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Aluminum alloy will rust when used?
Dec 27, 2017

We all know that rust appears in iron after a long time, and aluminum rusts like iron?
The answer is no, because the chemical reaction is different, aluminum will only form an oxide film.

In the aluminum processing, we can add other anti-rust and anti-corrosion metal elements inside the aluminum, so that the page can achieve the effect of rust prevention. Such as 3000 series aluminum added manganese alloy, manganese has a good anti-rust function, so that the 3000 series aluminum plate can become a rust-proof aluminum. Similarly, the addition of a magnesium alloy, the relative reduction of the density of aluminum (magnesium lower density, but higher strength) increased strength, as the aluminum-magnesium alloy.

This layer of ordinary aluminum pan oxide film is very thin, it is only 0.00001 mm so thick. Industrially, in order to make the aluminum products more durable, the prepared aluminum products are often immersed in a solution containing 20% sodium sulfate and 10% nitric acid to make the oxide film thicker (anodic oxidation processing), however This layer of oxide film is afraid of acid and fear of alkali, so aluminum should only cook cooking should not be cooking. People often think that aluminum pot is not bright, always use ash or sand to rub. In fact, this is a very unscientific approach. The ash is good enough to get rid of the "outer jacket" of an aluminum pan: first, it can be deduced from experiments by scientists that there is no metal that does not rust in the world, but the condition is different from the degree. Iron is rusting because it can not produce a protective layer, so the more rust the more students until the rust through, so we often see the dark rust. But aluminum is not the case, it rust rust cling to their own surface, hinder the oxygen into the aluminum inside, so the aluminum will not rust, this layer of rust has become the characteristics of aluminum protective film, we call It is alumina. Alumina has a characteristic, wipe it off, and soon will generate a new layer of alumina, continue to play a protective role.

Wipe the oxide film; second, ash contains potassium carbonate, etc., is a basic substance, can dissolve the oxide film by chemical action. However, when you have just wiped off a layer of oxide film, the aluminum pan brightens up. Before long, the aluminum continues to be oxidized due to the lack of protection of the oxide film, and the aluminum pan is still obscure . Although you pick up the grated ash every day, the aluminum pan re-generates the oxide film every day. In this "tug of war", the aluminum pan is getting thinner and thinner. Finally, the aluminum pan opened a "skylight" ─ ─ missed. And effort again, the pot broke again.

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