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I am planning an experiment for a chemistry class about corrosion. I am going to show how different prevention methods affects the corrosion of iron and aluminium parts using bleach as the oxidizer.

One of the methods I plan on is protecting the parts using cathodic protection, the iron nail will be protected by aluminium but I don't know a good, easily available metal to protect the aluminium stud. Any ideas?

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You might want to look at this link which has a nice general discussion about cathodic protection, with an abbreviated activity series for the metals of interest in cathodic protection. Typically, aluminum, magnesium and zinc are used as sacrificial anodes for cathodic protection.

Strictly speaking from a thermodynamic standpoint, one would suspect that magnesium would be needed to protect aluminum. However aluminum boat manufacturers state that zinc can be used for protecting aluminum boats in salt water.

I'm completely unfamiliar with the die casting industry, but they use Al/Zn alloys which, if affordable, may provide an interesting pedagogical component to your corrosion activity (namely, what do scientists do when the properties of the elements on the periodic table don't quite fit what we have in mind).

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  • $\begingroup$ Thanks for your answer! I will see if I can borrow some Mg from the lab. $\endgroup$
    – FilipeG
    Jun 14, 2013 at 16:31
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    $\begingroup$ Glad I could help - if you find the answer useful, you should also consider voting it up, as that helps the Chemistry.SE grow. $\endgroup$ Jun 14, 2013 at 18:15
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Of the metals lower in the Standard Electrode Potential list, Magnesium is probably easiest to come by and least problematic to handle.

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