Anodized aluminum alloy material having both durability and low polluting property

Abstract

An anodized aluminum alloy material is formed of an aluminum alloy having a Mg content between 0.1 and 2.0% by mass, a Si content between 0.1 and 2.0% by mass, a Mn content between 0.1 and 2.0% by mass, and an Fe, a Cr and a Cu content of 0.03% by mass or below and containing Al and unavoidable impurities as other components, and is coated with an anodic oxide film. Parts of the anodic oxide film at different positions with respect to thickness of the anodic oxide film have different hardnesses, respectively, and the difference in Vickers hardness between a part having the highest hardness and a part having the lowest hardness is Hv 5 or above.

1 . An anodized aluminum alloy material formed of an aluminum alloy having a Mg content between 0.1 and 2.0% by mass, a Si content between 0.1 and 2.0% by mass, a Mn content between 0.1 and 2.0% by mass, and an Fe, a Cr and a Cu content of 0.03% by mass or below and containing Al and unavoidable impurities as other components, and coated with an anodic oxide film;
 wherein parts of the anodic oxide film at different positions with respect to thickness of the anodic oxide film have different hardnesses, respectively, and difference in Vickers hardness between a part having the highest hardness and a part having the lowest hardness is Hv 5 or above.   
   
   
       2 . The anodized aluminum alloy material according to  claim 1 , wherein the hardness of the part having the lowest hardness of the anodic oxide film is Hv 365 or above.