Magnesium alloy AZ31B AZ31B
Wrought Mg-Al-Zn alloy: Al 2.5 to 3.5 wt%, Zn 0.7 to 1.3 wt%, Mn 0.2 min, Si max 0.05, Cu max 0.05, Ca max 0.04, Fe max 0.005, Ni max 0.005, other max 0.30 total, Mg balance. Nominal Mg 96, Al 3, Zn 1 (Goodfellow listing).
Also known as UNS M11311, EN name W.3504, EN name WS 3.5312, BS 3370 MAG-S-1110, BS 3370 MAG-E-111M, AMS 4375 · 15 more
AZ31B is a wrought magnesium alloy with about 3 wt% aluminium and 1 wt% zinc.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Weight
1.8 g/cm3
Strength, as rolled listing
290 MPa tensile
Heat conduction
96 W/(m·K)
Thermal expansion
26 ppm/K
Corrosion in salt water
0.27 mm/year
Recipe, share of the weight
- Mg balance (the rest)Magnesium
- Al 2.5 to 3.5%Aluminium
- Zn 0.7 to 1.3%Zinc
- Mn minimum (0.2 min on the data sheet)Manganese
- Si, Cu, Ca, Fe, Ni maximum: Si 0.05, Cu 0.05, Ca 0.04, Fe 0.005, Ni 0.005; other elements 0.30 totalImpurity limits
Best for
Light wrought sheet, plate and extrusions where weight matters and the part is kept out of chloride solutions. The stockist names aircraft fuselages and phone and laptop cases as uses.
Weakest at
Corrosion in chloride solutions (uncoated AZ31: 0.27 mm per year in 3.5 % NaCl and 9.7 mm per year in 5 M NaCl), and fire risk from magnesium metal (GHS statements for the element).
Risk at a glance
- People No data. No hazard data recorded
- If it fails High. Chloride corrosion of uncoated AZ31
- Corrosion Severe. Uncoated AZ31 corroded at 9.7 mm per year in continuous 5 M NaCl.
Quick facts: AZ31B
| Property | Value | Basis |
|---|---|---|
| Density | 1.8 g/cm³ | 1 sourced value |
| Tensile strength | 290 MPa | 1 sourced value |
| Young's modulus | 45 GPa | 1 sourced value |
| Hardness (Brinell) | 73 HB | 1 sourced value |
| Thermal conductivity | 96 W/(m·K) | 1 sourced value |
| Thermal expansion (CTE) | 26 ppm/K | 1 sourced value |
| Melting point | 605 to 630 °C | 1 sourced value |
| Specific heat | 1,001 J/(kg·K) | 1 sourced value |
What is the density of Magnesium alloy AZ31B?
Magnesium alloy AZ31B has a density of 1.8 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Magnesium alloy AZ31B?
Magnesium alloy AZ31B has a thermal conductivity of 96 W/(m·K). The source and test conditions are listed in the properties table on this page.
What is the coefficient of thermal expansion of Magnesium alloy AZ31B?
Magnesium alloy AZ31B has a coefficient of thermal expansion of 26 ppm/K. The source and test conditions are listed in the properties table on this page.
What is the melting point of Magnesium alloy AZ31B?
Magnesium alloy AZ31B has a melting point of 605 to 630 °C. The source and test conditions are listed in the properties table on this page.
What is the tensile strength of Magnesium alloy AZ31B?
Magnesium alloy AZ31B has a tensile strength of 290 MPa. The source and test conditions are listed in the properties table on this page.
What are the other names and codes for Magnesium alloy AZ31B?
Magnesium alloy AZ31B is also written as UNS M11311, EN name W.3504, EN name WS 3.5312, BS 3370 MAG-S-1110, BS 3370 MAG-E-111M, AMS 4375. Each code is printed in the source listed beside it in the designations table.
What is Magnesium alloy AZ31B used for?
Uses recorded in the sources include Aircraft fuselages; Cell phone and laptop cases.
Why it exists
AZ31B is a wrought magnesium alloy, which the stockist describes as having good room-temperature strength and ductility, with corrosion resistance and weldability. The Goodfellow listing gives the nominal composition as Mg 96, Al 3, Zn 1, and the stockist gives aluminium at 2.5 to 3.5 wt% and zinc at 0.7 to 1.3 wt%. The stockist also says most magnesium alloys are not heat treatable like aluminium. Magnesium's light weight is an advantage over aluminium and zinc in most wrought applications, according to the USGS. About 69% of the primary magnesium consumed in 2025 went into castings, principally automotive, so the wrought sheet, plate and extrusion this profile covers is a smaller part of the market.
Where it's used
Aircraft structure
The AircraftMaterials data sheet names aircraft fuselages among the uses of AZ31B.
Phone and laptop cases
The same data sheet names cell phone and laptop cases, with speaker cones and concrete tools.
Superformed automotive parts
The data sheet says AZ31B can be superformed at elevated temperatures into intricate components for automotive uses.
Recipe
Wrought Mg-Al-Zn alloy: Al 2.5 to 3.5 wt%, Zn 0.7 to 1.3 wt%, Mn 0.2 min, Si max 0.05, Cu max 0.05, Ca max 0.04, Fe max 0.005, Ni max 0.005, other max 0.30 total, Mg balance. Nominal Mg 96, Al 3, Zn 1 (Goodfellow listing).
Wrought magnesium alloy with aluminium and zinc additions. The stockist data sheet gives Al 2.5 to 3.5 wt%, Zn 0.7 to 1.3 wt%, Mn 0.2 min, magnesium as the balance, and maximum limits on silicon, copper, calcium, iron and nickel. The Goodfellow listing gives the nominal formula Mg 96, Al 3, Zn 1. The data sheet says the alloy is available as plate, tooling plate, sheet, rod and bar, with extrusions made to order.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Magnesium Mg | balance (the rest) | The base metal and the balance of the alloy. |
| Aluminium Al | 2.5 to 3.5% | Main alloying addition. |
| Zinc Zn | 0.7 to 1.3% | Second alloying addition. |
| Manganese Mn | minimum (0.2 min on the data sheet) | Minor addition, minimum limit. |
| Impurity limits Si, Cu, Ca, Fe, Ni | maximum: Si 0.05, Cu 0.05, Ca 0.04, Fe 0.005, Ni 0.005; other elements 0.30 total | Limits on impurities; the alloy is made to these maxima. |
Weight shares are as printed in the sources.
What it can do
Weight
1.8 g/cm3
measured
The Goodfellow listing gives density as 1.8 g/cm3. The USGS says magnesium's light weight is an advantage over aluminium and zinc in most wrought applications.
Strength, as rolled listing
290 MPa tensile
measured
The Goodfellow listing for foil and sheet, with temper As Rolled, gives 290 MPa tensile strength and 15 % elongation at break.
Heat conduction
96 W/(m·K)
measured
Thermal conductivity is 96 W/(m·K) on the Goodfellow listing, at a temperature the listing does not state.
Thermal expansion
26 ppm/K
measured
The Goodfellow listing gives a mean coefficient of thermal expansion of 26 ppm/K over 20 to 100 °C.
Corrosion in salt water
0.27 mm/year
measured
Uncoated AZ31 lost 0.27 mm per year in 3.5 % NaCl over 14 days at 37 °C in the PMC study.
How it compares
The USGS says aluminium and zinc can substitute for magnesium in castings and wrought products, and that magnesium's light weight is an advantage over them in most applications, although its high cost is a disadvantage. This profile holds no strength-per-mass figures for aluminium or zinc, so it does not rank AZ31B against them. The stockist says most magnesium alloys are not heat treatable like aluminium, and its H24 rows are cold rolled and partially annealed.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | AZ31B | Mg | AZ61 | AJ62 | EV31A |
|---|---|---|---|---|---|
| Thermal behavior and safety | |||||
| Melting rangeThermal Properties table of a supplier listing | 605 to 630 °C | 650 °C | 525 to 610 °C | no data | 545 to 640 °C |
| specific heat | 1001 J/(kg·K)2 | no data | 1050 J/(kg·K) | no data | 1086 J/(kg·K) |
| Thermal conductivity | 96 W/(m·K)3 | 156 W/m·K | 79.5 W/(m·K) | no data | 116 W/(m·K) |
| Physical and electrical | |||||
| Density | 1.8 g/cm³1 | 1.74 g/cm³ | 1.8 g/cm³ | no data | 1.82 g/cm³ |
| Hardness, Brinell | 73 HB7 | no data | no data | no data | 65 to 75 HB |
| Other measurements | |||||
| Coefficient of thermal expansion, 20 to 100 °CThermal Properties table of a supplier listing | 26 ppm/K | no data | 26 ppm/K | no data | 26.3 ppm/K |
| elastic modulus | 45 GPa4 | 45 GPa | no data | no data | 44.8 GPa |
| Tensile strength, As Rolled foil and sheet listing | 290 MPa5 | 140 to 160 MPa | 310 MPa | 225.3 MPa | 248 MPa |
| Elongation at break, As Rolled foil and sheet listing | 15 %6 | no data | 16 % | 7.43 % | no data |
| Elongation in 4D, H24 sheet, by thickness band | 6 to 8 %8 | no data | 16 % | 7.43 % | no data |
| Corrosion rate, uncoated AZ31, 3.5 % NaCl | 0.27 mm/year9 | no data | no data | no data | 1.14 mg/cm²/day |
| Corrosion rate, uncoated AZ31, 5 M NaCl, continuous | 9.7 mm/year10 | no data | no data | no data | 1.14 mg/cm²/day |
| Corrosion rate, uncoated AZ31, 5 M NaCl, intermittent | 7.8 mm/year11 | no data | no data | no data | 1.14 mg/cm²/day |
Why choose it, and why not
Good for
- Light sheet and plate parts. Density is 1.8 g/cm3 on the Goodfellow listing.
- Aircraft fuselage and phone or laptop case parts, the two uses named on the stockist data sheet.
- Parts that are formed hot. The stockist says AZ31B can be superformed at elevated temperatures into intricate components.
Watch out for
- Corrosion in chloride. Uncoated AZ31 lost 9.7 mm per year in continuous 5 M NaCl and 0.27 mm per year in 3.5 % NaCl (14 days at 37 °C, PMC study).
- Direction and temperature. The Hereon study of H24 sheet, tested from room temperature to 400 °C, found yield and maximum stress lower along the rolling direction than across it, and both fall as the temperature rises.
- Temper. The 290 MPa tensile value is for the As Rolled listing, not O or H24, and no O-temper strength was found in a readable source.
- Fire. The GHS statements for magnesium metal include flammable solid (H228) and catches fire spontaneously if exposed to air (H250).
AZ31B is a light, weldable wrought magnesium alloy that the stockist names for aircraft fuselages and phone and laptop cases. Its weak point is corrosion in salt solutions: uncoated AZ31 corroded fast in the PMC study. The strength figures here are a listing and typical values, and no O-temper value was found.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| UNS | M11311 |
| EN name | W.3504 (aerospace), WS 3.5312 |
| BS | 3370 MAG-S-1110, 3370 MAG-E-111M |
| AMS | 4375 (AZ31B-O sheet, plate), 4376 (AZ31B-H26 plate), 4377 (AZ31B-H24 sheet, plate), 4382 (AZ31B-O plate) |
| ASTM | B90, B107 |
| Name | AZ31B, AZ31B-H24, AZ31B-H26, AZ31B-O, QQ-M-44B, QQ-M-31B, EN1753 MG-P-62, AZ31 (grade name, Goodfellow), MgAl3Zn1 (Goodfellow synonym), AZ31B magnesium foil (Goodfellow synonym) |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density | Physical Properties table of a supplier listing (foil and sheet product group) | temperature not statedbasis one value for the product group on the Goodfellow listing, printed rounded as 1.8 | — |
| 2 | specific heat | Thermal Properties table of a supplier listing (printed as J K-1 kg-1) | temperature not stated | — |
| 3 | Thermal conductivity | Thermal Properties table of a supplier listing (printed as W m-1 K-1) | temperature not stated | — |
| 4 | elastic modulus | Mechanical Properties table of a supplier listing | temper As Rolled (printed on the listing)product form foil, film and sheet listing (a 0.25 mm disc is also listed)temperature not stated | — |
| 5 | Tensile strength, As Rolled foil and sheet listing | Mechanical Properties table of a supplier listing | temper As Rolled (printed on the listing; not O or H24)product form foil, film and sheet listingtemperature not stated | — |
| 6 | Elongation at break, As Rolled foil and sheet listing | Mechanical Properties table of a supplier listing | temper As Rolled (printed on the listing; not O or H24)product form foil, film and sheet listingtemperature not stated | — |
| 7 | Hardness, Brinell | Mechanical Properties table of a supplier listing (printed as Hardness - Brinell) | temper As Rolled (printed on the listing; not O or H24)product form foil, film and sheet listing | Not in spores/property-canon.yaml; the snake_case name hardness_brinell is used. |
| 8 | Elongation in 4D, H24 sheet, by thickness band | Typical Mechanical Properties table of a stockist technical data sheet | temper H24 (page condition: cold rolled, partially annealed)product form sheet, thickness bands from 0.016 to 3.00 inbasis elongation in 4D by thickness band | — |
| 9 | Corrosion rate, uncoated AZ31, 3.5 % NaCl | Immersion test; corrosion rate from mass loss over 14 days (the paper's equation) | alloy as tested AZ31 (Mg-Al 3 wt%, Zn 1 wt%, from Goodfellow), not AZ31Bsolution 3.5 wt % NaCl (35 g/L)temperature 37 °Cexposure 14 days immersion, mass loss | Not in spores/property-canon.yaml; the snake_case name corrosion_rate is used. |
| 10 | Corrosion rate, uncoated AZ31, 5 M NaCl, continuous | Immersion test; corrosion rate from mass loss over 14 days (the paper's equation) | alloy as tested AZ31 (Mg-Al 3 wt%, Zn 1 wt%), not AZ31Bsolution 5 M NaCl (292 g/L), continuous immersiontemperature 37 °Cexposure 14 days immersion, mass loss | — |
| 11 | Corrosion rate, uncoated AZ31, 5 M NaCl, intermittent | Immersion test; corrosion rate from mass loss over 14 days (the paper's equation) | alloy as tested AZ31 (Mg-Al 3 wt%, Zn 1 wt%), not AZ31Bsolution 5 M NaCl (292 g/L), intermittent (samples removed from the solution in the interrupted test)temperature 37 °Cexposure 14 days immersion, mass loss | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Immersion in 3.5 % NaCl at 37 °C for 14 days (uncoated AZ31) | moderate | Uncoated AZ31 corroded at 0.27 mm per year in 3.5 % NaCl.1 |
| Immersion in 5 M NaCl at 37 °C for 14 days, continuous and intermittent (uncoated AZ31) | severe | Uncoated AZ31 corroded at 9.7 mm per year in continuous 5 M NaCl.2 |
| Chloride-rich saline environments (general statement, magnesium alloys) | severe | Chloride-rich saline environments are the main corrosion concern for magnesium alloys.3 |
| 5 M NaCl at 37 °C, intermittent, with a PF or PFS coating | low | Coatings cut the rate to about 0.25 to 0.30 mm per year.4 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Immersion in 3.5 % NaCl at 37 °C for 14 days (uncoated AZ31) | Mass-loss immersion gave 0.27 mm per year. The paper says the corrosion products formed in all the saline solutions it tested were similar. | temperature 37 °Cduration 14 daysbasis mass loss; the rating is set by the profile writer from the rate, not from a standard |
| 2 | Immersion in 5 M NaCl at 37 °C for 14 days, continuous and intermittent (uncoated AZ31) | The study gives 9.7 mm per year for continuous 5 M NaCl and 7.8 mm per year for intermittent (interrupted) 5 M NaCl. The corrosion products were similar in all saline solutions. | temperature 37 °Cduration 14 daysbasis mass loss; the rating is set by the profile writer from the rate, not from a standard |
| 3 | Chloride-rich saline environments (general statement, magnesium alloys) | The introduction of the study says susceptibility to corrosion, particularly in chloride-rich saline environments, compromises the structural integrity of magnesium alloys, and that the rapid emission of hydrogen gas and gas bubbles restrict their wider use. | basis general statement in the introduction of the study, not a test result |
| 4 | 5 M NaCl at 37 °C, intermittent, with a PF or PFS coating | PF (phosphate and fluoride) and PFS (phosphate, silicate and fluoride) soft-sparking coatings of 15 µm gave about 0.30 and 0.25 mm per year in intermittent 5 M NaCl. The paper says that is more than 30 times lower than uncoated AZ31 (7.8 mm per year in the same test). | coating PF or PFS, 15 µmtemperature 37 °Cduration 14 daysbasis mass loss, same method as the uncoated tests |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The only hazard data opened is PubChem's GHS data for magnesium metal. It is element-level, not a classification of AZ31B as supplied.
- Fire statements
- 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).
- Not covered
- No safety data sheet for the alloy was opened, and no dust or fume data for machining or welding was found.
If it fails
The failure routes come from the corrosion tests, the study's introduction and the GHS statements.
- Chloride corrosion
- Uncoated AZ31 corroded at 0.27 mm per year in 3.5 % NaCl and 9.7 mm per year in continuous 5 M NaCl in the 14-day tests.
- Hydrogen gas
- The study's introduction says the rapid emission of hydrogen gas and gas bubbles restricts wider use of magnesium alloys in tissue.
- Rolling direction
- The Hereon study of H24 sheet found lower yield and maximum stress along the rolling direction than across it.
Handling and storage
- Water
- Contact with water releases flammable gas (H261), so keep the metal dry.
- Chlorides
- Uncoated AZ31 corrodes fast in chloride solutions. PF and PFS coatings cut the rate in the study.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Chloride corrosion of uncoated AZ31high severity | Immersion in chloride solutions (3.5 % and 5 M NaCl in the study)Corrosion rate of 9.7 mm per year in continuous 5 M NaCl and 0.27 mm per year in 3.5 % NaCl; the study says susceptibility to corrosion compromises structural integrity |
| Hydrogen gas evolution during corrosionmoderate severity | Degradation of magnesium alloys in chloride-rich saline environmentsRapid emission of hydrogen gas and gas bubble formation; the study says this restricts wider use in tissue |
| Fire or flammable gas from magnesium metalhigh severity | Contact with water (H260, H261) or exposure to air of pyrophoric forms (H250)The GHS statements say the element can release flammable gas, catch fire spontaneously or be a flammable solid (element-level, not the alloy as supplied) |
| Lower yield and maximum stress along the rolling direction (H24 sheet)moderate severity | Tensile loading parallel to the rolling directionYield and maximum stress are lower than for loading across the rolling direction; both fall as the test temperature rises (room temperature to 400 °C) |
Handling and storage
- The GHS statements say that contact with water releases flammable gas (H261). Keep the metal dry and away from water.
- Goodfellow's listing says a safety data sheet is available. Read the SDS for the exact product before cutting, grinding or welding.
- Uncoated AZ31 corrodes fast in chloride solutions. Keep uncoated parts out of salt water.
Mitigations
- In the PMC study, PF and PFS soft-sparking coatings of 15 µm cut the intermittent 5 M NaCl rate to about 0.30 and 0.25 mm per year, more than 30 times lower than uncoated AZ31 (7.8 mm per year).
Supply and geography
How common the raw materials are and where they come from.
Magnesium metal, world primary (smelter) production
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.
- Top producers (2025)
- China 87.7%, Russia 5.5%, Brazil 1.8%, Israel 1.8%, Turkey 1.4%, Kazakhstan 1.2%, Iran 0.5%, United States 0%
- Critical mineral lists
- US: listed
- Recycling
- USGS: about 110 thousand metric tons of secondary magnesium was recovered from scrap in 2025 (estimate). The only US primary smelter, in Utah, stopped in 2022.
- 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.
Magnesium metal imported to the United States, 2021 to 2024 (99.8 % purity)
- Top producers
- Israel 47%, Turkey 31%, Russia 8%, China 6%
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
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spore: profile
id: magnesium-az31b
spore_version: 0.2
family: magnesium-alloys
name: Magnesium alloy AZ31B
abbreviation: AZ31B
role: wrought structural alloy
category: metals
type: magnesium
summary: |
AZ31B is a wrought magnesium alloy with about 3 wt% aluminium and 1 wt% zinc. The stockist data sheet lists it as plate, sheet, rod and bar, with extrusions made to order. The USGS says magnesium's light weight is an advantage over aluminium and zinc in most wrought applications. Its weak point is corrosion in chloride solutions: in one 14-day test, uncoated AZ31 lost 9.7 mm per year in 5 M sodium chloride.
best_for: Light wrought sheet, plate and extrusions where weight matters and the part is kept out of chloride solutions. The stockist names aircraft fuselages and phone and laptop cases as uses.
weakest_at: 'Corrosion in chloride solutions (uncoated AZ31: 0.27 mm per year in 3.5 % NaCl and 9.7 mm per year in 5 M NaCl), and fire risk from magnesium metal (GHS statements for the element).'
identity:
formula: 'Wrought Mg-Al-Zn alloy: Al 2.5 to 3.5 wt%, Zn 0.7 to 1.3 wt%, Mn 0.2 min, Si max 0.05, Cu max 0.05, Ca max 0.04, Fe max 0.005, Ni max 0.005, other max 0.30 total, Mg balance. Nominal Mg 96, Al 3, Zn 1 (Goodfellow listing).'
designations:
- system: Name
code: AZ31B
- system: Name
code: AZ31B-H24
- system: Name
code: AZ31B-H26
- system: Name
code: AZ31B-O
- system: UNS
code: M11311
- system: AMS
code: '4375'
note: AZ31B-O sheet, plate
- system: AMS
code: '4376'
note: AZ31B-H26 plate
- system: AMS
code: '4377'
note: AZ31B-H24 sheet, plate
- system: AMS
code: '4382'
note: AZ31B-O plate
- system: ASTM
code: B90
- system: ASTM
code: B107
- system: Name
code: QQ-M-44B
- system: Name
code: QQ-M-31B
- system: BS
code: 3370 MAG-S-1110
- system: BS
code: 3370 MAG-E-111M
- system: EN name
code: W.3504
note: aerospace
- system: EN name
code: WS 3.5312
- system: Name
code: EN1753 MG-P-62
- system: Name
code: AZ31
note: grade name, Goodfellow
- system: Name
code: MgAl3Zn1
note: Goodfellow synonym
- system: Name
code: AZ31B magnesium foil
note: Goodfellow synonym
source: aircraftmaterials-az31b
where: Chemical Composition Limits table (AZ31B row) and Specifications list; UNS number and synonyms from the Goodfellow listing; Wikipedia composition table (AZ31B row)
tags:
environments: []
applications:
- structures
- electronics-and-chips
properties:
- benchmark: density
value: 1.8
unit: g/cm3
scope: material
conditions:
temperature: not stated
basis: one value for the product group on the Goodfellow listing, printed rounded as 1.8
method: Physical Properties table of a supplier listing (foil and sheet product group)
status: ground
source: goodfellow-az31-foil
where: Physical Properties table, Density row (gcm-3)
- benchmark: melting_point
label: Melting range
value: 605
value_high: 630
bound: range
unit: °C
scope: material
conditions:
basis: range as printed on the listing
method: Thermal Properties table of a supplier listing
status: ground
source: goodfellow-az31-foil
where: Thermal Properties table, Melting point row
- benchmark: specific_heat
value: 1001
unit: J/(kg·K)
scope: material
conditions:
temperature: not stated
method: Thermal Properties table of a supplier listing (printed as J K-1 kg-1)
status: ground
source: goodfellow-az31-foil
where: Thermal Properties table, Specific heat row
- benchmark: thermal_conductivity
value: 96
unit: W/(m·K)
scope: material
conditions:
temperature: not stated
method: Thermal Properties table of a supplier listing (printed as W m-1 K-1)
status: ground
source: goodfellow-az31-foil
where: Thermal Properties table, Thermal conductivity row
- benchmark: cte
label: Coefficient of thermal expansion, 20 to 100 °C
value: 26
unit: ppm/K
scope: material
conditions:
temperature_range: 20 to 100 °C
unit_in_source: x10-6 K-1 (same as ppm/K)
method: Thermal Properties table of a supplier listing
status: ground
source: goodfellow-az31-foil
where: Thermal Properties table, Coefficient of thermal expansion row (printed 26 at 20-100 °C)
- benchmark: elastic_modulus
value: 45
unit: GPa
scope: material
conditions:
temper: As Rolled (printed on the listing)
product_form: foil, film and sheet listing (a 0.25 mm disc is also listed)
temperature: not stated
method: Mechanical Properties table of a supplier listing
status: ground
source: goodfellow-az31-foil
where: Mechanical Properties table, Modulus of elasticity row
- benchmark: ultimate_tensile_strength
label: Tensile strength, As Rolled foil and sheet listing
value: 290
unit: MPa
scope: material
conditions:
temper: As Rolled (printed on the listing; not O or H24)
product_form: foil, film and sheet listing
temperature: not stated
method: Mechanical Properties table of a supplier listing
status: ground
source: goodfellow-az31-foil
where: Mechanical Properties table, Tensile strength row
- benchmark: elongation
label: Elongation at break, As Rolled foil and sheet listing
value: 15
unit: '%'
scope: material
conditions:
temper: As Rolled (printed on the listing; not O or H24)
product_form: foil, film and sheet listing
temperature: not stated
method: Mechanical Properties table of a supplier listing
status: ground
source: goodfellow-az31-foil
where: Mechanical Properties table, Elongation at break row
- benchmark: hardness_brinell
label: Hardness, Brinell
value: 73
unit: HB
scope: material
conditions:
temper: As Rolled (printed on the listing; not O or H24)
product_form: foil, film and sheet listing
method: Mechanical Properties table of a supplier listing (printed as Hardness - Brinell)
status: ground
source: goodfellow-az31-foil
where: Mechanical Properties table, Hardness - Brinell row
note: Not in spores/property-canon.yaml; the snake_case name hardness_brinell is used.
- benchmark: elongation
label: Elongation in 4D, H24 sheet, by thickness band
value: 6
value_high: 8
bound: range
unit: '%'
scope: material
conditions:
temper: 'H24 (page condition: cold rolled, partially annealed)'
product_form: sheet, thickness bands from 0.016 to 3.00 in
basis: elongation in 4D by thickness band
method: Typical Mechanical Properties table of a stockist technical data sheet
status: ground
source: aircraftmaterials-az31b
where: Typical Mechanical Properties table, Elongation in 4D (%) column, Cold Rolled partially annealed rows
- benchmark: corrosion_rate
label: Corrosion rate, uncoated AZ31, 3.5 % NaCl
value: 0.27
unit: mm/year
scope: material
conditions:
alloy_as_tested: AZ31 (Mg-Al 3 wt%, Zn 1 wt%, from Goodfellow), not AZ31B
solution: 3.5 wt % NaCl (35 g/L)
temperature: 37 °C
exposure: 14 days immersion, mass loss
method: Immersion test; corrosion rate from mass loss over 14 days (the paper's equation)
status: ground
source: pmc-az31-corrosion
where: Results, paragraph on the 14-day immersion (AZ31 in 3.5% NaCl)
note: Not in spores/property-canon.yaml; the snake_case name corrosion_rate is used.
- benchmark: corrosion_rate
label: Corrosion rate, uncoated AZ31, 5 M NaCl, continuous
value: 9.7
unit: mm/year
scope: material
conditions:
alloy_as_tested: AZ31 (Mg-Al 3 wt%, Zn 1 wt%), not AZ31B
solution: 5 M NaCl (292 g/L), continuous immersion
temperature: 37 °C
exposure: 14 days immersion, mass loss
method: Immersion test; corrosion rate from mass loss over 14 days (the paper's equation)
status: ground
source: pmc-az31-corrosion
where: Results, paragraph on the 14-day immersion (continuous 5 M NaCl)
- benchmark: corrosion_rate
label: Corrosion rate, uncoated AZ31, 5 M NaCl, intermittent
value: 7.8
unit: mm/year
scope: material
conditions:
alloy_as_tested: AZ31 (Mg-Al 3 wt%, Zn 1 wt%), not AZ31B
solution: 5 M NaCl (292 g/L), intermittent (samples removed from the solution in the interrupted test)
temperature: 37 °C
exposure: 14 days immersion, mass loss
method: Immersion test; corrosion rate from mass loss over 14 days (the paper's equation)
status: ground
source: pmc-az31-corrosion
where: Results, paragraph on the 14-day immersion (intermittent 5 M NaCl)
corrosion:
- environment: Immersion in 3.5 % NaCl at 37 °C for 14 days (uncoated AZ31)
headline: Uncoated AZ31 corroded at 0.27 mm per year in 3.5 % NaCl.
effect: Mass-loss immersion gave 0.27 mm per year. The paper says the corrosion products formed in all the saline solutions it tested were similar.
rating: moderate
conditions:
temperature: 37 °C
duration: 14 days
basis: mass loss; the rating is set by the profile writer from the rate, not from a standard
source: pmc-az31-corrosion
where: Results, 14-day immersion paragraph
- environment: Immersion in 5 M NaCl at 37 °C for 14 days, continuous and intermittent (uncoated AZ31)
headline: Uncoated AZ31 corroded at 9.7 mm per year in continuous 5 M NaCl.
effect: The study gives 9.7 mm per year for continuous 5 M NaCl and 7.8 mm per year for intermittent (interrupted) 5 M NaCl. The corrosion products were similar in all saline solutions.
rating: severe
conditions:
temperature: 37 °C
duration: 14 days
basis: mass loss; the rating is set by the profile writer from the rate, not from a standard
source: pmc-az31-corrosion
where: Results, 14-day immersion paragraph; Methods, immersion tests
- environment: Chloride-rich saline environments (general statement, magnesium alloys)
headline: Chloride-rich saline environments are the main corrosion concern for magnesium alloys.
effect: The introduction of the study says susceptibility to corrosion, particularly in chloride-rich saline environments, compromises the structural integrity of magnesium alloys, and that the rapid emission of hydrogen gas and gas bubbles restrict their wider use.
rating: severe
conditions:
basis: general statement in the introduction of the study, not a test result
source: pmc-az31-corrosion
where: Introduction, first paragraphs
- environment: 5 M NaCl at 37 °C, intermittent, with a PF or PFS coating
headline: Coatings cut the rate to about 0.25 to 0.30 mm per year.
effect: PF (phosphate and fluoride) and PFS (phosphate, silicate and fluoride) soft-sparking coatings of 15 µm gave about 0.30 and 0.25 mm per year in intermittent 5 M NaCl. The paper says that is more than 30 times lower than uncoated AZ31 (7.8 mm per year in the same test).
rating: low
conditions:
coating: PF or PFS, 15 µm
temperature: 37 °C
duration: 14 days
basis: mass loss, same method as the uncoated tests
source: pmc-az31-corrosion
where: Results, coated samples paragraph; Methods, sample preparation
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 the alloy as supplied.
ghs:
- H228
- H250
- H260
- H261
- H252
source: pubchem-mg
where: Safety and Hazards, GHS Classification (CID 5462224)
failure_risks:
- mode: Chloride corrosion of uncoated AZ31
trigger: Immersion in chloride solutions (3.5 % and 5 M NaCl in the study)
consequence: Corrosion rate of 9.7 mm per year in continuous 5 M NaCl and 0.27 mm per year in 3.5 % NaCl; the study says susceptibility to corrosion compromises structural integrity
severity: high
source: pmc-az31-corrosion
where: Results, 14-day immersion paragraph; Introduction
- mode: Hydrogen gas evolution during corrosion
trigger: Degradation of magnesium alloys in chloride-rich saline environments
consequence: Rapid emission of hydrogen gas and gas bubble formation; the study says this restricts wider use in tissue
severity: moderate
source: pmc-az31-corrosion
where: Introduction, first paragraphs
- mode: Fire or flammable gas from magnesium metal
trigger: Contact with water (H260, H261) or exposure to air of pyrophoric forms (H250)
consequence: The GHS statements say the element can release flammable gas, catch fire spontaneously or be a flammable solid (element-level, not the alloy as supplied)
severity: high
source: pubchem-mg
where: GHS Classification (CID 5462224)
- mode: Lower yield and maximum stress along the rolling direction (H24 sheet)
trigger: Tensile loading parallel to the rolling direction
consequence: Yield and maximum stress are lower than for loading across the rolling direction; both fall as the test temperature rises (room temperature to 400 °C)
severity: moderate
source: hereon-az31-h24-tension
where: Abstract
side_effects: []
handling:
- text: The GHS statements say that contact with water releases flammable gas (H261). Keep the metal dry and away from water.
source: pubchem-mg
where: GHS Classification, H261 and H260 statements (CID 5462224)
- text: Goodfellow's listing says a safety data sheet is available. Read the SDS for the exact product before cutting, grinding or welding.
source: goodfellow-az31-foil
where: Product page, SDS notice
- text: Uncoated AZ31 corrodes fast in chloride solutions. Keep uncoated parts out of salt water.
source: pmc-az31-corrosion
where: Results, 14-day immersion paragraph
mitigations:
- text: In the PMC study, PF and PFS soft-sparking coatings of 15 µm cut the intermittent 5 M NaCl rate to about 0.30 and 0.25 mm per year, more than 30 times lower than uncoated AZ31 (7.8 mm per year).
source: pmc-az31-corrosion
where: Results, coated samples paragraph; Methods, sample preparation
uses:
- application: structures
device: Aircraft fuselages
example: The stockist data sheet names aircraft fuselages among the uses of AZ31B.
source: aircraftmaterials-az31b
where: Technical data sheet, description paragraph
- application: electronics-and-chips
device: Cell phone and laptop cases
example: The same data sheet names cell phone and laptop cases, with speaker cones and concrete tools.
source: aircraftmaterials-az31b
where: Technical data sheet, description paragraph
supply:
- subject: Magnesium metal, world primary (smelter) production
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 final List of Critical Minerals (magnesium; page read through the fetch tool)
listed: true
recycling: 'USGS: about 110 thousand metric tons of secondary magnesium was recovered from scrap in 2025 (estimate). The only US primary smelter, in Utah, stopped in 2022.'
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 (world total 1,100 thousand t, rounded; shares calculated by Space Mushroom over the listed 2025 values, sum 1,083 thousand t). Recycling; Substitutes. Domestic Production and Use: about 69% of 2025 primary consumption went into castings, principally automotive. Salient Statistics: US net import reliance above 75% of apparent consumption (2025 estimate).'
- 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
source: usgs-mcs2026-magnesium-metal
where: Import Sources (2021 to 2024), magnesium metal (99.8% purity) row; the other 8% is not listed by country
documents:
- title: 'AircraftMaterialsUK technical data sheet: Magnesium Alloy AZ31B'
type: datasheet
url: https://aircraftmaterials.com/data/magnesium/az31b.html
- title: 'Goodfellow: AZ31 Magnesium Foil/Sheet, product listing with material properties'
type: datasheet
url: https://www.goodfellow.com/usa/az31-foil-group
- 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'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/5462224
- title: Evaluation of Corrosion Performance of AZ31 Mg Alloy in Physiological and Highly Corrosive Solutions (ACS Appl Bio Mater, 2024)
type: paper
url: https://pmc.ncbi.nlm.nih.gov/articles/PMC10952013
year: 2024
- title: 'Hereon publications record: Effect of temperature on tensile properties of hot rolled AZ31 Mg alloy sheets (Balik, Lukac, Bohlen, Kainer; Kovove materialy 2007)'
type: paper
url: https://publications.hereon.de/id/26479/index.php
year: 2007
- title: 'DLR eLib record: Influence of tension-compression asymmetry on the mechanical behavior of AZ31B magnesium alloy sheets in bending (2016)'
type: paper
url: https://elib.dlr.de/98810/
year: 2016
- title: 'Wikipedia: Magnesium alloy (compositions table)'
type: database
url: https://en.wikipedia.org/wiki/Magnesium_alloy
gaps:
- 'O-temper strength: no readable source with a printed unit was found. The Alloys International AZ31B-O page is rendered in the browser (no values in the HTML). MakeItFrom (a JavaScript and cookie check) and SuppliersOnline (no content) could not be read with curl, and the Smiths datasheet link returned an error page.'
- 'ASTM B90 (sheet and plate) and ASTM B107 (extrusions) minimums: the standards are paywalled and were not read. The copy of an older revision found on a university server was not used.'
- H24 yield and tensile strength are not recorded. The one stockist page that lists them prints no unit. No source read in this run gives a yield strength for AZ31B.
- The Goodfellow values are for the foil and sheet listing with temper As Rolled, not O or H24. Density is printed rounded (1.8), and the thermal and specific heat values give no test temperature (the CTE range is 20 to 100 °C).
- 'Not found in a readable source: Poisson''s ratio, shear modulus, electrical resistivity, compressive yield, cryogenic and space-environment data, outgassing, and an ignition temperature for chips or dust.'
- 'Property names: hardness_brinell and corrosion_rate are not in spores/property-canon.yaml and are used as snake_case names.'
- The Hereon H24 study (room temperature to 400 °C) and the DLR record (AZ31B-O sheet in tension, compression and bending) were read as abstracts only. Their numbers were not reachable.
- The DTIC report ADA494926 (AZ31B-H24 plate, Army Research Lab and Magnesium Elektron) returned a blocked page to curl, so its plate values are not used.
- The International Magnesium Association page on magnesium as the lightest structural metal returned a bot-check page, so that phrase is not used. The USGS wording (lighter than aluminium and zinc in most applications) is used instead.
- 'EU critical raw materials: the Commission page fetched did not show the list entries, so no EU listing is recorded.'
- Corrosion rates come from a biomedical study of AZ31 (Goodfellow composition Mg-Al 3 wt%, Zn 1 wt%), 14-day immersion at 37 °C by mass loss. No standard corrosion test of AZ31B was found.
- No safety data sheet for the alloy was opened. The PubChem GHS data are element-level and do not cover dust or fume from machining or welding.
- The Wikipedia composition row marks manganese 0.2 with a question mark, so Wikipedia is used only for the composition row. The stockist's Mn 0.2 min is the value used.
sources:
aircraftmaterials-az31b:
title: 'AircraftMaterialsUK technical data sheet: Magnesium Alloy AZ31B (composition, typical mechanical properties, specifications)'
url: https://aircraftmaterials.com/data/magnesium/az31b.html
kind: datasheet
license: Stockist web page, cited and not reproduced
goodfellow-az31-foil:
title: 'Goodfellow: AZ31 Magnesium Foil/Sheet, product listing with material properties'
url: https://www.goodfellow.com/usa/az31-foil-group
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)
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'
id: PubChem CID 5462224; aggregated from ECHA C&L notifications
url: https://pubchem.ncbi.nlm.nih.gov/compound/5462224
kind: database
license: PubChem (NCBI) public data
pmc-az31-corrosion:
title: Evaluation of Corrosion Performance of AZ31 Mg Alloy in Physiological and Highly Corrosive Solutions
id: PMC10952013; ACS Appl Bio Mater 2024, 7(3), 1735-1747
url: https://pmc.ncbi.nlm.nih.gov/articles/PMC10952013
year: 2024
kind: paper
license: PMC copy of the journal article, cited and not reproduced
hereon-az31-h24-tension:
title: Effect of temperature on tensile properties of hot rolled AZ31 Mg alloy sheets (Balik, Lukac, Bohlen, Kainer), Kovove materialy / Metallic materials 45 (2007) 135-140
url: https://publications.hereon.de/id/26479/index.php
year: 2007
kind: paper
license: Hereon publications repository record (abstract read)
dlr-az31b-bending:
title: Influence of tension-compression asymmetry on the mechanical behavior of AZ31B magnesium alloy sheets in bending (DLR eLib record)
url: https://elib.dlr.de/98810/
year: 2016
kind: paper
license: DLR eLib repository record (abstract read)
wikipedia-magnesium-alloy:
title: 'Wikipedia: Magnesium alloy (compositions table, AZ31B row)'
url: https://en.wikipedia.org/wiki/Magnesium_alloy
kind: web
license: CC BY-SA (Wikipedia), cited for composition only
license: CC-BY-4.0
updated: '2026-10-24'
review:
status: draft
method: assistant
checked_values: 15
unreachable: 0
caveats: 7
note: 'Written 2026-10-24 from pages fetched in this run (curl and the fetch tool). Values are as printed. The H24 strengths of one stockist page were left out because it prints no unit. Caveats: Goodfellow density rounded (1); corrosion rates are for AZ31, not AZ31B (3 values).'
story:
recipe:
line: Wrought magnesium alloy with aluminium and zinc additions. The stockist data sheet gives Al 2.5 to 3.5 wt%, Zn 0.7 to 1.3 wt%, Mn 0.2 min, magnesium as the balance, and maximum limits on silicon, copper, calcium, iron and nickel. The Goodfellow listing gives the nominal formula Mg 96, Al 3, Zn 1. The data sheet says the alloy is available as plate, tooling plate, sheet, rod and bar, with extrusions made to order.
parts:
- name: Magnesium
symbol: Mg
share_note: balance (the rest)
role: The base metal and the balance of the alloy.
source: aircraftmaterials-az31b
where: Chemical Composition Limits table, Mg row (bal)
- name: Aluminium
symbol: Al
share_percent: 2.5
share_high: 3.5
role: Main alloying addition.
source: aircraftmaterials-az31b
where: Chemical Composition Limits table, Al row
- name: Zinc
symbol: Zn
share_percent: 0.7
share_high: 1.3
role: Second alloying addition.
source: aircraftmaterials-az31b
where: Chemical Composition Limits table, Zn row
- name: Manganese
symbol: Mn
share_percent: 0.2
share_note: minimum (0.2 min on the data sheet)
role: Minor addition, minimum limit.
source: aircraftmaterials-az31b
where: Chemical Composition Limits table, Mn row
- name: Impurity limits
symbol: Si, Cu, Ca, Fe, Ni
share_note: 'maximum: Si 0.05, Cu 0.05, Ca 0.04, Fe 0.005, Ni 0.005; other elements 0.30 total'
role: Limits on impurities; the alloy is made to these maxima.
source: aircraftmaterials-az31b
where: Chemical Composition Limits table, Si, Cu, Ca, Fe, Ni and Others rows
risk_groups:
- title: For people
lead: The only hazard data opened is PubChem's GHS data for magnesium metal. It is element-level, not a classification of AZ31B as supplied.
gap: No safety data sheet for the alloy was opened, and no dust or fume data for machining or welding was found.
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).
- title: If it fails
lead: The failure routes come from the corrosion tests, the study's introduction and the GHS statements.
points:
- label: Chloride corrosion
line: Uncoated AZ31 corroded at 0.27 mm per year in 3.5 % NaCl and 9.7 mm per year in continuous 5 M NaCl in the 14-day tests.
- label: Hydrogen gas
line: The study's introduction says the rapid emission of hydrogen gas and gas bubbles restricts wider use of magnesium alloys in tissue.
- label: Rolling direction
line: The Hereon study of H24 sheet found lower yield and maximum stress along the rolling direction than across it.
- title: Handling and storage
points:
- label: Water
line: Contact with water releases flammable gas (H261), so keep the metal dry.
- label: Chlorides
line: Uncoated AZ31 corrodes fast in chloride solutions. PF and PFS coatings cut the rate in the study.
why: AZ31B is a wrought magnesium alloy, which the stockist describes as having good room-temperature strength and ductility, with corrosion resistance and weldability. The Goodfellow listing gives the nominal composition as Mg 96, Al 3, Zn 1, and the stockist gives aluminium at 2.5 to 3.5 wt% and zinc at 0.7 to 1.3 wt%. The stockist also says most magnesium alloys are not heat treatable like aluminium. Magnesium's light weight is an advantage over aluminium and zinc in most wrought applications, according to the USGS. About 69% of the primary magnesium consumed in 2025 went into castings, principally automotive, so the wrought sheet, plate and extrusion this profile covers is a smaller part of the market.
uses:
- where: Aircraft structure
line: The AircraftMaterials data sheet names aircraft fuselages among the uses of AZ31B.
- where: Phone and laptop cases
line: The same data sheet names cell phone and laptop cases, with speaker cones and concrete tools.
- where: Superformed automotive parts
line: The data sheet says AZ31B can be superformed at elevated temperatures into intricate components for automotive uses.
can_do:
- label: Weight
value: 1.8 g/cm3
line: The Goodfellow listing gives density as 1.8 g/cm3. The USGS says magnesium's light weight is an advantage over aluminium and zinc in most wrought applications.
benchmark: density
- label: Strength, as rolled listing
value: 290 MPa tensile
line: The Goodfellow listing for foil and sheet, with temper As Rolled, gives 290 MPa tensile strength and 15 % elongation at break.
benchmark: ultimate_tensile_strength
- label: Heat conduction
value: 96 W/(m·K)
line: Thermal conductivity is 96 W/(m·K) on the Goodfellow listing, at a temperature the listing does not state.
benchmark: thermal_conductivity
- label: Thermal expansion
value: 26 ppm/K
line: The Goodfellow listing gives a mean coefficient of thermal expansion of 26 ppm/K over 20 to 100 °C.
benchmark: cte
- label: Corrosion in salt water
value: 0.27 mm/year
line: Uncoated AZ31 lost 0.27 mm per year in 3.5 % NaCl over 14 days at 37 °C in the PMC study.
benchmark: corrosion_rate
compare: The USGS says aluminium and zinc can substitute for magnesium in castings and wrought products, and that magnesium's light weight is an advantage over them in most applications, although its high cost is a disadvantage. This profile holds no strength-per-mass figures for aluminium or zinc, so it does not rank AZ31B against them. The stockist says most magnesium alloys are not heat treatable like aluminium, and its H24 rows are cold rolled and partially annealed.
compare_rows:
- label: Density
benchmark: density
- label: Thermal conductivity
benchmark: thermal_conductivity
- label: Thermal expansion
benchmark: cte
handling:
- Keep the metal dry. The GHS statements say contact with water releases flammable gas (H261 in 44.8% of reports).
- Read the supplier's safety data sheet before cutting, grinding or welding. The Goodfellow listing offers one.
- Keep uncoated parts out of chloride solutions. The PMC study lost 9.7 mm per year in continuous 5 M NaCl.
- If chloride exposure cannot be avoided, the study's PF or PFS coatings cut the rate to about 0.25 to 0.30 mm per year in intermittent 5 M NaCl.
good_for:
- Light sheet and plate parts. Density is 1.8 g/cm3 on the Goodfellow listing.
- Aircraft fuselage and phone or laptop case parts, the two uses named on the stockist data sheet.
- Parts that are formed hot. The stockist says AZ31B can be superformed at elevated temperatures into intricate components.
watch_out:
- Corrosion in chloride. Uncoated AZ31 lost 9.7 mm per year in continuous 5 M NaCl and 0.27 mm per year in 3.5 % NaCl (14 days at 37 °C, PMC study).
- Direction and temperature. The Hereon study of H24 sheet, tested from room temperature to 400 °C, found yield and maximum stress lower along the rolling direction than across it, and both fall as the temperature rises.
- Temper. The 290 MPa tensile value is for the As Rolled listing, not O or H24, and no O-temper strength was found in a readable source.
- Fire. The GHS statements for magnesium metal include flammable solid (H228) and catches fire spontaneously if exposed to air (H250).
verdict: 'AZ31B is a light, weldable wrought magnesium alloy that the stockist names for aircraft fuselages and phone and laptop cases. Its weak point is corrosion in salt solutions: uncoated AZ31 corroded fast in the PMC study. The strength figures here are a listing and typical values, and no O-temper value was found.'
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.