Coated article and method for manufacturing same

Abstract

A coated article includes a substrate including a porous surface and an anodic oxidation film. The porous surface defines a plurality of nanopores. The anodic oxidation film is formed on the substrate covering the porous surface by anodic oxidation process. The anodic oxidation film has a plurality of bonding protrusions, and each bonding protrusion is retained in one of the nanopores to improve a binding force between the substrate and the anodic oxidation film.

1 . A coated article, comprising:
 a substrate including a porous surface, the porous surface defining a plurality of nanopores; and   an anodic oxidation film formed on the substrate covering the porous surface by anodic oxidation process;   wherein the anodic oxidation film has a plurality of bonding protrusions, and each bonding protrusion is retained in a nanopore to improve a binding force between the substrate and the anodic oxidation film.   
     
     
         2 . The coated article as claimed in  claim 1 , wherein the substrate is made of aluminum or aluminum alloy. 
     
     
         3 . The coated article as claimed in  claim 1 , wherein the nanopores are formed by electrochemical etching. 
     
     
         4 . The coated article as claimed in  claim 1 , wherein each nanopore has a pore opening size between 8 nm and 20 nm in circumference. 
     
     
         5 . The coated article as claimed in  claim 1 , wherein each nanopore has a pore opening size between 10 nm and 15 nm in circumference. 
     
     
         6 . The coated article as claimed in  claim 1 , wherein the anodic oxidation film has a thickness between about 5 micrometers and about 20 micrometers. 
     
     
         7 . The coated article as claimed in  claim 1 , further comprising a color layer formed on the anodic oxidation film opposite to the substrate. 
     
     
         8 . The coated article as claimed in  claim 7 , wherein the color layer has a thickness between about 0.5 micrometers and about 2 micrometers. 
     
     
         9 . The coated article as claimed in  claim 7 , wherein the color layer is one selecting from a group consisting of a titanium nitride layer, a titanium nitric-oxide layer, a titanium carbon-nitride layer, a chromium nitride layer and a chromium carbon-nitride layer. 
     
     
         10 . A method for manufacturing a coated article, the method comprising:
 providing a substrate, the substrate including a porous surface, the porous surface defining a plurality of nanopores;   forming an anodic oxidation film on the substrate covering the porous surface by anodic oxidation process;   during forming the anodic oxidation film, portions of the anodic oxidation film enter into the nanopores to form a plurality of bonding protrusions, and each bonding protrusion is retained in one of the nanopores to improve a binding force between the substrate and the anodic oxidation film.   
     
     
         11 . The method of  claim 10 , wherein the substrate is made of aluminum or aluminum alloy. 
     
     
         12 . The method of  claim 10 , wherein before the anodic oxidation film is deposited on the substrate, the substrate is treated by alkali treatment. 
     
     
         13 . The method of  claim 12 , wherein during the substrate is treated by alkali treatment, the substrate is dipped in a solution including 30-50 g/L of NaOH and 1-2 g/L of sodium gluconate at a temperature of 40-60° C. for a time of 1-5 minutes. 
     
     
         14 . The method of  claim 10 , wherein the nanopores are defined by electrochemical etching. 
     
     
         15 . The method of  claim 14 , wherein during electrochemical etching, the substrate acts as an anode, a platinum plate acts as cathode, using 20-30 g/L of hydrochloric acid or 250-350 g/L of sulphuric acid as electrolyte, a constant power applied between the anode and the cathode have a current density between about 6 A/d m 2  and about 10 A/d m 2  for about 5 minutes to about 10 minutes to define the nanopores. 
     
     
         16 . The method of  claim 10 , wherein during anodic oxidation, using 180-220 g/L of sulphuric acid as electrolyte, the electrolyte has a temperature between 19° C. and 21° C., a constant power applied to the electrolyte has a current density between about 1 A/m 2  and about 1.5 A/m 2  for about 20 minutes to about 40 minutes to form the anodic oxidation film. 
     
     
         17 . The method of  claim 10 , wherein after depositing the anodic oxidation film, the substrate is dipped in a 5-10 g/L of nickel acetate solution at a temperature between 90° C. and 100° C. for a time of 10 minutes to 15 minutes, to improve corrosion resistance of the anodic oxidation film. 
     
     
         18 . The method of  claim 10 , further comprising a step of depositing a color layer on the anodic oxidation film by vacuum deposition.