Stupid question of the day....

Op [GMT+1ΞT], hakte John Fields op ons in met:


You're right it needs also an electrlyt which is most of the times present.
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wrote:

Firstly, Aluminium is Al not Au. Au is gold. You are speaking of aluminium and coper?
Galvanic Corrosion Is possible when Al and Cu are in contact with one and other. If I recal correctly a dialectric such as water needs to be present. Cathodic protection, (electric current) can be used to slow or stop this proccess. I Imagine reversing the polarity may speed it up. Aluminium is the "Less Nobel" of the two metals so I would imagine that it would be the one to corrode.
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Op [GMT+1ΞT], hakte DBLEXPOSURE op ons in met:

Correct I also added the remark of the diλlectricum to the discussion. And your remark about Aluminium is correct, however as stated in some applications I have seen an Copper core and an Gold (aurum) shell. And since the combination gold-copper is worse then the well known combination aluminium-copper.
But at least ThanX for confirming my statement and not saying its not true without giving a reason as someone else did.
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wrote:

Your welcome, I thought you deserved a respectful reply...
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On Tue, 2 Aug 2005 18:59:37 +0200, "Alexander"

--
No you added the remark about the _electrolyte_, which was correct.
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On Tue, 2 Aug 2005 10:40:37 -0500, "DBLEXPOSURE"

--
I doesn't make any difference, (but there is no metal named "coper",
so i'll assume you meant "copper") there won't be any corrosion
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wrote:

--
Less "noble", or more anodic.
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On Tue, 2 Aug 2005 14:09:31 -0500, "DBLEXPOSURE"

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Hardly. "Nobel" was the inventor of dynamite, while "noble", in the
context which makes sense in this thread, refers to chemical
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On Tue, 02 Aug 2005 13:48:47 -0500, John Fields

BTW nearly any metal in contact with "pure water" makes it pure no more.
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On Tue, 02 Aug 2005 04:41:38 -0500, John Fields

It's called galvanic reaction.
The Navy seems to think it's real. Does that make you an idiot?
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AC,
the
the
The Navy seems to think there's a significant problem with gold over copper? Do tell....
Bob M.
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On Tue, 02 Aug 2005 18:43:52 GMT, "Bob Myers"

Look up Galvanic reaction in ship hulls, and you will find that all Navy ships have provisions to reduce it.
Note again that my reference is to the effect, not the remarks about specific elements. Learn to read.
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But that wasn't the question. You were responding to a comment made in the specific context of gold-on-copper, to the effect that "galvanic reaction" was the reason that such a combination wasn't a good idea. Sorry, but the "galvanic reaction" of dissimilar metals has absolutely nothing to do with the subject at hand.
There actually very often IS another layer (commonly, nickel) placed between a copper conductor and a top protective layer of gold, but this has nothing whatsoever to do with a "galvanic reaction" between these two metals. (If it did, following the original incorrect response on this subject, the problem would then become WORSE due to the fact that there would now be two such interfaces rather than one. Remember, if you can, that the original comment along these lines said that a "galvanic reaction" was a problem between ANY two metals.) The reason that an intermediate layer of nickel is often used in this case has to do with the fact that, left to themselves, gold and copper will tend to diffuse into one another. This causes a problem in electrical applications (where gold-plating copper conductors is being done to prevent corrosion) primarily on the gold side of things, as the copper diffusing up through the gold layer will eventually reach the surface and create the very same corrosion problem that the gold was supposed to be preventing. Nickel doesn't diffuse into gold like copper does, hence its use here.

My, again with the personal attacks; I suppose in the absence of practical knowledge, that's about all one is left with.
Bob M.
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On Tue, 02 Aug 2005 23:05:04 GMT, "Bob Myers"

As if declaring that someone has "no practical knowledge" isn't a personal attack.
Fuck off retard. You have social problems.
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Gave us:

Gee, someone must've received a bad grade last year in their freshman circuit analysis class...
Bob M.
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On Wed, 03 Aug 2005 18:30:47 GMT, "Bob Myers"

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LOL, as much circuit design and analysis as he's done around here
makes me think they kicked his sorry ass out of the class!
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On Tue, 02 Aug 2005 17:31:30 GMT, TokaMundo

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Back looking for some more lumps, bonehead? OK, I'm happy to
oblige...
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On Wed, 03 Aug 2005 01:20:29 GMT, TokaMundo
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Nothing of consequence, or eloquence, and ended it with:
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On Wed, 03 Aug 2005 05:01:54 -0500, John Fields

You wouldn't know what eloquence was if it bit you in the ass, you top posting Usenet retard.
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wrote:

The Navy knows it's a problem, but then naval ships are in seawater. One must have an electrolyte to complete the 'circuit'. This is one reason why commercial work with Al conductors often requires the application of special 'grease' to seal the connection from moisture intrusion.
daestrom
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