{ "spore": "profile", "id": "magnesium", "spore_version": "0.2", "family": "magnesium-alloys", "name": "Magnesium (pure metal)", "abbreviation": "Mg", "role": "light structural metal, alloying base and reducing metal", "category": "metals", "type": "magnesium", "summary": "Pure magnesium is the lightest common structural metal, at 1.74 g/cm3 at 20 degC (Goodfellow). It melts at 650 degC and is hexagonal close-packed, so it bends less easily than aluminium at room temperature. Its weak point is chemistry: it is the most electrochemically active structural metal, the native oxide film gives little protection in chloride, and finely divided powder or ribbon ignites in air. Most magnesium sold for structures is an alloy such as AZ31B; this profile covers the unalloyed metal in ingot, ribbon and powder form.\n", "best_for": "Light, unalloyed magnesium for research and for alloying or reducing use, such as Kroll-process titanium production and magnesium-ion battery anode research, where the purity matters more than structural strength.", "weakest_at": "Strength and corrosion resistance. Goodfellow gives 140 to 160 MPa tensile strength for pure magnesium against 260 MPa for wrought AZ31, and says chlorides break down the passive film. Powder and ribbon are pyrophoric.", "identity": { "formula": "Mg, elemental magnesium metal (hexagonal close-packed crystal; Goodfellow gives a = 3.209 A, c = 5.211 A)", "cas": "7439-95-4", "designations": [], "source": "goodfellow-mg-metal", "where": "Identifier table (CAS Number 7439-95-4; Symbol Mg; Atomic Number 12); Crystal Structure row of the General Properties table" }, "tags": { "environments": [], "stresses": [], "applications": [ "electronics-and-chips", "batteries" ] }, "properties": [ { "benchmark": "density", "label": "Density at 20 degC, supplier listing", "value": 1.74, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "temperature": "20 °C", "form": "pure magnesium metal (not an alloy)" }, "method": "General Properties table of a supplier product page, Density row", "status": "ground", "source": "goodfellow-mg-metal", "where": "General Properties table, Density (20 °C) row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "density", "label": "Density, Merck Index value quoted by PubChem", "value": 1.738, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "temperature": "20 °C", "basis": "value printed in the Experimental Properties section; PubChem cites the Merck Index, 13th edition" }, "method": "Experimental Properties, Density entry of the PubChem record", "status": "ground", "source": "pubchem-mg", "where": "Chemical and Physical Properties, Experimental Properties, Density (Merck Index entry)", "source_detail": { "title": "Magnesium, PubChem compound CID 5462224: Safety and Hazards, GHS Classification; Experimental Properties", "id": "PubChem CID 5462224; GHS aggregated from ECHA C&L notifications", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5462224/JSON", "kind": "database", "license": "PubChem (NCBI) public data" } }, { "benchmark": "melting_point", "value": 650, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "basis": "printed as 650 °C (923 K) on the supplier page" }, "method": "General Properties table of a supplier product page, Melting Point row", "status": "ground", "source": "goodfellow-mg-metal", "where": "General Properties table, Melting Point row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "boiling_point", "value": 1090, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pressure": "760 mmHg" }, "method": "Experimental Properties, Boiling Point entry of the PubChem record", "status": "ground", "source": "pubchem-mg", "where": "Chemical and Physical Properties, Experimental Properties, Boiling Point (1090 °C @760 [mm Hg])", "source_detail": { "title": "Magnesium, PubChem compound CID 5462224: Safety and Hazards, GHS Classification; Experimental Properties", "id": "PubChem CID 5462224; GHS aggregated from ECHA C&L notifications", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5462224/JSON", "kind": "database", "license": "PubChem (NCBI) public data" } }, { "benchmark": "thermal_conductivity", "value": 156, "bound": "exact", "unit": "W/m·K", "scope": "material", "conditions": { "temperature": "not stated on the page", "form": "pure magnesium metal" }, "method": "General Properties table of a supplier product page, Thermal Conductivity row (printed as W/m·K)", "status": "ground", "source": "goodfellow-mg-metal", "where": "General Properties table, Thermal Conductivity row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "electrical_resistivity", "value": 45.4, "bound": "exact", "unit": "nΩ·m", "scope": "material", "conditions": { "temperature": "20 °C" }, "method": "General Properties table of a supplier product page, Electrical Resistivity row", "status": "ground", "source": "goodfellow-mg-metal", "where": "General Properties table, Electrical Resistivity row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "elastic_modulus", "value": 45, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "temper": "annealed (table is headed Pure Mg, Annealed)", "temperature": "not stated" }, "method": "Mechanical Properties table (Pure Mg, Annealed) of a supplier product page", "status": "ground", "source": "goodfellow-mg-metal", "where": "Mechanical Properties (Pure Mg, Annealed) table, Elastic (Young's) Modulus row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "poissons_ratio", "value": 0.29, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "temper": "annealed (table is headed Pure Mg, Annealed)", "basis": "polycrystalline form, as the page states" }, "method": "Mechanical Properties table (Pure Mg, Annealed) of a supplier product page", "status": "ground", "source": "goodfellow-mg-metal", "where": "Mechanical Properties (Pure Mg, Annealed) table, Poisson's Ratio row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, pure magnesium, annealed", "value": 140, "value_high": 160, "bound": "range", "unit": "MPa", "scope": "material", "conditions": { "temper": "annealed (table is headed Pure Mg, Annealed)", "basis": "value printed for pure Mg in the Tensile Strength (Alloys) row; the same row gives 180 to 350 MPa for alloys" }, "method": "Mechanical Properties table (Pure Mg, Annealed) of a supplier product page", "status": "ground", "source": "goodfellow-mg-metal", "where": "Mechanical Properties (Pure Mg, Annealed) table, Tensile Strength (Alloys) row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "hardness_vickers", "label": "Hardness, Vickers, annealed", "value": 35, "bound": "exact", "unit": "HV", "scope": "material", "conditions": { "temper": "annealed" }, "method": "Mechanical Properties table (Pure Mg, Annealed) of a supplier product page; printed as approximately 35 HV, with Mohs about 2.5", "status": "ground", "note": "Printed with a tilde (about 35). Not in spores/property-canon.yaml, so the snake_case name hardness_vickers is used.", "source": "goodfellow-mg-metal", "where": "Mechanical Properties (Pure Mg, Annealed) table, Hardness row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "standard_electrode_potential", "label": "Standard electrode potential", "value": -2.37, "bound": "exact", "unit": "V vs SHE", "scope": "material", "conditions": { "basis": "as printed on the supplier page" }, "method": "Chemical Properties table of a supplier product page, Corrosion Behavior row", "status": "ground", "note": "Not in spores/property-canon.yaml, so the snake_case name standard_electrode_potential is used.", "source": "goodfellow-mg-metal", "where": "Chemical Properties table, Corrosion Behavior row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "atomic_mass", "label": "Atomic mass", "value": 24.305, "bound": "exact", "unit": "u", "scope": "material", "conditions": { "basis": "standard atomic weight range printed by Wikipedia as 24.304 to 24.307 (abridged 24.305 plus or minus 0.002)" }, "method": "General Properties table of a supplier product page, Atomic Mass row", "status": "ground", "note": "Not in spores/property-canon.yaml, so the snake_case name atomic_mass is used.", "source": "goodfellow-mg-metal", "where": "General Properties table, Atomic Mass row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "ignition_temperature", "label": "Ignition temperature, ribbon", "value": 650, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "form": "ribbon", "basis": "printed as about 650 °C on the supplier page" }, "method": "Combustion table of a supplier product page", "status": "ground", "note": "Not in spores/property-canon.yaml, so the snake_case name ignition_temperature is used. The page gives one figure for ribbon and does not give a powder value.", "source": "goodfellow-mg-metal", "where": "Combustion row (ignition temperature about 650 °C, ribbon); Reactivity with Water and Air row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } }, { "benchmark": "autoignition_temperature", "label": "Autoignition temperature, turnings", "value": 473, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "form": "turnings", "basis": "PubChem notes the value may be lower for finer forms" }, "method": "Experimental Properties, Autoignition Temperature entry of the PubChem record (cites NFPA Fire Protection Guide, 2002)", "status": "ground", "note": "Not in spores/property-canon.yaml, so the snake_case name autoignition_temperature is used. Finer powder ignites at a lower temperature, so this is an upper figure for powder.", "source": "pubchem-mg", "where": "Chemical and Physical Properties, Experimental Properties, Autoignition Temperature (883 °F (473 °C) for turnings)", "source_detail": { "title": "Magnesium, PubChem compound CID 5462224: Safety and Hazards, GHS Classification; Experimental Properties", "id": "PubChem CID 5462224; GHS aggregated from ECHA C&L notifications", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5462224/JSON", "kind": "database", "license": "PubChem (NCBI) public data" } }, { "benchmark": "combustion_burn_rate", "label": "Burn rate in oxygen", "value": 25, "bound": "exact", "unit": "MJ/kg", "scope": "material", "conditions": { "basis": "printed as about 25 MJ/kg on the supplier page" }, "method": "Combustion table of a supplier product page", "status": "ground", "note": "Not in spores/property-canon.yaml, so the snake_case name combustion_burn_rate is used.", "source": "goodfellow-mg-metal", "where": "Combustion row", "source_detail": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" } } ], "corrosion": [ { "environment": "Chloride solution, including 3.5 % NaCl saturated with Mg(OH)2 (electrochemical and weight-loss tests)", "headline": "Pure magnesium corrodes in chloride. This source gives no numerical rate for the pure metal.", "effect": "The 2012 Corrosion Science study (Qiao and co-authors, Hereon record) tested high-purity magnesium ingot in 3.5 % NaCl saturated with Mg(OH)2 for up to 14 days. The abstract says the electrochemical corrosion rate was consistently lower than the weight-loss and hydrogen-evolution rates. The supplier page says the native MgO and Mg(OH)2 film is disrupted in chloride environments.", "rating": "unknown", "conditions": { "temperature": "not stated", "duration": "up to 14 days", "basis": "abstract only; the study's rate figures were not readable, so no rate is given here" }, "source": "qiao2012", "where": "Abstract" }, { "environment": "Dry or moist air, and water (room temperature and steam)", "headline": "Magnesium reacts slowly with water at room temperature and faster with steam.", "effect": "The supplier page says bulk magnesium reacts slowly with liquid water at room temperature but rapidly with steam, and that the MgO and Mg(OH)2 passive film formed in dry air gives only limited protection.", "rating": "unknown", "conditions": { "temperature": "room temperature to steam", "basis": "qualitative statements; no rate or mass gain was read" }, "source": "goodfellow-mg-metal", "where": "Chemical Properties table, Reactivity with Water and Air row; Corrosion Behavior row" }, { "environment": "Galvanic contact with aluminium, steel or copper", "headline": "Galvanic corrosion is severe unless the parts are electrically isolated.", "effect": "The supplier page says magnesium has poor galvanic compatibility with most structural metals, and that galvanic corrosion with coupled aluminium, steel or copper is severe unless components are electrically isolated. Conversion coatings, anodising (PEO or MAO) and rare earth alloying are named as protective strategies.", "rating": "severe", "conditions": { "basis": "qualitative statement from the supplier page; no test result was read" }, "source": "goodfellow-mg-metal", "where": "Chemical Properties table, Corrosion Behavior row" }, { "environment": "Chloride solutions at three concentrations, 24 h immersion (pure magnesium and AZ31B-H24)", "headline": "The 2015 Corrosion study compared several ways of measuring pure magnesium corrosion in chloride.", "effect": "The 2015 Corrosion paper (Bland, King, Birbilis and Scully) compared electrochemical impedance, hydrogen collection, weight loss and ICP-OES on pure magnesium and AZ31B-H24 over 24 h immersion in three chloride concentrations. The abstract gives no numerical rates, so the study adds method context, not a value.", "rating": "unknown", "conditions": { "duration": "24 h immersion", "basis": "abstract only; the chloride concentrations are not stated numerically on the record" }, "source": "bland2015", "where": "Abstract" } ], "risks": { "hazards": [ { "text": "PubChem's aggregated GHS reports for magnesium metal (2,205 company reports from 27 ECHA notifications) give H228 (flammable solid) in 44.9% of reports, H250 (catches fire spontaneously if exposed to air) in 36.5%, H260 (in contact with water releases flammable gases which may ignite spontaneously) in 36.7%, H261 (in contact with water releases flammable gas) in 44.8% and H252 (self-heating in large quantities; may catch fire) in 18%. 18.4% of reports (405 of 2,205) say the element does not meet GHS criteria. These are element-level statements, not a classification of a particular powder or ribbon.", "ghs": [ "H228", "H250", "H260", "H261", "H252" ], "source": "pubchem-mg", "where": "Safety and Hazards, GHS Classification (CID 5462224)" }, { "text": "Fire fighting: PubChem's CHRIS and ERG (Guide 138) excerpts say not to use water, foam, halogenated agents or carbon dioxide on a magnesium fire, and to use dry sand, dry powder or inert powders such as graphite, limestone or salt. The Goodfellow page says burning magnesium cannot be put out with CO2 or N2.", "ghs": [], "source": "pubchem-mg", "where": "Safety and Hazards, Fire Hazards and Fire Fighting sections" }, { "text": "The Goodfellow page says the bright white flame of burning magnesium emits strong ultraviolet and visible light, and can cause permanent eye damage on direct viewing without UV-filtering eye protection.", "ghs": [], "source": "goodfellow-mg-metal", "where": "Combustion row" } ], "failure_risks": [ { "mode": "Ignition of powder or ribbon in air", "trigger": "Finely divided powder or ribbon exposed to air, or heating to about 650 degC for ribbon (Goodfellow) or about 473 degC for turnings (PubChem)", "consequence": "Vigorous burning. The Goodfellow page says magnesium fires cannot be extinguished with water or CO2, and that powder with more than 50% magnesium ignites readily in air (PubChem reactivity text).", "severity": "high", "source": "goodfellow-mg-metal", "where": "Combustion row; Reactivity with Water and Air row; PubChem Reactivity Profile (powder over 50% magnesium ignites readily in air) is cited in the same record" }, { "mode": "Reaction with water", "trigger": "Contact with water or moist air", "consequence": "Flammable hydrogen gas is released and may ignite spontaneously (H260, H261). The PubChem ERG excerpt says some reactions with water are vigorous or explosive.", "severity": "high", "source": "pubchem-mg", "where": "GHS Classification, H260 and H261 statements; Fire Hazards (ERG Guide 138)" }, { "mode": "Explosive or friction-sensitive mixtures", "trigger": "Finely divided magnesium mixed with oxidisers, for example potassium or sodium perchlorate, potassium chlorate or nitric acid", "consequence": "PubChem's reactivity profile lists several explosive or friction-sensitive mixtures with powdered magnesium.", "severity": "high", "source": "pubchem-mg", "where": "Stability and Reactivity, Reactivity Profile" }, { "mode": "Chloride corrosion of unprotected metal", "trigger": "Immersion or wet contact with chloride solutions", "consequence": "Corrosion rate is not given here as a number for pure metal. The supplier page says the passive film is disrupted in chloride environments, and that galvanic corrosion with other metals is severe unless isolated.", "severity": "moderate", "source": "goodfellow-mg-metal", "where": "Chemical Properties table, Corrosion Behavior row" } ], "side_effects": [], "handling": [ { "text": "The Goodfellow page says to keep magnesium dry and away from water. PubChem says contact with water releases flammable gas (H261).", "source": "pubchem-mg", "where": "GHS Classification, H260 and H261 statements (CID 5462224)" }, { "text": "Keep a dry sand, dry graphite or Met-L-X powder ready for fire fighting. The Goodfellow page says water and CO2 cannot be used on magnesium fires.", "source": "goodfellow-mg-metal", "where": "Chemical Properties table, Reactivity with Water and Air and Combustion rows" }, { "text": "Keep powder away from strong oxidisers, chlorine, nitric acid and perchlorates. PubChem lists explosive or friction-sensitive mixtures with these.", "source": "pubchem-mg", "where": "Stability and Reactivity, Reactivity Profile" }, { "text": "Melt and cast under a protective cover gas such as SF6 or CO2/SO2, because molten magnesium ignites readily in air.", "source": "goodfellow-mg-metal", "where": "General Properties table, Melting Point row" } ], "mitigations": [ { "text": "Goodfellow lists conversion coatings, anodising (PEO or MAO), and rare earth alloying as protective strategies for magnesium against corrosion.", "source": "goodfellow-mg-metal", "where": "Chemical Properties table, Corrosion Behavior row" } ] }, "uses": [ { "application": "electronics-and-chips", "device": "Magnesium laptop shells and die-cast housings", "example": "Goodfellow says a typical magnesium laptop shell weighs 30 to 40 percent less than an equivalent aluminium die-cast housing. The page's example is for magnesium alloys rather than pure metal.", "source": "goodfellow-mg-metal", "where": "Applications section, electronics housings paragraph" }, { "application": "batteries", "device": "Magnesium-ion battery anode (research stage)", "example": "Goodfellow calls magnesium an emerging anode material for next-generation magnesium-ion batteries. This is a research use, not a product in the sources read.", "source": "goodfellow-mg-metal", "where": "Uses paragraph (pyrotechnics, Kroll process, implants and batteries)" } ], "supply": [ { "subject": "Magnesium metal, world primary (smelter) production, 2025", "abundance": "USGS: resources for magnesium range from large to virtually unlimited and are globally widespread; magnesium-bearing brines are estimated to be a resource in the billions of tons.", "producers": [ { "country": "China", "share_percent": 87.7, "year": 2025 }, { "country": "Russia", "share_percent": 5.5, "year": 2025 }, { "country": "Brazil", "share_percent": 1.8, "year": 2025 }, { "country": "Israel", "share_percent": 1.8, "year": 2025 }, { "country": "Turkey", "share_percent": 1.4, "year": 2025 }, { "country": "Kazakhstan", "share_percent": 1.2, "year": 2025 }, { "country": "Iran", "share_percent": 0.5, "year": 2025 }, { "country": "United States", "share_percent": 0, "year": 2025 } ], "critical_lists": [ { "list": "USGS 2025 List of Critical Minerals: Magnesium, used in metal alloys used by aerospace, automotive and electronics industries", "listed": true } ], "recycling": "USGS: about 110 thousand t of secondary magnesium was recovered from scrap in 2025 (estimate); about 26,000 tons from old scrap and 82,000 tons from new scrap. The only US primary smelter, in Utah, stopped production in 2022, and its operator filed for Chapter 11 in September 2025.", "substitutes": [ "USGS: aluminium and zinc may substitute for magnesium in castings and wrought products. Magnesium's light weight is an advantage over them in most applications; its high cost is a disadvantage." ], "source": "usgs-mcs2026-magnesium-metal", "where": "World Primary Production and Reserves table, smelter production 2025 (tonnages in thousand t: China 950, Russia 60, Brazil 20, Israel 20, Turkey 15, Kazakhstan 13, Iran 5; world total 1,100 rounded). Shares calculated by Space Mushroom over the sum of the listed 2025 values (1,083 thousand t). Recycling; Substitutes; Events, Trends and Issues." }, { "subject": "Magnesium metal imported to the United States, 2021 to 2024 (99.8 % purity)", "producers": [ { "country": "Israel", "share_percent": 47 }, { "country": "Turkey", "share_percent": 31 }, { "country": "Russia", "share_percent": 8 }, { "country": "China", "share_percent": 6 } ], "critical_lists": [], "substitutes": [], "source": "usgs-mcs2026-magnesium-metal", "where": "Import Sources (2021-24), magnesium metal (99.8% purity) row; the other 8% is not listed by country" } ], "media": [], "documents": [ { "title": "Goodfellow: High-Purity Magnesium Metal, product page with general, mechanical and chemical property tables", "type": "datasheet", "url": "https://www.goodfellow.com/usa/material/metals/magnesium" }, { "title": "USGS Mineral Commodity Summaries 2026: Magnesium Metal", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-magnesium-metal.pdf", "year": 2026 }, { "title": "USGS: About the 2025 List of Critical Minerals", "type": "report", "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals", "year": 2025 }, { "title": "PubChem: Magnesium, CID 5462224, Safety and Hazards, GHS Classification and Experimental Properties", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/5462224" }, { "title": "Corrosion behaviour of a nominally high purity Mg ingot produced by permanent mould direct chill casting (Corrosion Science, 2012)", "type": "paper", "url": "https://publications.hzg.de/id/29895/index.php", "year": 2012 }, { "title": "Assessing the corrosion of commercially pure magnesium and AZ31B (Corrosion, NACE, 2015)", "type": "paper", "url": "https://research.monash.edu/en/publications/assessing-the-corrosion-of-commercially-pure-magnesium-and-commer/", "year": 2015 }, { "title": "AircraftMaterialsUK technical data sheet: Magnesium Alloy AZ31B (for the composition comparison only)", "type": "datasheet", "url": "https://aircraftmaterials.com/data/magnesium/az31b.html" }, { "title": "Wikipedia: Magnesium (history, crystal structure, standard atomic weight)", "type": "report", "url": "https://en.wikipedia.org/wiki/Magnesium" } ], "gaps": [ "Specific heat and coefficient of thermal expansion for pure magnesium were not found in a readable source in this run. The AZ31B figures are for an alloy and are not used here.", "No numerical corrosion rate for pure magnesium was read. The Corrosion Science 2012 and Corrosion 2015 records are abstract pages with no rate values, and the Elsevier full text (doi 10.1016/j.jma.2022.08.003) and the Atrens 2020 review could not be opened. The corrosion rating for each entry is therefore unknown or qualitative.", "Impurity limits for the 99.9% (3N) grade and the 99.8%+ ingot were not found as a table. The Goodfellow page gives only the purity figures; the USGS import line gives 99.8% purity.", "No UNS, EN, ASTM or other grade designation for unalloyed magnesium was read, so identity.designations is empty.", "No safety data sheet for pure magnesium powder or ribbon was opened. Hazard data rest on PubChem's element-level GHS summary, the ERG excerpts it carries, and the Goodfellow page.", "Ribbon ignition temperature (about 650 degC) and powder ignition behaviour are reported without a test method. The 473 degC figure is for turnings and PubChem notes finer forms ignite lower.", "Specific heat, Mohs-type and Brinell hardness rows, and electrode data at temperatures other than 20 degC were not found.", "Space and cryogenic data (outgassing, radiation, thermal-vacuum) were not searched for pure magnesium. The uses listed are terrestrial.", "Hardness and ignition property names (hardness_vickers, ignition_temperature, autoignition_temperature, combustion_burn_rate, standard_electrode_potential, atomic_mass) are not in spores/property-canon.yaml and are used as snake_case names.", "EU critical raw materials list not read for magnesium, so no EU listing is recorded.", "No images were read in this run, so the media section is not included.", "Wikipedia is used for crystal structure, history and standard atomic weight only." ], "story": { "why": "Magnesium is the lightest common structural metal, at 1.74 g/cm3 at 20 degC (Goodfellow). It is the third most used structural metal after iron and aluminium (Wikipedia). Pure magnesium is weaker than its alloys: the Goodfellow page gives 140 to 160 MPa tensile strength for pure metal and 260 MPa for wrought AZ31. The pure metal matters where chemistry, not strength, decides the use: as the reducing metal for titanium (Kroll process), as a pyrotechnic and flare fuel, and as an anode material under research for magnesium-ion batteries. Most magnesium sold for structures is an alloy, such as the AZ31B covered in its own profile.", "uses": [ { "where": "Electronics housings", "line": "Goodfellow says a typical magnesium laptop shell weighs 30 to 40 percent less than an equivalent aluminium die-cast housing. The page's example is for magnesium alloys, not the pure metal." }, { "where": "Titanium and zirconium production", "line": "Goodfellow says high-purity ingot of 99.8% or more is used in the Kroll process, which reduces titanium tetrachloride with magnesium in a sealed reactor." }, { "where": "Magnesium-ion battery research", "line": "Goodfellow calls magnesium an emerging anode material for next-generation magnesium-ion batteries. The sources read do not show a commercial cell." } ], "can_do": [ { "label": "Weight", "line": "Density is 1.74 g/cm3 at 20 degC (Goodfellow), and 1.738 g/cm3 at 20 degC in the Merck Index value that PubChem quotes.", "benchmark": "density", "scope": "material", "value": "1.74 g/cm3" }, { "label": "Melting", "line": "Melting point is 650 degC (923 K) on the Goodfellow page. The metal must be melted under a cover gas, because molten magnesium ignites readily in air.", "benchmark": "melting_point", "scope": "material", "value": "650 degC" }, { "label": "Heat conduction", "line": "Thermal conductivity is 156 W/m·K on the Goodfellow page, at a temperature the page does not state.", "benchmark": "thermal_conductivity", "scope": "material", "value": "156 W/m·K" }, { "label": "Strength", "line": "Annealed pure magnesium is printed at 140 to 160 MPa tensile strength on the Goodfellow page. The same row gives 180 to 350 MPa for alloys.", "benchmark": "ultimate_tensile_strength", "scope": "material", "value": "140 to 160 MPa tensile" } ], "compare": "Against its own alloy AZ31B, pure magnesium is less strong and more conductive. The Goodfellow page gives 140 to 160 MPa tensile strength for annealed pure metal and 260 MPa for wrought AZ31, and gives thermal conductivity of 156 W/m·K for pure magnesium. AZ31B is about 3 wt% aluminium and 1 wt% zinc, with magnesium as the balance (AircraftMaterials data sheet). Pure magnesium does not carry those additions, and its corrosion behaviour is set by the bare metal. The sources read do not give a corrosion rate for pure magnesium, so the corrosion comparison is qualitative.", "compare_rows": [ { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Tensile strength", "benchmark": "ultimate_tensile_strength", "scope": "material" }, { "label": "Thermal conductivity", "benchmark": "thermal_conductivity", "scope": "material" } ], "handling": [ "Keep the metal dry. PubChem gives H261 (flammable gas on contact with water) in 44.8% of its reports for magnesium metal.", "Keep dry sand, dry graphite or Met-L-X powder for a fire. Water and carbon dioxide cannot be used.", "Keep powder away from oxidisers, nitric acid and perchlorates.", "Melt and cast under a cover gas such as SF6 or CO2/SO2." ], "good_for": [ "Titanium and zirconium reduction. Goodfellow sells 99.8% or higher ingot for the Kroll process.", "Light metal where the pure metal is wanted for research on magnesium chemistry or magnesium-ion anodes." ], "watch_out": [ "Fire. Ribbon ignites at about 650 degC and turnings at about 473 degC, and water and carbon dioxide do not put out the fire.", "Chloride and galvanic contact. The Goodfellow page says galvanic corrosion with aluminium, steel or copper is severe unless parts are isolated.", "Strength. Annealed pure metal is 140 to 160 MPa in tension, well below the 260 MPa printed for wrought AZ31." ], "verdict": "Pure magnesium is the lightest common metal and the usual reducing metal for titanium, but it is a weak, reactive metal in its bare form. For structures, use an alloy such as AZ31B with protection; use the pure metal where its chemistry is the point.", "recipe": { "line": "Unalloyed magnesium metal, Mg, with atomic mass 24.305 u. Goodfellow sells it as ingot (99.8% or higher, for Kroll-process titanium production), ribbon, powder, foil, rod and wire, mostly at 99.9% (3N) purity. Goodfellow describes the Pidgeon process, which reduces magnesium oxide with silicon under vacuum, and the metal is also recovered from brine by electrolysis. The US primary smelter in Utah stopped in 2022.", "parts": [ { "name": "Magnesium", "symbol": "Mg", "role": "The whole metal. It is the reducing agent in the Kroll process and the active material in an anode, and it is the structural metal in its own right.", "atoms": 1, "atomic_weight": 24.305, "share_note": "99.8% or higher (ingot, Goodfellow), 99.9% (3N) (foil and powder listings); the rest is impurities", "source": "goodfellow-mg-metal", "where": "General Properties table, Atomic Mass row; Metal Reduction section (ingot 99.8%+); title line (Mg 99.9% 3N)" }, { "name": "Impurity limits", "symbol": "Fe, Ni, Cu, Si, Mn", "role": "Impurities control corrosion. Pure grades are chosen to keep iron, nickel and copper low; no limit table was read.", "share_note": "not given for the pure grades in the sources read", "source": "goodfellow-mg-metal", "where": "Gap noted; not read" } ] }, "risk_groups": [ { "title": "For people", "lead": "The only hazard data are PubChem's element-level GHS summary and the Goodfellow notes on fire. Neither classifies a specific powder or ribbon.", "points": [ { "label": "Fire statements", "line": "Magnesium metal is listed as a flammable solid (H228), as catching fire spontaneously if exposed to air (H250), and as releasing flammable gases on contact with water (H260, H261). Self-heating is also reported (H252)." }, { "label": "Eyes", "line": "Burning magnesium gives a bright white light with strong ultraviolet content, and the Goodfellow page says it can cause permanent eye damage on direct viewing." } ], "gap": "No safety data sheet for pure magnesium powder or ribbon was opened." }, { "title": "If it fails", "lead": "The routes to failure come from the fire data, the water reaction and the corrosion statements.", "points": [ { "label": "Ignition", "line": "Ribbon ignites at about 650 degC (Goodfellow) and turnings at about 473 degC (PubChem). Finer forms ignite at lower temperatures." }, { "label": "Water", "line": "Water releases flammable hydrogen gas and can ignite it. Water and carbon dioxide must not be used to fight a magnesium fire." }, { "label": "Chloride", "line": "The passive film is disrupted by chloride. No pure-metal rate was read, so the corrosion rate of unprotected pure magnesium in salt water is not quantified here." } ] }, { "title": "Handling and storage", "points": [ { "label": "Dry storage", "line": "Keep the metal dry and sealed. Keep powder away from oxidisers, nitric acid and perchlorates, which PubChem lists as explosive or friction-sensitive mixtures with powdered magnesium." }, { "label": "Fire kit", "line": "Keep dry sand, dry graphite or Met-L-X powder for a fire. The Goodfellow page names these as the extinguishing agents." } ] } ] }, "updated": "2026-10-26", "review": { "status": "draft", "method": "assistant", "checked_values": 15, "unreachable": 2, "caveats": 3, "note": "Written 2026-10-26 from pages fetched in this run. Values are as printed, except shares in supply that are calculated from printed tonnages. No pure-magnesium corrosion rate was read: the two corrosion papers are abstract pages without rates, and the full-text journal pages could not be opened." }, "sources": { "goodfellow-mg-metal": { "title": "Goodfellow: High-Purity Magnesium Metal (general, mechanical and chemical property tables)", "url": "https://www.goodfellow.com/usa/material/metals/magnesium", "kind": "datasheet", "license": "Supplier web page, cited and not reproduced" }, "usgs-mcs2026-magnesium-metal": { "title": "USGS Mineral Commodity Summaries 2026: Magnesium Metal", "id": "USGS MCS 2026, February 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-magnesium-metal.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "usgs-crit2025": { "title": "About the 2025 List of Critical Minerals (USGS, final list of 60 minerals)", "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals", "year": 2025, "kind": "web", "license": "public domain (USGS)" }, "pubchem-mg": { "title": "Magnesium, PubChem compound CID 5462224: Safety and Hazards, GHS Classification; Experimental Properties", "id": "PubChem CID 5462224; GHS aggregated from ECHA C&L notifications", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5462224/JSON", "kind": "database", "license": "PubChem (NCBI) public data" }, "qiao2012": { "title": "Corrosion behaviour of a nominally high purity Mg ingot produced by permanent mould direct chill casting (Qiao, Shi, Hort, Abidin, Atrens; Corrosion Science 61, 185-207)", "id": "doi:10.1016/j.corsci.2012.04.030", "url": "https://publications.hzg.de/id/29895/index.php", "year": 2012, "kind": "paper", "license": "publisher record (abstract read)" }, "bland2015": { "title": "Assessing the corrosion of commercially pure magnesium and AZ31B (Bland, King, Birbilis, Scully; Corrosion 71(2), 128-145)", "id": "doi:10.5006/1419", "url": "https://research.monash.edu/en/publications/assessing-the-corrosion-of-commercially-pure-magnesium-and-commer/", "year": 2015, "kind": "paper", "license": "publisher record (abstract read)" }, "aircraftmaterials-az31b": { "title": "AircraftMaterialsUK technical data sheet: Magnesium Alloy AZ31B (composition limits)", "url": "https://aircraftmaterials.com/data/magnesium/az31b.html", "kind": "datasheet", "license": "Stockist web page, cited and not reproduced" }, "wikipedia-magnesium": { "title": "Wikipedia: Magnesium", "url": "https://en.wikipedia.org/wiki/Magnesium", "kind": "web", "license": "CC BY-SA (Wikipedia), cited for history, structure and atomic weight only" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/magnesium/" }