Even the combination of copper and aluminum is highly corrosive in combination with water. It forms a electrochemical cell du to the difference in valence. Copper is a semi noble metal, whereas aluminum is far away from the noble metals so copper and aluminum form a redox potential. Never use copper bolts in aluminum, especially in humid environments! After some time you cannot loosen them and after a long time the aluminum around the bolt is rotten away. eric
_____ From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On Behalf Of taylorjpt Sent: dinsdag 16 december 2014 19:35 To: neonixie-l@googlegroups.com Subject: Re: [neonixie-l] Re: KLOK K7 broken from corrosive rot Aluminum and Lead and Tin all have different electrode potentials and will corrode when in direct contact. When not in direct contact, the slightest condensation of atmospheric water forms an electrolyte which then attracts and holds more water due to the increased surface area and surface tension of the resulting corrosion products. This can happen between metals held at the same external potential, i.e. no external potential. Add even the slightest external voltage and now you have and electroplating system. When we were designing the first cell phones, even the 500-600mV microphone bias on the external connector resulted in the gold plated pins (All pins of the same metal) falling off of the connectors in a matter of weeks. The solution was to ensure that all connector pins were at zero volts by periodically sampling the connector state, lowering the active duty cycles to a fraction of a percent. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/c624e6ec-2124-469f-a102-6adc567 04983%40googlegroups.com <https://groups.google.com/d/msgid/neonixie-l/c624e6ec-2124-469f-a102-6adc56 704983%40googlegroups.com?utm_medium=email&utm_source=footer> . For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/!%26!AAAAAAAAAAAYAAAAAAAAAPDddShx705MuX20yCpp0vvCgAAAEAAAAJVJTgFasCRPulDuqkJCohEBAAAAAA%3D%3D%40zeelandnet.nl. For more options, visit https://groups.google.com/d/optout.
