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  for Metal Finishing since 1989
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Nickel-Alumina composite coating

Hi,

I want to know if I want to make a Nickel-Alumina composite coating , is it necessary to make the alumina particles conductive or is agitating the solution enough.

Majid Alimadadi
RESEARCHER - Karaj, Tehran, Iran
2004

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First of two simultaneous responses --

You need to keep the alumina in suspension by uisng a suitable surfactant and enough agitation to prevent it from precipitating out.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

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Second of two simultaneous responses --

Metals or alloys deposit in a galvanic bath because their salts dissociate into ions under the bipolar effect of water or other specific solvent, not because they are conductive. You may have the metal with highest conductivity but if its not dissolved into ions it will not electroplate. Now, answering your Q, you cannot make alumina conductive for it is a ceramic, thus highly dielectric. Hope this helps you clarify your ideas.

Guillermo Marrufo
Monterrey, NL, Mexico
2004
2004