I want to remove corrosion products in aluminum, but I don't have supply of nitric acid, as suggested by an ASTM method. Which can be a good substitute?
1 Answer
Really, ASTM procedures must be followed as written for certified testing. However, if this is for your edification or for a school project, you might use a commercial cleaner, such as those below, or just one ingredient such as phosphoric acid.
There are a number of commercial aluminum corrosion cleaners, such as Loctite Duro Aluminum Jelly and CRC MaryKate Aluminex Clean and Shine.
If you want to make your own:
Ingredients listed in the Aluminum Jelly Material Safety Data Sheet include phosphoric acid, diethyleneglycol monoethyl ether, nonionic surfactant, isopropyl alcohol , polysaccharide and sulfuric acid. [Similar formulaions may have contained hydrofluoric acid to break the highly-adherent $\ce{Al2O3}$ surface film and corrosion, but due to the hazards of $\ce{HF}$, I believe it is no longer sold in most places, for good reason.]
Aluminex Clean and Shine's MSDS includes ethoxylated tallow alkyl amines, sodium decylglucosides, hydroxypropyl phosphate and potassium iodide.
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$\begingroup$ Can't I use hydrochloric acid? Most of these chemicals are not available and hardwares in my place don't sell this kind of products. $\endgroup$– AcidJul 28, 2017 at 10:15
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$\begingroup$ You can use anything you want -- but that is not ASTM testing. $\endgroup$ Jul 28, 2017 at 22:35