{
  "spore": "profile",
  "id": "metglas-2705m",
  "spore_version": "0.2",
  "family": "magnet-and-superconducting-alloys",
  "name": "METGLAS 2705M",
  "abbreviation": "Co-based amorphous ribbon",
  "role": "magnetic shield and high-frequency core alloy",
  "category": "metals",
  "type": "magnet-alloys",
  "summary": "METGLAS 2705M is a cobalt-based amorphous metal ribbon made by Metglas, Inc. Its technical bulletin gives a density of 7.80 g/cm3, a saturation induction of 0.77 T and a Curie temperature of 365 °C. In a 2011 University of Kentucky test, a human-size cylindrical shield made from the ribbon measured DC shielding factors of 267 axial and 1500 transverse in the Earth's magnetic field.\n",
  "best_for": "Flexible magnetic shields and high-permeability cores, where the ribbon is used without annealing (the manufacturer's product page makes this claim)",
  "weakest_at": "Ground data only: no corrosion rate, no long-term ageing data above the 90 °C continuous service temperature, and no vacuum or flight result were found in the sources read",
  "identity": {
    "formula": "Cobalt-based amorphous metal ribbon, Co-Fe-Ni-Mo-B-Si: cobalt 75 to 85, silicon 3 to 7, boron 1 to 5, iron 1 to 5, molybdenum 1 to 5 and nickel 1 to 5 (weight %, SDS ranges)",
    "crystal_system": "amorphous (no crystal lattice)",
    "designations": [
      {
        "system": "Trade name",
        "code": "2705M",
        "source": "metglas-2705m-datasheet",
        "where": "Title block, Magnetic Alloy 2705M (cobalt-based)"
      },
      {
        "system": "Trade name",
        "code": "2705M Cobalt Base Magnetic Alloy",
        "source": "metglas-2705m-sds",
        "where": "Title block on every page, METGLAS 2705M Cobalt Base Magnetic Alloy"
      }
    ],
    "source": "metglas-2705m-sds",
    "where": "Section 2, Composition table (weight %)"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, as printed in the technical bulletin",
      "value": 7.8,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "METGLAS 2705M ribbon",
        "condition": "as printed in the physical properties table"
      },
      "method": "Value printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Physical Properties table, Density (g/cm3) = 7.80",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "saturation_induction",
      "label": "Saturation induction",
      "value": 0.77,
      "bound": "exact",
      "unit": "T",
      "scope": "material",
      "conditions": {
        "grade": "METGLAS 2705M ribbon",
        "condition": "as printed in the magnetic properties table"
      },
      "method": "Value printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Magnetic Properties table, Saturation Induction (T) = 0.77",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "dc_permeability",
      "label": "Maximum DC permeability, annealed",
      "value": 600000,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "heat_treatment": "annealed",
        "printed_unit": "none"
      },
      "method": "Value printed in the technical bulletin; the bulletin prints no unit, so the value is entered as a dimensionless number",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Magnetic Properties table, Maximum D.C. Permeability, Annealed = 600,000",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "dc_permeability",
      "label": "Maximum DC permeability, as cast",
      "value": 290000,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "heat_treatment": "as cast",
        "printed_unit": "none"
      },
      "method": "Value printed in the technical bulletin; the bulletin prints no unit, so the value is entered as a dimensionless number",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Magnetic Properties table, Maximum D.C. Permeability, As Cast = 290,000",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "saturation_magnetostriction",
      "label": "Saturation magnetostriction",
      "value": 0.5,
      "bound": "upper",
      "unit": "ppm",
      "scope": "material",
      "conditions": {
        "printed_as": "<0.5 ppm",
        "condition": "as printed in the magnetic properties table"
      },
      "method": "Upper limit printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Magnetic Properties table, Saturation Magnetostriction (ppm) = <0.5",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity",
      "value": 136,
      "bound": "exact",
      "unit": "μΩ.cm",
      "scope": "material",
      "conditions": {
        "grade": "METGLAS 2705M ribbon",
        "temperature": "not stated"
      },
      "method": "Value printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Magnetic Properties table, Electrical Resistivity (μΩ.cm) = 136",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, technical bulletin",
      "value": 365,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "METGLAS 2705M ribbon",
        "condition": "as printed in the magnetic properties table"
      },
      "method": "Value printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Magnetic Properties table, Curie Temperature (°C) = 365",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, safety data sheet",
      "value": 365,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "printed_as": "689 °F (365 °C)",
        "grade": "METGLAS 2705M Cobalt Base Magnetic Alloy"
      },
      "method": "Value printed in the manufacturer's safety data sheet",
      "status": "ground",
      "note": "The bulletin and the safety data sheet give the same Curie temperature.",
      "source": "metglas-2705m-sds",
      "where": "Section 9, Physical and chemical properties, Curie temperature",
      "source_detail": {
        "title": "Material Safety Data Sheet: METGLAS 2705M Cobalt Base Magnetic Alloy",
        "id": "FRM 8200.007 Rev. 01; initial release October 2003, revision 01 dated 02/06/13",
        "url": "https://metglas.com/wp-content/uploads/2016/12/Metglas-Alloy-2705M-Cobalt-Based-Alloy.pdf",
        "year": 2013,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "crystallization_temperature",
      "label": "Crystallization temperature, technical bulletin",
      "value": 520,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "METGLAS 2705M ribbon",
        "condition": "as printed in the physical properties table"
      },
      "method": "Value printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Physical Properties table, Crystallization Temperature (°C) = 520",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "crystallization_temperature",
      "label": "Crystallization temperature, safety data sheet",
      "value": 520,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "printed_as": "968 °F (520 °C)",
        "grade": "METGLAS 2705M Cobalt Base Magnetic Alloy"
      },
      "method": "Value printed in the manufacturer's safety data sheet",
      "status": "ground",
      "source": "metglas-2705m-sds",
      "where": "Section 9, Physical and chemical properties, Crystallization temp",
      "source_detail": {
        "title": "Material Safety Data Sheet: METGLAS 2705M Cobalt Base Magnetic Alloy",
        "id": "FRM 8200.007 Rev. 01; initial release October 2003, revision 01 dated 02/06/13",
        "url": "https://metglas.com/wp-content/uploads/2016/12/Metglas-Alloy-2705M-Cobalt-Based-Alloy.pdf",
        "year": 2013,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, as printed in the technical bulletin",
      "value": 1,
      "value_high": 2,
      "bound": "range",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "ribbon",
        "heat_treatment": "not stated in the bulletin",
        "printed_as": "1-2 (GPa)"
      },
      "method": "Range printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Physical Properties table, Tensil Strength (GPa) = 1-2",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Elastic modulus, as printed in the technical bulletin",
      "value": 100,
      "value_high": 110,
      "bound": "range",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "ribbon",
        "printed_as": "100-110 (GPa)"
      },
      "method": "Range printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Physical Properties table, Elastic Modulus (GPa) = 100-110",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "lamination_factor",
      "label": "Lamination factor",
      "value": 75,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "printed_as": ">75 (%)",
        "form": "ribbon"
      },
      "method": "Lower limit printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Physical Properties table, Lamination Factor (%) = >75",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion",
      "value": 12.1,
      "bound": "exact",
      "unit": "ppm/°C",
      "scope": "material",
      "conditions": {
        "temperature_range": "not printed in the bulletin",
        "grade": "METGLAS 2705M ribbon"
      },
      "method": "Value printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Physical Properties table, Thermal Expansion (ppm/°C) = 12.1",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Continuous service temperature",
      "value": 90,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "basis": "continuous service temperature as printed",
        "grade": "METGLAS 2705M ribbon"
      },
      "method": "Value printed in the manufacturer's technical bulletin",
      "status": "ground",
      "source": "metglas-2705m-datasheet",
      "where": "Physical Properties table, Continuous Service Temp. (°C) = 90",
      "source_detail": {
        "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
        "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
        "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "shielding_factor",
      "label": "DC axial magnetic shielding factor, single-shell cylinder",
      "value": 267,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "assembly": "single-shell open-ended cylinder of 2705M ribbon, 0.61-m diameter and 1.83-m long",
        "thickness_total": "122 µm (6 foil layers)",
        "field": "DC, Earth's magnetic field",
        "shaking": "not used"
      },
      "method": "Measured by the authors of a 2011 University of Kentucky paper on large Metglas shields",
      "status": "ground",
      "source": "arxiv-1107-malkowski",
      "where": "Abstract",
      "source_detail": {
        "title": "Technique for high axial shielding factor performance of large-scale, thin, open-ended, cylindrical Metglas magnetic shields",
        "id": "arXiv:1107.2625 (S. Malkowski, R. Adhikari, B. Hona, C. Mattie, D. Woods, H. Yan, B. Plaster; University of Kentucky)",
        "url": "https://arxiv.org/pdf/1107.2625",
        "year": 2011,
        "kind": "paper",
        "license": "arXiv preprint"
      }
    },
    {
      "benchmark": "shielding_factor",
      "label": "DC transverse magnetic shielding factor, single-shell cylinder",
      "value": 1500,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "assembly": "single-shell open-ended cylinder of 2705M ribbon, 0.61-m diameter and 1.83-m long",
        "thickness_total": "122 µm (6 foil layers)",
        "field": "DC, Earth's magnetic field",
        "shaking": "not used"
      },
      "method": "Measured by the authors of a 2011 University of Kentucky paper on large Metglas shields",
      "status": "ground",
      "source": "arxiv-1107-malkowski",
      "where": "Abstract",
      "source_detail": {
        "title": "Technique for high axial shielding factor performance of large-scale, thin, open-ended, cylindrical Metglas magnetic shields",
        "id": "arXiv:1107.2625 (S. Malkowski, R. Adhikari, B. Hona, C. Mattie, D. Woods, H. Yan, B. Plaster; University of Kentucky)",
        "url": "https://arxiv.org/pdf/1107.2625",
        "year": 2011,
        "kind": "paper",
        "license": "arXiv preprint"
      }
    },
    {
      "benchmark": "thickness",
      "label": "Ribbon thickness, as printed in the 2011 paper",
      "value": 20.3,
      "bound": "exact",
      "unit": "µm",
      "scope": "material",
      "conditions": {
        "form": "ribbon foil",
        "width": "5.08-cm wide"
      },
      "method": "Value printed in the abstract of a 2011 university paper that tested the ribbon",
      "status": "ground",
      "source": "arxiv-1107-malkowski",
      "where": "Abstract, ribbon description",
      "source_detail": {
        "title": "Technique for high axial shielding factor performance of large-scale, thin, open-ended, cylindrical Metglas magnetic shields",
        "id": "arXiv:1107.2625 (S. Malkowski, R. Adhikari, B. Hona, C. Mattie, D. Woods, H. Yan, B. Plaster; University of Kentucky)",
        "url": "https://arxiv.org/pdf/1107.2625",
        "year": 2011,
        "kind": "paper",
        "license": "arXiv preprint"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Moisture and corrosive materials (storage and incompatibilities)",
      "headline": "The SDS says the product can be attacked by moisture and corrosive materials.",
      "effect": "Section 10 lists moisture and corrosive materials as incompatible, and Section 7 asks that the product not be exposed to moisture or any other substance. The SDS gives no corrosion rate, test or exposure time.",
      "rating": "unknown",
      "source": "metglas-2705m-sds",
      "where": "Section 10, Incompatibilities; Section 7, Storage recommendations"
    },
    {
      "environment": "Heating above the continuous service temperature (thermal ageing)",
      "headline": "The bulletin gives 90 °C as the continuous service temperature and prints no ageing data above it.",
      "effect": "The bulletin prints a crystallization temperature of 520 °C and a continuous service temperature of 90 °C. No property change after long heating at intermediate temperatures was found in the sources read.",
      "rating": "unknown",
      "source": "metglas-2705m-datasheet",
      "where": "Physical Properties table, Continuous Service Temp. and Crystallization Temperature"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "The SDS says the primary hazard as shipped is the sharp edges of the product. Some individuals may develop allergic skin reactions after repeated handling.",
        "ghs": [],
        "source": "metglas-2705m-sds",
        "where": "Section 3, Emergency overview"
      },
      {
        "text": "The SDS gives a WHMIS classification of D2B (sensitizer) for the product as shipped. Vapors and fumes from grinding, sanding, cutting or welding are harmful if inhaled.",
        "ghs": [],
        "source": "metglas-2705m-sds",
        "where": "Section 3, Inhalation; Section 15, WHMIS classification"
      },
      {
        "text": "The SDS lists cobalt as IARC group 2b (possible carcinogen) and says cobalt and nickel, and their compounds, should be treated as possible carcinogens.",
        "ghs": [],
        "source": "metglas-2705m-sds",
        "where": "Section 3, Delayed effects and carcinogen table"
      },
      {
        "text": "PubChem's record for the element cobalt (the alloy's main constituent, not the alloy itself) lists these EU CLP statements: H317, H334, H341, H350, H360F and H413.",
        "ghs": [
          "H317",
          "H334",
          "H341",
          "H350",
          "H360F",
          "H413"
        ],
        "source": "pubchem-cobalt",
        "where": "Safety and Hazards, GHS Classification, reference 71 (Regulation (EC) No 1272/2008)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Fire or melting of the ribbon",
        "trigger": "Melting or burning in a structural fire",
        "consequence": "The SDS says the product may burn in a structural fire, and toxic and irritating vapors may be released if it melts or burns.",
        "severity": "moderate",
        "source": "metglas-2705m-sds",
        "where": "Section 3 and Section 5, Special fire fighting precautions"
      },
      {
        "mode": "Operation above the continuous service temperature",
        "trigger": "Use above 90 °C",
        "consequence": "The bulletin gives 90 °C as the continuous service temperature. No property data above that limit were found in the sources read, so the effect of longer exposure is not documented.",
        "severity": "low",
        "source": "metglas-2705m-datasheet",
        "where": "Physical Properties table, Continuous Service Temp."
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "The edges are very sharp. Wear cut-resistant gloves and safety glasses when grinding, sanding, cutting or welding.",
        "source": "metglas-2705m-sds",
        "where": "Section 7, Normal handling; Section 8, Personal protective equipment"
      },
      {
        "text": "Use mechanical ventilation when cutting, grinding, sanding or welding the ribbon.",
        "source": "metglas-2705m-sds",
        "where": "Section 8, Engineering controls"
      },
      {
        "text": "Store the ribbon in a facility that protects it from physical damage, moisture and other contamination.",
        "source": "metglas-2705m-sds",
        "where": "Section 7, Storage recommendations"
      }
    ],
    "mitigations": [
      {
        "text": "The manufacturer says the alloy can be annealed for square or linear permeability.",
        "source": "metglas-magnetic-page",
        "where": "2705M section, Benefits"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Flexible electromagnetic shielding (human-size cylindrical shield)",
      "example": "A 2011 University of Kentucky paper built a single-shell, open-ended cylinder of 2705M ribbon, 0.61-m diameter and 1.83-m long, and measured DC shielding factors of 267 axial and 1500 transverse in the Earth's magnetic field.",
      "source": "arxiv-1107-malkowski",
      "where": "Abstract"
    },
    {
      "application": "electronics-and-chips",
      "device": "Internal magnetic shield in a cryogenic neutron electric dipole moment experiment (laboratory use, not flown)",
      "example": "A 2017 paper on a neutron electric dipole moment experiment used six layers of Metglas 2705M as the internal shield, because the alloy keeps high permeability from room temperature to cryogenic temperatures.",
      "source": "arxiv-1701-slutsky",
      "where": "Description of the internal Metglas shield (the paragraph citing Metglas, Inc.)"
    },
    {
      "application": "electronics-and-chips",
      "device": "Magnetic sensors, high frequency cores and magnetic switches",
      "example": "The manufacturer's 2705M section lists flexible electromagnetic shielding, magnetic sensors, high frequency cores and magnetic switches as applications.",
      "source": "metglas-magnetic-page",
      "where": "2705M section, Applications list"
    }
  ],
  "supply": [
    {
      "subject": "Cobalt",
      "producers": [
        {
          "country": "Congo (Kinshasa)",
          "share_percent": 73,
          "year": 2025
        },
        {
          "country": "Indonesia",
          "share_percent": 14,
          "year": 2025
        },
        {
          "country": "Australia",
          "share_percent": 1.2,
          "year": 2025
        },
        {
          "country": "Philippines",
          "share_percent": 1.2,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 2.5,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals (entry: Cobalt, used in batteries and metal alloys used in extreme temperatures)",
          "listed": true
        },
        {
          "list": "EU critical raw materials list (Cobalt entry, European Commission page)",
          "listed": true
        }
      ],
      "recycling": "USGS: cobalt content of purchased scrap represented 25% of estimated cobalt consumption in 2025.",
      "substitutes": [
        "USGS: substitution for cobalt could result in a loss in product performance or increased cost. Potential substitutes in some magnets include nickel-iron alloys."
      ],
      "source": "usgs-mcs2026-cobalt",
      "where": "World Mine Production table, 2025 column (world total 310,000 t); the 73% and 14% shares are printed in Events, Trends and Issues; the Australia, Philippines and Russia shares are calculated by Space Mushroom from tonnes (3,700, 3,700 and 7,700 of 310,000 t). Recycling; Substitutes."
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
      "type": "datasheet",
      "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
      "year": 2014
    },
    {
      "title": "METGLAS 2705M Cobalt Base Magnetic Alloy: Material Safety Data Sheet (FRM 8200.007 Rev. 01)",
      "type": "sds",
      "url": "https://metglas.com/wp-content/uploads/2016/12/Metglas-Alloy-2705M-Cobalt-Based-Alloy.pdf",
      "year": 2013
    },
    {
      "title": "Technique for high axial shielding factor performance of large-scale, thin, open-ended, cylindrical Metglas magnetic shields (arXiv:1107.2625)",
      "type": "paper",
      "url": "https://arxiv.org/pdf/1107.2625",
      "year": 2011
    },
    {
      "title": "Cryogenic magnetic coil and superconducting magnetic shield for neutron electric dipole moment searches (arXiv:1701.03101)",
      "type": "paper",
      "url": "https://arxiv.org/pdf/1701.03101",
      "year": 2017
    },
    {
      "title": "Mineral Commodity Summaries 2026, Cobalt (USGS)",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf",
      "year": 2026
    },
    {
      "title": "PubChem compound record, Cobalt (CID 104730), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/104730"
    }
  ],
  "gaps": [
    "No corrosion rate, humidity test, salt-spray result or exposure time for 2705M was found in the sources read; the only corrosion statement is the SDS line that moisture and corrosive materials can attack the product.",
    "No UNS, ASTM, EN, AISI or JIS designation for 2705M was printed in the sources read; only the trade names are listed.",
    "Vickers hardness is printed on the technical bulletin without a unit, so it is not recorded as a property.",
    "The two permeability values are printed without a unit and are entered as dimensionless numbers, as the bulletin prints them.",
    "Saturation induction, crystallization temperature, permeability, magnetostriction, lamination factor, shielding factor and thickness use names outside the canonical list (property-canon.yaml), as no canonical name fits.",
    "Composition is given only as weight-percent ranges from the SDS; no atomic-percent composition from a fetched source was found.",
    "Crustal abundance and producer shares for nickel, molybdenum, boron and silicon were not read; only cobalt supply is recorded.",
    "No long-term thermal ageing data for 2705M above its continuous service temperature were found in the sources read.",
    "The technical bulletin is dated 2014 by its copyright range and does not label its table values as typical; no newer datasheet was found in this run.",
    "No vacuum, radiation or flight data for 2705M were found; the shielding and cryogenic uses are ground laboratory tests, not flight.",
    "The 2011 shield measurements are from one cylinder geometry in the Earth's magnetic field; no other field strength was read for 2705M.",
    "The product page lists 2705M for shielding, sensors, high frequency cores and magnetic switches, but gives no numbers for it.",
    "The 2017 paper describes cryogenic permeability only qualitatively; no cryogenic permeability value was read.",
    "Hazard data rest on the 2705M SDS and the PubChem record for the element cobalt, which is not the alloy itself."
  ],
  "story": {
    "why": "METGLAS 2705M is a cobalt-based amorphous metal ribbon made by Metglas, Inc. Amorphous means the atoms are not arranged in a regular crystal lattice. A 2011 University of Kentucky paper calls the alloy a low-cost, high-permeability cobalt-based magnetic material. The manufacturer lists it for flexible electromagnetic shielding, magnetic sensors, high frequency cores and magnetic switches.",
    "uses": [
      {
        "where": "Magnetic shielding",
        "line": "A 2011 University of Kentucky paper built a human-size cylindrical shield from the ribbon. In the Earth's magnetic field, its DC shielding factors were 267 axial and 1500 transverse."
      },
      {
        "where": "Cryogenic experiment",
        "line": "A 2017 paper on a neutron electric dipole moment experiment used six layers of 2705M as the internal shield, because the alloy keeps high permeability from room temperature to cryogenic temperatures. This is a laboratory use, not a flight."
      },
      {
        "where": "Sensors and cores",
        "line": "The manufacturer's product page lists the alloy for magnetic sensors, high frequency cores and magnetic switches."
      }
    ],
    "can_do": [
      {
        "label": "Saturation induction",
        "line": "The technical bulletin gives a saturation induction of 0.77 T.",
        "benchmark": "saturation_induction",
        "scope": "material",
        "value": "0.77 T"
      },
      {
        "label": "Permeability",
        "line": "The bulletin gives a maximum DC permeability of 600,000 when annealed and 290,000 as cast. The bulletin prints no unit for these values.",
        "benchmark": "dc_permeability",
        "scope": "material",
        "value": "600,000 annealed; 290,000 as cast"
      },
      {
        "label": "Shielding",
        "line": "In the 2011 test of a 0.61-m diameter, 1.83-m long shield of six foil layers, the DC shielding factors in the Earth's magnetic field were 267 axial and 1500 transverse.",
        "benchmark": "shielding_factor",
        "scope": "material",
        "value": "267 axial; 1500 transverse"
      },
      {
        "label": "Temperature",
        "line": "The bulletin gives 90 °C as the continuous service temperature.",
        "benchmark": "max_service_temp",
        "scope": "material",
        "value": "90 °C"
      },
      {
        "label": "Curie temperature",
        "line": "The bulletin and the SDS both give a Curie temperature of 365 °C.",
        "benchmark": "curie_temperature",
        "scope": "material",
        "value": "365 °C"
      }
    ],
    "compare": "METGLAS 2705M is a cobalt-based ribbon, and its 2705M section on the manufacturer's product page lists it for shielding, sensors and high frequency cores. The sources read do not compare its numbers directly with other magnetic alloys, so the table below shows its own datasheet values for the three properties.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Saturation induction",
        "benchmark": "saturation_induction",
        "scope": "material"
      },
      {
        "label": "Curie temperature",
        "benchmark": "curie_temperature",
        "scope": "material"
      }
    ],
    "handling": [
      "The edges are very sharp. Wear cut-resistant gloves and safety glasses.",
      "Ventilate when cutting, grinding, sanding or welding the ribbon.",
      "Store it away from moisture and corrosive materials.",
      "The bulletin gives 90 °C as the continuous service temperature."
    ],
    "good_for": [
      "Flexible electromagnetic shielding, the first use the manufacturer lists for 2705M.",
      "Single-shell shielding of a steady field: the 2011 test measured 267 axial and 1500 transverse DC shielding factors."
    ],
    "watch_out": [
      "The bulletin prints its permeability values without a unit, so they are entered as dimensionless numbers.",
      "The continuous service temperature is 90 °C, and the sources read give no data above it.",
      "No corrosion rate was found. The SDS only says moisture and corrosive materials can attack the product."
    ],
    "verdict": "METGLAS 2705M is a documented cobalt-based shielding ribbon with datasheet values and one 2011 university shield test. Its corrosion, long-term ageing and flight behaviour are not documented in the sources read.",
    "recipe": {
      "line": "METGLAS 2705M is a ribbon of cobalt with smaller amounts of boron, iron, molybdenum, nickel and silicon. The SDS gives weight-percent ranges rather than a fixed composition. The manufacturer says its magnetic materials are made on a proprietary high-speed casting process.",
      "parts": [
        {
          "name": "Cobalt",
          "symbol": "Co",
          "role": "Main constituent, given as a weight-percent range in the SDS.",
          "share_percent": 75,
          "share_high": 85,
          "source": "metglas-2705m-sds",
          "where": "Section 2, Composition table, weight %"
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Alloying element, given as a weight-percent range in the SDS.",
          "share_percent": 3,
          "share_high": 7,
          "source": "metglas-2705m-sds",
          "where": "Section 2, Composition table, weight %"
        },
        {
          "name": "Boron",
          "symbol": "B",
          "role": "Alloying element, given as a weight-percent range in the SDS.",
          "share_percent": 1,
          "share_high": 5,
          "source": "metglas-2705m-sds",
          "where": "Section 2, Composition table, weight %"
        },
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "Alloying element, given as a weight-percent range in the SDS.",
          "share_percent": 1,
          "share_high": 5,
          "source": "metglas-2705m-sds",
          "where": "Section 2, Composition table, weight %"
        },
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "Alloying element, given as a weight-percent range in the SDS.",
          "share_percent": 1,
          "share_high": 5,
          "source": "metglas-2705m-sds",
          "where": "Section 2, Composition table, weight %"
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Alloying element, given as a weight-percent range in the SDS.",
          "share_percent": 1,
          "share_high": 5,
          "source": "metglas-2705m-sds",
          "where": "Section 2, Composition table, weight %"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The SDS says the sharp edges are the main hazard as shipped. Fumes from grinding, cutting or welding are harmful if inhaled.",
        "points": [
          {
            "label": "Edges",
            "line": "The edges are very sharp. The SDS asks for cut-resistant gloves and safety glasses when the ribbon is ground, sanded, cut or welded."
          },
          {
            "label": "Fumes",
            "line": "Vapors and fumes from grinding, sanding, cutting or welding are harmful if inhaled. The SDS asks for mechanical ventilation during those operations."
          },
          {
            "label": "Cobalt",
            "line": "The SDS lists cobalt as IARC group 2b, a possible carcinogen, and says cobalt and nickel, and their compounds, should be treated as possible carcinogens."
          }
        ],
        "level": 1,
        "verdict": "Sharp edges and fumes from cutting"
      },
      {
        "title": "If the ribbon melts or burns",
        "lead": "These points come from the SDS and are not based on field incidents.",
        "points": [
          {
            "label": "Fire",
            "line": "The product may burn in a structural fire. Toxic and irritating vapors may be released if it melts or burns, and the SDS asks for self-contained respiratory protection."
          }
        ],
        "level": 2,
        "verdict": "Toxic fumes if melted or burned"
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Storage",
            "line": "The SDS asks that the ribbon be kept from physical damage, moisture and other contamination."
          },
          {
            "label": "Incompatibility",
            "line": "The SDS says the product can be attacked by moisture and corrosive materials."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 18,
    "unreachable": 0,
    "caveats": 3,
    "note": "Read by an AI assistant on 2026-11-01 from the technical bulletin, the SDS, the product page, two arXiv papers, the USGS cobalt chapter and the PubChem record; values copied as printed. Cobalt shares are from USGS tonnes."
  },
  "sources": {
    "metglas-2705m-datasheet": {
      "title": "METGLAS Magnetic Alloy 2705M (cobalt-based) technical bulletin",
      "id": "Metglas, Inc. technical bulletin, ref 2705M08202014",
      "url": "https://metglas.com/wp-content/uploads/2021/06/2705M-Magnetic-Alloy-updated.pdf",
      "year": 2014,
      "kind": "datasheet",
      "license": "manufacturer document, linked not reproduced"
    },
    "metglas-2705m-sds": {
      "title": "Material Safety Data Sheet: METGLAS 2705M Cobalt Base Magnetic Alloy",
      "id": "FRM 8200.007 Rev. 01; initial release October 2003, revision 01 dated 02/06/13",
      "url": "https://metglas.com/wp-content/uploads/2016/12/Metglas-Alloy-2705M-Cobalt-Based-Alloy.pdf",
      "year": 2013,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "metglas-magnetic-page": {
      "title": "METGLAS Magnetic Materials: 2705M section (Applications and Benefits)",
      "id": "Metglas, Inc. product page",
      "url": "https://metglas.com/magnetic-materials/",
      "kind": "web",
      "license": "manufacturer web page, linked not reproduced"
    },
    "arxiv-1107-malkowski": {
      "title": "Technique for high axial shielding factor performance of large-scale, thin, open-ended, cylindrical Metglas magnetic shields",
      "id": "arXiv:1107.2625 (S. Malkowski, R. Adhikari, B. Hona, C. Mattie, D. Woods, H. Yan, B. Plaster; University of Kentucky)",
      "url": "https://arxiv.org/pdf/1107.2625",
      "year": 2011,
      "kind": "paper",
      "license": "arXiv preprint"
    },
    "arxiv-1701-slutsky": {
      "title": "Cryogenic magnetic coil and superconducting magnetic shield for neutron electric dipole moment searches",
      "id": "arXiv:1701.03101 (S. Slutsky et al.)",
      "url": "https://arxiv.org/pdf/1701.03101",
      "year": 2017,
      "kind": "paper",
      "license": "arXiv preprint"
    },
    "usgs-mcs2026-cobalt": {
      "title": "Mineral Commodity Summaries 2026, Cobalt",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-crit2025": {
      "title": "About the 2025 List of Critical Minerals (USGS)",
      "id": "Final 2025 List of Critical Minerals",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025,
      "kind": "web",
      "license": "public domain (USGS)"
    },
    "ec-crm": {
      "title": "Critical raw materials (European Commission, list of critical raw materials)",
      "id": "EU critical raw materials list, Cobalt entry",
      "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en",
      "kind": "web",
      "license": "European Commission web page"
    },
    "pubchem-cobalt": {
      "title": "PubChem compound record, Cobalt (CID 104730), GHS classification",
      "id": "CID 104730",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/104730",
      "kind": "database",
      "license": "public domain (NCBI)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/metglas-2705m/"
}