overview (secondary statement, no test method given)",
      "status": "ground",
      "note": "The overview adds that lower-phosphorus coatings are typically harder than higher-phosphorus coatings.",
      "source": "dextermag",
      "where": "Nickel Plating Advantageous Properties, hardness paragraph",
      "source_detail": {
        "title": "Nickel Plating Overview: composition, formation and advantageous properties of nickel plating on NdFeB magnetic materials (Dexter Magnetic Technologies)",
        "id": "Nickel-Plating-Overview-revised-6-5-2023",
        "url": "https://dextermag.com/wp-content/uploads/2024/12/Nickel-Plating-Overview-revised-6-5-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "plated_hardness_electrolytic",
      "label": "Hardness of electrolytic (electroplated) nickel",
      "value": 190,
      "bound": "exact",
      "unit": "kg/mm2",
      "scope": "material",
      "conditions": {
        "process": "electrolytic nickel from a nickel-anode cell",
        "state": "as plated",
        "scale": "kg/mm2 as printed (hardness scale not named)",
        "qualifier": "usually around"
      },
      "method": "Typical value stated in a magnet-coating supplier's overview (no test method given)",
      "status": "ground",
      "source": "dextermag",
      "where": "Nickel Plating Advantageous Properties, hardness paragraph",
      "source_detail": {
        "title": "Nickel Plating Overview: composition, formation and advantageous properties of nickel plating on NdFeB magnetic materials (Dexter Magnetic Technologies)",
        "id": "Nickel-Plating-Overview-revised-6-5-2023",
        "url": "https://dextermag.com/wp-content/uploads/2024/12/Nickel-Plating-Overview-revised-6-5-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "plated_hardness_as_deposited",
      "label": "Hardness of nickel-phosphorus (8 to 12 % P), as deposited",
      "value": 500,
      "value_high": 600,
      "bound": "range",
      "unit": "VPN",
      "scope": "material",
      "conditions": {
        "process": "electroless nickel-phosphorus, 8 to 12 % P",
        "state": "as deposited",
        "scale": "VPN (Vickers pyramid number)"
      },
      "method": "Range stated in an Open University teaching page (no test load or standard given)",
      "status": "ground",
      "note": "Page title: Electroless plating, updated 8 March 2018.",
      "source": "openlearn-ep",
      "where": "Hardness line of the electroless nickel-phosphorus summary",
      "source_detail": {
        "title": "Electroless plating (Open University OpenLearn, updated 8 March 2018)",
        "id": "OpenLearn engineering and technology course page",
        "url": "https://www.open.edu/openlearn/science-maths-technology/engineering-technology/electroless-plating",
        "year": 2018,
        "kind": "web",
        "license": "OpenLearn terms (cited, not reproduced)"
      }
    },
    {
      "benchmark": "plated_hardness_heat_treated",
      "label": "Hardness of nickel-phosphorus (8 to 12 % P), after heat treatment",
      "value": 800,
      "value_high": 1000,
      "bound": "range",
      "unit": "VPN",
      "scope": "material",
      "conditions": {
        "process": "electroless nickel-phosphorus, 8 to 12 % P",
        "state": "heat treated at 400 °C for 60 min",
        "scale": "VPN (Vickers pyramid number)"
      },
      "method": "Range stated in an Open University teaching page (no test load or standard given)",
      "status": "ground",
      "note": "The page also says coatings can be post-heat treated to raise hardness up to 1000 VPN (1 h at 400 °C).",
      "source": "openlearn-ep",
      "where": "Hardness line of the electroless nickel-phosphorus summary",
      "source_detail": {
        "title": "Electroless plating (Open University OpenLearn, updated 8 March 2018)",
        "id": "OpenLearn engineering and technology course page",
        "url": "https://www.open.edu/openlearn/science-maths-technology/engineering-technology/electroless-plating",
        "year": 2018,
        "kind": "web",
        "license": "OpenLearn terms (cited, not reproduced)"
      }
    },
    {
      "benchmark": "plating_adhesion_electroplated",
      "label": "Adhesion strength of electroplated nickel on NdFeB",
      "value": 22,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "substrate": "sintered NdFeB magnet",
        "process": "electroplated nickel",
        "qualifier": "up to around",
        "test_method": "not stated in the overview"
      },
      "method": "Value stated in a magnet-coating supplier's overview, citing studies (not named in the text read)",
      "status": "ground",
      "note": "Overview also gives about 10 MPa for electroless NiP with a phosphate interlayer and 27 MPa for ion-beam-sputtered nickel, and says cracks in the plating are often the source of adhesion failures.",
      "source": "dextermag",
      "where": "Nickel Plating Adhesion to NdFeB Magnet Surfaces",
      "source_detail": {
        "title": "Nickel Plating Overview: composition, formation and advantageous properties of nickel plating on NdFeB magnetic materials (Dexter Magnetic Technologies)",
        "id": "Nickel-Plating-Overview-revised-6-5-2023",
        "url": "https://dextermag.com/wp-content/uploads/2024/12/Nickel-Plating-Overview-revised-6-5-2023.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "hdd_nickel_layer_thickness",
      "label": "Thickness of the nickel layer on hard-drive platters",
      "value": 10,
      "bound": "exact",
      "unit": "µm",
      "scope": "material",
      "conditions": {
        "object": "aluminium-magnesium alloy hard-drive platters, 810 to 1800 µm thick",
        "sides": "both sides coated",
        "method": "cross-section microscopy"
      },
      "method": "Measured by the authors from cross-section micrographs (Figure 4)",
      "status": "ground",
      "note": "The authors found the nickel layer was 10 µm regardless of the platter thickness, and call it the magnetic (nickel) coating. Its phosphorus content was not stated in the passages read.",
      "source": "skrzekut2023",
      "where": "Section 3, Results and Discussion, paragraph on Figure 4",
      "source_detail": {
        "title": "Recycling of Hard Disk Drive Platters via Plastic Consolidation (Skrzekut, Wedrychowicz and Piotrowicz, Materials 16(20), 6745)",
        "id": "doi:10.3390/ma16206745, PMC10608267",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC10608267/",
        "year": 2023,
        "kind": "paper",
        "license": "open access (MDPI)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Outdoor air (industrial, urban, marine and rural)",
      "headline": "Commercially pure nickel corrodes very slowly in air, fastest in sulfur-rich industrial air.",
      "effect": "Special Metals says Nickel 200 stays bright indoors, and outdoors forms a thin protective film, usually a sulfate. The rate rises with the sulfur dioxide content of the air. In a 20-year exposure study begun in 1931 the corrosion rate was 0.0056 mm/a at a heavy railroad-industrial site (Altoona, PA), 0.0036 mm/a in urban-industrial New York City, 0.0002 mm/a at a rural site (State College, PA) and 0.00004 mm/a at a semi-arid rural site (Phoenix, AZ). In a 2-year test begun in 1957 the rate was 0.0003 mm/a at a marine site (Kure Beach, NC) and 0.0020 mm/a at an industrial site (Newark, NJ).",
      "rating": "low",
      "conditions": {
        "material": "Nickel 200 sheet exposure coupons (form not stated in the text read)",
        "durations": "20 years (study begun 1931) and 2 years (1957 tests)",
        "grade_note": "for all environments above 600 °F (315 °C) Special Metals names Nickel 201 as the preferred material"
      },
      "source": "sm-nickel200",
      "where": "Corrosion Resistance > Atmosphere, Tables 15 and 16"
    },
    {
      "environment": "Water and sea water",
      "headline": "Excellent in distilled and flowing sea water, but stagnant sea water under deposits can cause severe local attack.",
      "effect": "In distilled water the corrosion rate was found to be less than 0.0003 mm/a. In domestic hot water up to 95 °C rates are normally less than 0.0005 mm/a. Special Metals says Nickel 200 gives excellent service in flowing sea water even at high velocity, but in stagnant or very low-velocity sea water severe local attack may occur under fouling organisms or other deposits.",
      "rating": "low",
      "conditions": {
        "material": "Nickel 200",
        "distilled_water": "less than 0.01 mpy (0.0003 mm/a)",
        "hot_water": "up to 200 °F (95 °C)",
        "sea_water_caution": "stagnant or very low velocity"
      },
      "source": "sm-nickel200",
      "where": "Corrosion Resistance > Water"
    },
    {
      "environment": "Caustic alkalies (sodium and potassium hydroxide)",
      "headline": "Nickel is described as unexcelled in resistance to caustic alkalies.",
      "effect": "The Special Metals bulletin says commercially pure nickel is unexcelled in resistance to caustic alkalies and attributes this to a passive oxide film. Strong ammonium hydroxide is an exception: Nickel 200 is not attacked by anhydrous ammonia or by ammonium hydroxide up to 1 percent concentration, and stronger concentrations are not recommended in the passage read. Oxidizable sulfur compounds and chlorates in caustic raise the corrosion rate.",
      "rating": "low",
      "conditions": {
        "basis": "qualitative statements in a manufacturer's bulletin; numerical rates are in its Table 21 and were not copied"
      },
      "source": "sm-nickel200",
      "where": "Introduction and Corrosion Resistance > Alkalies"
    },
    {
      "environment": "Acids (sulfuric, hydrochloric, hydrofluoric, nitric)",
      "headline": "Nickel suits some acids at low temperature without air, but nitric acid and aerated or hot acids attack it.",
      "effect": "Special Metals says Nickel 200 can be used with sulfuric acid at low or moderate temperatures, but aeration and higher temperature raise the rate; for example 2 percent acid at 21 °C without aeration gave 0.051 mm/a, while air-saturated 1 percent acid at 30 °C gave 1.2 mm/a. Nickel 200 should be used in nitric acid only up to 0.5 percent concentration at room temperature. In aqueous hydrofluoric acid service is usually limited to below 80 °C, and 60 to 65 percent commercial acid severely corrodes it even at room temperature, though it resists anhydrous hydrofluoric acid even at elevated temperature.",
      "rating": "severe",
      "conditions": {
        "material": "Nickel 200",
        "basis": "laboratory and plant tests in a manufacturer's bulletin",
        "note": "rates depend strongly on aeration, temperature and oxidizing salts"
      },
      "source": "sm-nickel200",
      "where": "Corrosion Resistance > Acids, Table 17 (lab sulfuric acid tests), Nitric and Hydrofluoric paragraphs"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem lists the ECHA Classification and Labelling Inventory result for nickel (CAS 7440-02-0): signal word Danger, hazard statement H317 (May cause an allergic skin reaction), reported by 99.9 percent of 4778 company reports; 0.1 percent (5 of 4778) said the substance does not meet GHS hazard criteria. PubChem also lists a separate single-company notification of H250 (catches fire spontaneously) for a pyrophoric form, which is not the bulk metal.",
        "ghs": [
          "H317"
        ],
        "source": "pubchem-nickel",
        "where": "Safety and Hazards > Hazards Identification > GHS Classification (ECHA C&L Notifications Summary)"
      },
      {
        "text": "Skin sensitisation (nickel allergy). The ILO International Chemical Safety Card text recorded by PubChem says repeated or prolonged skin contact may cause skin sensitization and repeated or prolonged inhalation may cause asthma. PubChem's hazard summary names nickel dermatitis, with itching of the fingers, hands and forearms, as the most common effect of long-term skin contact.",
        "ghs": [
          "H317"
        ],
        "source": "pubchem-nickel",
        "where": "Safety and Hazards > Effects of Long Term Exposure; Hazards Summary"
      },
      {
        "text": "Cancer. The US National Toxicology Program (15th Report on Carcinogens) lists metallic nickel as reasonably anticipated to be a human carcinogen, based on sufficient evidence from animal studies: nickel powder caused tumours in rats and hamsters by intratracheal instillation and by injection. Nickel compounds as a class are listed as known human carcinogens. PubChem also records IARC Group 2B (possibly carcinogenic to humans, 1989 evaluation) for metallic nickel, with inadequate evidence in humans and sufficient evidence in animals, and ACGIH category A5 (not suspected as a human carcinogen).",
        "ghs": [],
        "source": "ntp-roc15",
        "where": "Nickel Compounds and Metallic Nickel profile, Introduction and Metallic Nickel > Carcinogenicity; IARC and ACGIH entries from PubChem Toxicity > Carcinogen Classification and Evidence for Carcinogenicity"
      },
      {
        "text": "Workplace air limits recorded by PubChem for nickel metal and insoluble compounds: OSHA permissible exposure limit 1 mg/m3 (8-hour average); NIOSH recommended exposure limit 0.015 mg/m3 (carcinogen notation); ACGIH threshold limit value 1.5 mg/m3 (inhalable fraction) for the metal. The ICSC text adds that a dust explosion is possible if nickel is in powder or granular form mixed with air.",
        "ghs": [],
        "source": "pubchem-nickel",
        "where": "Safety and Hazards > Exposure Control and Personal Protection (PEL, REL, TLV); Safety and Hazard Properties > Physical Dangers"
      }
    ],
    "failure_risks": [
      {
        "mode": "Embrittlement by sulfur and low-melting metals during heating",
        "trigger": "Heating Nickel 200 with traces of sulfur or of lead, tin, zinc or bismuth (for example from lubricants, marking paints or shop soil)",
        "consequence": "The bulletin says Nickel 200 is sensitive to intergranular attack from sulfur and from metals with low melting points, so all traces of forming lubricants, marking paints and shop soil must be removed before heating.",
        "severity": "high",
        "source": "sm-nickel200",
        "where": "Heat treatment section (annealing)"
      },
      {
        "mode": "Cracked or poorly bonded plating",
        "trigger": "Cracks in the nickel plating or poor surface preparation on a magnet substrate",
        "consequence": "The magnet-coating overview says cracks in the plating are often the source of adhesion failures, and that adhesion depends strongly on surface preparation and process parameters.",
        "severity": "moderate",
        "source": "dextermag",
        "where": "Nickel Plating Adhesion to NdFeB Magnet Surfaces"
      },
      {
        "mode": "Hydrogen embrittlement of the substrate from electroless plating",
        "trigger": "Electroless nickel deposition on an NdFeB magnet (hydrogen is released as a by-product)",
        "consequence": "The overview says hydrogen can embrittle the NdFeB substrate, causing voiding beneath the nickel plating and potential catastrophic failure; it lists jet electrodeposition, multilayer Cu/Ni/Cu electrodeposition and ion-beam deposition as ways to mitigate it.",
        "severity": "high",
        "source": "dextermag",
        "where": "Nickel Plating Adhesion to NdFeB Magnet Surfaces"
      },
      {
        "mode": "Cracking of electroless nickel on high-temperature heat treatment",
        "trigger": "Heat-treating electroless nickel coatings at high temperature",
        "consequence": "The overview says electrolytic nickel has lower internal stress and does not crack during high-temperature heat treatment, unlike electroless nickel, which may show extensive cracking.",
        "severity": "moderate",
        "source": "dextermag",
        "where": "Nickel Plating Advantageous Properties"
      }
    ],
    "side_effects": [
      {
        "text": "When aluminium hard-drive platters are remelted, the 10 µm nickel layer reacts with the aluminium and forms the Al3Ni intermetallic phase, so no separate nickel particles remain in the melt. When the platters are only fragmented and pressed, nickel particles stay in the material and Al3Ni forms at the boundary with the Al-Mg matrix.",
        "affects": "Purity and microstructure of recycled aluminium from hard-drive platters",
        "source": "skrzekut2023",
        "where": "Section 3, Results and Discussion (Figures 5 to 7, Tables 3 and 4)"
      }
    ],
    "handling": [
      {
        "text": "Keep nickel powder away from ignition sources and avoid dust clouds, since the ICSC text records that a dust explosion is possible with powder or granules mixed with air. For dust and fume exposure follow the supplier's safety data sheet; no supplier SDS for a specific nickel product was opened for this profile.",
        "source": "pubchem-nickel",
        "where": "Safety and Hazards > Physical Dangers"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Aluminium-magnesium alloy hard-drive platters with a 10 µm nickel layer on both sides (recycling study)",
      "example": "A 2023 study of about 30 hard-drive platters describes the magnetic nickel coating on old-type drives and measured it at 10 µm; a protective layer, usually aluminium oxide, and a very thin perfluoropolyether lubricant layer sit on top.",
      "source": "skrzekut2023",
      "where": "Section 1 and Section 3 (Figure 4)"
    },
    {
      "application": "electronics-and-chips",
      "device": "Nickel and nickel-phosphorus plating on NdFeB magnets",
      "example": "A magnet-coating supplier says nickel plating is typically used as a barrier coating rather than a sacrificial coating on NdFeB magnets, using electrolytic or electroless nickel.",
      "source": "dextermag",
      "where": "Nickel Plating Adhesion to NdFeB Magnet Surfaces; Nickel Plating Composition"
    },
    {
      "application": "mechanisms",
      "device": "Electroplated and electroless nickel coatings on machined parts",
      "example": "USGS names electroplating among the leading US uses of primary nickel, after alloys and steels. Electroless nickel is described as giving a uniform thickness on complex shapes.",
      "source": "usgs-mcs2026-nickel",
      "where": "Domestic Production and Use"
    },
    {
      "application": "electronics-and-chips",
      "device": "Bulk Nickel 200 for electrical and electronic parts, aerospace and missile components, and chemical shipping drums",
      "example": "Special Metals lists these among typical applications of Nickel 200. No specific spacecraft part is named.",
      "source": "sm-nickel200",
      "where": "Introduction"
    }
  ],
  "supply": [
    {
      "subject": "Nickel (mine production, nickel content)",
      "abundance": "USGS: world nickel resources are estimated to contain more than 350 million tons of nickel, with 54 percent in laterites and 35 percent in magmatic sulfide deposits; world reserves are more than 140,000,000 tons.",
      "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": "Canada",
          "share_percent": 3.6,
          "year": 2025
        },
        {
          "country": "New Caledonia",
          "share_percent": 3.6,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (final list, 6 November 2025)",
          "listed": true
        }
      ],
      "recycling": "USGS: in 2025 nickel recovered from scrap accounted for approximately 60% of US apparent consumption, mostly as the nickel content of stainless-steel scrap.",
      "substitutes": [
        "USGS: low-nickel, duplex or ultrahigh-chromium stainless steels replace austenitic grades in construction; nickel-free specialty steels are sometimes used in place of stainless steel in power generation and petrochemicals; titanium alloys can replace 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 tons; shares calculated by Space Mushroom); World Resources; Recycling; Substitutes. Critical-list entry from the USGS 2025 list page (see sources)."
    },
    {
      "subject": "Nickel (United States market, 2025e)",
      "abundance": "USGS: US net import reliance was 41% of apparent consumption in 2025e (nearly 100% excluding scrap); the average London Metal Exchange cash price was estimated at 15,000 dollars per metric ton (6.90 dollars per pound) in 2025.",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "usgs-mcs2026-nickel",
      "where": "Salient Statistics (United States)"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Wikipedia: Nickel (crystal structure, ores, Mond process)",
      "type": "database",
      "url": "https://en.wikipedia.org/wiki/Nickel",
      "year": 2026
    },
    {
      "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201",
      "type": "datasheet",
      "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf"
    },
    {
      "title": "PubChem compound record: Nickel (CID 935)",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Nickel",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Nickel",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf",
      "year": 2026
    },
    {
      "title": "NTP Report on Carcinogens, 15th edition: Nickel Compounds and Metallic Nickel",
      "type": "report",
      "url": "https://ntp.niehs.nih.gov/sites/default/files/ntp/roc/content/profiles/nickel.pdf"
    },
    {
      "title": "Recycling of Hard Disk Drive Platters via Plastic Consolidation (Materials 2023, open access)",
      "type": "paper",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC10608267/",
      "year": 2023
    },
    {
      "title": "Dexter Magnetic Technologies: Nickel Plating Overview (NdFeB magnets)",
      "type": "datasheet",
      "url": "https://dextermag.com/wp-content/uploads/2024/12/Nickel-Plating-Overview-revised-6-5-2023.pdf",
      "year": 2023
    },
    {
      "title": "Open University OpenLearn: Electroless plating",
      "type": "report",
      "url": "https://www.open.edu/openlearn/science-maths-technology/engineering-technology/electroless-plating",
      "year": 2018
    }
  ],
  "gaps": [
    "The nickel process steps are taken from Wikipedia and the USGS 2026 summary only; the USGS nickel processing text and an industry process reference were not opened, so laterite smelting to ferronickel or matte is not described from a primary source.",
    "No space-environment data for nickel was found in the sources opened: no vacuum outgassing (ASTM E595), atomic-oxygen, UV, radiation or flight result for bare or plated nickel. Nickel has no entry for these benchmarks in this record.",
    "The harmonised EU (CLP) classification of nickel metal, including any carcinogenicity (H351) or repeated-exposure (H372) statements, was not seen. PubChem's ECHA summary shows only H317 for the metal; the full ECHA registration dossier and a supplier safety data sheet were not opened.",
    "Nickel allergy prevalence and the EU nickel release limits (EN 1811 test, REACH Annex XVII) were searched for but not read from a primary source. The Nickel Institute page returned an access error and the Acta Dermato-Venereologica article page was empty, so no prevalence figure or release limit is recorded.",
    "The phosphorus content, hardness and exact composition of the nickel layer on hard-drive platters were not found; the recycling study gives only its thickness (10 µm) and calls it a nickel coating, while a CMP presentation (not opened in full) was only seen in a search snippet describing electroless NiP. Whether platter plating is NiP or pure nickel is therefore not confirmed here.",
    "Plated-coating hardness comes from a supplier overview (300 to 600 kg/mm2, electrolytic about 190 kg/mm2) and a teaching page (500 to 600 VPN as deposited); neither gives a test load, standard or the phosphorus content tied to each number, and the two use different scales, so they were not converted or merged. No ASTM B733 or B689 standard value was read.",
    "Magnetic properties beyond the Curie temperature (saturation magnetisation, permeability, magnetostriction coefficient) were not found as numbers; the Special Metals bulletin only says nickel has good magnetostrictive properties.",
    "The cryogenic values are for annealed 0.750 in. bar only; fracture toughness, fatigue limit and fatigue crack growth values were not extracted (the bulletin gives fatigue in Table 12 and figures).",
    "Electrical conductivity is given only as resistivity (0.096 µΩ·m at 20 °C); no IACS percentage was found in a source.",
    "Only one value for each of the boiling and melting points of the pure element was entered; PubChem lists other entries (for example 2913 °C for boiling) whose original sources were not opened. The 2831 °F melting-point entry conflicts with 1455 °C and was not used.",
    "Crystal structure, atomic data and the NIST element data were not opened, so no lattice parameter is recorded.",
    "The EU critical raw materials list and nickel's status on it were not checked.",
    "Strength and hardness values are nominal ranges for Nickel 200 forms, not specification minimums. Properties of other commercially pure grades (for example Nickel 201 and nickel plated on specific substrates) were not entered."
  ],
  "story": {
    "why": "Nickel is a silvery metal that is ferromagnetic, which means it is strongly attracted by magnets and can hold magnetisation until it is heated past its Curie temperature. For commercially pure Nickel 200 that temperature is 360 °C. The metal is heavy (8.89 g/cm3 for Nickel 200) and melts at 1435 to 1446 °C, while the pure element melts at 1455 °C. It is tough and ductile when annealed, and stays ductile when cold: in one test an annealed bar was stronger and stretched further at -185 °C than at room temperature. Special Metals says that commercially pure nickel has high electrical and thermal conductivity compared with nickel alloys. Nickel forms a thin protective film in air and resists caustic alkalies, which is why it is used both as a bulk metal and as a plated skin on other metals. That skin is the form most people meet: a layer about 10 µm thick was found on aluminium hard-drive platters, and nickel plating is used as a barrier coating on NdFeB magnets. The same metal is a skin allergen and a listed possible carcinogen, so handling matters. Pure nickel is not a superalloy, even though this site files it next to them.",
    "uses": [
      {
        "where": "Hard-drive platters",
        "line": "A 2023 recycling study of about 30 hard drives found a nickel layer 10 µm thick on both sides of aluminium-magnesium platters, whatever the platter thickness. When the platters were remelted the layer reacted with the aluminium to form Al3Ni particles."
      },
      {
        "where": "Magnets",
        "line": "A magnet-coating supplier says nickel plating, either electrolytic or electroless, is typically used as a barrier coating on NdFeB magnets rather than a sacrificial one."
      },
      {
        "where": "Plated and bulk parts",
        "line": "USGS lists electroplating among the leading uses of primary nickel in the United States, after alloys and steels. Special Metals lists electrical and electronic parts, aerospace and missile components and chemical shipping drums as uses of Nickel 200."
      }
    ],
    "can_do": [
      {
        "label": "Weight",
        "line": "Nickel 200 has a density of 8.89 g/cm3. Compiled handbook values for the pure metal read 8.908 g/cm3.",
        "benchmark": "density",
        "scope": "material",
        "value": "8.89 g/cm3"
      },
      {
        "label": "Heat",
        "line": "The Nickel 200 melting range is 1435 to 1446 °C; the pure element is listed at 1455 °C. Special Metals says that above 315 °C the lower-carbon Nickel 201 is the preferred grade.",
        "scope": "material",
        "value": "Melts at 1435 to 1446 °C"
      },
      {
        "label": "Magnetism",
        "line": "Nickel 200 loses its ferromagnetism above a Curie temperature of 360 °C.",
        "benchmark": "curie_temperature",
        "scope": "material",
        "value": "Curie point 360 °C"
      },
      {
        "label": "Heat conduction",
        "line": "Thermal conductivity at 20 °C is 70.3 W/(m·K), and it falls to 55.4 W/(m·K) at 400 °C. Electrical resistivity at 20 °C is 0.096 µΩ·m.",
        "benchmark": "thermal_conductivity",
        "scope": "material",
        "value": "70.3 W/(m·K)"
      },
      {
        "label": "Strength when annealed",
        "line": "Annealed rod and bar has a nominal tensile strength of 380 to 520 MPa, a yield strength of 105 to 210 MPa, and elongation of 40 to 55 percent. Cold working raises strength: cold-drawn rod and bar has yield strength of 275 to 690 MPa. Young's modulus is 205 GPa.",
        "scope": "material",
        "value": "380 to 520 MPa tensile"
      },
      {
        "label": "Cold",
        "line": "An annealed 0.750 in. bar had a tensile strength of 621 MPa at -185 °C, against 441 MPa at 21 °C, and elongation of 61 percent against 48 percent.",
        "scope": "material",
        "value": "621 MPa at -185 °C"
      },
      {
        "label": "Plated hardness",
        "line": "A magnet-coating supplier gives 300 to 600 kg/mm2 for electroless nickel before heat treatment and about 190 kg/mm2 for electrolytic nickel. A teaching page gives 500 to 600 VPN as deposited and 800 to 1000 VPN after 60 minutes at 400 °C for nickel-phosphorus with 8 to 12 percent phosphorus. The scales and test methods differ, so these figures should not be directly compared.",
        "scope": "material",
        "value": "300 to 600 kg/mm2 (electroless)"
      },
      {
        "label": "Corrosion",
        "line": "In a 20-year outdoor study the corrosion rate of Nickel 200 was 0.0002 mm/a at a rural site and 0.0056 mm/a at a heavy industrial site.",
        "scope": "material",
        "value": "0.0002 mm/a in rural air"
      }
    ],
    "compare": "The record supports only a limited comparison. Electroless nickel is described by one supplier as harder than electrolytic nickel (300 to 600 against about 190 kg/mm2), with more uniform thickness, but electrolytic nickel has lower internal stress and does not crack in high-temperature heat treatment. Adhesion to NdFeB magnets was up to around 22 MPa for electroplated nickel and about 10 MPa for electroless nickel-phosphorus with a phosphate interlayer. This profile holds no side-by-side numbers for nickel against other metals, so it does not rank it.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      },
      {
        "label": "Thermal expansion",
        "benchmark": "cte",
        "scope": "material"
      }
    ],
    "handling": [
      "Avoid prolonged skin contact; nickel is a skin sensitiser (H317).",
      "Avoid dust clouds from nickel powder and follow the workplace limits in the supplier safety data sheet.",
      "Remove oils, paints and shop soil before heating, because sulfur and low-melting metals attack nickel.",
      "Do not use Nickel 200 in nitric acid above 0.5 percent or in aqueous hydrofluoric acid at room temperature."
    ],
    "good_for": [
      "Corrosion resistance in air, flowing sea water and caustic alkalies. The rural outdoor rate was 0.0002 mm/a.",
      "Ductile toughness that holds when cold. Elongation was 61 percent at -185 °C.",
      "A barrier coating on NdFeB magnets and a thin layer on aluminium platters."
    ],
    "watch_out": [
      "Skin allergy (H317) and a carcinogen listing for the metal. Nickel compounds are listed as known human carcinogens.",
      "No outgassing, atomic-oxygen, radiation or flight data were found, so nothing here shows how nickel behaves in orbit.",
      "Plated-hardness figures come from a supplier and a teaching page with no test method, and use different scales.",
      "Electroless plating on magnets can release hydrogen that embrittles NdFeB; plating cracks cause adhesion failures."
    ],
    "verdict": "Nickel is a tough, corrosion-resistant, magnetic metal and a widely used barrier plating, with well-documented bulk properties for Nickel 200. Its health hazards are skin allergy and a listed possible carcinogen, and no space-environment data was found for it in this record.",
    "recipe": {
      "line": "Nickel is a single-element metal (Ni) with a face-centred cubic crystal structure (Wikipedia). Its ores are laterites, mainly nickeliferous limonite and garnierite, and magmatic sulfides, and most of the world resource is in laterites (Wikipedia, USGS 2026). Sulfide concentrate is sent to smelters, as the Eagle Mine in Michigan does (USGS 2026). The Mond process is used to purify nickel (Wikipedia).",
      "parts": [
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "The whole material. PubChem prints the molecular weight of the element as 58.693.",
          "atoms": 1,
          "atomic_weight": 58.693
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "Nickel is a common cause of skin allergy, and the US National Toxicology Program lists the metal as reasonably anticipated to be a human carcinogen.",
        "points": [
          {
            "label": "Skin allergy",
            "line": "The European chemicals inventory summary on PubChem shows hazard statement H317, may cause an allergic skin reaction, for nickel metal (99.9 percent of 4778 company reports). Repeated or prolonged skin contact may cause sensitisation, and nickel dermatitis is described as the most common effect of long-term skin contact."
          },
          {
            "label": "Cancer",
            "line": "The metal is listed by the US National Toxicology Program as reasonably anticipated to be a human carcinogen, based on animal studies in which nickel powder caused tumours in rats and hamsters. Nickel compounds as a class are listed as known human carcinogens. IARC puts the metal in Group 2B, possibly carcinogenic to humans."
          },
          {
            "label": "Dust",
            "line": "Workplace limits recorded include an OSHA limit of 1 mg/m3 and a NIOSH recommended limit of 0.015 mg/m3. Nickel powder mixed with air can explode."
          }
        ],
        "level": 3,
        "verdict": "Skin allergen; metal listed as possible carcinogen"
      },
      {
        "title": "If it fails",
        "lead": "These failure routes come from a manufacturer's bulletin and a magnet-coating supplier's overview, not from field incident data.",
        "points": [
          {
            "label": "Cracked or lifted plating",
            "line": "Cracks in nickel plating are often the source of adhesion failures. Adhesion depends strongly on surface preparation."
          },
          {
            "label": "Hydrogen from electroless plating",
            "line": "Electroless plating releases hydrogen, which can embrittle an NdFeB magnet and cause voids beneath the plating. The supplier lists other deposition methods that reduce this."
          },
          {
            "label": "Sulfur and low-melting metals",
            "line": "Nickel 200 is sensitive to intergranular attack from sulfur and from metals such as lead, tin, zinc and bismuth when heated, so lubricants, paints and shop soil must be removed first."
          }
        ],
        "level": 2,
        "verdict": "Plating can crack or lift; heating with sulfur embrittles"
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Dust",
            "line": "Avoid dust clouds from nickel powder. No supplier safety data sheet for a specific nickel product was opened for this profile."
          },
          {
            "label": "Chemicals",
            "line": "Nickel 200 resists caustic alkalies and flowing sea water, but strong aqueous hydrofluoric acid, nitric acid above 0.5 percent and aerated hot acids attack it."
          }
        ],
        "level": 1,
        "verdict": "Control dust; read the supplier safety sheet"
      }
    ]
  },
  "updated": "2026-10-17",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 22,
    "unreachable": 3,
    "caveats": 6,
    "note": "Written by an AI assistant on 2026-10-17. Special Metals values, USGS values, Skrzekut text and Dexter text were read in text extracted from the source PDF or HTML; PubChem values were read from its JSON record; the OpenLearn hardness figures were read once through a page summary because the page blocked direct download. Three pages could not be read (Nickel Institute, Acta Dermato-Venereologica article, sterc.org). Caveats: strengths are nominal ranges; plated-hardness figures come from a supplier and a teaching page with no test method; no space-environment data."
  },
  "sources": {
    "wikipedia-ni": {
      "title": "Nickel (crystal structure, ores, Mond process)",
      "url": "https://en.wikipedia.org/wiki/Nickel",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0 (cited, not reproduced)"
    },
    "sm-nickel200": {
      "title": "Special Metals technical bulletin: Nickel 200 and Nickel 201 (Special Metals Corporation)",
      "id": "Nickel 200 and 201 technical bulletin (publication number not read)",
      "url": "https://www.specialmetals.com/documents/technical-bulletins/nickel-200.pdf",
      "kind": "datasheet",
      "license": "Special Metals bulletin, linked not reproduced"
    },
    "pubchem-nickel": {
      "title": "PubChem compound summary for Nickel (CID 935), data from CRC Handbook, NTP, NIOSH, ILO ICSC, OSHA, ACGIH, IARC and the ECHA C&L Inventory",
      "id": "PubChem CID 935; CAS 7440-02-0",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Nickel",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "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",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-crit2025": {
      "title": "About the 2025 List of Critical Minerals (USGS, final list)",
      "id": "Final 2025 List of Critical Minerals, 6 November 2025",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025,
      "kind": "web",
      "license": "public domain (USGS)"
    },
    "ntp-roc15": {
      "title": "Report on Carcinogens, Fifteenth Edition: Nickel Compounds and Metallic Nickel (NTP)",
      "id": "NTP RoC 15th edition profile, CAS 7440-02-0 for metallic nickel",
      "url": "https://ntp.niehs.nih.gov/sites/default/files/ntp/roc/content/profiles/nickel.pdf",
      "kind": "report",
      "license": "public domain (US Government)"
    },
    "skrzekut2023": {
      "title": "Recycling of Hard Disk Drive Platters via Plastic Consolidation (Skrzekut, Wedrychowicz and Piotrowicz, Materials 16(20), 6745)",
      "id": "doi:10.3390/ma16206745, PMC10608267",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC10608267/",
      "year": 2023,
      "kind": "paper",
      "license": "open access (MDPI)"
    },
    "dextermag": {
      "title": "Nickel Plating Overview: composition, formation and advantageous properties of nickel plating on NdFeB magnetic materials (Dexter Magnetic Technologies)",
      "id": "Nickel-Plating-Overview-revised-6-5-2023",
      "url": "https://dextermag.com/wp-content/uploads/2024/12/Nickel-Plating-Overview-revised-6-5-2023.pdf",
      "year": 2023,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "openlearn-ep": {
      "title": "Electroless plating (Open University OpenLearn, updated 8 March 2018)",
      "id": "OpenLearn engineering and technology course page",
      "url": "https://www.open.edu/openlearn/science-maths-technology/engineering-technology/electroless-plating",
      "year": 2018,
      "kind": "web",
      "license": "OpenLearn terms (cited, not reproduced)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/nickel/"
}