I suggested repeatedly to electroform Ni and Ni-Co, possibly allied with Mo, for music instruments
and more scienceforums
and later and elsewhereStrong electroformed alloys
would serve many more uses. For instance rocket chambers
are of nickel electrodeposited on an inner copper jacket where cooling channels have been milled. But what alloys might be possible?
Please remember I'm not reliable on electrochemistry.
Strong nickel alloys are known, mainly for superalloys used in gas turbines. They consist of Ni, 20% Cr, 0-20% Fe, <20% Co, <10% Mo, <5% Ti, ~1% Al, Nb, and some more. Nice source: Nickel and Its Alloys
, monograph 106 by the National Bureau of Standards
Based on redox potentials, which are not the whole story for electrodeposition, Co (-0.26V) is fully compatible with Ni (-0.28V), and both are indeed codeposited routinely.
Mo (-0.20V) looks easy, and Ni-Mo compound precipitation knowingly hardens Ni alloys without embrittlement. Mo is a very strong candidate
If Cr (-0.91V, forms an oxide layer) can be co-deposited, fine! Zn (-0.76V) is commonly deposited together with Cu (+0.52V) to make brass. My understanding is that Cr protects Ni alloys against corrosion as it does for steel, but isn't a vital hardening element. Since Ni and Co alloys resist corrosion enough at room temperature, Cr can be dropped.
Maybe Fe (-0.45V) can be co-deposited. It's present in some Ni superalloys, not in others. It must reduce the density and the cost, little more. Easily dropped.
Can Ti, Si, Zr, C, B, Al (-1.67V) be electrodeposited? I suppose not, based on their solubility, potential and oxide layer. Precipitates of Ni-Ti and Ni-Al compounds are very important hardeners of Ni superalloys, but ciao. C is undesired, Si doesn't seem useful. B is sometimes used in tiny amounts in superalloys, adiós.
Nb (-1.10V), or rather unseparated Nb+Ta, precipitates as Ni-Nb to harden superalloys. I suggest to try Ta (-0.60V) instead
: same atom size, same effects in alloys. If deposition works despite the oxide (it does for Zn), electrodeposited Ni and Ni-Co have a second precipitation hardener.
W is sometimes added in tiny amounts. Re (+0.30V) could be a candidate equivalent.
Cu-Zn brass is routinely deposited. Cu-Ni-Zn "nickel silver"
must be about as difficult and is the common alloy for keyworks of woodwind instruments. Though, I want to make keys hollow and thin to be lighter and stiffer. Bigger diameters help, stronger alloys too, as inspired by nickel superalloys.
Lighter keys would be very appreciated at the German bassoon, at other instruments too, lighter and stiffer keys at the baritone saxophone.
Since I'm here: the cooling jackets of rocket engines
mention exotic Cu alloys meant to conduct well and be harder than pure Cu. The widely available Cu-Cr1Zr
was developed for that purpose, along with few more. For electrical conductivity, but it's the same.
Marc Schaefer, aka Enthalpy