Thanks to its special anti-corrosion treatment and the use of a dry resistance that is to say it never comes into contact with water, MICHELINI boiler offers performances and durability far better than traditional models. Aluminium is a light but resistant metal, silvery in appearance due to the thin layer of oxidation that forms quickly when it is exposed to air and that prevents corrosion as it is insoluble. Aluminium is the most abundant metal on Earth. The aluminium production process involves the extraction from its bauxite; once it has been purified to pure alumina, the metal is extracted by electrolysis. Thanks to its characteristics, aluminium is the most widely used metal after iron, with an annual production capacity of about 31 million tonnes. Aluminium is not normally used in the pure form, but in alloy form, which enhances its numerous properties. In Europe a quarter of the aluminium needs is met by using secondary smelting metals that can be recycled an infinite number of times. Aluminium alloys usually undergo various thermal and mechanical processes in order to increase hardness, to improve mechanical properties and to enhance corrosion resistance. The anodization process takes place in the lower part of MICHELINI boilers. Anodizing is an irreversible electrochemical process where a protective aluminium oxide coating is grown on the treated article surface to protect it from corrosion. An outward transformation occurs on the material. The treatment consists of the following steps: degreasing, possible chemical etch, desmutting, anodic oxidation, neutralisation, possible colouring, sealing and drying. Thanks to this treatment, corrosion resistance, surface hardness, wear and abrasion resistance are improved and a moderate thermal insulation is also provided.