Precious Metal BAu-1 AS-BRAZED
Heat-treated state
UNS P00375
Use these in-situ solidified filler values, 320 MPa tensile, 20% elongation and 425 °C maximum service, when verifying joint strength rather than selecting a supply form.
Values for the AS-BRAZED condition
What is BAu-1 AS-BRAZED?
BAu-1 AS-BRAZED is BAu-1 heat treated to AS-BRAZED — use these in-situ solidified filler values, 320 MPa tensile, 20% elongation and 425 °C maximum service, when verifying joint strength rather than selecting a supply form. BAu-1 AS-BRAZED has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 59% of precious metal grades. Elongation at break is 20% and the elastic modulus is 105 GPa (15.2 Msi). BAu-1 AS-BRAZED has a density of 11.4 g/cm³ (0.412 lb/in³), heavier than 62% of precious metal grades. It melts at 990°C (1,814 °F).
Limitations
- Limited ductility — 20%, worse than 77% of precious metal grades
BAu-1 AS-BRAZED properties
Typical room-temperature values for BAu-1 AS-BRAZED; 5 are specific to this condition. Other listed values are BAu-1 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
BAu-1 AS-BRAZED has a density of 11.4 g/cm³ (0.412 lb/in³), heavier than 62% of precious metal grades. It melts at 990°C (1,814 °F).
Mechanical9
BAu-1 AS-BRAZED has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 59% of precious metal grades. Elongation at break is 20% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
BAu-1 AS-BRAZED is rated for continuous service to 425°C (797 °F). It conducts heat at 65 W/m·K (37.6 BTU/hr·ft·°F), worse than 67% of precious metal grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical3
BAu-1 AS-BRAZED conducts electricity at 17 % IACS, worse than 56% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 61% of precious metal grades.
Sustainability4
Producing a kilogram of BAu-1 AS-BRAZED takes about 94,000 MJ of energy and emits 6,800 kg of CO₂ — more than 67% of precious metal grades. Typical recycled content is 50%.
Manufacturability4
BAu-1 AS-BRAZED's machinability is fair (45/100, better than 59% of precious metal grades); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BAu-1 AS-BRAZED
Is BAu-1 easy to machine?
Effectively no machining stock; preforms are blanked, sheared or laser cut from foil. Collect all offcuts and scrap for refining.
Can BAu-1 be welded?
This is a braze filler, not a weld consumable. Braze in vacuum below 1×10⁻⁴ mbar or in dry hydrogen with dew point at or below -50 °C at 1020-1090 °C, holding as briefly as possible to limit erosion of the base metal.
Can BAu-1 be formed, bent or molded?
Good ductility in the annealed condition (formability score 85): draws to fine wire, rolls to 0.025 mm foil and coils into rings. Intermediate anneal at 600-700 °C after heavy cold reduction.
What surface finishes work on BAu-1?
The joint surface is pale gold and can be polished directly. Remove all flux residue before gold or nickel plating, and degrease and de-oxidise base metals before brazing.
BAu-1 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| AuAWS A5.8 BAu-1 | 37 – 38 | 37.5 |
| Other (total)upper limit on total impurities | ≤ 0.15 | |
| Cu | balance |
BAu-1 AS-BRAZED — frequently asked
What is BAu-1 AS-BRAZED used for?
BAu-1 AS-BRAZED is typically used for vacuum-tight electronic housings, aerospace component brazing, high-temperature furnace parts and kovar-to-metal seals. In short: strongest gold-copper filler; vacuum-tight hermetic joints; lower gold than BAu-2.
What is the yield strength of BAu-1 AS-BRAZED?
BAu-1 AS-BRAZED has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 320 MPa (46.4 ksi) — weaker than 59% of precious metal grades.
Is BAu-1 AS-BRAZED easy to machine?
Reasonably — machinability is rated fair (45/100, better than 59% of precious metal grades). Effectively no machining stock; preforms are blanked, sheared or laser cut from foil. Collect all offcuts and scrap for refining.
Can BAu-1 AS-BRAZED be welded?
This is a braze filler, not a weld consumable. Braze in vacuum below 1×10⁻⁴ mbar or in dry hydrogen with dew point at or below -50 °C at 1020-1090 °C, holding as briefly as possible to limit erosion of the base metal.
What surface finishes work on BAu-1 AS-BRAZED?
The joint surface is pale gold and can be polished directly. Remove all flux residue before gold or nickel plating, and degrease and de-oxidise base metals before brazing.
Can BAu-1 AS-BRAZED be formed, bent or molded?
Good ductility in the annealed condition (formability score 85): draws to fine wire, rolls to 0.025 mm foil and coils into rings. Intermediate anneal at 600-700 °C after heavy cold reduction.
What is the maximum service temperature of BAu-1 AS-BRAZED?
BAu-1 AS-BRAZED is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- AWS A5.8M/A5.8 Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- ASM Handbook Vol.6 — Welding, Brazing, and Soldering (Precious Metal Filler Metals) — ASM International (1993)
- Gold-copper brazing alloy (37.5Au) data sheet — Lucas-Milhaupt / Morgan Advanced Materials (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.