The aluminum in aluminum foil is easy to produce dense alumina passivation film on its surface in air and oxidizing aqueous solution medium, and it has good corrosion resistance in some oxidizing media. The corrosion resistance of pure aluminum is better than that of stainless steel in high temperature concentrated nitric acid. Aluminum is often used as corrosion resistant container material.
For some corrosion is not too strong, but the requirement of anti-iron pollution media, such as chemical fiber production media, aluminum has better corrosion resistance, and no iron pollution materials, therefore, aluminum is often used as anti-iron pollution container material. Other non-ferrous containers also protect against iron contamination, but aluminum is the cheapest.
Aluminum foil, which has no isomers, does not have the brittle transition at low temperatures that ferritic steel does. The lowest design temperature of aluminum vessels can reach -269℃. Aluminum is often used as a material for cryogenic vessels. When the magnesium content of Al-Mg alloy is high, the intermetallic compounds Mg2Al3 and Mg5Al8 will precipitate between the crystals, resulting in the stress corrosion sensitivity of Al-Mg alloy in some media. The stress corrosion will not occur when the magnesium alloy is used below 65℃. Therefore, the specified design temperature of Al-Mg alloy with more than 3% magnesium content should not exceed 65℃. Too much precipitated phase will also reduce the impact toughness, so the impact toughness of Al magnesium alloy and its welded joints with more than 3% magnesium content should be tested. Impact toughness tests are not required for other aluminum and aluminum containers, including cryogenic aluminum containers.