Why doesn't aluminum rust?　

　　 This is a wrong question. Aluminum also rusts, but aluminum does not rust like iron until the rust is finished.　　

　　 Metal is oxidized by oxygen in the air, which is called rust. Aluminum reacts with oxygen to form aluminum oxide, which is aluminum rust. Aluminum rust is very thin, its thickness is only one ten thousandth of a millimeter, but it is very hard and very wear-resistant. It is close to the surface of the aluminum, so that the aluminum inside cannot reach the outside air, and prevents the aluminum from continuing to rust.　　

　　 Alumina film also has a "nemesis": one is alkali and the other is acid. Alumina encounters them and chemically reacts, forming compounds, which are very easy to fall off. Dishes often contain acid and alkali ingredients, so no! want! Put the fruit wine in the dish in aluminum utensils to avoid corrosion and damage to the aluminum pan. Besides, no! want! Because the surface of the aluminum pan is gray and embarrassing, use sand to wipe it. Although you wipe a layer of oxide film, the aluminum pan will be brighter, but this can only make you happy for a while. If the protective film on the surface is lost, the aluminum pan will continue to oxidize, and the gray color of the aluminum oxide will still show up in front of your eyes; and the aluminum pan is getting thinner and thinner, affecting its service life.