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When I put aluminium parts into my dishwasher, they get tainted and they are sometime covered with white dots similar to salt.

I don't think it is aluminium oxide.

What are the chemical reactions that have an effect on aluminium but not other metals?

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    $\begingroup$ I'm not 100% sure, but I think it is just alkalinity. Unlike many other metals, aluminum is amophoteric, so it dissolves in both strong base and in strong acid. Most dishwashing detergents are fairly alkaline, probably at pH 11 or 12 or so. That and the heat may be enough to corrode Al. $\endgroup$
    – Curt F.
    Jul 18, 2015 at 22:43
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    $\begingroup$ Closely related to cooking.stackexchange.com/questions/8375/… $\endgroup$
    – Todd Minehardt
    Jul 19, 2015 at 1:39
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    $\begingroup$ Suggestion: @Curt F, make your comment an answer (as you wrote, sodium carbonate in the detergent, with aluminum, forms sodium aluminate, see en.wikipedia.org/wiki/…) $\endgroup$
    – DrMoishe Pippik
    Jul 19, 2015 at 2:24

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I think it is just alkalinity. Unlike many other metals, aluminum is amophoteric, so it dissolves in both strong base and in strong acid. Most dishwashing detergents are fairly alkaline, probably at pH 11 or 12 or so. That and the heat may be enough to corrode Al. Most other common metals are attacked by strong acids but not by alkali.

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  • $\begingroup$ Nice answer thanks. What is the white residue on the aluminum? $\endgroup$
    – nowox
    Jul 19, 2015 at 13:59
  • $\begingroup$ Maybe another question. What if I protect my aluminum with a thick aluminum oxyde layer? $\endgroup$
    – nowox
    Jul 19, 2015 at 14:00
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    $\begingroup$ The white stuff is probably ${\rm Al(OH)}_{3}$ (aluminum hydroxide). See here for a general description. $\endgroup$
    – Todd Minehardt
    Jul 19, 2015 at 16:52

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