Metallic glass (amorphous metal ribbons) MG
Iron-based amorphous ribbon, nominal Fe80 Si9 B11 at % for Metglas 2605SA1 (DOE/NETL core report)
Also known as AMS 4777, 2605SA1, 2714A, MBF20, Vitreloy
Metallic glasses are alloys cooled so fast that they do not crystallise, which leaves a disordered atomic structure.
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.
Carry flux with low loss
0.17 W/kg core loss
Saturate at high field
1.56 T
Join stainless steel
969 to 1024 °C
Strength of the Zr-based glass
1986 MPa
Recipe, share of the weight
- Fe nominal, 80 at % in 2605SA1Iron
- Si nominal, 9 at % in 2605SA1Silicon
- B nominal, 11 at % in 2605SA1Boron
Best for
Tape-wound transformer and switch-mode power cores, where Metglas 2605SA1 has core loss of at most 0.17 W/kg at 60 Hz and 1.3 T, and brazing foils that join stainless steel and superalloys
Weakest at
Heat and thermal stability. The 2714A bulletin gives a continuous service temperature of 90 °C, and the ribbons crystallise at 510 °C (2605SA1) and 550 °C (2714A)
Risk at a glance
- People Low. Metal hazard codes only
- If it fails High. Crystallisation on overheating
- Corrosion Low. Metglas lists excellent corrosion resistance for 2714A
Quick facts: MG
| Property | Value | Basis |
|---|---|---|
| Density | 7.18 to 7.59 g/cm³ | 2 sourced values across conditions |
| Yield strength | 1,986 to 2,073 MPa | 2 sourced values across conditions |
| Tensile strength | 1,000 to 2,000 MPa | 2 sourced values across conditions |
| Young's modulus | 100 to 110 GPa | 2 sourced values across conditions |
| Thermal expansion (CTE) | 12.7 ppm/K | 1 sourced value |
| Melting point | 969 to 1,024 °C | 1 sourced value |
| Electrical resistivity | 0.0000013 to 0.0000014 Ω·m | 2 sourced values across conditions |
| Maximum service temperature | 90 °C | 1 sourced value |
What is the density of Metallic glass (MG)?
Metallic glass (MG) has a density of 7.18 to 7.59 g/cm³. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the coefficient of thermal expansion of Metallic glass (MG)?
Metallic glass (MG) has a coefficient of thermal expansion of 12.7 ppm/K. The source and test conditions are listed in the properties table on this page.
What is the melting point of Metallic glass (MG)?
Metallic glass (MG) has a melting point of 969 to 1,024 °C. The source and test conditions are listed in the properties table on this page.
What is the yield strength of Metallic glass (MG)?
Metallic glass (MG) has a yield strength of 1,986 to 2,073 MPa. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the tensile strength of Metallic glass (MG)?
Metallic glass (MG) has a tensile strength of 1,000 to 2,000 MPa. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What are the other names and codes for Metallic glass (MG)?
Metallic glass (MG) is also written as AMS 4777, 2605SA1, 2714A, MBF20, Vitreloy. Each code is printed in the source listed beside it in the designations table.
What is Metallic glass (MG) used for?
Uses recorded in the sources include Tape-wound power transformer cores; Switch-mode and high sensitivity transformers, and current transformers; Brazing foil for stainless steel and superalloy joints.
Why it exists
Metallic glasses are used where a magnetic core must lose little energy, or where a brazing foil must be ductile and stampable. The 2605SA1 datasheet gives core loss of at most 0.17 W/kg at 60 Hz and 1.3 T. Wikipedia credits Klement, Willens and Duwez at Caltech with the first reported metallic glass, Au75Si25, and says that the low magnetisation loss is used in high efficiency transformers at line frequency.
Where it's used
Tape-wound power transformer cores
DOE NETL built a 2605-SA1 tape-wound core of 180 by 240 by 30 mm with a mass of 5.95 kg after impregnation, and lists transformers, pulse power cores, motors and high frequency inductors as applications.
High sensitivity and switch-mode transformers
Metglas lists 2714A for switch-mode power supplies, high frequency transformers, ultra-sensitive current transformers, shielding and sensors.
Brazing foil for stainless steel and superalloys
Metglas says MBF20 replaces copper foil or nickel powder for brazing stainless steel, and lists aerospace, heat exchangers, catalytic substrates and preforms as uses. These are vendor claims with no test data on the page.
Cryogenic bulk metallic glass gears
NASA says its BMGG project has gearboxes running at surface temperatures of -173 °C (-280 °F) for heater-free designs for missions such as a Europa Lander.
Recipe
Iron-based amorphous ribbon, nominal Fe80 Si9 B11 at % for Metglas 2605SA1 (DOE/NETL core report); cobalt-based ribbon, nominal Co66 Fe4 Ni1 B15 Si14 for Metglas 2714A (Yang et al. 1997, abstract); nickel-based brazing foil MBF20, nominal Cr 7.0, Fe 3.0, Si 4.5, B 3.2 wt %, C max 0.06 wt %, balance Ni (Metglas page)
Metglas 2605SA1 is an iron-based amorphous ribbon of nominal Fe80 Si9 B11 at %, supplied as 25 ± 4 µm foil (datasheet, DOE NETL). Metglas 2714A is cobalt-based, nominal Co66 Fe4 Ni1 B15 Si14 (Yang abstract). MBF20 is a nickel-based brazing foil, nominal Cr 7.0, Fe 3.0, Si 4.5, B 3.2 wt %, C max 0.06 wt %, balance Ni (Metglas page). Wikipedia describes melt spinning as sputtering molten metal onto a spinning metal disk.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Iron Fe | nominal, 80 at % in 2605SA1 | Main element of the iron-based ribbon |
| Silicon Si | nominal, 9 at % in 2605SA1 | Minor element, described by DOE as present in small percentages |
| Boron B | nominal, 11 at % in 2605SA1 | Minor element, described by DOE as present in small percentages |
Weight shares are as printed in the sources.
What it can do
Carry flux with low loss
0.17 W/kg core loss
measured
At 60 Hz and 1.3 T the 2605SA1 specification allows at most 0.17 W/kg, measured to ASTM A 932 (Metglas datasheet).
Saturate at high field
1.56 T
measured
The 2605SA1 saturation induction is 1.56 T, and the 2714A value is 0.57 T (both Metglas datasheets).
Join stainless steel
969 to 1024 °C
measured
MBF20 melts between its solidus of 969 °C and liquidus of 1024 °C (Metglas page), a range suited to brazing stainless steel.
Strength of the Zr-based glass
1986 MPa
measured
A lecture slide gives 1986 MPa yield or fracture strength for Vitreloy in tension under 0.1 MPa hydrostatic pressure (Greer).
How it compares
These three families are not interchangeable. The iron-based 2605SA1 has the highest saturation induction of the ribbons read here at 1.56 T, the cobalt-based 2714A has the lowest at 0.57 T but a much higher maximum DC permeability of up to 1,000,000 when annealed (Metglas bulletin), and it is 7.59 g/cm3 and has a continuous service limit of 90 °C. The nickel-based MBF20 is a brazing foil and has no magnetic data in this profile. The zirconium-based Vitreloy family has a yield strength of 1986 MPa in one lecture figure, which is much higher than the Metglas ribbons, but no density or modulus for it was found in this run. The Curie temperatures printed for the ribbons are 395 °C for 2605SA1 and 225 °C for 2714A.
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 | MG | NdFeB | SmCo | Alnico | FeCoV | CoFe / Co-W / Co-Ti / Co-Al | Ni-Fe-Mo | Ni-Fe-Mo | Fe-Si | NbTi | MgB2, REBCO, BSCCO |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Thermal behavior and safety | |||||||||||
| Solidus to liquidus, MBF20 brazing foil | 969 to 1024 °C29 | no data | no data | 1200 to 1450 °C | no data | no data | 1450 °C | 1450 °C | no data | 2300 °C | 830 °C |
| Physical and electrical | |||||||||||
| Density, Metglas 2605SA1 | 7.18 g/cm³3 | 7.6 g/cm³ | 8.2 to 8.4 g/cm³ | 6.9 to 7.3 g/cm³ | 8.12 g/cm³ | 7.9 g/cm³ | 8.7 g/cm³ | 8.7 g/cm³ | 7.6 kg/dm3 | 6.4 to 6.5 g/cm³ | 2.57 g/cm³ |
| Vickers hardness, Metglas 2605SA1 | 900 HV7 | no data | no data | no data | 205 HV | 439 HV 0.1 | no data | no data | no data | no data | no data |
| Electrical resistivity, Metglas 2605SA1 | 1.3 µΩm12 | 150 uohm cm | 80 to 90 uohm cm | 45 to 75 uohm cm | 0.401 Ω·mm²/m | 0.3 µΩm | 55 µΩcm | 60 µΩ·cm | 59 µΩ·cm | no data | no data |
| Density, Metglas 2714A | 7.59 g/cm³15 | 7.6 g/cm³ | 8.2 to 8.4 g/cm³ | 6.9 to 7.3 g/cm³ | 8.12 g/cm³ | 7.9 g/cm³ | 8.7 g/cm³ | 8.7 g/cm³ | 7.6 kg/dm3 | 6.4 to 6.5 g/cm³ | 2.57 g/cm³ |
| Vickers hardness, Metglas 2714A | 960 HV16 | no data | no data | no data | 205 HV | 439 HV 0.1 | no data | no data | no data | no data | no data |
| Electrical resistivity, Metglas 2714A | 142 µΩ·cm27 | 150 uohm cm | 80 to 90 uohm cm | 45 to 75 uohm cm | 0.401 Ω·mm²/m | 0.3 µΩm | 55 µΩcm | 60 µΩ·cm | 59 µΩ·cm | no data | no data |
| Temperature behavior | |||||||||||
| Curie temperature, Metglas 2605SA1 | 395 °C2 | 310 °C | 700 to 750 °C | 860 °C | 950 °C | 940 °C | 410 °C | 420 °C | no data | no data | no data |
| Crystallization temperature, Metglas 2605SA1 | 510 °C4 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Crystallization temperature, Metglas 2714A | 550 °C21 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Curie temperature, Metglas 2714A | 225 °C26 | 310 °C | 700 to 750 °C | 860 °C | 950 °C | 940 °C | 410 °C | 420 °C | no data | no data | no data |
| Glass transition temperature, Zr51Al14.2Ni15.9Cu18.9 research bulk glassThermal analysis value in a research paper table | 725.7 K | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Other measurements | |||||||||||
| Saturation induction, Metglas 2605SA1 | 1.56 T1 | no data | no data | no data | 2.35 T | no data | 0.8 T | 0.75 T | no data | no data | no data |
| Tensile strength, Metglas 2605SA1 | 2000 N/mm25 | no data | no data | no data | 350 MPa | no data | 450 N/mm2 | 500 to 700 N/mm2 | 535 MPa | no data | no data |
| Young's modulus, Metglas 2605SA1 | 110 GPa6 | no data | 1.2 10^11 N/m2 | no data | 190 to 210 GPa | 440 GPa | 190 to 221 kN/mm2 | 190 to 221 kN/mm2 | 185 GPa | no data | 149 to 186 GPa |
| Thermal expansion coefficient, Metglas 2605SA1 | 7.6 x10-6/°C8 | 7 1e-6 per °C (dL/L) | 8 to 10 1e-6 per °C | 11 to 13 1e-6 per °C | 9.4 ppm/K | no data | 12 10-6/K | 12 10-6/K | 12 10-6/C | no data | no data |
| Core loss, Metglas 2605SA1, 60 Hz and 1.3 TSpecification table printed by the manufacturer | 0.17 W/kg9 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Core loss, Metglas 2605SA1, 60 Hz and 1.4 TSpecification table printed by the manufacturer | 0.2 W/kg10 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Induction at 60 Hz and 80 A/m, Metglas 2605SA1Specification table printed by the manufacturer | 1.35 T11 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Magnetostriction, Metglas 2605SA1 | 27 x10-613 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Lamination factor, Metglas 2605SA1 ribbon | 84 %14 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Tensile strength, Metglas 2714A | 1 to 2 GPa17 | no data | no data | no data | 350 MPa | no data | 450 N/mm2 | 500 to 700 N/mm2 | 535 MPa | no data | no data |
| Elastic modulus, Metglas 2714A | 100 to 110 GPa18 | no data | 1.2 10^11 N/m2 | no data | 190 to 210 GPa | 440 GPa | 190 to 221 kN/mm2 | 190 to 221 kN/mm2 | 185 GPa | no data | 149 to 186 GPa |
| Lamination factor, Metglas 2714A | 75 %19 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Thermal expansion coefficient, Metglas 2714A | 12.7 ppm/°C20 | 7 1e-6 per °C (dL/L) | 8 to 10 1e-6 per °C | 11 to 13 1e-6 per °C | 9.4 ppm/K | no data | 12 10-6/K | 12 10-6/K | 12 10-6/C | no data | no data |
| Continuous service temperature, Metglas 2714A | 90 °C22 | 80 °C | 250 °C | 525 °C | no data | no data | no data | no data | no data | no data | no data |
| Saturation induction, Metglas 2714A | 0.57 T23 | no data | no data | no data | 2.35 T | no data | 0.8 T | 0.75 T | no data | no data | no data |
| Maximum DC permeability, Metglas 2714A, annealed | 1×10^6 -24 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Maximum DC permeability, Metglas 2714A, as cast | 80000 -25 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Saturation magnetostriction, Metglas 2714A | 0.5 ppm28 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Yield or fracture strength, Vitreloy (Zr-Ti-Ni-Cu-Be) | 1986 MPa30 | no data | no data | no data | 250 MPa | no data | 170 N/mm2 | 200 to 450 N/mm2 | 435 MPa | no data | 694 to 957 MPa |
| Yield strength, Zr51Al14.2Ni15.9Cu18.9 research bulk glass | 2073 MPa31 | no data | no data | no data | 250 MPa | no data | 170 N/mm2 | 200 to 450 N/mm2 | 435 MPa | no data | 694 to 957 MPa |
Why choose it, and why not
Good for
- Low-loss transformer and switch-mode power cores, with 2605SA1 core loss of at most 0.17 W/kg at 60 Hz and 1.3 T.
- High-permeability sensors and current transformers using 2714A, with maximum DC permeability of up to 1,000,000 when annealed.
- Brazing stainless steel and superalloys with the MBF20 foil, a ductile foil that can be bent 180 degrees (Metglas page).
Watch out for
- Heat limit: 2714A has a continuous service temperature of 90 °C, and both ribbons crystallise at 510 to 550 °C.
- Vitreloy values: only a yield strength (1986 MPa) was read, and its density and modulus were not found in this run.
- No corrosion or ageing test data for the ribbons were read; the Metglas corrosion claim for 2714A is a manufacturer statement.
- The NASA gear alloy is not named in the sources, so the -173 °C gearbox figure cannot be assigned to a specific composition.
Metallic glasses are soft magnetic ribbons and brazing foils that trade a disordered structure for low core loss and easy shaping. The iron-based 2605SA1 is a transformer core with a saturation induction of 1.56 T, the cobalt-based 2714A is a high permeability sensor ribbon limited to 90 °C service, and the MBF20 foil brazes steel at about 1000 °C. The Zr-based Vitreloy family is included for its strength only, and its density and modulus were not verified in this run.
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 |
|---|---|
| AMS | 4777 |
| Trade name | 2605SA1 (Metglas transformer core alloy), 2714A (Metglas Magnetic Alloy, cobalt-based), MBF20 (Metglas brazing foil, AWS BNi2 family), Vitreloy |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Saturation induction, Metglas 2605SA1 | General properties table printed by the manufacturer | grade Metglas 2605SA1temperature not statednote the datasheet says these numbers are not guaranteed | — |
| 2 | Curie temperature, Metglas 2605SA1 | General properties table printed by the manufacturer | grade Metglas 2605SA1note the datasheet says these numbers are not guaranteed | — |
| 3 | Density, Metglas 2605SA1 | Physical properties table printed by the manufacturer | grade Metglas 2605SA1note the datasheet says these numbers are not guaranteed | — |
| 4 | Crystallization temperature, Metglas 2605SA1 | Physical properties table printed by the manufacturer | grade Metglas 2605SA1note the datasheet says these numbers are not guaranteed | — |
| 5 | Tensile strength, Metglas 2605SA1 | Physical properties table printed by the manufacturer | grade Metglas 2605SA1note printed as 2,000 N/mm2; the datasheet says these numbers are not guaranteed | — |
| 6 | Young's modulus, Metglas 2605SA1 | Physical properties table printed by the manufacturer | grade Metglas 2605SA1note the datasheet says these numbers are not guaranteed | — |
| 7 | Vickers hardness, Metglas 2605SA1 | Physical properties table printed by the manufacturer | grade Metglas 2605SA1load 50 g (Hv-50 g load as printed) | — |
| 8 | Thermal expansion coefficient, Metglas 2605SA1 | Physical properties table printed by the manufacturer | grade Metglas 2605SA1temperature range 30 to 300 °C | — |
| 9 | Core loss, Metglas 2605SA1, 60 Hz and 1.3 T | — | grade Metglas 2605SA1 transformer core alloyfrequency 60 Hzinduction 1.3 Tstandard ASTM A 932 (as printed)note printed as an upper limit, less than or equal to 0.17 | — |
| 10 | Core loss, Metglas 2605SA1, 60 Hz and 1.4 T | — | grade Metglas 2605SA1 transformer core alloyfrequency 60 Hzinduction 1.4 Tstandard ASTM A 932 (as printed)note printed as an upper limit, less than or equal to 0.20 | — |
| 11 | Induction at 60 Hz and 80 A/m, Metglas 2605SA1 | — | grade Metglas 2605SA1 transformer core alloyfrequency 60 Hzfield 80 A/mnote printed as a lower limit, greater than or equal to 1.35 | — |
| 12 | Electrical resistivity, Metglas 2605SA1 | General properties table printed by the manufacturer | grade Metglas 2605SA1note printed as 1.3 µΩm; the datasheet says these numbers are not guaranteed | — |
| 13 | Magnetostriction, Metglas 2605SA1 | General properties table printed by the manufacturer | grade Metglas 2605SA1note the datasheet says these numbers are not guaranteed | — |
| 14 | Lamination factor, Metglas 2605SA1 ribbon | Ribbon dimensions and lamination factor table printed by the manufacturer | grade Metglas 2605SA1 ribbon, 25 ± 4 µm thick as printednote printed as a lower limit, greater than or equal to 84 | — |
| 15 | Density, Metglas 2714A | Physical properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbon | — |
| 16 | Vickers hardness, Metglas 2714A | Physical properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbonload 50 g (as printed) | — |
| 17 | Tensile strength, Metglas 2714A | Physical properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbon | — |
| 18 | Elastic modulus, Metglas 2714A | Physical properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbon | — |
| 19 | Lamination factor, Metglas 2714A | Physical properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbonnote printed as a lower limit, greater than 75 | — |
| 20 | Thermal expansion coefficient, Metglas 2714A | Physical properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbon | — |
| 21 | Crystallization temperature, Metglas 2714A | Physical properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbon | — |
| 22 | Continuous service temperature, Metglas 2714A | Physical properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbonnote printed as continuous service temperature | — |
| 23 | Saturation induction, Metglas 2714A | Magnetic properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbon | — |
| 24 | Maximum DC permeability, Metglas 2714A, annealed | Magnetic properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbontreatment annealed | — |
| 25 | Maximum DC permeability, Metglas 2714A, as cast | Magnetic properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbontreatment as castnote printed as greater than 80,000 | — |
| 26 | Curie temperature, Metglas 2714A | Magnetic properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbon | — |
| 27 | Electrical resistivity, Metglas 2714A | Magnetic properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbon | — |
| 28 | Saturation magnetostriction, Metglas 2714A | Magnetic properties table printed by the manufacturer | grade Metglas 2714A cobalt-based ribbonnote printed as less than 0.5 ppm | — |
| 29 | Solidus to liquidus, MBF20 brazing foil | Solidus and liquidus columns of the Metglas brazing grades table | grade MBF20, AWS BNi2 family, nominal composition in wt %note solidus 969 °C (1776 °F) and liquidus 1024 °C (1875 °F) as printed | — |
| 30 | Yield or fracture strength, Vitreloy (Zr-Ti-Ni-Cu-Be) | Value printed on a stress-strain plot in a lecture slide | alloy Vitreloy, as titled on the slide (Zr-Ti-Ni-Cu-Be bulk metallic glass)test tension, true stress, 0.1 MPa hydrostatic pressurestrain f = 0 %note the slide gives the value as yield or fracture strength on one curve | — |
| 31 | Yield strength, Zr51Al14.2Ni15.9Cu18.9 research bulk glass | Compression or yield value in a research paper table | alloy Zr51Al14.2Ni15.9Cu18.9 (at %), research alloy from the Zr-Al-Ni-Cu series, not Vitreloynote column sigma y in Table 1, printed without unit suffix; MPa from the column header | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Uncoated ribbon in ordinary air (2714A) | low | Metglas lists excellent corrosion resistance for 2714A1 |
| Ordinary air (2605SA1 ribbon) | not rated | No corrosion data was read for 2605SA12 |
| Brazed stainless steel joints (MBF20 foil) | not rated | Metglas claims corrosion resistance for brazed joints3 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Uncoated ribbon in ordinary air (2714A) | The bulletin lists excellent corrosion resistance among the benefits. No corrosion rate, humidity or salt-spray test is printed in the bulletin. | grade Metglas 2714Aexposure not statedbasis manufacturer statement, no test data |
| 2 | Ordinary air (2605SA1 ribbon) | The 2605SA1 datasheets give no corrosion statement or test result, so the rating is unknown until a source is read. | grade Metglas 2605SA1exposure not stated |
| 3 | Brazed stainless steel joints (MBF20 foil) | The page claims high strength and corrosion resistance for the joints. No test data is printed on the page. | grade MBF20exposure not statedbasis vendor claim, no test data |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The hazard codes in the sources are for the pure metals in the alloys. No classification of the ribbons or foils themselves was found.
- Nickel as a substance
- PubChem notifier list for nickel gives H317 (allergic skin reaction, 100 % of notifications), H351 (suspected cancer, 100 %) and H372 (organ damage from repeated exposure, 100 %).
- Cobalt as a substance
- PubChem notifier list for cobalt gives H317 (allergic skin reaction), H334 (allergy or asthma symptoms if inhaled) and H350 (may cause cancer) among its codes, with H317 and H334 the most widely notified.
- Alloy as handled
- No health classification of the alloy ribbons or the MBF20 foil was found in the sources read.
If it fails
The failure routes in the sources are thermal. None of them is a flight result for these grades.
- Overheating
- Both ribbons crystallise at a printed temperature, 510 °C for 2605SA1 and 550 °C for 2714A. The 2714A datasheet prints 90 °C as its continuous service limit.
- Heavy parts
- At 7.59 g/cm3 for 2714A and 7.18 g/cm3 for 2605SA1 the ribbon adds mass. No Vitreloy density was read, so no mass figure is given for the Zr-based family.
Handling and storage
- Anneal first
- The 2605SA1 datasheet anneals at 370 °C for 2 hours in a magnetic field of 2400 A/m to set the magnetic axis. Use the same anneal for the stress release the datasheet names.
- Keep the foil clean
- Metglas describes the MBF20 foil as contaminant-free with no organic binders, and states unlimited shelf life.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Crystallisation on overheatinghigh severity | Heating near the printed crystallisation temperatureMetglas prints a crystallisation temperature of 510 °C for 2605SA1 and 550 °C for 2714A. The values in this profile apply only to the glassy state. |
| Use above the 2714A service limitmoderate severity | Continuous use above 90 °CMetglas prints 90 °C as the continuous service temperature for 2714A. The bulletin gives no figure for longer or peak exposures. |
| Crystallisation in a thick castingmoderate severity | Cooling slower than the critical cooling rateGreer slides give a critical cooling rate of about 1 K/s for bulk metallic glasses, so a thick section can crystallise. |
Side effects on surrounding parts
| Affects | Effect |
|---|---|
| Mass of a core or foil | At 7.59 g/cm3 for 2714A and 7.18 g/cm3 for 2605SA1, a core or foil adds mass. |
Handling and storage
- Anneal 2605SA1 at 370 °C for 2 hours in a magnetic field of 2400 A/m along the ribbon long axis, to release stress and induce magnetic anisotropy, as the datasheet directs.
- NETL's core is impregnated with 100 % solids epoxy after winding.
- Metglas says the MBF20 foil can be stamped or cut into preforms and has unlimited shelf life.
Mitigations
- Anneal 2605SA1 in the field the datasheet specifies, and keep the core well below its 510 °C crystallisation temperature.
Supply and geography
How common the raw materials are and where they come from.
Cobalt (main element of Metglas 2714A)
- Top producers (2025)
- Congo (Kinshasa) 73%, Indonesia 14%
- Recycling
- USGS: cobalt content of purchased scrap represented 25% of estimated cobalt consumption in 2025.
- Substitutes
- USGS: substitution for cobalt could cause a loss in product performance or increased cost, depending on the application; nickel-iron alloys are listed as potential substitutes in some magnets.
Nickel (balance of MBF20 brazing foil)
- Top producers (2025)
- Indonesia 66.7%, Philippines 6.9%, Russia 5.1%
- Recycling
- USGS: in 2025 nickel recovered from scrap accounted for approximately 60% of apparent consumption, and most recycled nickel was used to produce new alloys and stainless steel.
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spore: profile
id: metallic-glass
spore_version: 0.2
family: magnet-and-superconducting-alloys
name: Metallic glass (amorphous metal ribbons)
abbreviation: MG
role: amorphous magnetic core and brazing alloy
category: metals
type: magnet-alloys
summary: |
Metallic glasses are alloys cooled so fast that they do not crystallise, which leaves a disordered atomic structure. This profile covers three commercial families read in this run. Metglas 2605SA1 is an iron-based transformer ribbon with a saturation induction of 1.56 T and a Curie temperature of 395 °C (Metglas datasheet). Metglas 2714A is a cobalt-based ribbon with a saturation induction of 0.57 T, a Curie temperature of 225 °C and near-zero magnetostriction (Metglas bulletin). MBF20 is a nickel-based brazing foil with a solidus of 969 °C and a liquidus of 1024 °C (Metglas page). A zirconium-based bulk metallic glass family, called Vitreloy here, is covered only by a yield strength from a lecture slide (1986 MPa); no density or modulus for Vitreloy was found in this run.
best_for: Tape-wound transformer and switch-mode power cores, where Metglas 2605SA1 has core loss of at most 0.17 W/kg at 60 Hz and 1.3 T, and brazing foils that join stainless steel and superalloys
weakest_at: Heat and thermal stability. The 2714A bulletin gives a continuous service temperature of 90 °C, and the ribbons crystallise at 510 °C (2605SA1) and 550 °C (2714A)
identity:
formula: Iron-based amorphous ribbon, nominal Fe80 Si9 B11 at % for Metglas 2605SA1 (DOE/NETL core report); cobalt-based ribbon, nominal Co66 Fe4 Ni1 B15 Si14 for Metglas 2714A (Yang et al. 1997, abstract); nickel-based brazing foil MBF20, nominal Cr 7.0, Fe 3.0, Si 4.5, B 3.2 wt %, C max 0.06 wt %, balance Ni (Metglas page)
source: netl-2605sa1-core
where: 'Table 2, Characteristics, row Chemistry: Fe80 Si9 B11 at %'
designations:
- system: Trade name
code: 2605SA1
note: Metglas transformer core alloy
source: metglas-2605sa1-datasheet
where: Title block and General Properties table, row 2605SA1
- system: Trade name
code: 2714A
note: Metglas Magnetic Alloy, cobalt-based
source: metglas-2714a-bulletin
where: 'Title block: Magnetic Alloy 2714A (cobalt-based), Technical Bulletin'
- system: Trade name
code: MBF20
note: Metglas brazing foil, AWS BNi2 family
source: metglas-brazing-foil-page
where: Brazing alloy grades table, row MBF20
- system: AMS
code: '4777'
source: metglas-brazing-foil-page
where: 'Brazing grades table, row MBF20, AWS and AMS column: AWS BNi2, AMS 4777'
- system: Trade name
code: Vitreloy
source: greer-lecture-2012
where: Slide titled Vitreloy with 0.1 MPa hydrostatic pressure stress-strain plot
tags:
environments: []
applications:
- electronics-and-chips
- thermal-control
- mechanisms
properties:
- benchmark: saturation_induction
label: Saturation induction, Metglas 2605SA1
value: 1.56
unit: T
scope: material
conditions:
grade: Metglas 2605SA1
temperature: not stated
note: the datasheet says these numbers are not guaranteed
method: General properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, row 2605SA1, Saturation Induction column
- benchmark: curie_temperature
label: Curie temperature, Metglas 2605SA1
value: 395
unit: °C
scope: material
conditions:
grade: Metglas 2605SA1
note: the datasheet says these numbers are not guaranteed
method: General properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, row 2605SA1, Curie Temperature column
- benchmark: density
label: Density, Metglas 2605SA1
value: 7.18
unit: g/cm3
scope: material
conditions:
grade: Metglas 2605SA1
note: the datasheet says these numbers are not guaranteed
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, Physical table, row 2605SA1, Density column
- benchmark: crystallization_temperature
label: Crystallization temperature, Metglas 2605SA1
value: 510
unit: °C
scope: material
conditions:
grade: Metglas 2605SA1
note: the datasheet says these numbers are not guaranteed
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, Physical table, row 2605SA1, Crystallization Temperature column
- benchmark: ultimate_tensile_strength
label: Tensile strength, Metglas 2605SA1
value: 2000
unit: N/mm2
scope: material
conditions:
grade: Metglas 2605SA1
note: printed as 2,000 N/mm2; the datasheet says these numbers are not guaranteed
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, Physical table, row 2605SA1, Tensile Strength column
- benchmark: elastic_modulus
label: Young's modulus, Metglas 2605SA1
value: 110
unit: GPa
scope: material
conditions:
grade: Metglas 2605SA1
note: the datasheet says these numbers are not guaranteed
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, Physical table, row 2605SA1, Young's Modulus column
- benchmark: hardness_vickers
label: Vickers hardness, Metglas 2605SA1
value: 900
unit: HV
scope: material
conditions:
grade: Metglas 2605SA1
load: 50 g (Hv-50 g load as printed)
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, Physical table, row 2605SA1, Vickers Hardness Hv-50 g load column
- benchmark: cte
label: Thermal expansion coefficient, Metglas 2605SA1
value: 7.6
unit: x10-6/°C
scope: material
conditions:
grade: Metglas 2605SA1
temperature_range: 30 to 300 °C
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, Physical table, row 2605SA1, Thermal Expansion Coefficient column
- benchmark: core_loss
label: Core loss, Metglas 2605SA1, 60 Hz and 1.3 T
value: 0.17
unit: W/kg
scope: material
conditions:
grade: Metglas 2605SA1 transformer core alloy
frequency: 60 Hz
induction: 1.3 T
standard: ASTM A 932 (as printed)
note: printed as an upper limit, less than or equal to 0.17
method: Specification table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 1. Alloys and the specification, row Core Loss at 60 Hz and 1.3 T, 2605SA1 column
- benchmark: core_loss
label: Core loss, Metglas 2605SA1, 60 Hz and 1.4 T
value: 0.2
unit: W/kg
scope: material
conditions:
grade: Metglas 2605SA1 transformer core alloy
frequency: 60 Hz
induction: 1.4 T
standard: ASTM A 932 (as printed)
note: printed as an upper limit, less than or equal to 0.20
method: Specification table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 1. Alloys and the specification, row Core Loss at 60 Hz and 1.4 T, 2605SA1 column
- benchmark: induction_60hz_80am
label: Induction at 60 Hz and 80 A/m, Metglas 2605SA1
value: 1.35
unit: T
scope: material
conditions:
grade: Metglas 2605SA1 transformer core alloy
frequency: 60 Hz
field: 80 A/m
note: printed as a lower limit, greater than or equal to 1.35
method: Specification table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 1. Alloys and the specification, row Induction at 60 Hz and 80 A/m, 2605SA1 column
- benchmark: electrical_resistivity
label: Electrical resistivity, Metglas 2605SA1
value: 1.3
unit: µΩm
scope: material
conditions:
grade: Metglas 2605SA1
note: printed as 1.3 µΩm; the datasheet says these numbers are not guaranteed
method: General properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, Electromagnetic table, row 2605SA1, Electrical Resistivity column
- benchmark: magnetostriction
label: Magnetostriction, Metglas 2605SA1
value: 27
unit: x10-6
scope: material
conditions:
grade: Metglas 2605SA1
note: the datasheet says these numbers are not guaranteed
method: General properties table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 2. General Properties and Characteristics, Electromagnetic table, row 2605SA1, Magnetostriction column
- benchmark: lamination_factor
label: Lamination factor, Metglas 2605SA1 ribbon
value: 84
unit: '%'
scope: material
conditions:
grade: Metglas 2605SA1 ribbon, 25 ± 4 µm thick as printed
note: printed as a lower limit, greater than or equal to 84
method: Ribbon dimensions and lamination factor table printed by the manufacturer
status: ground
source: metglas-2605sa1-datasheet
where: 3. Ribbon Dimensions and Lamination Factor, row 2605SA1, Lamination Factor column
- benchmark: density
label: Density, Metglas 2714A
value: 7.59
unit: g/cm3
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Physical Properties, Density (g/cm3)
- benchmark: hardness_vickers
label: Vickers hardness, Metglas 2714A
value: 960
unit: HV
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
load: 50 g (as printed)
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Physical Properties, Vicker's Hardness (50g load)
- benchmark: ultimate_tensile_strength
label: Tensile strength, Metglas 2714A
value: 1
value_high: 2
bound: range
unit: GPa
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Physical Properties, Tensile Strength (GPa), printed as 1-2
- benchmark: elastic_modulus
label: Elastic modulus, Metglas 2714A
value: 100
value_high: 110
bound: range
unit: GPa
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Physical Properties, Elastic Modulus (GPa), printed as 100-110
- benchmark: lamination_factor
label: Lamination factor, Metglas 2714A
value: 75
unit: '%'
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
note: printed as a lower limit, greater than 75
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Physical Properties, Lamination Factor (%)
- benchmark: cte
label: Thermal expansion coefficient, Metglas 2714A
value: 12.7
unit: ppm/°C
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Physical Properties, Thermal Expansion (ppm/°C)
- benchmark: crystallization_temperature
label: Crystallization temperature, Metglas 2714A
value: 550
unit: °C
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Physical Properties, Crystallization Temperature (°C)
- benchmark: max_service_temp
label: Continuous service temperature, Metglas 2714A
value: 90
unit: °C
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
note: printed as continuous service temperature
method: Physical properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Physical Properties, Continuous Service Temp. (°C)
- benchmark: saturation_induction
label: Saturation induction, Metglas 2714A
value: 0.57
unit: T
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
method: Magnetic properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Magnetic Properties, Saturation Induction (T)
- benchmark: permeability_dc_max
label: Maximum DC permeability, Metglas 2714A, annealed
value: 1000000
unit: '-'
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
treatment: annealed
method: Magnetic properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Magnetic Properties, Maximum D.C. Permeability, Annealed row
- benchmark: permeability_dc_max
label: Maximum DC permeability, Metglas 2714A, as cast
value: 80000
unit: '-'
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
treatment: as cast
note: printed as greater than 80,000
method: Magnetic properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Magnetic Properties, Maximum D.C. Permeability, As Cast row
- benchmark: curie_temperature
label: Curie temperature, Metglas 2714A
value: 225
unit: °C
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
method: Magnetic properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Magnetic Properties, Curie Temperature (°C)
- benchmark: electrical_resistivity
label: Electrical resistivity, Metglas 2714A
value: 142
unit: µΩ·cm
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
method: Magnetic properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Magnetic Properties, Electrical Resistivity (µΩ.cm)
- benchmark: magnetostriction
label: Saturation magnetostriction, Metglas 2714A
value: 0.5
unit: ppm
scope: material
conditions:
grade: Metglas 2714A cobalt-based ribbon
note: printed as less than 0.5 ppm
method: Magnetic properties table printed by the manufacturer
status: ground
source: metglas-2714a-bulletin
where: Magnetic Properties, Saturation Magnetostriction (ppm)
- benchmark: melting_point
label: Solidus to liquidus, MBF20 brazing foil
value: 969
value_high: 1024
bound: range
unit: °C
scope: material
conditions:
grade: MBF20, AWS BNi2 family, nominal composition in wt %
note: solidus 969 °C (1776 °F) and liquidus 1024 °C (1875 °F) as printed
method: Solidus and liquidus columns of the Metglas brazing grades table
status: ground
source: metglas-brazing-foil-page
where: Brazing alloy grades table, row MBF20, Solidus and Liquidus columns
- benchmark: yield_strength
label: Yield or fracture strength, Vitreloy (Zr-Ti-Ni-Cu-Be)
value: 1986
unit: MPa
scope: material
conditions:
alloy: Vitreloy, as titled on the slide (Zr-Ti-Ni-Cu-Be bulk metallic glass)
test: tension, true stress, 0.1 MPa hydrostatic pressure
strain: f = 0 %
note: the slide gives the value as yield or fracture strength on one curve
method: Value printed on a stress-strain plot in a lecture slide
status: ground
source: greer-lecture-2012
where: Slide with stress-strain plot titled Vitreloy, 0.1 MPa Hydrostatic Pressure, label Yield/Fracture Strength = 1986 MPa
- benchmark: yield_strength
label: Yield strength, Zr51Al14.2Ni15.9Cu18.9 research bulk glass
value: 2072.5
unit: MPa
scope: material
conditions:
alloy: Zr51Al14.2Ni15.9Cu18.9 (at %), research alloy from the Zr-Al-Ni-Cu series, not Vitreloy
note: column sigma y in Table 1, printed without unit suffix; MPa from the column header
method: Compression or yield value in a research paper table
status: ground
source: pmc-zr-bmg-series
where: Section 2.1, Table 1, row Zr51Al14.2Ni15.9Cu18.9, sigma y column
- benchmark: glass_transition_temperature
label: Glass transition temperature, Zr51Al14.2Ni15.9Cu18.9 research bulk glass
value: 725.7
unit: K
scope: material
conditions:
alloy: Zr51Al14.2Ni15.9Cu18.9 (at %), research alloy, not Vitreloy
heating_rate: 30 K/min (table caption)
method: Thermal analysis value in a research paper table
status: ground
source: pmc-zr-bmg-series
where: Section 2.1, Table 1, row Zr51Al14.2Ni15.9Cu18.9, Tg column
corrosion:
- environment: Uncoated ribbon in ordinary air (2714A)
headline: Metglas lists excellent corrosion resistance for 2714A
effect: The bulletin lists excellent corrosion resistance among the benefits. No corrosion rate, humidity or salt-spray test is printed in the bulletin.
rating: low
conditions:
grade: Metglas 2714A
exposure: not stated
basis: manufacturer statement, no test data
source: metglas-2714a-bulletin
where: Benefits list, first page
- environment: Ordinary air (2605SA1 ribbon)
headline: No corrosion data was read for 2605SA1
effect: The 2605SA1 datasheets give no corrosion statement or test result, so the rating is unknown until a source is read.
rating: unknown
conditions:
grade: Metglas 2605SA1
exposure: not stated
source: metglas-2605sa1-datasheet
where: Whole datasheet read, no corrosion section
- environment: Brazed stainless steel joints (MBF20 foil)
headline: Metglas claims corrosion resistance for brazed joints
effect: The page claims high strength and corrosion resistance for the joints. No test data is printed on the page.
rating: unknown
conditions:
grade: MBF20
exposure: not stated
basis: vendor claim, no test data
source: metglas-brazing-foil-page
where: Application and joining claims, vendor claims paragraph
risks:
hazards:
- text: PubChem notifier list for nickel gives H317, H351 and H372. Nickel is the balance of the MBF20 foil. These classes are for nickel metal, not for the foil.
ghs:
- H317
- H351
- H372
source: pubchem-ni
where: GHS Hazard Statements section, PubChem record for CID 935
- text: PubChem notifier list for cobalt gives H317, H334 and H350 among its codes. These classes are for cobalt metal, not for the 2714A ribbon, which has a nominal Co66 composition in the Yang abstract.
ghs:
- H317
- H334
- H350
source: pubchem-co
where: GHS Hazard Statements section, PubChem record for CID 104730
failure_risks:
- mode: Crystallisation on overheating
trigger: Heating near the printed crystallisation temperature
consequence: Metglas prints a crystallisation temperature of 510 °C for 2605SA1 and 550 °C for 2714A. The values in this profile apply only to the glassy state.
severity: high
source: metglas-2605sa1-datasheet
where: Physical table, Crystallization Temperature column (2714A in its bulletin, Physical Properties)
- mode: Use above the 2714A service limit
trigger: Continuous use above 90 °C
consequence: Metglas prints 90 °C as the continuous service temperature for 2714A. The bulletin gives no figure for longer or peak exposures.
severity: moderate
source: metglas-2714a-bulletin
where: Physical Properties, Continuous Service Temp. (°C)
- mode: Crystallisation in a thick casting
trigger: Cooling slower than the critical cooling rate
consequence: Greer slides give a critical cooling rate of about 1 K/s for bulk metallic glasses, so a thick section can crystallise.
severity: moderate
source: greer-lecture-2012
where: Slide Bulk Metallic Glasses, bullet on critical cooling rate
side_effects:
- text: At 7.59 g/cm3 for 2714A and 7.18 g/cm3 for 2605SA1, a core or foil adds mass.
affects: Mass of a core or foil
source: metglas-2714a-bulletin
where: Physical Properties, Density (g/cm3)
handling:
- text: Anneal 2605SA1 at 370 °C for 2 hours in a magnetic field of 2400 A/m along the ribbon long axis, to release stress and induce magnetic anisotropy, as the datasheet directs.
source: metglas-2605sa1-datasheet
where: 4. Typical Magnetic Properties, heat treatment paragraph
- text: NETL's core is impregnated with 100 % solids epoxy after winding.
source: netl-2605sa1-core
where: Table 2, Characteristics, row Impregnation
- text: Metglas says the MBF20 foil can be stamped or cut into preforms and has unlimited shelf life.
source: metglas-brazing-foil-page
where: Foil form paragraph
mitigations:
- text: Anneal 2605SA1 in the field the datasheet specifies, and keep the core well below its 510 °C crystallisation temperature.
source: metglas-2605sa1-datasheet
where: 4. Typical Magnetic Properties, heat treatment paragraph and Physical table
uses:
- application: electronics-and-chips
device: Tape-wound power transformer cores
example: DOE NETL built a 2605-SA1 tape-wound core, 180 by 240 by 30 mm, with a mass of 5.95 kg after impregnation.
source: netl-2605sa1-core
where: Table 1 core dimensions; Table 2 mass after impregnation
- application: electronics-and-chips
device: Switch-mode and high sensitivity transformers, and current transformers
example: Metglas lists 2714A for switch-mode power supplies, high frequency transformers and ultra-sensitive current transformers.
source: metglas-2714a-bulletin
where: Applications list, first page
- application: thermal-control
device: Brazing foil for stainless steel and superalloy joints
example: Metglas lists heat exchangers, aerospace parts and metallic catalytic substrates as MBF20 applications. These are vendor claims with no test data on the page.
source: metglas-brazing-foil-page
where: Application and joining claims, applications paragraph
- application: mechanisms
device: Bulk metallic glass flexspline gears for heater-free gearboxes
example: NASA says its BMGG project has gearboxes running at surface temperatures of -173 °C (-280 °F) for heater-free designs. NTRS names the Europa Lander as the target cryogenic application.
source: nasa-bmgg-page
where: Project description paragraph
supply:
- subject: Cobalt (main element of Metglas 2714A)
producers:
- country: Congo (Kinshasa)
share_percent: 73
year: 2025
- country: Indonesia
share_percent: 14
year: 2025
critical_lists: []
recycling: 'USGS: cobalt content of purchased scrap represented 25% of estimated cobalt consumption in 2025.'
substitutes:
- 'USGS: substitution for cobalt could cause a loss in product performance or increased cost, depending on the application; nickel-iron alloys are listed as potential substitutes in some magnets.'
source: usgs-mcs2026-cobalt
where: Events, Trends, and Issues paragraph (Congo 73 %, Indonesia 14 % of world mined cobalt, 2025); Recycling and Substitutes paragraphs
- subject: Nickel (balance of MBF20 brazing foil)
producers:
- country: Indonesia
share_percent: 66.7
year: 2025
- country: Philippines
share_percent: 6.9
year: 2025
- country: Russia
share_percent: 5.1
year: 2025
critical_lists: []
recycling: 'USGS: in 2025 nickel recovered from scrap accounted for approximately 60% of apparent consumption, and most recycled nickel was used to produce new alloys and stainless steel.'
substitutes: []
source: usgs-mcs2026-nickel
where: 'World Mine Production and Reserves table, 2025e column, metric tons of nickel content: Indonesia 2,600,000; Philippines 270,000; Russia 200,000; world total (rounded) 3,900,000. Shares calculated by Space Mushroom from these figures. Recycling paragraph.'
documents:
- title: Metglas Amorphous transformer cores, Metglas 2605SA1 and 2605HB1M datasheet (29 April 2011)
type: datasheet
url: https://metglas.com/wp-content/uploads/2021/06/2605SA1-Magnetic-Alloy-Updated.pdf
year: 2011
- title: Metglas Magnetic Alloy 2714A (cobalt-based) Technical Bulletin
type: datasheet
url: https://metglas.com/wp-content/uploads/2016/12/2714A-Technical-Bulletin.pdf
year: 2011
- title: Metglas, Metal joining brazing foil product page with grades table
type: datasheet
url: https://metglas.com/metal-joining-brazing-foil/
- title: DOE NETL, METGLAS 2605-SA1 core datasheet (June 2018)
type: report
url: https://netl.doe.gov/projects/files/METGLAS2605SA1core_060118.pdf
year: 2018
- title: Yang et al., Soft Magnetic Properties of Annealed Co-Based Amorphous Co66Fe4Ni1B15Si14 Alloy Ribbon
type: paper
url: https://koreascience.or.kr/article/JAKO199711920253955.page?lang=en
year: 1997
- title: A. L. Greer, Bulk metallic glasses, lecture 1 slides (January 2012)
type: report
url: https://www.icts.res.in/sites/default/files/1267685796Lindsay-Greer-Jan12-Lecture1.pdf
year: 2012
- title: A series of Zr-based bulk metallic glasses with room temperature plasticity (Section 2.1, Table 1)
type: paper
url: https://pmc.ncbi.nlm.nih.gov/articles/PMC5456836/
- title: Hales and Stegall, Qualifying Bulk Metallic Glass Gear Materials for Spacecraft Applications, NASA/TP-2018-220246
type: report
url: https://ntrs.nasa.gov/citations/20190001052
year: 2018
- title: NASA, Bulk Metallic Glass Gear (BMGG) project page
type: report
url: https://www.nasa.gov/?p=96234
- title: 'USGS Mineral Commodity Summaries 2026: Cobalt'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Nickel'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
year: 2026
- title: PubChem compound record for nickel (CID 935), GHS classification
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/Nickel
- title: PubChem compound record for cobalt (CID 104730), GHS classification
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/Cobalt
- title: Wikipedia, Metallic glass
type: report
url: https://en.wikipedia.org/wiki/Metallic_glass
gaps:
- Vitreloy density, Young's modulus, shear and bulk moduli, Tg and Tx were not read on any page in this run. The only Vitreloy values in the search results came from a Caltech thesis, which the host refused to serve (connection refused), and from a Springer abstract that redirected to a login page, so none is entered.
- The nominal Vitreloy 1 composition (Zr41.2 Ti13.8 Cu12.5 Ni10 Be22.5 at %) was seen only in a patent search snippet and is not entered. The Greer slides name the family only as Zr-Ti-Ni-Cu-Be.
- No Vitreloy hardness value was found. The Greer strength values are from a stress-strain plot under 0.1 MPa and 450 MPa hydrostatic pressure, and are not a datasheet minimum.
- No corrosion rate, salt-spray, humidity or long-term ageing data was found for 2605SA1 or 2714A. The only statement is the Metglas bulletin claim of excellent corrosion resistance for 2714A (rated low on that basis only).
- The Metglas brazing grades table was read as printed. The element assignments come from column order in the extracted page text, so the MBF20 composition should be checked against the full MBF20 datasheet before use.
- MBF20 solidus and liquidus are in wt %; no atomic composition is given for any brazing foil. The ASM Alloy Digest entries for MBF-80 and MBF-20 are paywalled and were not read beyond the abstract.
- 'Property names not in spores/property-canon.yaml (short snake_case names used): hardness_vickers, saturation_induction, permeability_dc_max, crystallization_temperature, magnetostriction, lamination_factor, induction_60hz_80am, core_loss.'
- Iron, silicon, boron, zirconium and beryllium supply shares were not read, and no supplier shares are given. NASA NTRS names Materion as the producer of re-melt stock and Visser Precision Cast as the maker of bulk metallic glass castings for gears, with no shares.
- Critical-mineral lists for cobalt and nickel were not checked against the final 2025 list, so critical_lists is empty for both.
- The nickel and cobalt hazard codes are PubChem aggregated notifier lists for the metals, not classifications of the alloys. The 2714A composition Co66 Fe4 Ni1 B15 Si14 is from the Yang abstract, whose units are not printed in the abstract.
- The NASA BMGG page gives -173 °C (-280 °F) as the surface operating temperature for gearboxes. The gear alloy is not named in the sources read, so this value is not attributed to Vitreloy.
- Radiation, outgassing, cold welding and thermal cycling behaviour of these ribbons and foils were not looked up. No flight record was found for any of these grades.
- The Metglas 2605SA1 ribbon and core values are typical or not guaranteed, as the datasheet says. Corrosion and long-term ageing values are missing.
- The Metglas 2605SA1 datasheet gives the anneal of 370 °C for 2 hours in a magnetic field of 2400 A/m. That is the only anneal read, and it is not checked against a second source.
- The Zr51Al14.2Ni15.9Cu18.9 values are from a research paper and describe a different alloy from Vitreloy. They are shown only to bracket the Zr-based family.
sources:
metglas-2605sa1-datasheet:
title: Metglas Amorphous Alloys for Transformer Cores, 2605SA1 and 2605HB1M datasheet (29 April 2011)
url: https://metglas.com/wp-content/uploads/2021/06/2605SA1-Magnetic-Alloy-Updated.pdf
kind: datasheet
license: Manufacturer data sheet (cited, not reproduced)
metglas-2714a-bulletin:
title: Metglas Magnetic Alloy 2714A (cobalt-based) Technical Bulletin
url: https://metglas.com/wp-content/uploads/2016/12/2714A-Technical-Bulletin.pdf
kind: datasheet
license: Manufacturer data sheet (cited, not reproduced)
metglas-brazing-foil-page:
title: Metglas, Metal joining brazing foil product page
url: https://metglas.com/metal-joining-brazing-foil/
kind: web
license: Manufacturer web page (cited, not reproduced)
netl-2605sa1-core:
title: DOE NETL, METGLAS 2605-SA1 core datasheet (June 2018)
url: https://netl.doe.gov/projects/files/METGLAS2605SA1core_060118.pdf
kind: report
license: US Government report (public)
yang-co-ribbon-1997:
title: Yang et al., Soft Magnetic Properties of Annealed Co-Based Amorphous Co66Fe4Ni1B15Si14 Alloy Ribbon
url: https://koreascience.or.kr/article/JAKO199711920253955.page?lang=en
kind: paper
license: KoreaScience abstract (cited, not reproduced)
greer-lecture-2012:
title: Lindsay Greer, Bulk metallic glasses, lecture 1 slides (January 2012)
url: https://www.icts.res.in/sites/default/files/1267685796Lindsay-Greer-Jan12-Lecture1.pdf
kind: report
license: Lecture slides (cited, not reproduced)
pmc-zr-bmg-series:
title: A series of Zr-based bulk metallic glasses with room temperature plasticity
url: https://pmc.ncbi.nlm.nih.gov/articles/PMC5456836/
kind: paper
license: PMC open access (cited, not reproduced)
nasa-ntrs-bmg-gear-2018:
title: Hales and Stegall, Qualifying Bulk Metallic Glass Gear Materials for Spacecraft Applications, NASA/TP-2018-220246
url: https://ntrs.nasa.gov/citations/20190001052
id: NASA/TP-2018-220246
kind: report
license: NASA public (cited, not reproduced)
nasa-bmgg-page:
title: NASA, Bulk Metallic Glass Gear (BMGG) project page
url: https://www.nasa.gov/?p=96234
kind: report
license: NASA public (cited, not reproduced)
usgs-mcs2026-cobalt:
title: 'USGS Mineral Commodity Summaries 2026: Cobalt'
id: USGS MCS 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf
year: 2026
kind: report
license: Public domain (USGS)
usgs-mcs2026-nickel:
title: 'USGS Mineral Commodity Summaries 2026: Nickel'
id: USGS MCS 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
year: 2026
kind: report
license: Public domain (USGS)
pubchem-ni:
title: 'PubChem compound record: Nickel (CID 935), GHS classification'
id: CID 935
url: https://pubchem.ncbi.nlm.nih.gov/compound/Nickel
kind: database
license: PubChem (NCBI), public domain; sections attributed to ECHA and notifiers
pubchem-co:
title: 'PubChem compound record: Cobalt (CID 104730), GHS classification'
id: CID 104730
url: https://pubchem.ncbi.nlm.nih.gov/compound/Cobalt
kind: database
license: PubChem (NCBI), public domain; sections attributed to ECHA and notifiers
wikipedia-metallic-glass:
title: 'Wikipedia: Metallic glass'
url: https://en.wikipedia.org/wiki/Metallic_glass
kind: report
license: CC BY-SA (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-26'
review:
status: draft
method: assistant
checked_values: 32
unreachable: 2
caveats: 4
note: 'Values were read by an AI assistant on 2026-10-26 from the datasheets, web pages, reports and papers named in each entry. Two sources were unreachable in this run (a Caltech thesis returned connection refused and a Springer abstract redirected to a login page), so no Vitreloy density or modulus is entered. Caveats: the Metglas values are typical or not guaranteed; the Vitreloy strength is from a lecture slide and a different stress state; the Zr-Al-Ni-Cu row is a research alloy, not Vitreloy; hazard codes are for the metals.'
story:
risk_groups:
- title: For people
lead: The hazard codes in the sources are for the pure metals in the alloys. No classification of the ribbons or foils themselves was found.
level: 1
verdict: Metal hazard codes only
points:
- label: Nickel as a substance
line: PubChem notifier list for nickel gives H317 (allergic skin reaction, 100 % of notifications), H351 (suspected cancer, 100 %) and H372 (organ damage from repeated exposure, 100 %).
- label: Cobalt as a substance
line: PubChem notifier list for cobalt gives H317 (allergic skin reaction), H334 (allergy or asthma symptoms if inhaled) and H350 (may cause cancer) among its codes, with H317 and H334 the most widely notified.
- label: Alloy as handled
line: No health classification of the alloy ribbons or the MBF20 foil was found in the sources read.
- title: If it fails
lead: The failure routes in the sources are thermal. None of them is a flight result for these grades.
points:
- label: Overheating
line: Both ribbons crystallise at a printed temperature, 510 °C for 2605SA1 and 550 °C for 2714A. The 2714A datasheet prints 90 °C as its continuous service limit.
- label: Heavy parts
line: At 7.59 g/cm3 for 2714A and 7.18 g/cm3 for 2605SA1 the ribbon adds mass. No Vitreloy density was read, so no mass figure is given for the Zr-based family.
- title: Handling and storage
points:
- label: Anneal first
line: The 2605SA1 datasheet anneals at 370 °C for 2 hours in a magnetic field of 2400 A/m to set the magnetic axis. Use the same anneal for the stress release the datasheet names.
- label: Keep the foil clean
line: Metglas describes the MBF20 foil as contaminant-free with no organic binders, and states unlimited shelf life.
why: Metallic glasses are used where a magnetic core must lose little energy, or where a brazing foil must be ductile and stampable. The 2605SA1 datasheet gives core loss of at most 0.17 W/kg at 60 Hz and 1.3 T. Wikipedia credits Klement, Willens and Duwez at Caltech with the first reported metallic glass, Au75Si25, and says that the low magnetisation loss is used in high efficiency transformers at line frequency.
uses:
- where: Tape-wound power transformer cores
line: DOE NETL built a 2605-SA1 tape-wound core of 180 by 240 by 30 mm with a mass of 5.95 kg after impregnation, and lists transformers, pulse power cores, motors and high frequency inductors as applications.
- where: High sensitivity and switch-mode transformers
line: Metglas lists 2714A for switch-mode power supplies, high frequency transformers, ultra-sensitive current transformers, shielding and sensors.
- where: Brazing foil for stainless steel and superalloys
line: Metglas says MBF20 replaces copper foil or nickel powder for brazing stainless steel, and lists aerospace, heat exchangers, catalytic substrates and preforms as uses. These are vendor claims with no test data on the page.
- where: Cryogenic bulk metallic glass gears
line: NASA says its BMGG project has gearboxes running at surface temperatures of -173 °C (-280 °F) for heater-free designs for missions such as a Europa Lander.
recipe:
line: Metglas 2605SA1 is an iron-based amorphous ribbon of nominal Fe80 Si9 B11 at %, supplied as 25 ± 4 µm foil (datasheet, DOE NETL). Metglas 2714A is cobalt-based, nominal Co66 Fe4 Ni1 B15 Si14 (Yang abstract). MBF20 is a nickel-based brazing foil, nominal Cr 7.0, Fe 3.0, Si 4.5, B 3.2 wt %, C max 0.06 wt %, balance Ni (Metglas page). Wikipedia describes melt spinning as sputtering molten metal onto a spinning metal disk.
parts:
- name: Iron
symbol: Fe
share_percent: 80
share_note: nominal, 80 at % in 2605SA1
role: Main element of the iron-based ribbon
source: netl-2605sa1-core
where: 'Table 2, Characteristics, row Chemistry: Fe80 Si9 B11 at %'
- name: Silicon
symbol: Si
share_percent: 9
share_note: nominal, 9 at % in 2605SA1
role: Minor element, described by DOE as present in small percentages
source: netl-2605sa1-core
where: 'Table 2, Characteristics, row Chemistry: Fe80 Si9 B11 at %'
- name: Boron
symbol: B
share_percent: 11
share_note: nominal, 11 at % in 2605SA1
role: Minor element, described by DOE as present in small percentages
source: netl-2605sa1-core
where: 'Table 2, Characteristics, row Chemistry: Fe80 Si9 B11 at %'
can_do:
- label: Carry flux with low loss
value: 0.17 W/kg core loss
benchmark: core_loss
line: At 60 Hz and 1.3 T the 2605SA1 specification allows at most 0.17 W/kg, measured to ASTM A 932 (Metglas datasheet).
- label: Saturate at high field
value: 1.56 T
benchmark: saturation_induction
line: The 2605SA1 saturation induction is 1.56 T, and the 2714A value is 0.57 T (both Metglas datasheets).
- label: Join stainless steel
value: 969 to 1024 °C
benchmark: melting_point
line: MBF20 melts between its solidus of 969 °C and liquidus of 1024 °C (Metglas page), a range suited to brazing stainless steel.
- label: Strength of the Zr-based glass
value: 1986 MPa
benchmark: yield_strength
line: A lecture slide gives 1986 MPa yield or fracture strength for Vitreloy in tension under 0.1 MPa hydrostatic pressure (Greer).
compare: These three families are not interchangeable. The iron-based 2605SA1 has the highest saturation induction of the ribbons read here at 1.56 T, the cobalt-based 2714A has the lowest at 0.57 T but a much higher maximum DC permeability of up to 1,000,000 when annealed (Metglas bulletin), and it is 7.59 g/cm3 and has a continuous service limit of 90 °C. The nickel-based MBF20 is a brazing foil and has no magnetic data in this profile. The zirconium-based Vitreloy family has a yield strength of 1986 MPa in one lecture figure, which is much higher than the Metglas ribbons, but no density or modulus for it was found in this run. The Curie temperatures printed for the ribbons are 395 °C for 2605SA1 and 225 °C for 2714A.
compare_rows:
- label: Density
benchmark: density
- label: Saturation induction
benchmark: saturation_induction
- label: Curie temperature
benchmark: curie_temperature
handling:
- Anneal the 2605SA1 ribbon at 370 °C for 2 hours in a magnetic field of 2400 A/m along the ribbon axis, as the datasheet directs.
- Keep the 2714A ribbon below its 90 °C continuous service temperature, and avoid holding it near its 550 °C crystallisation temperature.
- Keep the MBF20 foil free of contamination, and stamp or cut it into preforms as the page describes.
good_for:
- Low-loss transformer and switch-mode power cores, with 2605SA1 core loss of at most 0.17 W/kg at 60 Hz and 1.3 T.
- High-permeability sensors and current transformers using 2714A, with maximum DC permeability of up to 1,000,000 when annealed.
- Brazing stainless steel and superalloys with the MBF20 foil, a ductile foil that can be bent 180 degrees (Metglas page).
watch_out:
- 'Heat limit: 2714A has a continuous service temperature of 90 °C, and both ribbons crystallise at 510 to 550 °C.'
- 'Vitreloy values: only a yield strength (1986 MPa) was read, and its density and modulus were not found in this run.'
- No corrosion or ageing test data for the ribbons were read; the Metglas corrosion claim for 2714A is a manufacturer statement.
- The NASA gear alloy is not named in the sources, so the -173 °C gearbox figure cannot be assigned to a specific composition.
verdict: Metallic glasses are soft magnetic ribbons and brazing foils that trade a disordered structure for low core loss and easy shaping. The iron-based 2605SA1 is a transformer core with a saturation induction of 1.56 T, the cobalt-based 2714A is a high permeability sensor ribbon limited to 90 °C service, and the MBF20 foil brazes steel at about 1000 °C. The Zr-based Vitreloy family is included for its strength only, and its density and modulus were not verified in this run.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.