O
Annealed. The most ductile condition, for preforms that are formed or wrapped around tubes.
Aerospace · Al-12Si brazing sheet
4047 Aerospace Aluminium Sheet for Brazing
4047 sheet, strip and foil are used in aerospace as brazing filler: cut into shims and preforms placed in heat-exchanger and duct joints, or roll-bonded as cladding on a 3xxx core. With 11 – 13 % silicon it melts at about 577 – 582 °C, well below the parts it joins. Metline supplies 4047 sheet and foil to AMS 4185 or your specification, worldwide.
- Alloy
- 4047 (Al-12Si)
- Tempers
- O, H14, H18, F / H112
- Spec
- AMS 4185 · AWS A5.8 BAlSi-4
- Use
- Brazing shims, preforms, cladding
Why 4047 sheet is bought for what it does at brazing temperature
4047 is the near-eutectic Al-Si alloy. It is chosen not for its room-temperature strength but because it melts sharply, flows freely and wets aluminium surfaces when the assembly is heated to about 590 – 600 °C.
In aerospace manufacturing, thin 4047 sheet and foil are punched or cut into shims, washers and preforms that sit between the parts of a heat exchanger, cold plate or duct manifold before furnace or dip brazing. Strip is also roll-bonded onto a 3003 or 3103 core to make clad brazing sheet. Thicker sheet is occasionally machined into special preforms.
As a structural sheet 4047 has no place in an aircraft: it is not heat-treatable, its strength is modest and the high silicon makes it brittle in thick sections and abrasive to machine. Statements that 4047 sheet is used for wings, fuselages or tails are incorrect.
4047 chemical composition (wt %)
| Element | Limit |
|---|---|
| Silicon (Si) | 11.0 – 13.0 |
| Iron (Fe) | 0.8 max |
| Copper (Cu) | 0.30 max |
| Manganese (Mn) | 0.15 max |
| Magnesium (Mg) | 0.10 max |
| Zinc (Zn) | 0.20 max |
| Beryllium (Be) | 0.0003 max (welding grades) |
| Others, each / total | 0.05 / 0.15 |
| Aluminium (Al) | Remainder |
Iron, copper and zinc are kept low so the filler flows cleanly and does not leave brittle phases in the joint. Magnesium is limited to 0.10 % for flux brazing; vacuum-brazing alloys add magnesium deliberately and are a different product.
Physical properties and tempers
Physical properties (typical)
- Density
- about 2.66 g/cm³
- Solidus / liquidus
- about 577 / 582 °C
- Brazing range
- about 582 – 604 °C
- Heat-treatable
- No
H14 / H18
Cold-rolled for flat, stiff shims that punch cleanly and keep their shape in fixtures.
F / H112
As fabricated, mainly for thicker sheet and plate to be machined.
We do not quote tensile figures for 4047 sheet. They are not a design value for brazing filler, and some older tables for this product put elongation and shear values in the wrong rows.
Specifications
| Document | Covers |
|---|---|
| SAE AMS 4185 | 12Si aluminium brazing filler in wire, sheet, foil and other forms |
| AWS A5.8 | BAlSi-4 brazing filler classification |
| EN 573-3 | EN AW-4047A (AlSi12(A)) chemical composition |
| Customer specification | Programme-specific thickness, flatness and cleanliness requirements |
Forms and sizes
4047 supply range
- Foil and thin strip
- For shims and preforms; slit to width
- Sheet
- Typically up to about 3 mm for brazing use; thicker sheet and plate on request
- Preforms
- Punched washers, rings and shaped shims to drawing
- Surface
- Clean and degreased, free of rolling oil residue that would contaminate the braze
- Packing
- Interleaved and sealed with desiccant
Exact thickness and width tolerances are agreed with the order; brazing foil normally needs tighter thickness control than general sheet.
Getting good joints with 4047 preforms
- CleanDegrease parts and preforms; remove heavy oxide on the base metal.
- FitHold joint clearances at about 0.1 – 0.25 mm and place enough filler to form full fillets.
- Flux or atmosphereApply flux for torch, dip or controlled-atmosphere brazing; vacuum brazing needs a Mg-bearing filler instead.
- HeatBring the assembly evenly to about 590 – 600 °C and hold only as long as needed to flow.
- Clean up and inspectRemove flux residues fully, then leak- or pressure-test and inspect fillets.
Aerospace uses
- Heat exchangers: oil coolers, fuel-oil exchangers and environmental-control exchangers
- Cold plates: avionics and power-electronics cooling plates
- Ducting: brazed manifolds and branch joints
- Clad sheet: filler layer on 3xxx core brazing sheet
How to order 4047 sheet
- SpecifyAlloy and temper, thickness, width and form, quantity and the governing specification with its revision (AMS 4185, AWS A5.8 BAlSi-4 or EN 573-3).
- ConfirmWe confirm the specification can be met, the tolerance class, test requirements and delivery terms (EXW, FOB, CIF or DAP).
- InspectMaterial is checked for dimensions and surface condition; any extra tests named on the order are carried out or arranged.
- DocumentEach lot ships with a mill test certificate to EN 10204 3.1 showing chemistry and mechanical results, traceable to the cast or lot number.
- Pack and shipExport packing in sealed, moisture-protected cases or on pallets, shipped by sea or air to your port or door.
References and standards
- SAE AMS 4185 – Filler Metal, Aluminum Brazing, 12Si (4047)
- AWS A5.8/A5.8M – Specification for Filler Metals for Brazing and Braze Welding
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
4047 aerospace aluminium (aluminum) sheet: questions
Is 4047 sheet used for aircraft structure?
No. It is a brazing filler material. Its value is its low, narrow melting range, not its strength.
What tempers is 4047 sheet supplied in?
O, H14, H18 and F / H112. It is not heat-treatable, so T tempers do not apply.
Can 4047 be used for vacuum brazing?
Standard 4047 is for flux and controlled-atmosphere brazing. Vacuum brazing uses Al-Si fillers with added magnesium.
What brazing temperature does 4047 need?
About 582 – 604 °C, which is why the base metal must have a solidus well above that range.
Do you ship 4047 sheet worldwide?
Yes. Metline supplies 4047 sheet, strip, foil and preforms from Mumbai worldwide.
Need 4047 sheet, foil or preforms?
Send thickness, width, form and quantity. We will confirm availability and certification.
