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  for Metal Finishing since 1989
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Coating aluminum to withstand temperature changes and vibration

I have a dilemma, I need to know what type of coating can be applied to an aluminum bar and will be able to withstand rapidly extreme temperature changes from -70 °C to +90 °C and undergo vibration testing without cracking. I have a couple of choices that I know about such as: Vinyl coating, Nylon coating, or a new one called ?Plastocal?. Does anyone know which type or can suggest a coating that will be able to handle the situation I described?

Eric Jerke
Mechanical engineering student - Cedar Rapids, Iowa, USA
2004

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Wow! That is some range. What is your rate of temperature change and what if the frequency of vibration? My first feelings are that plastics will not stand up to the low temperature and they will shatter. Secondly I would be concerned about the relative coefficients of thermal expansion; generally metals and plastics are quite dissimilar. Thirdly, must the coating be non conductive? If not, you may want to try electroplating the aluminium with another metal such as copper or nickel. At least they will have similar rates of expansion. If you get the right type of aluminium and do the processing correctly, it may just stand up to these extremes.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004