"Alexander" schreef in bericht
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"John Fields" schreef in bericht
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On Mon, 1 Aug 2005 18:23:25 +0200, "Alexander"
wrote:


Sometimes you have something like Aluminium inside (for the weight) and
Cupper on the outside for conductivity. Due to the Skin Effect this is
where
the most (AC) current will flow.
On some application I have even seen Cu on the inside and Au on the
outside,
my guess there is at least one other material between the two for obvious
reasons.

Really? The reasoning for that layering doesn't seem obvious to me,
so would you mind explaining it in greater detail?

--
John Fields
Professional Circuit Designer

If you connect Au to Cu and put a Current through it, for best results AC,
the Cu starts corroding at the transistion from Cu to Au. This is always
the case when putting to metals together, the greater the difference
between the metals the faster the corroding will be.

This is also the reason why silver and gold contacts should never be
soldered with normal Sn63Pb37 solderwire