TMCCL - The Metals Consultancy Company Ltd

 - was founded in 1999 and for the next 15 years supplied thousands of tonnes of rolled aluminium very successfully for the manufacture of brazed heat exchangers to hundreds of customers all around the world.

The company specialised in smaller batches of materials in specifications which were a little bit out of the ordinary, were difficult to obtain quickly or because of small volumes were of little interest to the major rolling mills. This was once referred to as the PPPP market - Prototypes, Panics and Pains in the Proverbial. All of which were true at various times!!!

TMCCL also carried out many trials and investigations into the aluminium brazing process and presented many papers at conferences in Europe and USA - copies are available free on request.

In response to wide demand, TMCCL has once again resumed activity and is now offering ALUMINIUM BRAZING FOIL in a range of alloys, widths, thicknesses and coil sizes for all brazing processes.

Tube to fin brazed joint
Bob at his microscope
The brazed LCP joint he is looking at

When can you use aluminium brazing foil?

If you wish to join two or more aluminium heat exchanger components together with a permanent strong bond, but where it is not possible to use clad aluminium, then brazing foil can offer a precision solution.

The alloy can be chosen to be appropriate for the brazing process you are using and its thickness and shape specified to give exactly the right amount of braze alloy in exactly the right place. Brazing foil can even be used to join aluminium to stainless steel - for instance in the base of saucepans and other cookware.

Decoiling 0.10mm brazing foil for cutting to length
Cutting foil to size

I have had the opportunity to work with Bob Ward and TMCCL since the beginning of 2000 and his technical knowledge has strongly helped me in many projects. TMCCL products and services are excellent and our Company continuously benefitted of them over the years.

Alessandro Bizzarri
General Manager, Priatherm, Italy

There are 4 main alloys used in aluminium brazing:

AA 4047 (AWS BAlSi-4)

This is the eutectic composition of the Al-Si phase diagram with 12% silicon and melting takes place pretty much immediately at 577°C, with no "mushy" phase where solid and liquid are both present. A suitable flux is required in order to form an effective joint.

Composition: 11.0%-13.0% Si
Typical brazing range: 582-604°C
AA 4045 (AWS BAlSi-5)

This alloy has a nominal composition of 10% Silicon (9%-11%). Melting occurs over a temperature range of 577°C to 600°C, with a mixture of solid and liquid phases present in the joint. This is often beneficial in keeping braze alloy in the correct location, rather than running out of the joint prematurely leaving voids or causing erosion. Flux is required as above.

Composition: 9.0%-11.0% Si
Typical brazing range: 588-604°C
AA 4343 (AWS BAlSi-2)

This has a nominal composition of 7.5% Silicon and melts in the range 577°C to 617°C. It therefore has a larger "mushy range" than 4045 and 4047. Once again flux is required.

Composition: 6.8-8.2% Si
Typical brazing range: 593-621°C
AA 4004 (AWS BAlSi-7)

This is the alloy commonly used in vacuum brazing applications. Its has 9.0-10.5% Si and an additional 1.5% Mg. The presence of magnesium reduces the solidus temperature by just over 20°C. Flux is not required, as the magnesium begins to vapourise from the surface of the alloy, disrupting the oxide layer and then "gettering" the oxygen. The melting range is 559-596°C.

Composition: 9.0-10.5% Si
Typical brazing range: 588-604°C
Correct amount of brazing alloy
Slightly too much brazing alloy
Far too much brazing alloy
Base plate, turbulator and cover, brazed with 0.10mm foil

4045 alloy, 0.10mm thick

By far the most commonly-used and versatile alloy/thickness combination is 4045 alloy in a thickness of 0.10mm.

This is usually supplied in half-hard temper (H24) which is suitable for using as a flat sheet (or "shim") between the 2 surfaces to be joined, but also has some formability if the brazing foil needs to be fitted into or around a shaped surface.

A range of widths can be supplied exactly to your own needs - any quantity and width from 15mm up to 600mm and in coils of the appropriate ID, OD and weight to match exactly what you require.

We hold substantial stocks of this alloy and thickness and can usually supply within a week of receiving your order.

Pallet of 10 coils 0.10 x 450mm 4045-24, 25 kgs each

Coils of 0.10 x 42mm 4045-24, 100 kgs each, being stacked by vacuum lifter

Pallet of 0.10 x 42mm coils 4045-24 ready for export to Asia

Boxes of 3 coils of 0.05 x 400mm 4045-18 being packed for export to Asia

4045 alloy 0.05mm thick

Sometimes 100 microns of braze alloy is too much, so we can also offer 50 microns, and once again in a variety of widths and coil sizes according to your needs.

If you require other thicknesses to get exactly the right amount of braze alloy, such as 0.04mm or 0.07mm, that is no problem.

If you should happen to need more than 0.10mm, then just use multiple layers to get to 0.15mm for instance. Or we can roll to 0.30mm, 0.40mm or whatever you want.

4004 alloy

Available to special order within a few weeks, in 0.10mm or other thicknesses and in widths up to 350mm and coil ID, OD and weight according to your needs. This alloy is ideal for vacuum brazing applications.

Usually supplied in hard temper (H18).

4047 and 4343

Can be rolled at 350mm in thickness down to 0.07mm with a lead time usually about 6 weeks. It can then be slit to whatever width and coil ID/OD you need.

Get in touch

Would you like a sample to test?

Thanks - your enquiry has been received.
Please allow up to 2 days for a reply.

If you would like a small FREE sample of 4045 (0.10mm x 300mm x 600mm), just ask. Please give brief details of the assembly you would like to test it on, and what you are using at present.

The Metals Consultancy Company Ltd
18 Gledhow Park Drive

Email:[email protected]
Tel:+44 (0)7860 511 703

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