Anodised aluminum sheet is to place the aluminum sheet in corresponding electrolyte (such as sulfuric acid, chromic acid, oxalic acid, etc.) as the anode for electrolysis under specific conditions with externally applied current. The aluminum sheet of the anode is oxidized and has an aluminum oxide film formed on the surface; the film is 5-20μm thick, and a hard anodic oxidation film can be up to 60-200μm thick. After anodization, the aluminum sheet achieves greater hardness, better abrasive resistance (up to 250-500 kg/mm2), and good resistance to heat; the hard anodic oxidation film also features a melting point of up to 2320 K, excellent insulativity, high breakdown voltage (up to 2000V), and enhanced resistance to corrosion (it may stand salt spray under ω=0.03NaCl for thousands of hours without being corroded). Additionally, the oxide film is distributed with numerous pores that can absorb various lubricants, thus making the anodised aluminum sheet suitable for manufacturing engine cylinder or other wear-resistant parts; the strong absorbability of the film can also be well utilized to form various bright colors.
Procedures for anodization of aluminum sheets: racking – degreasing – rinsing – alkaline corrosion – rinsing – neutralizing – rinsing - anodizing – rinsing – pore sealing – rinsing – off rack – testing – packing.
Among the procedures, degreasing, alkaline corrosion, neutralizing, anodizing and pore sealing are key to ensure the oxidation quality.
The top-grade quality anodized mirror aluminum sheet/anodised aluminum sheets are widely used in such fields as mechanical parts, airplane and automobile parts, precise instruments, wireless electrical appliances, building decorations, mechanical housing, illumination lamps, electronic consumables, art wares, household appliances, indoor decorations, sign boards, furniture automobile decorations, etc.