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Cathode material for Chromic Acid
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Customer is using Aluminum Cathodes in their Chromic Acid Anodize. Large tank - 55,000 Liters. Application is for aircraft / aerospace parts. Problem they are having is when power is turned off the aluminum is attacked. They have a recovery system that is working overtime to clean up the aluminum in the bath. Aluminum cathodes are replaced more frequently than they would like to.
What might be other option for cathode material? I am guessing Lead. Has anyone information on other materials besides aluminum or lead that would "work" in this application? I was asked about Titanium for Cathode material - not a very good conductor and probbaly a worse choice than aluminum - yes? When power is turned off the titanium probably would hold up pretty well. Negative charge on Titanium in Chromic doesn't sound good. Any information would be appreciated.
Vulcanium Corp. - Northbrook, IL, U.S.A.
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British defense standards advice the use of mild steel or stainless steel for cathodic materials in chromic acid anodizing.
Arnoldo CastroStudent - San José, Costa Rica
November 29, 2008
Hi, folks. The subject of cathode material for chromic acid anodizing has come up repeatedly. So, for more insights see letters 524, 19316, 26783 and 35181.
Regards,
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