I read in !emc-pstc that Barker, Neil <[email protected]> wrote (in <[email protected]>) about 'Maintaining conductivity of freshly machined aluminum' on Thu, 6 Feb 2003: >Aluminium oxidises extremely rapidly in normal atmospheric conditions.
Indeed. See what happens when mercury removes the oxide film. >You really cannot rely on untreated aluminium to aluminium interfaces >unless they are closely mated immediately The oxide film forms in milliseconds. You would have to be VERY quick. >after machining or abrasive >cleaning and are subsequently protected from the atmosphere. If that were entirely true, aluminium exposed to air would appear to be a non-conductor, and it doesn't. The oxide film is only about 1 molecule thick, and the measured conductivity with it present is little different >from that of aluminium machined in a vacuum or under argon. I'd like to see some results of conductivity testing two blocks bolted together with no surface treatment and two similar blocks bolted together with the surface treatment of your choice. The only stipulation is that the atmosphere is not abnormally corrosive. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
