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Posted by TokaMundo on 08/27/05 22:40
On Sat, 27 Aug 2005 18:38:31 GMT, "Mark Jones"
<noemail@mindspring.com> Gave us:
>WinField wrote:
>> Gold - 14
>> Copper - 10.4
>> Silver - 9.8
>>
>> Wipe the egg off your face, if/when you get a gripe on reality.
>> Copper & Silver connects would have LESS of your precious contact
>> resistance.
>
>The problem with your position is that this is only true if the copper
>and silver conductors are sealed against contact with the air.
Not true.
> Both
>of these metals are very prone to the development of a film of corrosion
>that drastically reduces their conductivity.
It isn't a film. It is called oxidation, and it takes place on the
surface, and is no way in the form of a film.
> Gold is very resistant to
>corrosion and will quickly have a better conductivity than either
>silver or copper when they are all exposed to the air.
Not true. While copper oxide is a poor conductor, one rarely sees
it used for connectors used in low power analog signal passes.
One would see copper used in high power, high current, large lug
connectors that explicitly scrape their pins as the connectors halves
mate.
Also, silver oxide is actually a better conductor than silver
itself.
>
>I have seen this based on actual experience and not by just quoting
>some numbers out of a text book without being able to understand
>how to use these numbers.
There is a lot you assume. One is that WinField doesn't understand
the electrical and chemical properties of metals and alloys.
>
>Care to try again?
>
The facts are the facts. You'll get used to shoe leather soon, if
you continue to embrace foot in mouth practices.
The only thing you have said that is correct is that gold is used
for reasons that center around oxidation and the fact that it oxidizes
very slowly and at a very thin surface depth.
The actual best contact plating material is platinum, as it oxidizes
even less than gold, and carries better physical properties that
increase its longevity in this application. It is cost prohibitive,
however.
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