Any Metallurgists out there?

I had an idea but I'm not sure what would happen. If I melted copper and aluminum separately but poured them into a mold together would they bond into one piece without completely mixing into an alloy? Basically I wanted to turn a tap handle with more character to it kind of like having wood grain.

Copper and aluminum mix to form aluminum bronze. Very pretty when polished, a former boss of mine made a batch of funeral urns out of it.

http://www.anchorbronze.com/alloydatabase.htm

what if you had a 3rd metal with a low melting point *(what's the melting point of lead?)
take chunks of 'metal number 3' and pour your copper around it. let cool.
melt out the lead, leaving big voids. pour in aluminum. spin on your axis of choice.

Interesting idea. Could also make a die mold and do a pressed and sintered handle as both Al and Cu are soft metals. You'd need access to a pretty hefty press as well as the machine tools to do the work...



There are also wood composite plastics out there as well. Not sure where to source though...

What about going with folded metal like damascus steel? I'm not sure which metals would bond to one another. Once you got them folded/twisted you could hammer or press it into a shape that you could turn.

What about this type of material? http://www.m3ci.com/m3-blanks-for-craftspeople (manufacturers website) http://www.metalpenblanks.com/mokume_gane_standard.htm (blanks and billets for sale)

It sounds like the Copper/Galactic Silver Mokume Gane would look right for your requirements.




I did a mechanical pencil out of this and it is fairly easy to work if a bit brittle. It turns easily with a light touch and sharp tools and polishes great but is a little hard to drill.

These are all neat ideas, that Mokume Gane is very nice but pricey. I like the damascus steel concept, there's a big press, anvil, and forge in Grandpa's old workshop that would probably get the job done. My plan on the copper and aluminum was to gently pour them in simutaneously on opposite sides of a mold while turning it so they'd layer upwards in a spiral, hopefully just mixing together a little bit where the two metals meet but leaving distinct layers of individual metals. As far as turning them, I got a job about a month ago at a small machine shop (9 of us including the owner and secretary) and we're allowed to use the tools and machines on saturdays.

bneal said:

What about this type of material? http://www.m3ci.com/m3-blanks-for-craftspeople (manufacturers website) http://www.metalpenblanks.com/mokume_gane_standard.htm (blanks and billets for sale)

It sounds like the Copper/Galactic Silver Mokume Gane would look right for your requirements.

I did a mechanical pencil out of this and it is fairly easy to work if a bit brittle. It turns easily with a light touch and sharp tools and polishes great but is a little hard to drill.

Click to expand...

That's some cool material! Bookmarked that site, thanks!

You could try casting the copper, then re-investing it and casting the aluminum (lower melting point) around the copper. More steps, and you'll need a burn-out furnace, but it could work really well.

B

I don't think the forging (damascus) method will work because you will need to get the copper temperature close to or above the melting point of the aluminum just to make the copper workable. For the layers to weld together you would need to be at an even higher temperature.

From http://metalpass.com/metaldoc/paper.aspx?docID=297 the copper and alloy forge in a range from 1100 to 1650F. Aluminum (pure) melts around 1220F. Pure copper melts around 1983F so I'm not sure how well the turn-and-pour method would work.The closer you can keep the copper to it's melting point the less the materials will alloy but the less working time you will have. The skin will begin to form the instant the melted metal touches the mold. The 750 degrees of superheat into the aluminum might cause the two metals to react.

It would be relatively easy to try an small scale experiment with a little copper, aluminum, and a torch to see if they are in anyway compatible. You might need 2 torches and 2 crucibles to get everything hot at the same time... Melt the metals and pour into a mold (a small piece of steel pipe maybe?) Instead of spinning, you could probably just use a steel rod to stir the mixture together. It would also benefit from pre-heating the mold and argon or nitrogen blanketing the entire process. Sounds like a fun experiment but I don't have any metalworking tools/torches.

Just a warning -- molten metals are DANGEROUS! Make sure everything the melted materials will touch is dry. A small puddle of water in the mold will make superheated steam that will send the still liquid metal straight to the ceiling.

BTW I used to work as a Process Metallurgist in a steel melt shop but we were always trying to make homogenous alloys not pretty things.

Another idea if you are really good on the lathe -- turn 2 spirals that would thread together (think interlocked coil springs) If the fit was tight enough you could turn to whatever final shape you desired or fill with epoxy and then turn.

Good luck and hope all turns out well!