{
  "spore": "profile",
  "id": "molybdenum-tungsten",
  "spore_version": "0.2",
  "family": "refractory-metals",
  "name": "Molybdenum-tungsten alloy (Mo-30W)",
  "abbreviation": "Mo-30W",
  "role": "high-temperature molybdenum-tungsten alloy for furnace hot zones, crucibles, zinc-bath heaters and sputtering targets",
  "category": "metals",
  "type": "refractory-metals",
  "summary": "Mo-30W is a molybdenum alloy with about 30 % tungsten (Climelt, Polema, ASTM B386 Alloy 366). Polema sells it as sintered and forged crucibles with minimum densities of 10.9 and 11.2 g/cm3, and it also lists the alloy for vacuum and hydrogen furnace parts and for sputtering targets. Burman (1984) gives a melting point of 2829 °C. A powder-metallurgy bar of the alloy had a tensile strength of 170 MPa at 1600 °C and 385 MPa at 1500 °C after full recrystallisation. In molten zinc, a factory test of heater casings ties corrosion to bath temperature and to aluminium in the zinc, although an older datasheet calls the alloy chemically inert in molten zinc. Thermal conductivity, electrical resistivity, expansion and modulus were not found in any readable source.\n",
  "best_for": "Refractory parts that must hold shape at high temperature in vacuum or inert furnaces, where the 2829 °C melting point and the 10.9 g/cm3 sintered minimum density are the reference figures",
  "weakest_at": "Strength falls off above about 1500 °C in the powder-metallurgy bar tested by Wang et al., and the zinc-bath factory test found aluminium in the bath attacks the alloy",
  "identity": {
    "formula": "Mo-30W: molybdenum base with about 30 wt % tungsten (28 to 32 % in Polema, 27 to 33 wt % in ASTM B386 Alloy 366, nominal 30 % in Climelt)",
    "designations": [
      {
        "system": "ASTM",
        "code": "366",
        "note": "Molybdenum Alloy 366, vacuum arc-cast Mo-30W, plate, sheet and strip under ASTM B386",
        "source": "gsalloy-b386",
        "where": "Grade definitions: Molybdenum Alloy 366, vacuum arc-cast molybdenum-30 % tungsten alloy"
      },
      {
        "system": "Trade name",
        "code": "CLIMELT Mo-30W",
        "source": "climelt-mo30w",
        "where": "Page title of the Alloy Digest entry, Mo-9"
      },
      {
        "system": "Trade name",
        "code": "MoW30-PM",
        "note": "Polema grade, sintered and forged crucibles and rod",
        "source": "polema",
        "where": "Section 3, crucibles, and Section 4, products for high-temperature furnaces"
      }
    ],
    "source": "polema",
    "where": "Section 3, Chemical composition of crucibles: molybdenum is the base, with 28-32% tungsten"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "extreme-heat"
    ],
    "applications": [
      "electronics-and-chips",
      "thermal-control"
    ]
  },
  "properties": [
    {
      "benchmark": "melting_point",
      "label": "Melting point of Mo-30W",
      "value": 2829,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "composition": "Mo-30W, 30 % tungsten"
      },
      "method": "Value printed in the summary text of the 1984 ASTM symposium paper; no test method printed",
      "status": "ground",
      "source": "burman1984",
      "where": "Summary text on the ASTM store page (paper visible in summary; full text paywalled)",
      "source_detail": {
        "title": "Symposium paper by R. Burman (AMAX Specialty Metals), ASTM STP 326, 1984 (full title not read)",
        "id": "DOI 10.1520/STP32629S (STP 326)",
        "url": "https://store.astm.org/stp32629s.html",
        "year": 1984,
        "kind": "paper",
        "license": "ASTM (summary only)"
      }
    },
    {
      "benchmark": "density",
      "label": "Minimum density of sintered MoW30-PM crucibles",
      "value": 10.9,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "sintered MoW30-PM crucible",
        "spec": "guaranteed minimum"
      },
      "method": "Manufacturer minimum specification for crucible density",
      "status": "ground",
      "source": "polema",
      "where": "Section 3, Crucible density: sintered MoW30-PM crucibles, at least 10.9 g/cm3",
      "source_detail": {
        "title": "POLEMA: molybdenum-tungsten alloy products (MoW-PM, MoW-2-PM, MoW30-PM crucibles, MoW10-PM sputtering targets)",
        "id": "Polema catalogue page, molybdenum alloys",
        "url": "https://polema.net/en/catalog/molibden/molibdenovye-splavy-mow-mola-i-drugie/",
        "kind": "datasheet",
        "license": "supplier catalogue; facts cited"
      }
    },
    {
      "benchmark": "density",
      "label": "Minimum density of forged MoW30-PM crucibles",
      "value": 11.2,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "forged MoW30-PM crucible",
        "spec": "guaranteed minimum"
      },
      "method": "Manufacturer minimum specification for crucible density",
      "status": "ground",
      "source": "polema",
      "where": "Section 3, Crucible density: forged MoW30-PM crucibles, at least 11.2 g/cm3",
      "source_detail": {
        "title": "POLEMA: molybdenum-tungsten alloy products (MoW-PM, MoW-2-PM, MoW30-PM crucibles, MoW10-PM sputtering targets)",
        "id": "Polema catalogue page, molybdenum alloys",
        "url": "https://polema.net/en/catalog/molibden/molibdenovye-splavy-mow-mola-i-drugie/",
        "kind": "datasheet",
        "license": "supplier catalogue; facts cited"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength of Mo-30W bar at 1600 °C",
      "value": 170,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "1600 °C",
        "form": "bar made by powder metallurgy",
        "state": "tested as reported in the abstract"
      },
      "method": "Tensile test as reported in the Wang et al. abstract",
      "status": "ground",
      "source": "wang2018",
      "where": "Abstract, sentence beginning 'the tensile strength of Mo-30 W molybdenum alloy bar at 1600'",
      "source_detail": {
        "title": "Study on recrystallization behavior of Mo-30W molybdenum alloy",
        "id": "DOI 10.19591/j.cnki.cn11-1974/tf.2018.06.003",
        "url": "https://pmt.ustb.edu.cn/en/article/doi/10.19591/j.cnki.cn11-1974/tf.2018.06.003",
        "year": 2018,
        "kind": "paper",
        "license": "Powder Metallurgy Technology (journal abstract)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation of Mo-30W bar at 1600 °C",
      "value": 10,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temperature": "1600 °C",
        "form": "bar made by powder metallurgy"
      },
      "method": "Tensile test as reported in the Wang et al. abstract",
      "status": "ground",
      "source": "wang2018",
      "where": "Abstract, same sentence as the 170 MPa value",
      "source_detail": {
        "title": "Study on recrystallization behavior of Mo-30W molybdenum alloy",
        "id": "DOI 10.19591/j.cnki.cn11-1974/tf.2018.06.003",
        "url": "https://pmt.ustb.edu.cn/en/article/doi/10.19591/j.cnki.cn11-1974/tf.2018.06.003",
        "year": 2018,
        "kind": "paper",
        "license": "Powder Metallurgy Technology (journal abstract)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength of fully recrystallised Mo-30W at 1500 °C",
      "value": 385,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "1500 °C",
        "state": "completely recrystallised bar"
      },
      "method": "Tensile test as reported in the Wang et al. abstract; lowest strength in the study",
      "status": "ground",
      "source": "wang2018",
      "where": "Abstract, sentence beginning 'The Mo-30 W molybdenum alloy are completely recrystallized at 1500'",
      "source_detail": {
        "title": "Study on recrystallization behavior of Mo-30W molybdenum alloy",
        "id": "DOI 10.19591/j.cnki.cn11-1974/tf.2018.06.003",
        "url": "https://pmt.ustb.edu.cn/en/article/doi/10.19591/j.cnki.cn11-1974/tf.2018.06.003",
        "year": 2018,
        "kind": "paper",
        "license": "Powder Metallurgy Technology (journal abstract)"
      }
    },
    {
      "benchmark": "hardness_vickers",
      "label": "Vickers hardness of fully recrystallised Mo-30W at 1500 °C",
      "value": 185,
      "bound": "exact",
      "unit": "HV10",
      "scope": "material",
      "conditions": {
        "temperature": "1500 °C",
        "state": "completely recrystallised bar"
      },
      "method": "Vickers hardness as reported in the Wang et al. abstract; lowest hardness in the study",
      "status": "ground",
      "source": "wang2018",
      "where": "Abstract, HV10 185 at 1500 °C (hardness_vickers is not in property-canon.yaml; see gaps)",
      "source_detail": {
        "title": "Study on recrystallization behavior of Mo-30W molybdenum alloy",
        "id": "DOI 10.19591/j.cnki.cn11-1974/tf.2018.06.003",
        "url": "https://pmt.ustb.edu.cn/en/article/doi/10.19591/j.cnki.cn11-1974/tf.2018.06.003",
        "year": 2018,
        "kind": "paper",
        "license": "Powder Metallurgy Technology (journal abstract)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Molten zinc in a hot-dip galvanizing bath (heater casing)",
      "headline": "Corrosion speeds up with bath temperature, and aluminium in the zinc is the main cause.",
      "effect": "The factory test of Mo-30W inner heating casings in molten zinc found that bath temperature is an important factor and that higher temperature speeds corrosion. The abstract says aluminium in the molten zinc reacts with Mo-30W and is the main reason for corrosion. Heater life also depends on impurities in the bath, heater design, heating power and alloy quality. The abstract prints no corrosion rate.",
      "rating": "unknown",
      "conditions": {
        "bath": "hot-dip galvanizing, three working conditions (not quantified in the abstract)"
      },
      "source": "mattest",
      "where": "Abstract of the Chinese-language article, title 热镀锌用Mo-30W合金内加热套管的腐蚀性能"
    },
    {
      "environment": "Molten zinc, high-purity Mo-30W grades",
      "headline": "Claimed chemically inert in molten zinc, with no rate given.",
      "effect": "Burman (1984) says Mo-30W is commercially used for its melting point of 2829 °C and its chemical inertness in corrosive molten zinc, especially the high-purity grades. The Climelt datasheet abstract says the alloy is recommended for resistance to molten zinc. Neither source gives a corrosion rate, and this claim is at odds with the aluminium-attack finding above.",
      "rating": "low",
      "conditions": {
        "basis": "claim in a 1984 paper and a datasheet abstract; no test conditions printed"
      },
      "source": "burman1984",
      "where": "Summary text on the ASTM store page"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem GHS aggregated notifications for the element molybdenum: H228 flammable solid (30 % of reports), H361 suspected of damaging fertility or the unborn child (29.5 %), H315 causes skin irritation and H319 causes serious eye irritation. PubChem also says 57.4 % of 1523 reports meet no GHS criteria.",
        "ghs": [
          "H228",
          "H361",
          "H315",
          "H319"
        ],
        "source": "pubchem-mo",
        "where": "GHS Classification, aggregated notifications (CID 23932)"
      },
      {
        "text": "PubChem GHS aggregated notifications for the element tungsten: H228 flammable solid (73.4 % of reports), H252 self-heating in large quantities, H320 eye irritation and H335 respiratory irritation. These describe the element, not the alloy, and the record does not give the physical form.",
        "ghs": [
          "H228",
          "H252",
          "H320",
          "H335"
        ],
        "source": "pubchem-w",
        "where": "GHS Classification, aggregated notifications (CID 23964)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Loss of strength at high temperature",
        "trigger": "Testing or service above the 1300 to 1500 °C range in the powder-metallurgy bar",
        "consequence": "Strength and hardness stay stable between 1300 and 1500 °C and then drop significantly. The fully recrystallised bar was lowest, at 385 MPa and HV10 185 at 1500 °C.",
        "severity": "moderate",
        "source": "wang2018",
        "where": "Abstract"
      },
      {
        "mode": "Aluminium attack on a heater casing in zinc",
        "trigger": "Aluminium in a hot-dip galvanizing bath at higher bath temperature",
        "consequence": "Heater life is shortened. The factory test calls aluminium in the zinc the main reason for corrosion.",
        "severity": "high",
        "source": "mattest",
        "where": "Abstract"
      }
    ],
    "side_effects": [
      {
        "text": "The zinc-bath heater casing is a surface that wears by corrosion, so its life sets how often the heater is replaced. The sources do not give a replacement rate.",
        "affects": "Zinc bath maintenance",
        "source": "mattest",
        "where": "Abstract"
      }
    ],
    "handling": [
      {
        "text": "During use, the products should not be subjected to shocks.",
        "source": "polema"
      },
      {
        "text": "Specify the form, because the minimum density differs between sintered (10.9 g/cm3) and forged (11.2 g/cm3) crucibles.",
        "source": "polema"
      }
    ],
    "mitigations": [
      {
        "text": "Heater life depends on bath temperature, impurities in the bath, heater design, heating power and alloy quality, and the factory test lists these as the factors to control.",
        "source": "mattest"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Sputtering target for thin-film coatings",
      "example": "Polema lists MoW alloy sputtering targets for thin films in electronic components and other functional coatings, and says MoW layers etch well in thin-film transistor work (matmatch, not opened).",
      "source": "polema",
      "where": "Section 5, Products from Molybdenum-tungsten alloy MoW10-PM for sputtering targets (the section title says MoW10-PM while the text says MoW30-PM (MoW10))"
    },
    {
      "application": "thermal-control",
      "device": "Hot-zone parts of vacuum and hydrogen furnaces",
      "example": "Polema lists heat zones for smelting quartz glass, sapphire crystal growth and furnaces for annealing uranium fuel.",
      "source": "polema",
      "where": "Section 4, Products made from molybdenum, tungsten and their alloys for use in high-temperature furnaces"
    },
    {
      "application": "thermal-control",
      "device": "Crucible for melting corundum to grow sapphire monocrystals",
      "example": "Sintered and forged MoW30 crucibles (TMB30-MP) used primarily to melt corundum for extremely pure sapphire.",
      "source": "polema",
      "where": "Section 3, Crucibles from molybdenum-tungsten alloy"
    },
    {
      "application": "thermal-control",
      "device": "Inner heating casing (heater sleeve) in a hot-dip galvanizing zinc bath",
      "example": "A factory test of Mo-30W heater casings in molten zinc, reported in the Chinese-language article in the sources list.",
      "source": "mattest",
      "where": "Abstract. No application slug in the taxonomy fits a zinc-bath heater; the thermal-control slug is used as the nearest match."
    }
  ],
  "supply": [
    {
      "subject": "Molybdenum",
      "abundance": "World mine production 260,000 t in 2025 (estimated), 256,000 t in 2024. World reserves 17,000 thousand t. Identified resources are about 5.4 million tons in the United States and about 20 million tons in the rest of the world.",
      "producers": [
        {
          "country": "China",
          "year": 2025
        },
        {
          "country": "Chile",
          "year": 2025
        },
        {
          "country": "United States",
          "year": 2025
        },
        {
          "country": "Peru",
          "year": 2025
        },
        {
          "country": "Mexico",
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "Molybdenum recycled in new and old steel and other scrap may be as much as 30 % of the apparent supply of molybdenum (USGS). There is no separate recovery process for secondary molybdenum from its alloys.",
      "substitutes": [
        "There is little substitution for molybdenum in its major application in steels and cast irons (USGS)."
      ],
      "source": "usgs-mo-2026",
      "where": "Molybdenum chapter: Events, Trends and Issues; World Mine Production and Reserves table; Recycling; Substitutes"
    },
    {
      "subject": "Tungsten",
      "abundance": "World mine production 85,000 t in 2025 (estimated), 82,000 t in 2024. China 67,000 t in both years, with reserves of 2,500,000 t. World reserves more than 4,700,000 t.",
      "producers": [
        {
          "country": "China",
          "year": 2025
        },
        {
          "country": "Russia",
          "year": 2025
        },
        {
          "country": "Vietnam",
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "Not read in this run.",
      "substitutes": [],
      "source": "usgs-w-2026",
      "where": "Tungsten chapter: World Mine Production and Reserves table; Events, Trends and Issues"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "USGS Mineral Commodity Summaries 2026: Molybdenum",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Tungsten",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tungsten.pdf",
      "year": 2026
    },
    {
      "title": "PubChem: Molybdenum (CID 23932), GHS classification summary",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23932",
      "year": 2026
    },
    {
      "title": "PubChem: Tungsten (CID 23964), GHS classification summary",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23964",
      "year": 2026
    },
    {
      "title": "Study on recrystallization behavior of Mo-30W molybdenum alloy (Powder Metallurgy Technology 2018)",
      "type": "paper",
      "url": "https://pmt.ustb.edu.cn/en/article/doi/10.19591/j.cnki.cn11-1974/tf.2018.06.003",
      "year": 2018
    },
    {
      "title": "POLEMA: molybdenum-tungsten alloy products, crucibles and sputtering targets",
      "type": "datasheet",
      "url": "https://polema.net/en/catalog/molibden/molibdenovye-splavy-mow-mola-i-drugie/"
    },
    {
      "title": "CLIMELT Mo-30W High Temperature Alloy, Alloy Digest Mo-9 (abstract only, full datasheet paywalled)",
      "type": "datasheet",
      "url": "https://dl.asminternational.org/alloy-digest/article/19/4/Mo-9/1733/CLIMELT-Mo-30WHigh-Temperature-Alloy",
      "year": 1970
    }
  ],
  "gaps": [
    "Thermal conductivity of Mo-30W: no readable source found (Climelt datasheet paywalled, Plansee MoW30 datasheet not reachable, Wieland and matmatch not opened).",
    "Electrical resistivity of Mo-30W: no value found in any readable source.",
    "Coefficient of thermal expansion of Mo-30W: no value found in a readable source (a third-party comparison page printed one for a grade called 366, but it could not be re-opened in this run).",
    "Elastic modulus of Mo-30W: no value found in a readable source.",
    "Yield strength of Mo-30W: the Polema page gives only a conditional yield limit for MoW-2-PM, with no number. Not used, since its composition is not stated.",
    "Hardness at temperatures other than 1500 °C: no value found; the Wang abstract gives stability between 1300 and 1500 °C but no numbers.",
    "The Polema hot-rolled sheet (MoW-PM) and extruded stock (MoW-2-PM) tables are not used: neither page states the tungsten content, so the values may not belong to Mo-30W.",
    "Polema's sputtering section is titled MoW10-PM but its text says MoW30-PM (MoW10). The product name is inconsistent and was not resolved.",
    "Hardness is named hardness_vickers because property-canon.yaml has no Vickers hardness name; the value is in units of HV10.",
    "No application slug in the taxonomy fits a zinc-bath heater; thermal-control is the nearest match.",
    "Corrosion rate in molten zinc is not printed in any readable source. The factory-test full text was not available, only the Chinese abstract.",
    "Burman (1984) calls the alloy chemically inert in molten zinc, but the Mo-30W factory test names aluminium in the zinc as the main cause of corrosion. The two claims conflict and were not resolved.",
    "No oxidation or high-temperature atmosphere data for Mo-30W were found in a readable source.",
    "Critical-mineral list status for molybdenum and tungsten is not stated in the USGS summaries read in this run. The EU and BGS lists were not checked.",
    "Tungsten recycling and substitutes were not in the USGS tungsten summary read in this run.",
    "PubChem hazard codes are aggregated notifications for the pure elements, not for the alloy. No Mo-30W safety data sheet was found.",
    "Publication year of the Polema page is not printed on the page.",
    "Year and author of the Chinese-language zinc-bath article were not visible in the fetched abstract.",
    "No openly licensed image was checked, so media is empty.",
    "The Plansee MoW30 datasheet, the matmatch MW30 page and the gsalloy product page were not reachable for full text (403 or DNS failure), so values from them are not used except the designation text from the gsalloy page."
  ],
  "story": {
    "why": "Mo-30W is a molybdenum alloy with about 30 % tungsten. It is used where the part must keep its shape at high temperature, in vacuum or hydrogen furnaces, for sapphire crucibles and for thin-film sputtering targets. Burman (1984) gives a melting point of 2829 °C, and Polema gives minimum crucible densities of 10.9 g/cm3 (sintered) and 11.2 g/cm3 (forged). The zinc-bath use depends on bath temperature and aluminium content.",
    "uses": [
      {
        "where": "Sputtering targets",
        "line": "Polema lists MoW alloy sputtering targets for thin-film electronic components and functional coatings."
      },
      {
        "where": "Furnace hot zones",
        "line": "Polema lists heat zones of vacuum and hydrogen furnaces, for smelting quartz glass and growing sapphire crystals."
      },
      {
        "where": "Zinc-bath heater casings",
        "line": "A factory test of Mo-30W inner heating casings in molten zinc was reported in a Chinese-language article (abstract read)."
      }
    ],
    "can_do": [
      {
        "label": "Melting point",
        "line": "Burman (1984) gives 2829 °C, cited for its high melting temperature and its inertness in molten zinc.",
        "benchmark": "melting_point",
        "scope": "material",
        "value": "2829 °C"
      },
      {
        "label": "Weight",
        "line": "Polema gives at least 10.9 g/cm3 for sintered MoW30-PM crucibles.",
        "benchmark": "density",
        "scope": "material",
        "value": "10.9 g/cm3 minimum"
      },
      {
        "label": "Strength when hot",
        "line": "The Wang et al. bar has a tensile strength of 170 MPa and 10 % elongation at 1600 °C.",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material",
        "value": "170 MPa at 1600 °C"
      },
      {
        "label": "Strength after recrystallisation",
        "line": "The fully recrystallised bar has a tensile strength of 385 MPa and HV10 185 at 1500 °C, the lowest values in the study.",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material",
        "value": "385 MPa at 1500 °C"
      }
    ],
    "compare": "Polema says Mo-30W has temperature resistance and creep resistance higher than molybdenum, and higher machinability than tungsten. No numeric comparison with pure molybdenum was read in this run, so the compare rows show Mo-30W values only.",
    "compare_rows": [
      {
        "label": "Density (crucible minimum)",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Tensile strength at 1500 °C",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      }
    ],
    "handling": [
      "Do not subject the products to shocks during use (Polema).",
      "Specify sintered or forged form, because the minimum density differs (Polema).",
      "Test the zinc-bath heater casing against the bath temperature and aluminium content in the bath, since the factory test ties corrosion to both."
    ],
    "good_for": [
      "High-temperature furnace and hot-zone parts in vacuum or hydrogen: melting point 2829 °C (Burman, 1984).",
      "Sapphire crucibles and thin-film sputtering targets: Polema lists both uses.",
      "Heat resistance with better creep resistance and machinability than tungsten (Polema)."
    ],
    "watch_out": [
      "Strength falls significantly above the 1300 to 1500 °C range in the Wang et al. bar.",
      "Aluminium in a galvanizing bath is named as the main cause of corrosion of Mo-30W heater casings.",
      "The zinc-bath claim of chemical inertness (Burman 1984, Climelt) conflicts with the factory-test finding, and no corrosion rate is printed.",
      "Thermal conductivity, electrical resistivity, expansion and modulus for Mo-30W were not found in a readable source."
    ],
    "verdict": "Mo-30W is a molybdenum alloy with about 30 % tungsten, used for furnace hot zones, sapphire crucibles and sputtering targets. Burman (1984) gives a melting point of 2829 °C, Polema gives minimum crucible densities of 10.9 and 11.2 g/cm3, and the Wang et al. bar holds 385 MPa at 1500 °C after recrystallisation. For zinc baths the sources disagree, and the factory test names aluminium in the zinc as the main cause of corrosion. The thermal and electrical data that a designer would need are not in any source read here, so they should be obtained from the manufacturer before a design is fixed.",
    "recipe": {
      "line": "Mo-30W is a molybdenum-base alloy with about 30 % tungsten. Polema gives 28 to 32 % tungsten for its crucibles, ASTM B386 Alloy 366 is 27 to 33 wt %, and Climelt is nominal 70 % Mo to 30 % W. Polema makes it as sintered or forged shapes, and the Wang et al. bar was made by powder metallurgy. ASTM B386 Alloy 366 is vacuum arc-cast.",
      "parts": [
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "The matrix of the alloy, with a body-centred cubic structure.",
          "share_note": "balance (about 70 %)"
        },
        {
          "name": "Tungsten",
          "symbol": "W",
          "role": "Forms a solid solution with molybdenum, which Polema credits for the alloy's creep resistance and machinability.",
          "share_percent": 28,
          "share_high": 32
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The hazard notifications are for the pure elements, not the alloy.",
        "points": [
          {
            "label": "Molybdenum as a substance",
            "line": "PubChem notifications for molybdenum give H228 flammable solid for 30 % of reports and H361 for 29.5 %, but 57.4 % of 1523 reports meet no GHS criteria."
          },
          {
            "label": "Tungsten as a substance",
            "line": "PubChem notifications for tungsten give H228 flammable solid for 73.4 % of reports, with H252, H320 and H335 also listed."
          }
        ],
        "level": 1,
        "verdict": "Mixed notifications"
      },
      {
        "title": "If it fails",
        "lead": "The failure route in the sources is high temperature and aluminium in the zinc.",
        "points": [
          {
            "label": "High temperature",
            "line": "Strength and hardness stay stable between 1300 and 1500 °C in the Wang et al. bar and then drop significantly, with 385 MPa and HV10 185 at 1500 °C after full recrystallisation."
          },
          {
            "label": "Aluminium in zinc",
            "line": "The Mo-30W heater casing factory test calls aluminium in the molten zinc the main reason for corrosion."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Shock",
            "line": "Polema says the products should not be subjected to shocks during use."
          },
          {
            "label": "Specify the form",
            "line": "Sintered and forged crucibles have different minimum densities (10.9 and 11.2 g/cm3), so state the form when you order."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 7,
    "unreachable": 4,
    "caveats": 3,
    "note": "Written by an AI assistant on 2026-10-26. Seven property values were read in this run. Thermal conductivity, electrical resistivity, expansion and modulus were not found. The Plansee, matmatch, Climelt full-text and mat-test full-text pages were not reachable."
  },
  "sources": {
    "usgs-mo-2026": {
      "title": "Mineral Commodity Summaries 2026: Molybdenum",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain"
    },
    "usgs-w-2026": {
      "title": "Mineral Commodity Summaries 2026: Tungsten",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tungsten.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain"
    },
    "polema": {
      "title": "POLEMA: molybdenum-tungsten alloy products (MoW-PM, MoW-2-PM, MoW30-PM crucibles, MoW10-PM sputtering targets)",
      "id": "Polema catalogue page, molybdenum alloys",
      "url": "https://polema.net/en/catalog/molibden/molibdenovye-splavy-mow-mola-i-drugie/",
      "kind": "datasheet",
      "license": "supplier catalogue; facts cited"
    },
    "wang2018": {
      "title": "Study on recrystallization behavior of Mo-30W molybdenum alloy",
      "id": "DOI 10.19591/j.cnki.cn11-1974/tf.2018.06.003",
      "url": "https://pmt.ustb.edu.cn/en/article/doi/10.19591/j.cnki.cn11-1974/tf.2018.06.003",
      "year": 2018,
      "kind": "paper",
      "license": "Powder Metallurgy Technology (journal abstract)"
    },
    "burman1984": {
      "title": "Symposium paper by R. Burman (AMAX Specialty Metals), ASTM STP 326, 1984 (full title not read)",
      "id": "DOI 10.1520/STP32629S (STP 326)",
      "url": "https://store.astm.org/stp32629s.html",
      "year": 1984,
      "kind": "paper",
      "license": "ASTM (summary only)"
    },
    "climelt-mo30w": {
      "title": "CLIMELT Mo-30W High Temperature Alloy, Alloy Digest Mo-9 (Climax Molybdenum)",
      "id": "DOI 10.31399/asm.ad.mo0009",
      "url": "https://dl.asminternational.org/alloy-digest/article/19/4/Mo-9/1733/CLIMELT-Mo-30WHigh-Temperature-Alloy",
      "year": 1970,
      "kind": "datasheet",
      "license": "ASM Alloy Digest (abstract only)"
    },
    "mattest": {
      "title": "热镀锌用Mo-30W合金内加热套管的腐蚀性能 (Corrosion properties of Mo-30W alloy inner heating casing for hot-dip galvanizing)",
      "id": "Chinese-language article, mat-test.com record",
      "url": "https://fsyfh.mat-test.com/article/id/60433c86-e02c-4b74-bf52-93dddd198504",
      "kind": "paper",
      "license": "abstract read; full text not opened"
    },
    "gsalloy-b386": {
      "title": "ASTM B386 molybdenum and molybdenum alloy plate and sheet (supplier product page, Mo Alloy 366)",
      "id": "ASTM B386/B386M",
      "url": "https://gsalloy.com/product/astm-b386-molybdenum-and-molybdenum-alloy-plate-and-sheet/",
      "kind": "web",
      "license": "supplier page"
    },
    "pubchem-mo": {
      "title": "PubChem: Molybdenum (CID 23932), GHS classification",
      "id": "CID 23932",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23932",
      "kind": "database",
      "license": "PubChem, public domain"
    },
    "pubchem-w": {
      "title": "PubChem: Tungsten (CID 23964), GHS classification",
      "id": "CID 23964",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23964",
      "kind": "database",
      "license": "PubChem, public domain"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/molybdenum-tungsten/"
}