Aluminum BAlSi-9
ASTM AWS A5.8 BAlSi-9 · EN B Al 4004
BAlSi-9 is a high-silicon aluminum brazing filler to AWS A5.8, equivalent to B Al 4004, with magnesium and trace additions that improve flow and allow flux-free brazing.
Reference datasheet — BAlSi-9 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-9 tempers and conditions
BAlSi-9 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 | Soft annealed rod, coil wire or preform ring supply condition where bending and ring-forming are required. | 70 | 150 | 4 | 50 HB | 39 % IACS |
AS-BRAZEDDefault solidified filler deposit / joint fillet | Default condition: properties of the solidified BAlSi-9 fillet after vacuum brazing at 590–610 °C. | 90 | 165 | 2 | 60 HB | 37 % IACS |
Strain hardened, half hard | Cold-drawn spooled wire for automatic feeders and preform coiling where stiffness and straightness matter. | 150 | 195 | 2 | 70 HB | 37 % IACS |
Supply forms, finishes and certifications
Ways BAlSi-9 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
POWDER | Powder / paste | Printing process |
CLAD | Clad layer | Coating |
What is BAlSi-9?
BAlSi-9 is a high-silicon aluminum brazing filler to AWS A5.8, equivalent to B Al 4004, with magnesium and trace additions that improve flow and allow flux-free brazing. It is used for vacuum and controlled-atmosphere brazing of complex heat exchanger geometries and is supplied as clad sheet, foil, preform rings, powder and paste. The as-brazed deposit gives about 165 MPa tensile, 90 MPa yield, 2% elongation, 60 HB, 140 W/m·K, 37% IACS and a service limit near 150 °C. Its 559-596 °C melting range sits close to the 6000-series core solidus, so furnace control is critical; BAlSi-5 (4045) is the usual choice for fluxed or CAB processes. BAlSi-9 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 559°C (1,038 °F). BAlSi-9 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 87% of aluminum grades. Elongation at break is 2% and the elastic modulus is 71 GPa (10.3 Msi).
What is BAlSi-9 used for?
- vacuum brazing
- aluminum heat exchangers
- controlled-atmosphere brazing
Limitations
- Hard to polish — 40/100, worse than 91% of aluminum grades
- Low strength — 90 MPa (13.1 ksi), worse than 87% of aluminum grades
- Limited ductility — 2%, worse than 87% of aluminum grades
- Difficult to machine — 35/100, worse than 86% of aluminum grades
BAlSi-9 properties
Typical room-temperature values for BAlSi-9-AS-BRAZED; bars are the position among aluminum grades.
Physical3
BAlSi-9 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 559°C (1,038 °F).
Mechanical15
BAlSi-9 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 87% of aluminum grades. Elongation at break is 2% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
BAlSi-9 is rated for continuous service to 150°C (302 °F). It conducts heat at 140 W/m·K (80.9 BTU/hr·ft·°F), worse than 52% of aluminum grades. Thermal expansion is 20.5 µm/m·K (11.4 µin/in·°F).
Electrical3
BAlSi-9 conducts electricity at 37 % IACS, better than 58% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of BAlSi-9 takes about 205 MJ of energy and emits 12 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 10%.
Manufacturability8
BAlSi-9's machinability is fair (35/100, worse than 86% of aluminum grades); weldability poor (30/100); formability poor (25/100).
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-9 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BAlSi-9
Is BAlSi-9 easy to machine?
Rarely machined; the near-eutectic Si phase is abrasive — use PCD or polished carbide, high speed, low feed and flood coolant.
Can BAlSi-9 be welded?
Not a structural weld metal; it is a filler — brazing is done at 590–610 °C in vacuum (10⁻⁴–10⁻⁵ mbar) or inert atmosphere without flux, with tight furnace temperature control because the 559–596 °C melting range sits close to 6000-series core solidus.
Can BAlSi-9 be formed, bent or molded?
Supplied as clad sheet, foil, preform ring or paste; cold forming of the deposit itself is limited by low ductility, so form the core sheet before brazing.
BAlSi-9 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 |
|---|---|---|
| Siprimary melting-point depressant | 9 – 10.5 | 9.8 |
| Mggetter/oxide disrupter for fluxless vacuum brazing | 1 – 2 | 1.5 |
| Fe | ≤ 0.8 | |
| Cu | ≤ 0.25 | |
| Mn | ≤ 0.1 | |
| Zn | ≤ 0.2 | |
| Bipresent in the Bi-modified vacuum-brazing version (4104); absent in plain 4004 | 0.02 – 0.2 | 0.1 |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on BAlSi-9?
Anodizes dark and patchy; for corrosion protection use chromate-free conversion coating, epoxy or hydrophilic coatings applied after brazing.
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-9 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- AWS A5.8 BAlSi-9
- EN / DIN / Werkstoff-Nr.
- B Al 4004
- Other
- 4004
How much does BAlSi-9 cost?
BAlSi-9 is a premium-cost aluminum ($$$), cheaper than about 51% 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-9 — frequently asked
What is BAlSi-9 used for?
BAlSi-9 is typically used for vacuum brazing, aluminum heat exchangers and controlled-atmosphere brazing. In short: flux-free vacuum brazing filler; mg-bearing 4004 chemistry; narrow furnace temperature window.
What is the yield strength of BAlSi-9?
BAlSi-9 has a typical yield strength of 90 MPa (13.1 ksi) and a tensile strength of 165 MPa (23.9 ksi) — weaker than 87% of aluminum grades. Strength varies by condition: see the 3 listed tempers.
Is BAlSi-9 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 86% of aluminum grades). Rarely machined; the near-eutectic Si phase is abrasive — use PCD or polished carbide, high speed, low feed and flood coolant.
Can BAlSi-9 be welded?
Not readily — weldability is rated poor (30/100). Not a structural weld metal; it is a filler — brazing is done at 590–610 °C in vacuum (10⁻⁴–10⁻⁵ mbar) or inert atmosphere without flux, with tight furnace temperature control because the 559–596 °C melting range sits close to 6000-series core solidus.
What surface finishes work on BAlSi-9?
Anodizes dark and patchy; for corrosion protection use chromate-free conversion coating, epoxy or hydrophilic coatings applied after brazing.
Can BAlSi-9 be formed, bent or molded?
Supplied as clad sheet, foil, preform ring or paste; cold forming of the deposit itself is limited by low ductility, so form the core sheet before brazing.
What is the maximum service temperature of BAlSi-9?
BAlSi-9 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-9 AS-BRAZED and BAlSi-9-H14?
AS-BRAZED is the default condition — default condition: properties of the solidified BAlSi-9 fillet after vacuum brazing at 590–610 °C. H14: cold-drawn spooled wire for automatic feeders and preform coiling where stiffness and straightness matter. Yield strength is 90 MPa in AS-BRAZED versus 150 MPa in H14.
How much does BAlSi-9 cost?
BAlSi-9 is a premium-cost aluminum ($$$), cheaper than about 51% 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)
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering — ASM International (1993)
- Aluminium vacuum brazing sheet product literature — Constellium / Gränges (2022)
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.