Replacement to copper winding

Aluminium...but it is difficult to connect to.

Yes, there are some problems connecting aluminium, especially with creeping effects when clamped, but crimping shoes will solve this problem. Todays busbars often have an aluminium core and are copper plated - this is done by use of extremely high pressure with which a copper tube is tightly fitted on the core.

Apart from that, experts forecast that aluminium will displace copper as no.1 conductor because of the shrinking resources resp. increasing demand.

The disadvantage is a worst volume/conductivity- relation, the benefit is an improved weight/conductivity-relation.

The only points that constrict the conversion for (tens of) years are gigantic investment costs and the necessity to rephrase all accordant standards and recommendations.
Regards Uwe

Got platinum. Platinum is always cool!

How large are your windings, and do you really need something more cheap than copper?!

For the coil to be effective, you need the material to be as conductive as can be. I'm afraid copper is the choice when u compare conductivity / pricing. If money is of no issue, use gold!

but platinum is in this year!

I have heard that current flows on the surface of the wire, that the maximum surface will provide the least resistance. Would copper-plated aluminum be a reasonable compromise? I've seen recording studios where the wiring is in the form of thin copper sheets. I assume that the bulk of the wire provides ruggedness and resistance to heat. What if wires were not drawn as solid cylinders but as micron-thick sheets which were then rolled up like a newspaper, providing huge amounts of surface area--wouldn't that reduce resistance to an absolute minimum?

That is a very interesting question!!! Later today, when the electrical engineers get off work, I'll have to check back to see what they say.

Just off the top of my head, could your structure induce either capacitance or inductance into the wire?

At DC or power line frequencies the 'skin' effect is miniscule.Your current is carried by the whole cross section of the conductor. Some automotive starter motors use aluminium strip for field windings but as a previous correspondent commented suffered from highly unreliable connections.I must admit to trying to solder an aluminium strip field to a brass terminal for b ages before realising it wasn't tinned copper.Aluminium wire is very fragile and winding for instance a contactor or solenoid coil with say 0.1 mm would be nearly impossible. Copper is the only realistic material for coils.

Brass, bronze?

Thanks a ton guys for responding with all your answers.

Well the coil is a basic one operating a plunger. The magnetic pull is abt 5-6 kg and consumes abt 25amps at 12/24v albeit with different gauges. With copper prices shooting up, I was looking for a suitable replacement without compromising quality and making any radical design changes. Unfortunately as always, Price is severe constraint. My conclusion was that it might not be easily possible, and you all helped in arriving at a decision.

Thanks again,

Dev

You know, as I've given thought to your question, it's occurred to me that copper is really somewhat special on the elemental chart. There doesn't seem to be any cheaper metals that have all the electrical properties of copper.

Anyway, good luck with your search, and please keep us informed of your progress!

Hi

the only possibility you have is with aluminum alloy containing magnesium or calcium.

These are used heavily for power transmission lines if high voltage long distance is to be connected.

So the aluminum companies will know which of the 3 or 4 different alloys are best suited for your purpose.

You will have 1.5 to 2 times the resistance if you use the same volume, so try to alllow more volume to your coil.

If not cooling has to be better.

You will have difficulties to get an insulated wire so prepare to do this by yourself.

We tried 2 approaches : High temp plastics as used in type H or C insulation and pure anodising without any additional treatment. Bot is good but the extra cost exceeds the copper cost unless you are very restricted with weight.

Have success

RHABE

Thanks for responding. My rough estimate is that such an alloy would not be easily available and thus would have to be manufactured against order. would therefore be bring parity in cost. Still its a thought will pursue it and let you guys know, what came out of it.

Regards,

Dev

Hi,

I asked the local (Germany) supplyers, they asked for a minimum order of 100 to 500kg.

As the typical alloys are drawn to wires for the power transmission lines they do not have problems to get the ingots.

We did not get a suitable diameter in our small scale experiments (a few kg only) but for a trial we used either welding wire (0.8mm) or from power semiconductor connection there exists 0.2mm diameter.

The problem with cost will be the insulation.

RHABE