Why not silver?

[Connecteur]

Silver metal is one of the most efficient conductors of electricity.  Imaging how much faster your device would charge through USB if it had silver wires.  One trick Apple seems to have missed.

Of course all of this is moot; silver is simply too expensive.  Perhaps it shouldn't be, after the demise of the photographic film industry, which was likely the biggest industrial user of silver.  Silver has become one of the precious metals of choice for financial speculation, even though there is really no tangible basis for it.  Both silver and gold are very useful metals in electronics, and would probably be a boon to industry if they were cheaper, instead of being a medium of speculation as they currently are.

The only way I see this changing, is if vastly abundant sources were somehow found.  Seems unlikely, in this lifetime at least.

[wraper]

Imaging how much faster your device would charge through USB if it had silver wires.

You could increase current by 5% for the same wire cross section.

[dferyance]

Charging efficiency isn't really a priority to anyone. The existence and popularity of wireless charging is what proves this. Wireless charging is incredibly inefficient.

Keep in mind that power is voltage * current. It is possible to transfer more power by boosting the voltage and keeping current constant. Power transmission lines are an obvious example of this. They get by with aluminum + steel which is worse than copper. But they run high-voltage which reduces how much current needs to travel (also 3 phase but that is a different topic).

USB PD already supports higher voltage charging. So USB cable resistance isn't really a limitation for charging. Battery cell construction and temperature tends to be a larger factor.

Silver is great. It just isn't enough better than copper to justify the cost in most cases.

[jzx]

They used silver for coils in isotope separators for the Manhattan project, bud they had good budgets.

Sometimes silver is used in rf applications, to have better Q in coils, less resistance.

But it is expensive. For a faster charge of your phone, you can use USB C with an higher voltage. With more volts, resistance is less important.

[wraper]

Conductivity difference with copper is marginal. There is more tolerance in cross section of usual wire than cross section/resistance advantage silver would offer.

[chilternview]

You could use it for all those high voltage DC power lines round the country. At 400kV it would be more difficult to steal 

[zilp]

They used silver for coils in isotope separators for the Manhattan project, bud they had good budgets.

It's not so much that they had a good budget, but that there was a copper shortage, and that the treasury happened to have a few thousand tons of silver lying around that they could borrow ... which is what they did.

[David Hess]

They used silver for coils in isotope separators for the Manhattan project, bud they had good budgets.

There was a copper shortage because the copper was going into brass for fixed ammunition.

During the war, they also pulled the copper bus bars out of the powerhouses along the Columbia river and replaced them with silver bus bars, guarded by men with guns, and it was not for greater efficiency.  They simply needed the copper for the war.

[coppice]

They used silver for coils in isotope separators for the Manhattan project, bud they had good budgets.

It's not so much that they had a good budget, but that there was a copper shortage, and that the treasury happened to have a few thousand tons of silver lying around that they could borrow ... which is what they did.

They borrowed it, and at the end of the war they returned it with a small interest. The story of this is really interesting. When the workers realised how must silver they were handling each day, pilfering apparently exploded, and they had to run a tight security regime to stop it all disappearing.

[coppice]

Silver is widely used as a conductor, in very thin films, for RF applications. When the skin depth get really low you need the lowest skin resistance possible, but the bulk of the conductor, carrying only DC, can still be copper.

[coppercone2]

i wonder how good it is for magnet wire and stuff like that. like mechanically

[TimFox]

Also note that aluminum, which has lower conductivity than copper, is often used for conductors in long transmission lines (usually at high voltage) instead of copper due to its lower weight for a given resistance.
Conductivity:  Cu/Al = 1/0.61 = 1.64:1
Volume density:  Cu/Al = 8.94/2.70 = 3.31:1
If weight is the only issue, then aluminum wins.
Different applications, such as transformers, depend more on the volume of the conductor for a given resistance, and copper is preferred.
Mixing aluminum and copper is a well-known hazard.
General reference:  https://www.wilsonpowersolutions.co.uk/app/uploads/WPS_Aluminium-v-Copper_white-paper_-2021.pdf

[David Hess]

i wonder how good it is for magnet wire and stuff like that. like mechanically

As far as I know, silver works just as well as copper for wire.  Teflon insulated copper wire uses silver plating instead of tin plating because the lower melting point of tin would defeat using Teflon in high temperature applications.  The audio fanatics sometimes use silver wire and silver wire transformers for its 5% improvmenet, and I have not heard of any problems with that.

[coppice]

Also note that aluminum, which has lower conductivity than copper, is often used for conductors in long transmission lines (usually at high voltage) instead of copper due to its lower weight for a given resistance.

Weight and cost. If you wanted to make major distribution cables from copper the demand would drive its cost and availability into a very dark place.

[coppice]

i wonder how good it is for magnet wire and stuff like that. like mechanically

As far as I know, silver works just as well as copper for wire.  Teflon insulated copper wire uses silver plating instead of tin plating because the lower melting point of tin would defeat using Teflon in high temperature applications.  The audio fanatics sometimes use silver wire and silver wire transformers for its 5% improvmenet, and I have not heard of any problems with that.

Most of the wire used in defence applications is silver plated, for similar temperature tolerance reasons.

[coppercone2]

but as far as ripping and work hardening etc?

[SiliconWizard]

We make bullets out of silver and this is a very effective conductor of BS.

Jokes aside, as others have said. Benefits relatively marginal apart from niche applications, and too expensive. Weight also as the density of silver is ~17% higher than that of copper.

[coppercone2]

maybe it can make a stronger pen drill.

you know it is more thermally conductive. a potted winding might be able to really dissipate more heat.

you get 5% less resistance and 5% higher thermal conduction. for a motor that might mean something if heat burried deep can get out quicker. it might translate to a substantial performance increase. IDK what the net effect of both is. You would have to rewind a motor.

[vk6zgo]

They used silver for coils in isotope separators for the Manhattan project, bud they had good budgets.

Sometimes silver is used in rf applications, to have better Q in coils, less resistance.

But it is expensive. For a faster charge of your phone, you can use USB C with an higher voltage. With more volts, resistance is less important.

RF coils are often silver plated copper, which is just as effective as solid silver, due to "skin effect".

There is a caveat with silver plating----the plating solutions used for normal decorative purpose are optimised for lustre & durability in use, so contain specially selected impurities to achieve those ends.
Unfortunately, those impurities increase the resistivity of the deposited silver, so special solutions must be used for RF purposes.

[Circlotron]

They used silver for coils in isotope separators for the Manhattan project, bud they had good budgets.

There was a copper shortage because the copper was going into brass for fixed ammunition.

Of topic, so let's not get too sidetracked, but why is brass used for ammunition? Why not plain old cheap steel?
And when a war is finished, scrap metal scroungers must have a field day.

[T3sl4co1l]

Brass is formed several times for ammunition: deep drawn to forge a solid thick base with thin walls; rolled or swaged to hold the bullet; and one last time, when it's actually fired, to expand into and seal the breech of the barrel.  It has an excellent combination of formability, machinability, ductility, strength, and also lubricity to move smoothly through the mechanism, and corrosion resistance to survive years in the field and remain usable.

I think blanks would still need to be annealed once or twice on the way through deep drawing?  But maybe they can manage it in one hit.  Huh, come to think of it, I've never looked up an ammunition manufacturing video.  Let me see...
...Or even just an article, that'll do.  Looks like four anneals total: https://www.petersoncartridge.com/technical-information/drawing-brass/ For a rifle cartridge anyway; maybe a pistol round only needs three, maybe even two, but three more likely.

Brass can even be reused once, maybe even twice or more, if it's clean and not dented, and probably many times with additional annealing and swaging steps to keep it in tolerance.

Steel might be too strong, having difficulties in forming a thin shape, or fitting the bullet without turning up burrs (it's only soft lead, or copper jacketed, after all), or not conforming to the barrel well enough on firing, and obviously is prone to rusting.  Hmm, I see plenty of hits for steel rounds, so it's definitely used, and many of those issues might be mitigated say by lacquer to improve lubricity and corrosion resistance, but given the quoted text on most hits, it seems it tends to be poor quality, loose tolerance, "dirty", etc.  That kind of goes with it being cheaper in general, but perhaps that also speaks to manufacturing variation due to material differences.  Steel is quite ductile, but not as much as copper and alloys are; it probably needs one or two additional annealing steps to complete (and higher temperature is required to anneal steel).  Or maybe they manage with a less strenuous process, like rolling seamless tube down to shape, but maybe that only works with certain types of bases.

I'm quite removed from gun lore, myself; this is more motivated by the metallurgical relevance.  Others can chime in with actual practice.


On a related note, I wouldn't at all mind tin-plated steel crimp terminals, for connectors carrying signals; it should be workable, and perhaps they could be cheaper, or the higher strength allows more flex and thus vibration resistance, or contact pressure (but then again, it can't be too high where the tin plating gets squidged out), so there could be reliability gains; but probably between the ductility, and the dissimilarity to the wire it's crimped on (crimping pressure/depth needs to be more carefully calibrated to avoid pinching through the wire entirely), this just isn't a good idea.  But maybe they do indeed use it some places, dunno.

Tim

[xrunner]

Yes steel is used for ammo -

https://ammo.com/casing-type/steel

[coppercone2]

steel anything instead of brass is like soviet crap IMO.

Like steel connectors. I don't mean some fancy stainless. The soviet union loved making things out of steel.

THink you can get a bronze or brass heat exchanger for your car? nope, it was cast iron. at least i suspect so.

steel vacuum cleaners too. 

[TimFox]

i wonder how good it is for magnet wire and stuff like that. like mechanically

As far as I know, silver works just as well as copper for wire.  Teflon insulated copper wire uses silver plating instead of tin plating because the lower melting point of tin would defeat using Teflon in high temperature applications.  The audio fanatics sometimes use silver wire and silver wire transformers for its 5% improvmenet, and I have not heard of any problems with that.

The temperature used to fuse Teflon to stranded wire during manufacture would melt tin (on tinned strands), thus losing the flexibility of stranded wire.
Most Teflon-insulated copper wire is therefore silver-plated, although some is unplated.

[David Hess]

Most of the wire used in defense applications is silver plated, for similar temperature tolerance reasons.

We used Teflon insulated silver plated wire already because we had assemblies which had to be baked at higher temperatures, but when we did some military contracts, the military really liked that type of wire even when it was not necessary.

Incidentally Teflon insulated wire is not a panacea.  UV (and ozone?) will apparently degrade Teflon, and abrasion can be a problem.

Of topic, so let's not get too sidetracked, but why is brass used for ammunition? Why not plain old cheap steel?
And when a war is finished, scrap metal scroungers must have a field day.

Steel did get used when they got desperate, but it is more difficult to form and use.  Aluminum can also be used but again, is more difficult to work with.  Brass has a really good combination of ductility and work hardening for cartridge cases.

After World War 2, areas that had large tank battles were mined for the tank ammunition penetrators which often used expensive tungsten alloys.