I think you will find that Alodyne is a chromate conversion coating; Alodyne is one trade name, Alocrom another. The yellow clour comes from the chromium. The down side is that the jury is out on whether or not such a coating complies with the RoHS Directive. Is there still hexavalent chromium in the coating, and is the coating mechanically separable from the base metal? Fortunately there are clear-coloured alternatives that are definitely free of hex-chrome and that can be proven to be equally corrosion resistant and equally conductive (there are also some that are corrosion resistant, but non-conductive). I agree that coloured anodizing is simply dyed, and you can have almost any colour you want; black, blue, red, gold, green, etc. Best regards
Neil R. Barker CEng MIET HonFSEE MIEEE Manager Quality Engineering e2v technologies (uk) ltd 106 Waterhouse Lane Chelmsford Essex CM1 2QU UK Tel: (+44) 1245 453616 Fax: (+44) 1245 453571 Mob: (+44) 7801 723735 P Please consider the environment before printing this email. From: Fred Townsend [mailto:[email protected]] Sent: 14 January 2008 23:31 To: Tarver, Peter Cc: [email protected] Subject: Re: Zinc passivation vs. Stainless Steel hardware selection I'm not an anodize or Alodyne expert but I will offer a few notes: 1. You will get more hits when looking up Alodyne if you spell it correctly. See http://en.wiktionary.org/wiki/alodyne 2. Both processes are clear. Some sort of dye is added for coloring. Yellow is popular for Alodyne and black for anodize. 3. Anodize is an oxide forming process. Aluminum oxide (and most oxides) are insulators. 4. Alodyne is a different process, i.e. not a type of Anodize and is conductive. Fred Townsend DC to Light Inc. Tarver, Peter wrote: From: Curt McNamara Sent: Thursday, January 10, 2008 2:33 PM In my experience almost all anodize is non- conductive. The only conductive one that I recall is black zinc. I don't know if the process to which you refer is the form of anodizing I've come across called 'Alodine' (also black), but I've seen Alodine used in earthing paths with several mating interfaces with success. Regards, Peter L. Tarver, PE [email protected] Sent by E2V TECHNOLOGIES PLC or a member of the E2V group of companies. A company registered in England and Wales. Company number 04439718. Registered address 106 Waterhouse Lane, Chelmsford, Essex, CM1 2QU, UK. - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
