Precious Metal BVAg-8b AS-BRAZED
Heat-treated state
UNS P07728
Property set for the solidified fillet/gap metal in a finished vacuum-brazed assembly.
Values for the AS-BRAZED condition
What is BVAg-8b AS-BRAZED?
BVAg-8b AS-BRAZED is BVAg-8b heat treated to AS-BRAZED — property set for the solidified fillet/gap metal in a finished vacuum-brazed assembly. BVAg-8b AS-BRAZED has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 65% of precious metal grades. Elongation at break is 20% and the elastic modulus is 85 GPa (12.3 Msi). BVAg-8b AS-BRAZED has a density of 9.9 g/cm³ (0.358 lb/in³), lighter than 70% of precious metal grades. It melts at 766°C (1,411 °F).
Advantages
- High electrical conductivity — 87 % IACS, better than 93% of precious metal grades
- Conducts heat well — 355 W/m·K (205.1 BTU/hr·ft·°F), better than 92% of precious metal grades
Limitations
- Limited ductility — 20%, worse than 77% of precious metal grades
BVAg-8b AS-BRAZED properties
Typical room-temperature values for BVAg-8b AS-BRAZED; 5 are specific to this condition. Other listed values are BVAg-8b reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
BVAg-8b AS-BRAZED has a density of 9.9 g/cm³ (0.358 lb/in³), lighter than 70% of precious metal grades. It melts at 766°C (1,411 °F).
Mechanical10
BVAg-8b AS-BRAZED has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 65% of precious metal grades. Elongation at break is 20% and the elastic modulus is 85 GPa (12.3 Msi).
Thermal6
BVAg-8b AS-BRAZED is rated for continuous service to 370°C (698 °F). It conducts heat at 355 W/m·K (205.1 BTU/hr·ft·°F), better than 92% of precious metal grades. Thermal expansion is 19.6 µm/m·K (10.9 µin/in·°F).
Electrical3
BVAg-8b AS-BRAZED conducts electricity at 87 % IACS, better than 93% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), worse than 66% of precious metal grades.
Sustainability3
Producing a kilogram of BVAg-8b AS-BRAZED takes about 1,100 MJ of energy and emits 95 kg of CO₂ — less than 71% of precious metal grades. Typical recycled content is 35%.
Manufacturability6
BVAg-8b AS-BRAZED's machinability is fair (40/100, worse than 60% of precious metal grades); formability excellent (85/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BVAg-8b AS-BRAZED
Is BVAg-8b easy to machine?
Rarely machined — soft and gummy; supplied as drawn wire, rolled foil or stamped preforms, sheared/blanked rather than turned.
Can BVAg-8b be welded?
Not a structural weld metal; it is the filler itself — vacuum or dry-hydrogen furnace braze at roughly 780–900 °C with 0.025–0.075 mm joint clearance and no flux.
Can BVAg-8b be formed, bent or molded?
Highly ductile: drawn to fine wire, rolled below 0.05 mm foil and stamped into rings/washers; interanneal to avoid work-hardening cracks.
What surface finishes work on BVAg-8b?
Keep parts and filler oil- and sulfur-free before brazing; as-brazed fillets can be lightly brushed or passivated with the base metal, and silver-rich fillets will tarnish in sulfur-bearing air.
BVAg-8b 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 |
|---|---|---|
| Ag | 71 – 73 | 72 |
| Liactive element; reduces surface oxides for self-fluxing action | 0.15 – 0.3 | 0.22 |
| Cdvacuum-grade limit (low vapour pressure) | ≤ 0 | |
| Znvacuum-grade limit | ≤ 0 | |
| Pvacuum-grade limit | ≤ 0 | |
| Pbvacuum-grade limit | ≤ 0 | |
| other (total)total of all other elements | ≤ 0.15 | |
| Curemainder, nominally ~27.8 % | balance |
BVAg-8b AS-BRAZED — frequently asked
What is BVAg-8b AS-BRAZED used for?
BVAg-8b AS-BRAZED is typically used for vacuum furnace brazing without flux, stainless steel and superalloy joints and aerospace vacuum assemblies. In short: self-fluxing eutectic filler; brazes stainless without flux; vacuum-purity BAg-8 variant.
What is the yield strength of BVAg-8b AS-BRAZED?
BVAg-8b AS-BRAZED has a typical yield strength of 165 MPa (23.9 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 65% of precious metal grades.
Is BVAg-8b AS-BRAZED easy to machine?
Not especially — machinability is rated fair (40/100, worse than 60% of precious metal grades). Rarely machined — soft and gummy; supplied as drawn wire, rolled foil or stamped preforms, sheared/blanked rather than turned.
Can BVAg-8b AS-BRAZED be welded?
Not a structural weld metal; it is the filler itself — vacuum or dry-hydrogen furnace braze at roughly 780–900 °C with 0.025–0.075 mm joint clearance and no flux.
What surface finishes work on BVAg-8b AS-BRAZED?
Keep parts and filler oil- and sulfur-free before brazing; as-brazed fillets can be lightly brushed or passivated with the base metal, and silver-rich fillets will tarnish in sulfur-bearing air.
Can BVAg-8b AS-BRAZED be formed, bent or molded?
Highly ductile: drawn to fine wire, rolled below 0.05 mm foil and stamped into rings/washers; interanneal to avoid work-hardening cracks.
What is the maximum service temperature of BVAg-8b AS-BRAZED?
BVAg-8b AS-BRAZED is rated for continuous use to about 370°C (698 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- AWS A5.8/A5.8M — Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- ASM Handbook Vol. 6 — Welding, Brazing, and Soldering — ASM International (1993)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Ag-Cu system) — ASM International (1990)
- Silver-copper-lithium vacuum brazing filler metal data (Cusil-ABA/Cusil family bulletins) — Morgan Advanced Materials (Wesgo Metals) (2022)
- BVAg vacuum-grade brazing alloy product data — Lucas-Milhaupt / Handy & Harman (2021)
- GB/T 10046 (2018)
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.