Method for colorizing aluminum-containing object and colorized aluminum-containing object therefrom

Abstract

A method for colorizing an aluminum-containing object includes the steps of: (a) subjecting the aluminum-containing object to a first pretreatment, so as to remove contaminants from a surface thereof; and (b) subjecting the pretreated aluminum-containing object obtained in step (a) to an anodizing treatment which is accomplished by applying N cycles of periodic current signals, thereby forming an aluminum oxide film with a plurality of nanopores on the surface of the aluminum-containing object. In step (b), each cycle of the periodic current signals includes a first to fourth predetermined time periods. A colorized aluminum-containing object prepared by the aforesaid method is also provided.

What is claimed is: 
     
         1 . A method for colorizing an aluminum-containing object, comprising:
 (a) subjecting the aluminum-containing object to a first pretreatment, so as to remove contaminants from a surface of the aluminum-containing object; and   (b) subjecting the pretreated aluminum-containing object obtained in step (a) to an anodizing treatment which is accomplished by applying N cycles of periodic current signals, thereby forming an aluminum oxide film with a plurality of nanopores on the surface of the aluminum-containing object;   
       wherein in step (b), each cycle of the periodic current signals includes a first predetermined time period in which a first constant current density is applied, a second predetermined time period in which the first constant current density decreases to a second constant current density at a decreasing rate of current density, a third predetermined time period in which the second constant current density is applied, and a fourth predetermined time period in which the second constant current density rapidly increases to the first constant current density at an increasing rate of current density. 
     
     
         2 . The method according to  claim 1 , wherein in step (a), the first pretreatment is conducted by subjecting the aluminum-containing object to polishing, degreasing, and sandblasting in sequence. 
     
     
         3 . The method according to  claim 2 , further comprising, after performing step (a) and before performing step (b), step (a′) of subjecting the aluminum-containing object obtained after performing the sandblasting to a second pretreatment which includes degreasing, alkaline cleaning, pre-pickling, chemical polishing, and post-pickling in sequence. 
     
     
         4 . A colorized aluminum-containing object, comprising:
 an aluminum-containing object; and   an aluminum oxide film which has a number M of film bodies sequentially stacked on a surface of the aluminum-containing object, and a plurality of photonic crystals distributed within each of the film bodies, each of the photonic crystals having a first pore structure, a second pore structure, a plurality of third pore structures, and a fourth pore structure in sequence along a first horizontal direction, the first horizontal direction being a direction from the film bodies toward the surface of the aluminum-containing object;   
       wherein the first pore structure of each of the photonic crystals is a nanopore having an equal diameter and extending along the first horizontal direction; 
       wherein the second pore structure of each of the photonic crystals is a nanopore being in communication with the first pore structure of the same photonic crystal, and having a decreasing diameter that gradually tapers and extends along the first horizontal direction; 
       wherein the plurality of third pore structures of each of the photonic crystals extend along the first horizontal direction, and are spaced apart from each other along a second horizontal direction perpendicular to the first horizontal direction; and 
       wherein the fourth pore structure of each of the photonic crystals extends along the first horizontal direction. 
     
     
         5 . The colorized aluminum-containing object according to  claim 4 , wherein the plurality of third pore structures of each of the photonic crystals are not in communication with the second pore structure of the same photonic crystal. 
     
     
         6 . The colorized aluminum-containing object according to  claim 5 , wherein each of the third pore structures of each of the photonic crystals is a nanopore having an equal diameter which is smaller than the equal diameter of the nanopore of each of the first pore structures. 
     
     
         7 . The colorized aluminum-containing object according to  claim 5 , wherein the fourth pore structure of each of the photonic crystals is a nanopore having an increasing diameter that rapidly enlarges and extends along the first horizontal direction. 
     
     
         8 . The colorized aluminum-containing object according to  claim 7 , wherein the first pore structure and the fourth pore structure of each of the photonic crystals in the first horizontal direction are respectively in communication with the fourth pore structure of an adjacent one of the photonic crystals above and the first pore structure of an adjacent one of the photonic crystals below. 
     
     
         9 . The colorized aluminum-containing object according to  claim 7 , wherein the fourth pore structure of each of the photonic crystals is in communication with the plurality of third pore structures of the same photonic crystal.