The airport chair that material is more durable?

Airport chair is the basic material of aluminum alloy, stainless steel, steel, according to the three kinds of material composition, the quality of aluminum alloy is more durable, but also want to consider different factors, such as use of the environment, whether outside, whether weathered, because with the acidic rain, more easy to corrosion of metal. Also want to consider the human factor, also with the usage of each country, Asian slants thin, the use of low intensity, Africa, Europe, the americas people's body slants big, using strength, so different material, the use of different environment, different durability.