Aluminum BAlSi-11
ASTM AWS A5.8 BAlSi-11
BAlSi-11 is an aluminum-silicon-magnesium brazing filler to AWS A5.8 that contains bismuth to break down surface oxide during flux-free and vacuum brazing.
Reference datasheet — BAlSi-11 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the AS-BRAZED condition
BAlSi-11 tempers and conditions
BAlSi-11 is supplied in 3 conditions, soft to hard. AS-BRAZED is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose for hand-fed rod, coiled wire and rolled foil preform stock supplied soft for easy shaping. | 65 | 145 | 8 | 50 HB | 38 % IACS |
AS-BRAZEDDefault filler deposit after vacuum/flux-free braze cycle | Default condition: properties of the solidified fillet/joint after a 588–604 °C vacuum braze cycle. | 90 | 170 | 3 | 60 HB | 37 % IACS |
Strain hardened, half hard | Choose when the filler is rolled as the clad layer of vacuum brazing sheet or supplied as stiffer strip for stamped preforms. | 150 | 195 | 3 | 70 HB | 37 % IACS |
Supply forms, finishes and certifications
Ways BAlSi-11 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
PREFORM | Stamped rings, washers and shims of BAlSi-11 foil | Supply form |
POWDER | Powder / paste | Printing process |
What is BAlSi-11?
BAlSi-11 is an aluminum-silicon-magnesium brazing filler to AWS A5.8 that contains bismuth to break down surface oxide during flux-free and vacuum brazing. It is used in specialty heat exchanger and vacuum-brazed assemblies and is supplied as rolled foil or clad layer, drawn wire, powder and preforms. The as-brazed deposit reaches about 170 MPa tensile and 90 MPa yield at 3% elongation, 60 HB, with 130 W/m·K thermal conductivity, 37% IACS and a 150 °C service limit. The Mg and Bi content rules out arc welding and gives blotchy anodizing; BAlSi-9 (4004) is the nearest alternative for vacuum brazing without bismuth. BAlSi-11 has a density of 2.66 g/cm³ (0.0961 lb/in³), lighter than 84% of aluminum grades. It melts at 559°C (1,038 °F). BAlSi-11 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 87% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi).
What is BAlSi-11 used for?
- Flux-free vacuum brazing of aluminum assemblies
- Specialty heat exchanger cores
- Brazing preforms and rings
- Clad foil layers on brazing sheet
- Vacuum-brazed cold plates and manifolds
- Powder and paste braze deposits
Limitations
- Hard to polish — 35/100, worse than 98% of aluminum grades
- Low strength — 90 MPa (13.1 ksi), worse than 87% of aluminum grades
- Low fracture toughness — 17 MPa·√m (15.5 ksi·√in), worse than 83% of aluminum grades
- Difficult to machine — 40/100, worse than 81% of aluminum grades
- Limited ductility — 3%, worse than 79% of aluminum grades
BAlSi-11 properties
Typical room-temperature values for BAlSi-11-AS-BRAZED; bars are the position among aluminum grades.
Physical3
BAlSi-11 has a density of 2.66 g/cm³ (0.0961 lb/in³), lighter than 84% of aluminum grades. It melts at 559°C (1,038 °F).
Mechanical15
BAlSi-11 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 87% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
BAlSi-11 is rated for continuous service to 150°C (302 °F). It conducts heat at 130 W/m·K (75.1 BTU/hr·ft·°F), worse than 65% of aluminum grades. Thermal expansion is 21 µm/m·K (11.7 µin/in·°F).
Electrical3
BAlSi-11 conducts electricity at 37 % IACS, better than 58% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 51% of aluminum grades.
Sustainability4
Producing a kilogram of BAlSi-11 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 10%.
Manufacturability8
BAlSi-11's machinability is fair (40/100, worse than 81% of aluminum grades); weldability poor (30/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. BAlSi-11 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BAlSi-11
Is BAlSi-11 easy to machine?
Rarely machined as a bulk product; braze fillets are abrasive from primary Si — use sharp polished-flute carbide, high speed and generous lubricant to avoid smearing.
Can BAlSi-11 be welded?
Not a structural welding filler — the high Mg plus Bi content is intended for brazing; arc welding of the deposit causes Mg loss and porosity.
Can BAlSi-11 be formed, bent or molded?
Supplied as rolled foil/clad layer or drawn wire; anneal between passes since the near-eutectic Si structure work-hardens and cracks quickly in cold forming.
BAlSi-11 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 |
|---|---|---|
| Simelting-point depressant, near-eutectic flow | 9 – 10.5 | 9.8 |
| Mgoxide-disrupting getter for vacuum brazing | 1 – 2 | 1.5 |
| Bilowers surface tension, improves flow without flux | 0.02 – 0.2 | 0.1 |
| Feimpurity limit | ≤ 0.8 | |
| Cuimpurity limit | ≤ 0.25 | |
| Mnimpurity limit | ≤ 0.1 | |
| Znimpurity limit | ≤ 0.2 | |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on BAlSi-11?
Anodizes dark and blotchy because of the Si and Bi phases; for cosmetic assemblies use chemical conversion coating or paint rather than clear anodize.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum BAlSi-11 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- AWS A5.8 BAlSi-11
- Other
- 4104
How much does BAlSi-11 cost?
BAlSi-11 is a high-cost aluminum ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
BAlSi-11 — frequently asked
What is BAlSi-11 used for?
BAlSi-11 is typically used for flux-free vacuum brazing of aluminum assemblies, specialty heat exchanger cores, brazing preforms and rings, clad foil layers on brazing sheet, vacuum-brazed cold plates and manifolds and powder and paste braze deposits. In short: bismuth-modified vacuum braze filler; no flux required; low-ductility brittle deposit.
What is the yield strength of BAlSi-11?
BAlSi-11 has a typical yield strength of 90 MPa (13.1 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 87% of aluminum grades. Strength varies by condition: see the 3 listed tempers.
Is BAlSi-11 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 81% of aluminum grades). Rarely machined as a bulk product; braze fillets are abrasive from primary Si — use sharp polished-flute carbide, high speed and generous lubricant to avoid smearing.
Can BAlSi-11 be welded?
Not readily — weldability is rated poor (30/100). Not a structural welding filler — the high Mg plus Bi content is intended for brazing; arc welding of the deposit causes Mg loss and porosity.
What surface finishes work on BAlSi-11?
Anodizes dark and blotchy because of the Si and Bi phases; for cosmetic assemblies use chemical conversion coating or paint rather than clear anodize.
Can BAlSi-11 be formed, bent or molded?
Supplied as rolled foil/clad layer or drawn wire; anneal between passes since the near-eutectic Si structure work-hardens and cracks quickly in cold forming.
What is the maximum service temperature of BAlSi-11?
BAlSi-11 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between BAlSi-11 AS-BRAZED and BAlSi-11-H14?
AS-BRAZED is the default condition — default condition: properties of the solidified fillet/joint after a 588–604 °C vacuum braze cycle. H14: choose when the filler is rolled as the clad layer of vacuum brazing sheet or supplied as stiffer strip for stamped preforms. Yield strength is 90 MPa in AS-BRAZED versus 150 MPa in H14.
How much does BAlSi-11 cost?
BAlSi-11 is a high-cost aluminum ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- AWS A5.8/A5.8M — Specification for Filler Metals for Brazing and Braze Welding — American Welding Society (2019)
- AWS Brazing Handbook, 5th ed. — Aluminum and Aluminum Alloys — American Welding Society (2007)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering — ASM International (1993)
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.