spore: profile
id: silver-alloys
spore_version: 0.2
family: precious-metals
name: Silver alloys (brazing, silver-gold and contact alloys)
abbreviation: Ag alloys
role: brazing filler / conductor / electrical contact
category: metals
type: precious-metals
summary: |
  A family profile for silver-rich alloys. The main grade read in this run is BAg-8, the 72 Ag / 28 Cu eutectic brazing alloy, which melts at 780 degC (solidus and liquidus) and is used for vacuum and furnace brazing of aero-engine and fuel-line parts. A Morgan (Wesgo) data sheet gives a density of 10.0 Mg/m3, a thermal conductivity of 371 W/m K (calculated), a 0.2 percent yield strength of 272 MPa and a resistivity of 20.4 x10-9 ohm m. Silver-gold alloys AgAu 0.2 to AgAu 10 are listed by Heimerle + Meule with densities of 10.5 to 10.9 g/cm3 and melting ranges of 960 to 975 degC. Silver-antimony, silver-zirconium-copper and silver-palladium contact alloys are covered only as gaps: no datasheet for their properties was read in this run.
best_for: Silver brazing of copper, nickel and steel at about 780 degC (BAg-8 eutectic, 72 Ag and 28 Cu)
weakest_at: Tarnish in sulphur-bearing air and atomic-oxygen exposure in orbit; no sourced rate for any of these alloys was read in this run
identity:
  formula: 'Silver-rich alloys: Ag-28 wt% Cu eutectic (BAg-8), silver-gold alloys AgAu 0.2 to AgAu 10, Ag-1 wt% Sb (Ag99/Sb1), Ag-Cu-Zr active-braze compositions and Ag-Pd contact grades'
  composition: 'BAg-8: Ag 72 wt%, Cu 28 wt%. AgAu 0.2 to AgAu 10: gold content not printed in the extracted datasheet text. Ag99/Sb1: Ag 99 wt%, Sb 1 wt%.'
  source: morgan-cusil
  where: Description and Physical Properties sections of the Cusil (BAg-8) data sheet; composition line of the Goodfellow Ag99/Sb1 page
tags:
  environments: []
  stresses: []
  applications:
    - propulsion-and-tanks
    - in-space-manufacturing
    - electronics-and-chips
properties:
  - benchmark: melting_point
    label: Solidus and liquidus of BAg-8 (72 Ag, 28 Cu)
    value: 780
    unit: degC
    scope: material
    conditions:
      alloy: BAg-8, 72 wt% Ag and 28 wt% Cu
      basis: eutectic, solidus equal to liquidus as printed
    method: Printed as both liquidus and solidus in the Physical Properties table; the data sheet calls its values indicative only
    status: ground
    note: Aimtek S72 data sheet prints 779 degC for solidus and liquidus of the same nominal composition (1435 degF); the two sources differ by 1 degC.
    source: morgan-cusil
    where: Physical Properties table, Liquidus Temperature and Solidus Temperature rows
  - benchmark: density
    label: Density of BAg-8 (Cusil)
    value: 10
    unit: Mg/m3
    scope: material
    conditions:
      alloy: BAg-8, 72 wt% Ag and 28 wt% Cu
      temperature: not stated
    method: Printed in the Physical Properties table of the data sheet as 10.0 Mg/m3 (0.361 lb/in3)
    status: ground
    source: morgan-cusil
    where: Physical Properties table, Density row
  - benchmark: thermal_conductivity
    label: Thermal conductivity of BAg-8 (calculated)
    value: 371
    unit: W/m K
    scope: material
    conditions:
      alloy: BAg-8, 72 wt% Ag and 28 wt% Cu
      temperature: not stated
    method: Printed as calculated by the supplier, not measured
    status: calculated
    source: morgan-cusil
    where: Physical Properties table, Thermal Conductivity (Calculated) row
  - benchmark: cte
    label: Coefficient of thermal expansion of BAg-8
    value: 19.6
    unit: x10-6 per degC
    scope: material
    conditions:
      temperature_range: 20 to 850 degC
      alloy: BAg-8, 72 wt% Ag and 28 wt% Cu
    method: Printed as 19.6 x 10-6 per degC for 20 to 850 degC (also 10.9 x 10-6 per degF for 68 to 1562 degF)
    status: ground
    source: morgan-cusil
    where: Physical Properties table, Coefficient of Thermal Expansion row
  - benchmark: yield_strength
    label: 0.2 percent offset yield strength of BAg-8
    value: 272
    unit: MPa
    scope: material
    conditions:
      test: 0.2 percent offset
      temper: not stated on the data sheet
      form: test pieces, not specified
    method: Printed in the Physical Properties table; the data sheet says all values are indicative and based on test pieces
    status: ground
    source: morgan-cusil
    where: Physical Properties table, Yield Strength (0.2% offset) row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of BAg-8
    value: 372
    unit: MPa
    scope: material
    conditions:
      temper: not stated on the data sheet
      form: test pieces, not specified
    method: Printed in the Physical Properties table
    status: ground
    source: morgan-cusil
    where: Physical Properties table, Tensile Strength row
  - benchmark: elongation
    label: Elongation of BAg-8
    value: 19
    unit: '%'
    scope: material
    conditions:
      gage: 2 in (50 mm) gage section
      temper: not stated on the data sheet
    method: Printed in the Physical Properties table
    status: ground
    source: morgan-cusil
    where: Physical Properties table, Elongation row
  - benchmark: electrical_resistivity
    label: Electrical resistivity of BAg-8
    value: 20.4
    unit: x10-9 ohm m
    scope: material
    conditions:
      alloy: BAg-8, 72 wt% Ag and 28 wt% Cu
      temperature: not stated
    method: Printed as 20.4 x 10-9 ohm m in the Physical Properties table, which equals 2.04 microohm cm; the conversion is not applied in this file
    status: ground
    source: morgan-cusil
    where: Physical Properties table, Electrical Resistivity row
  - benchmark: melting_point
    label: Melting range of silver-gold alloys AgAu 0.2 to AgAu 10
    value: 960
    value_high: 975
    bound: range
    unit: degC
    scope: material
    conditions:
      alloys: AgAu 0.2 (lowest) to AgAu 10 (highest), as listed in the table
      basis: printed as melting range per alloy
    method: Row values of the German silver-gold table, read from the printed PDF text
    status: ground
    source: heimerle-agau
    where: Table Silber-Gold-Legierungen, Schmelzintervall (melting range) column, rows AgAu 0,2 to AgAu 10
  - benchmark: density
    label: Density of silver-gold alloys AgAu 0.2 to AgAu 10
    value: 10.5
    value_high: 10.9
    bound: range
    unit: g/cm3
    scope: material
    conditions:
      alloys: AgAu 0.2 to AgAu 10
      temperature: not stated
    method: Row values of the German silver-gold table
    status: ground
    source: heimerle-agau
    where: Table Silber-Gold-Legierungen, Dichte (density) column, rows AgAu 0,2 to AgAu 10
  - benchmark: elastic_modulus
    label: Modulus of elasticity of soft silver-gold alloys
    value: 80
    value_high: 85
    bound: range
    unit: GPa
    scope: material
    conditions:
      temper: soft
      alloys: AgAu 0.2 to AgAu 10
    method: Row values of the German silver-gold table, soft column
    status: ground
    source: heimerle-agau
    where: Table Silber-Gold-Legierungen, Elastizitaetsmodul (modulus of elasticity) column
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of soft silver-gold alloys
    value: 200
    value_high: 220
    bound: range
    unit: MPa
    scope: material
    conditions:
      temper: soft
      alloys: AgAu 0.2 to AgAu 10
    method: Row values of the German silver-gold table, soft column; the table gives a tolerance of plus or minus 30 MPa that is not entered
    status: ground
    source: heimerle-agau
    where: Table Silber-Gold-Legierungen, Zugfestigkeit (tensile strength) soft column
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of hard silver-gold alloys
    value: 380
    value_high: 440
    bound: range
    unit: MPa
    scope: material
    conditions:
      temper: hard
      alloys: AgAu 0.2 to AgAu 10
    method: Row values of the German silver-gold table, hard column; the table gives a tolerance of plus or minus 30 MPa that is not entered
    status: ground
    source: heimerle-agau
    where: Table Silber-Gold-Legierungen, Zugfestigkeit (tensile strength) hard column
corrosion:
  - environment: Sulphur-bearing air (tarnish)
    headline: No tarnish rate for any silver alloy in this family was read in this run.
    effect: The Cusil, Aimtek and Heimerle + Meule data sheets give no corrosion, tarnish or sulphidation data. No sulphur test or rate for BAg-8, silver-gold, silver-antimony, silver-zirconium-copper or silver-palladium alloys was entered.
    rating: unknown
    conditions:
      basis: absence of data in the three datasheets read in this run
    source: morgan-cusil
    where: Whole data sheet (no corrosion section)
  - environment: Low Earth orbit, silver-backed second-surface mirror (vapour-deposited silver under FEP, not an alloy)
    headline: After almost six years in low Earth orbit the silvered FEP mirror changed from a specular to a diffuse reflector.
    effect: The NASA LDEF analysis reports that after almost six years of exposure the silvered FEP second-surface mirror changed from a specular reflector to a diffuse one, by surface roughening that depended on atomic-oxygen fluence. The silver layer is about 1600 A of vapour-deposited silver behind the FEP film. The report does not give an erosion rate for a silver alloy.
    rating: unknown
    conditions:
      exposure: about six years in low Earth orbit on LDEF
      material: silvered FEP Teflon thermal blanket, pure silver backing
      basis: reported appearance change, not a silver-alloy erosion yield
    source: nasa-ldef-silvered-fep
    where: Abstract and summary of the analysis; silver backing description in the Introduction
risks:
  hazards:
    - text: NIOSH REL and current OSHA PEL are both 0.01 mg/m3 as an 8-hour TWA for silver metal dust and soluble compounds (as Ag); the NIOSH IDLH is 10 mg Ag/m3, based on acute oral toxicity data in humans with no inhalation data.
      ghs: []
      source: cdc-niosh-idlh
      where: Chemical data block (REL and PEL) and Revised IDLH section
    - text: No GHS classification for any alloy in this family was read in this run. The PubChem silver record was blocked by a reCAPTCHA page, so its hazard codes are not entered.
      ghs: []
      source: morgan-cusil
      where: Not in the data sheet; gap recorded in gaps
  failure_risks: []
  side_effects: []
  handling:
    - text: 'Cusil data sheet: braze under a vacuum of 10-5 mm Hg, in hydrogen, or in an inert gas. Impurity limits are Zn below 0.001 percent, Cd below 0.001 percent, Pb below 0.002 percent, P below 0.002 percent and C below 0.01 percent.'
      source: morgan-cusil
      where: Recommended Brazing Atmospheres row and Impurity Limits box
    - text: Dust from silver metal is limited to 0.01 mg/m3 (as Ag) in air; keep dust and fume below that level in workplace air.
      source: cdc-niosh-idlh
      where: Chemical data block
  mitigations: []
uses:
  - application: propulsion-and-tanks
    device: Brazed joints in aero-engines and aerospace fuel-line assemblies (BAg-8 Cusil)
    example: Morgan Advanced Materials lists the Cusil BAg-8 alloy for aero-engine work (OEM and repair), aerospace fuel-line assemblies, vacuum tubes, waveguide and klystron assemblies, and power supply surge arrestors.
    source: morgan-cusil
    where: Typical Applications box
  - application: in-space-manufacturing
    device: Silver-copper-lithium braze in the Skylab M-552 brazing experiment (related braze, not BAg-8)
    example: In 1974 NASA's Skylab M-552 brazed a nickel ferrule to a nickel tube with Lithobraze BT, a braze of 71.8 percent Ag, 28 percent Cu and 0.2 percent Li, in near-zero gravity. The Oak Ridge tracer study traced the braze flow with a silver-110 isotope.
    source: nasa-skylab-m552
    where: Abstract and Introduction, NASA CR-129035
  - application: electronics-and-chips
    device: Brazing of electrical components to copper and nickel (BAg-8 S72)
    example: Aimtek lists electrical components, copper and nickel as the common applications of its S72 silver braze, which has the nominal composition Ag 72 percent and Cu 28 percent.
    source: aimtek-s72
    where: Nominal Composition and Common Applications boxes
supply:
  - subject: Silver
    abundance: 'USGS: silver is primarily obtained as a byproduct from lead-zinc, copper and gold mines; polymetallic deposits account for more than two-thirds of US and world resources. World mine production was an estimated 26,000 tons in 2025 compared with 25,300 tons in 2024.'
    producers:
      - country: Mexico
        share_percent: 24.2
        year: 2025
      - country: Peru
        share_percent: 13.8
        year: 2025
      - country: China
        share_percent: 13.1
        year: 2025
      - country: Bolivia
        share_percent: 5.8
        year: 2025
      - country: Chile
        share_percent: 5.4
        year: 2025
    critical_lists:
      - list: USGS Final 2025 List of Critical Minerals (silver added; 90 FR 50494, 7 November 2025)
        listed: true
    recycling: 'USGS: about 1,000 tons of silver was recovered from new and old scrap in 2025, about 11 percent of apparent consumption. Brazing and solder took about 3 percent of US silver use in 2025, electrical and electronics 25 percent, and photovoltaics 15 percent.'
    substitutes:
      - 'USGS: aluminum and rhodium may be used to replace silver in some applications; stainless steel, tantalum and titanium may replace silver in some surgical pins and plates.'
    source: usgs-mcs2026-silver
    where: Mineral Commodity Summaries 2026, Silver chapter; World Mine Production and Reserves table (2025e, world total 26,000); shares calculated by Space Mushroom from that total; Recycling; Substitutes
  - subject: Copper
    abundance: Copper is the alloying metal in BAg-8 at 28 percent by weight. Its crust abundance was not read in this run.
    producers:
      - country: Chile
        share_percent: 23
        year: 2025
      - country: Congo (Kinshasa)
        share_percent: 13.9
        year: 2025
      - country: Peru
        share_percent: 11.7
        year: 2025
      - country: China
        share_percent: 7.8
        year: 2025
      - country: United States
        share_percent: 4.3
        year: 2025
    critical_lists:
      - list: USGS Final 2025 List of Critical Minerals (copper added; 90 FR 50494, 7 November 2025)
        listed: true
    recycling: 'USGS: about 30 percent of US copper supply came from scrap in 2025; brass and wire-rod mills accounted for about 80 percent of copper recovered from scrap.'
    substitutes: []
    source: usgs-mcs2026-copper
    where: Mineral Commodity Summaries 2026, Copper chapter; World Mine and Refinery Production table (2025e, world total 23,000 kt); shares calculated by Space Mushroom from that total; Recycling paragraph
media: []
documents:
  - title: 'Morgan Advanced Materials (Wesgo): Cusil (BAg-8) data sheet, 72 percent Ag, 28 percent Cu'
    type: datasheet
    url: https://morgantechnicalceramics.com/media/6940/wesgo_cusil_technical-data-sheet-2018.pdf
    year: 2018
  - title: AIMTEK Silver Braze Alloy S72 technical data sheet
    type: datasheet
    url: https://aimtek.com/wp-content/uploads/2019/08/Aimtek-Silver-Alloy-S72-Technical-Data-Sheet.pdf
    year: 2019
  - title: 'Heimerle + Meule: Silber-Gold-Legierungen (silver-gold alloys) data table, form dated 03.16'
    type: datasheet
    url: https://www.heimerle-meule.com/fileadmin/dateien-global/02_Products/Technik-Halbzeuge/Legierungen/Datenblaetter/Datenblatt_Silber-Gold-Legierungen.pdf
    year: 2016
  - title: 'USGS Mineral Commodity Summaries 2026: Silver'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silver.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Copper'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
  - title: CDC NIOSH IDLH entry for silver (metal dust and soluble compounds, as Ag)
    type: database
    url: https://www.cdc.gov/niosh/idlh/7440224.html
    year: 2026
  - title: 'NASA CR-129035: Radioisotope tracer studies in the NASA Skylab brazing experiment M-552 (Oak Ridge National Laboratory, September 1974)'
    type: report
    url: https://ntrs.nasa.gov/citations/19750002891
    year: 1974
  - title: 'NASA TM 104096 (December 1991): An Analysis of LDEF-Exposed Silvered FEP Teflon Thermal Blanket Material'
    type: report
    url: https://ntrs.nasa.gov/api/citations/19920005971/downloads/19920005971.pdf
    year: 1991
  - title: 'Goodfellow: Silver-antimony (Ag99/Sb1) wire material information'
    type: datasheet
    url: https://www.goodfellow.com/usa/resources/silver-antimony-ag99-sb1-wire-material-information/
    year: 2026
gaps:
  - 'Silver-antimony: the Goodfellow Ag99/Sb1 page prints the composition (99 percent Ag, 1 percent Sb) but no density, melting point, resistivity or hardness number. Its statements that antimony raises hardness and keeps conductivity are not numeric and are not entered.'
  - 'Silver-zirconium-copper (active braze): no datasheet was read. A research search result on rapidly quenched Ag-Cu-Zr ribbon was not opened, so no composition, melting range, wetting or joint-strength value is entered.'
  - 'Silver-palladium contacts: no manufacturer datasheet was read. MakeItFrom returned HTTP 403, and the mfgrobots and American Elements pages were search snippets only. No density, resistivity, tarnish or contact-life value is entered for Ag-Pd.'
  - 'Silver-gold: the table names the alloys AgAu 0.2 to AgAu 10, but the gold content it refers to is not printed in the extracted text. Electrum (about 20 to 80 percent gold) is not covered.'
  - Silver-gold electrical resistance (printed 0,0167 to 0,02 in the table, with a decimal comma) was left out because the value check could not match the printed form. Re-add it once the number format is handled.
  - 'Silver-gold: the table gives Vickers hardness and electrical conductivity in m/(Ohm mm2); these were not entered and the elongation of the silver-gold alloys was not read.'
  - BAg-8 electrical conductivity is printed as 49.0 x10^6 per ohm m but was not entered, because the resistivity row already covers it and the unit form would need conversion.
  - BAg-8 Vickers hardness and elastic modulus are not printed in the Cusil data sheet.
  - 'Tarnish and sulphidation: no sourced rate, sulphur test or atomic-oxygen erosion value for any silver alloy in this family was read in this run. The LDEF result is for a silver-backed FEP mirror, not an alloy.'
  - 'Hazards: the PubChem silver record (CID 23954) returned a reCAPTCHA page, so its GHS codes are not entered. Hazards rest on the NIOSH and OSHA exposure limits. No alloy safety data sheet was read.'
  - Failure modes (for example brazed-joint cracking, silver-copper eutectic effects or electromigration in contacts) were not sourced, so failure_risks is empty.
  - 'Designations: the Aimtek data sheet prints AWS A5.8 BAg-8 and BVAg-8. BVAg-8 is a vacuum-service grade and is left out; identity.designations is empty because this profile covers a family of grades, not one grade.'
  - 'Space data: no flight, thermal-vacuum or radiation result for BAg-8, silver-gold, silver-antimony, silver-zirconium-copper or silver-palladium alloys was read. The Skylab braze is a related Ag-Cu-Li alloy, not BAg-8.'
  - Supply shares for silver and copper are calculated from the USGS world totals by Space Mushroom. They are not printed in the USGS chapters.
  - Uses for silver-antimony, silver-zirconium-copper and silver-palladium were not sourced.
sources:
  morgan-cusil:
    title: Cusil (BAg-8) data sheet, Morgan Advanced Materials (Wesgo), 72 percent Ag and 28 percent Cu
    id: wesgo_cusil_technical-data-sheet-2018.pdf (copyright 06/2018)
    url: https://morgantechnicalceramics.com/media/6940/wesgo_cusil_technical-data-sheet-2018.pdf
    year: 2018
    kind: datasheet
    license: supplier data sheet, cited not reproduced
  aimtek-s72:
    title: AIMTEK Silver Braze Alloy S72 technical data sheet
    id: Aimtek-Silver-Alloy-S72-Technical-Data-Sheet.pdf
    url: https://aimtek.com/wp-content/uploads/2019/08/Aimtek-Silver-Alloy-S72-Technical-Data-Sheet.pdf
    year: 2019
    kind: datasheet
    license: supplier data sheet, cited not reproduced
  heimerle-agau:
    title: 'Heimerle + Meule: Silber-Gold-Legierungen (silver-gold alloys), German and English table'
    id: Datenblatt_Silber-Gold-Legierungen.pdf, form dated 03.16
    url: https://www.heimerle-meule.com/fileadmin/dateien-global/02_Products/Technik-Halbzeuge/Legierungen/Datenblaetter/Datenblatt_Silber-Gold-Legierungen.pdf
    year: 2016
    kind: datasheet
    license: supplier data table, cited not reproduced
  usgs-mcs2026-silver:
    title: 'Mineral Commodity Summaries 2026: Silver'
    id: U.S. Geological Survey, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silver.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-copper:
    title: 'Mineral Commodity Summaries 2026: Copper'
    id: U.S. Geological Survey, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  cdc-niosh-idlh:
    title: 'NIOSH IDLH entry: silver (metal dust and soluble compounds, as Ag)'
    id: CDC NIOSH IDLH 7440224
    url: https://www.cdc.gov/niosh/idlh/7440224.html
    year: 2026
    kind: database
    license: public domain (CDC)
  nasa-skylab-m552:
    title: Radioisotope tracer studies in the NASA Skylab exothermic brazing experiment M-552
    id: NASA CR-129035 (NTRS 19750002891), Oak Ridge National Laboratory, September 1974
    url: https://ntrs.nasa.gov/citations/19750002891
    year: 1974
    kind: report
    license: public domain (NASA)
  nasa-ldef-silvered-fep:
    title: An Analysis of LDEF-Exposed Silvered FEP Teflon Thermal Blanket Material
    id: NASA Technical Memorandum 104096 (NTRS 19920005971)
    url: https://ntrs.nasa.gov/api/citations/19920005971/downloads/19920005971.pdf
    year: 1991
    kind: report
    license: public domain (NASA)
  goodfellow-agsb:
    title: Silver/antimony (Ag99/Sb1) wire, material information (Goodfellow)
    id: Goodfellow Ag99/Sb1 wire, material information page
    url: https://www.goodfellow.com/usa/resources/silver-antimony-ag99-sb1-wire-material-information/
    year: 2026
    kind: datasheet
    license: supplier web page, cited not reproduced
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 13
  unreachable: 4
  caveats: 5
  note: 'Written by an AI assistant on 2026-10-26. Values are from the Cusil BAg-8 data sheet (Morgan), the Heimerle + Meule silver-gold table and USGS 2026 chapters, read in this run. The Aimtek S72 sheet prints 779 degC for the same BAg-8 composition, noted above. Unreachable or blocked in this run: PubChem silver (reCAPTCHA), OSHA chemical data (HTTP 403), MakeItFrom Ag-Pd (HTTP 403), Heritage Science sulphidation paper (not opened). Silver-antimony, silver-zirconium-copper and silver-palladium have no property values; see gaps.'
story:
  recipe:
    line: BAg-8 is a silver-copper eutectic with 72 percent silver and 28 percent copper by weight; its solidus and liquidus are both 780 degC as printed by the Cusil data sheet. Silver-gold alloys AgAu 0.2 to AgAu 10 are listed in one German table. Silver-antimony (Ag99/Sb1, 1 percent antimony) is listed by Goodfellow. Silver-zirconium-copper and silver-palladium compositions are not covered by a data sheet read in this run.
    parts:
      - name: Silver
        symbol: Ag
        share: 72 wt% in BAg-8
        role: The base metal of the brazing alloy. It gives the low melting point of the eutectic and a conductive, reflective surface in the other grades.
      - name: Copper
        symbol: Cu
        share: 28 wt% in BAg-8
        role: Forms the eutectic with silver at 780 degC. It is the hardening addition and the reason the alloy is stronger than fine silver; the Aimtek sheet calls it a Cu 28 percent alloy.
      - name: Antimony
        symbol: Sb
        share: 1 wt% in Ag99/Sb1
        role: Listed by Goodfellow as the alloying addition in its Ag99/Sb1 wire. The page does not print a number for the change it causes.
  risk_groups:
    - title: For people
      level: 1
      verdict: Exposure limit set for silver dust
      lead: No GHS classification for any alloy in this family was read in this run. The exposure limit for silver metal dust is the relevant control.
      points:
        - label: Dust
          line: NIOSH and OSHA both set 0.01 mg/m3 as an 8-hour TWA for silver metal dust and soluble compounds, as Ag.
        - label: Acute exposure
          line: NIOSH sets the IDLH at 10 mg Ag/m3, based on acute oral toxicity data in humans; no inhalation data were available for the IDLH.
    - title: If it fails
      lead: No failure record for these alloys was read in this run, so this group is left as a gap.
      points:
        - label: Gap
          line: The Skylab braze shows silver-copper-lithium brazing in space, but no braze failure data are sourced here.
    - title: Handling and storage
      points:
        - label: Brazing
          line: BAg-8 is brazed under vacuum at 10-5 mm Hg, in hydrogen or in an inert gas, according to the Cusil data sheet.
        - label: Impurities
          line: The Cusil data sheet caps Zn and Cd at 0.001 percent and Pb and P at 0.002 percent.
  why: 'Silver-rich alloys are used where a low melting point, good conduction and a known joining record matter. BAg-8 melts at 780 degC and is used for brazing copper, nickel and steel in aero-engines and fuel lines. Silver-gold alloys melt at 960 to 975 degC and have a density of 10.5 to 10.9 g/cm3. Space data for these alloys are thin: the Skylab braze used a related silver-copper-lithium alloy, and no flight result for BAg-8 was read.'
  uses:
    - where: Aerospace brazing
      line: Morgan's Cusil BAg-8 data sheet lists aero-engine repair, aerospace fuel-line assemblies, vacuum tubes and waveguide assemblies as typical uses.
    - where: Brazing in space
      line: NASA's Skylab M-552 experiment in 1974 brazed a nickel ferrule to a nickel tube with Lithobraze BT (71.8 percent Ag, 28 percent Cu, 0.2 percent Li) in near-zero gravity. The alloy is related to BAg-8, not the same grade.
  can_do:
    - label: Braze at low temperature
      benchmark: melting_point
      line: BAg-8 melts at 780 degC, both solidus and liquidus, so it can be used as a eutectic filler.
    - label: Carry a little load
      benchmark: yield_strength
      line: The Cusil data sheet prints a 0.2 percent yield strength of 272 MPa and a tensile strength of 372 MPa for test pieces.
    - label: Conduct heat and electricity
      benchmark: thermal_conductivity
      line: The supplier calculates a thermal conductivity of 371 W/m K for BAg-8 and prints a resistivity of 20.4 x10-9 ohm m.
  compare: No source in this record compares the silver alloys with each other or with other fillers under the same test, so no ranking is made. BAg-8 is a eutectic and is brazed at one temperature; the silver-gold alloys melt over a 15 degC range from 960 to 975 degC. The values come from one supplier each, so they should be checked against the supplier certificate for the form and temper.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Melting point or range
      benchmark: melting_point
    - label: Electrical resistivity
      benchmark: electrical_resistivity
  handling:
    - Braze BAg-8 under vacuum at 10-5 mm Hg, in hydrogen or in an inert gas, according to the Cusil data sheet.
    - Keep silver dust in workplace air below 0.01 mg/m3 as Ag, the NIOSH and OSHA limit.
    - Check the supplier certificate for impurity limits. The Cusil sheet caps cadmium at 0.001 percent.
  good_for:
    - Eutectic brazing filler for copper, nickel and steel at 780 degC. The Cusil sheet lists copper, nickel, Kovar and carbon steel as suggested base materials.
    - Silver-gold alloys where a melting range near 960 to 975 degC and a density of about 10.5 to 10.9 g/cm3 are needed.
  watch_out:
    - Tarnish. No sourced sulphur or tarnish rate was read for any silver alloy in this family.
    - Space data. No atomic-oxygen, outgassing or thermal-vacuum record for BAg-8 or the silver-gold alloys was read. The LDEF silver mirror result is for silver under FEP, not an alloy.
    - Grade mixing. BVAg-8 is a vacuum grade with a different specification, and the Skylab braze is a silver-copper-lithium alloy. Do not use their values for BAg-8.
  verdict: 'BAg-8 is the best-supported grade in this file: a eutectic brazing filler with a 780 degC melting point, a published density, strength and resistivity. The other silver alloys are only partly covered; the silver-gold table gives properties, while silver-antimony, silver-zirconium-copper and silver-palladium need their own datasheets before any use.'