Pattern welding copper and aluminum

[Mason Protter]

hey guys, I'm Mason, I'm new here. A friend and I are going to try some pattern welding and are planning on trying to do it with copper and aluminum because they are both pretty easy for us to get, and have low melting points. We're probably gonna try and make some rings or something, not quite sure yet. Right now the plan is to take an aluminum rod and wrap it in copper wire then heat that. Aluminum has the lower melting point of the two, so having it in the core in rod form and having the copper on the outside in wire form will help them initially melt at similar times (hopefully).

does anyone have any advice? do you know if this will work or not? I haven't heard of anyone trying this, so I'm taking that as a bad sign. If you have tried this, what's the best acid to use to etch it?

[Timothy Miller]

It won't work.

[ThomasPowers]

Pattern welding is a Solid Phase welding process----the stuff doesn't melt! If you are melting one of the alloys you are more into a brazing than a welding.

May I commend to your attention "Solid Phase Welding of Metals" Tylecote; if you live in the USA you should be able to ILL it at your local public library.

Note that you can bond some metals by creating a eutectic of lower melting point where they touch---look at historical granulation work in gold for an example.

[Steve Sells]

It won't work.

Actually it does work, but not in the sense of pattern welding steels, read up on Mokume a bit, there is plenty of Copper and Aluminum done already.

[781]

usually mokume is made between two plates held together with bolts
the material is brought to heat then brought out and squeezed with a press, vise or hammered
Once the initial squeze is finished and it has fused it is hammered or rolled to thickness with pattern manpulation done before it is at finished dimension
It is only helf together for the first heat by the plates
I have done a few billets using US quarters or US nickles and copper

[Timothy Miller]

Actually it does work, but not in the sense of pattern welding steels, read up on Mokume a bit, there is plenty of Copper and Aluminum done already.

I have done a few billets of Mokume when I was getting my BFA in Metalsmithing. I have also done some pattern welded stuff. From what I have seen and read getting Aluminum to fuse copper requires high teck engineering and is not something two raw beginners could do on their first try and without some expensive equipment. Wile it is possible it is outside of the realm of the capabilities of 99.5% of us.

[Dave Budd]

if they look up how to make mokume and have a go at it, the worst that can happen is that they cover the workshop in aluminium splatter. I reckon anything is worth trying :)

[Timothy Miller]

You would be much better off doing copper and bronze or brass.

[Mason Protter]

Yeah, we found out much to our disappointment that heated aluminum behaves less like other hot metals and more like dirt, so it was not a very successful endeavor.

The reason we tried this is that we didn't think we could get our ghetto-XXX kitchen sink forge to welding temperatures for steel, after the failure with the aluminum-copper weld (or mokume or whatever the proper term is) tried it with steel anyways and much to our surprise, we managed to weld two files together, so we're going to try and make a Damascus knife. We'll see how that turns out when we're done though

[Bentiron1946]

The joys of experimentation are the staff of life for newbies. I remember those days with fondness. Just do it and find out what works and what doesn't, failure is as good a teacher as success, maybe better if it hurts because we seem to remember something painful longer. Anyway have a good time as you go along with your experiments in smithing and do try to be safe. You only have so many fingers and toes.

[r smith]

Mokume is commonly copper and brass, can be other metals. An easy one is a stack of quarters ($0.25). I think you will want something else in addition to your files otherwise little to no pattern will show up if you are succsesful.

[Robert Yates]

It Can be done ! as an art

http://news.alibaba.com/article/detail/metalworking/100186291-1-metals-knowledge%253Awelding-dissimilar-metals.html

[Mason Protter]

Mokume is commonly copper and brass, can be other metals. An easy one is a stack of quarters ($0.25). I think you will want something else in addition to your files otherwise little to no pattern will show up if you are succsesful.

Yeah, I'm currently bring to decide what to add to the files. I might as well just try and combine your two suggestions and put quarters into the files, could make some cool patterns. Another thing that I really want to try and pattern weld is steel cable. I've seen some beautiful knives made from steel cable. Basically the just welded the end cable together, then left a section of unwelded cable on the end which was put through an antler handle as the tang. Beautiful knife with a really cool pattern.

[Steve Sells]

Have you actually ever done anything in a forge? quarters with files? huh

[ThomasPowers]

The welding temp of the files will be above the melting point of copper and copper alloys melt even lower.

you might look up dambrascus for a mixed metal method.

I've done pattern welding in a hole in the ground using charcoal sieved out of old bonfire ashes and using a claw hammer and a chunk of rr rail. it's the *skills* you need not fancy equipment!

[r smith]

I was talking about the mokume seperatly from the files, NOT sugesting mixing the two as others have already said

[Frosty]

when you tried your Al Cu mokume did you have it wrapped in SS foil to keep the oxy off it? Some charcoal or better, graphite powder (available at an art supply in the paint section, stick with black/gray) in the package to absorb any residual oxy. The biggest problem with al is you can't see it's sweating temp, copper is easy but way too hot. what makes metal a metal is the extra electrons in the outer/valence shell, put in close contact with another metal they will eventually start trading electrons and the rest of the atoms will follow soon. Of course if you add an electrolite they make a battery and no bond occurs except maybe a corrosion scale bond and that's just interlocked crud with no strength.

Certain eutectic bonds aren't good choices, the most common mistake is brass and silver, well before you get a diffusion bond you WILL get a silver solder puddle. Silver and copper or bronze has nice contrast and is easy to bond, not needing a wrapper. They MUST be very clean, a light sanding wearing linen gloves, immediately stacked and clamped is better than cleaning with solvent. For the most part a steel clamp is plenty, steel has a much lower coefficient of expansion than most non-ferrous metals so as the stack heats it expands a lot more than the clamp putting a serious squeeze on the stack.

Quarter mokume is an excellent place to start, both copper and nickle are pretty easy diffusion candidates and the contrast is nice. Be careful they make a puddle at a medium orange, it's a eutectic thing. You don't need to get them super clean either, the high nickle alloy outer on quarters bond together easily. I usually just flatten them on the anvil for good contact and have at it.

Frosty The Lucky.

[Frosty]

Oh shoot, I forgot to say Welcome aboard Mason, glad to have you! If you'll put your general location in the header you might be surprised at how many folk here live within visiting distance. I have another snappy sentence I usually put here but I've rambled enough for now.

Frosty The Lucky.

[timgunn1962]

Usually, it's necessary to have a clean, oxide-free surface on each of the metals being joined. Aluminium is very reactive indeed, and almost instantly forms a stable oxide layer in contact with air. I don't think the charcoal-in-the-foil trick will work with Aluminium, which is much more reactive than carbon, so isn't likely to release the Oxygen from its Oxide layer to the carbon. As a result, it will be difficult to diffusion bond Aluminium to anything else with simple equipment of the sort available to the average enthusiast. I think the guys who do it use Argon to exclude air.

It's probably better to try the technique with less reactive metals first, then progress to the more advanced combinations if you decide it's what you want to do.

It's certainly worth researching it a bit first. There are good books by Ian Ferguson and Steve Midgett, both titled "Mokume Gane". I've not read Midgett's yet, but Ferguson's seems to give good technical information on the process (and is the cheaper of the two). Midgett is on my "must read" list.