An aluminum alloy is described and has compositions with mass percentage content consisting of: 5.0%-5.4% Zn; 0.9%-1.2% Mg; Cu<0.05%; Si<0.05%; Fe<0.1%; Mn<0.05%; Zr<0.1%; Ti<0.05%; other impurities<0.15%; and the remaining composition being Al. An anodizing method of the aluminum alloy described above is described and has: a degreasing treatment, a first black-film stripping treatment, a chemical polishing treatment, a second black-film stripping treatment, an anodizing treatment, a hole filling treatment, and a drying treatment which are performed in turn. The aluminum alloy has a higher strength while eliminating an influence of a formed compound phase on a material texture.

A method of anodic treatment for a metal workpiece combined with a non-metallic material includes steps as follows. A pretreatment process is applied to the metal workpiece. The metal workpiece is anodic oxidized, and washed with water. Then, the metal workpiece is put in a vacuum environment to evaporate a residual chemical agent between a metal part and a plastic part of the metal workpiece. The metal workpiece is washed with water. An activating treatment is applied to the metal workpiece. The metal workpiece is dyed, and is sealed.

A method of anodic treatment for a metal workpiece combined with a non-metallic material includes steps as follows. A pretreatment process is applied to the metal workpiece. The metal workpiece is anodic oxidized, and washed with water. Then, the metal workpiece is put in a vacuum environment to evaporate a residual chemical agent between a metal part and a plastic part of the metal workpiece. The metal workpiece is washed with water. An activating treatment is applied to the metal workpiece. The metal workpiece is dyed, and is sealed.

A chemical polishing bath for polishing a part made of aluminum or of aluminum alloy, or a portion of such a part, which bath includes an oxidizing agent capable of attacking the aluminum, chosen from nitric acid, hydrogen peroxide, permanganate, or a mixture thereof, at a concentration between 1.2 and 3.0 mol/L. The polishing bath also includes a fluoride complexing agent capable of forming a complex with the oxidized aluminum, at a concentration between 0.3 and 1.6 mol/L; a catalyst (Cu); and phosphoric acid at a concentration between 10.10 and 14.30 mol/L and also sulfuric acid at a concentration between 1.50 and 3.60 mol/L. The bath is particularly suitable for polishing parts resulting from additive manufacturing (3D printing).

A chemical polishing bath for polishing a part made of aluminum or of aluminum alloy, or a portion of such a part, which bath includes an oxidizing agent capable of attacking the aluminum, chosen from nitric acid, hydrogen peroxide, permanganate, or a mixture thereof, at a concentration between 1.2 and 3.0 mol/L. The polishing bath also includes a fluoride complexing agent capable of forming a complex with the oxidized aluminum, at a concentration between 0.3 and 1.6 mol/L; a catalyst (Cu); and phosphoric acid at a concentration between 10.10 and 14.30 mol/L and also sulfuric acid at a concentration between 1.50 and 3.60 mol/L. The bath is particularly suitable for polishing parts resulting from additive manufacturing (3D printing).