[kja07]

First of all, thanks in advance for any help

I'm trying to determine how you can make an alloy dissolve when exposed to fresh water. There is currently technology used in the oil and gas industry that is used to make 'frac balls' degrade when exposed to fresh water. The only info i can read about on the internet claims it to be either an aluminum or magnesium alloy. I have a totally different application in mind but would need to be able to readily change the rate of reaction. can someone please tell me how this is done. For my application, i really need something with the mechanical properties similar to that of aluminum initially, but would then start a fairly quick degradation process when exposed to water.

[Enthalpy]

Welcome, Kja07!

So you want an alloy that corrodes quickly? If your water is aggressive enough, it can go in a few weeks or days even at room temperature.

Already AA7049A (Al-Zn8-Mg-Cu) loses superficial sheets, 0.5mm thick, within few days in a soil. Adding more Cu should make this faster. You could experiment with RSP' alloys
http://www.rsp-technology.com/technology/material-specifications.html
which are alloyed beyond the element solubility by using rapid solidification. I used them in mechanical engineering, nice toys - but the corrosion in air isn't spectacular.

A radical way to spoil Al's corrosion resistance is to alloy it with Ga.

Mg alloys are known to be weak against corrosion, limiting their use, but I don't know how to make it worse. Alloy them with Cu rather than Al and Zn?

[jeffmoonchop]

try sodium

[OrganicDan96]

sodium/potassium (NaK) allow works well for this