Methods for coloring aluminum-containing objects and their products

Abstract

A method for coloring an aluminum-containing object and an article thereof, the method comprising (a) applying a first pretreatment to the aluminum-containing object to remove contaminants from the surface of the aluminum-containing object; and (b) applying an anodizing treatment to the aluminum-containing object after step (a) to form an aluminum oxide film with nanopores on the surface of the aluminum-containing object. Step (b) is performed by providing N periodic current signals, each periodic current signal including first, second, third, and fourth predetermined time periods. The first predetermined time period is a constant current signal having a first current value. The second predetermined time period is a decreasing current signal gradually decreasing from the first current value to a second current value. The third predetermined time period is a constant current signal having the second current value. The fourth predetermined time period is a rapidly increasing current signal rapidly rising from the second current value to the first current value.

Description

Colorization Method for Aluminum-Containing Articles and Products Thereof The present invention relates to a colorization method for aluminum-containing articles, and particularly to a colorization method for aluminum-containing articles and products thereof that can exhibit different colors from different viewing angles. Anodizing, also known as anodic aluminum treatment, is a common method of forming a highly dense aluminum oxide film on the surface of aluminum or aluminum alloy through an electrochemical method. Anodizing can prevent the oxidation of the interior of aluminum or aluminum alloy, and improve the corrosion resistance, wear resistance, and aesthetics of aluminum or aluminum alloy. Based on the above advantages, anodizing has been widely used in the casings of electronic products. In addition, in order to increase the aesthetics of the casings of electronic products, colored anodic aluminum oxide films have received increasing attention in recent years. In existing colored anodizing processes, a thicker or higher-purity aluminum substrate is subjected to secondary or more anodizing treatments for a long time to produce an aluminum oxide film with regular nanopores, and dyes are filled into the nanopores of the aluminum oxide film to achieve colorization. There are also means in the prior art to color the anodized aluminum oxide film without the need for additional dyes. For example, the invention patent case with the publication number TWI553165B of the Republic of China (hereinafter referred to as the previous case 1) discloses a surface colorization method for anodic aluminum oxide, which sequentially includes: a step S10 of providing an aluminum-containing substrate, a one-time anodizing treatment step S11, an etching step S12, and a step S13 of plating a metal layer. In the step S10 of providing the aluminum-containing substrate, an aluminum layer with a thickness between 10 nm and 1000 nm is deposited on a substrate through sputtering. In the one-time anodizing treatment step S11, a three-electrode electrochemical potentiostat is used for anodizing; wherein, the aluminum-containing substrate is used as the working electrode, and Ag / AgCl and a platinum mesh are used as the auxiliary electrode and the reference electrode respectively. At room temperature, the aluminum-containing substrate is placed in a 0.3 M oxalic acid electrolyte, and a pulse signal with a period of 2 seconds is provided to the working electrode (that is, a constant voltage between 20 V and 60 V is maintained for 1 second, and then immediately a constant voltage of -2 V is maintained for 1 second), so as to form a porous aluminum oxide layer on the aluminum layer. In the etching step S12, a protective layer is first covered on a part of the porous aluminum oxide layer through a photolithography process to expose a remaining area of the porous aluminum oxide layer, and then it is immersed in an etching agent for a period of time, and then the protective layer is removed and it is immersed in the etching agent to continue soaking for another period of time, so that the porous aluminum oxide layer achieves pore expansion in two regions and at different times. In the step S13 of plating a metal layer, a metal layer with a reflectivity greater than 70% is plated on the surface of the porous aluminum oxide layer after pore expansion, and the material of the metal layer can be, for example, platinum, aluminum, silver, etc. Although the previous case 1 can use the metal layer to replace the use of dyes, thereby reducing the wastewater treatment problems faced after using dyes. However, when implementing the one-time anodizing treatment step S11 in the previous case 1, a pulsed signal with positive and negative fixed voltages is provided. Once the fixed voltage of each pulsed signal changes from a positive voltage value to a negative voltage value, problems such as excessive resistance leading to a decrease in the stability of the aluminum oxide film will occur. In addition, during the implementation of the etching step S12 in the previous case 1, the photolithography process still requires multiple sub-steps to complete the protective layer, and the steps are also very cumbersome. As can be seen from the above description, improving the stability of the aluminum oxide film obtained after anodizing treatment and simplifying the process are important issues that those skilled in the art need to break through. Therefore, the first object of the present invention is to provide a method for colorizing an aluminum-containing object with excellent stability of the aluminum oxide film. Thus, the method for colorizing an aluminum-containing object includes a step (a) and a step (b). The step (a) is to perform a first pretreatment on an aluminum-containing object to remove contaminants on the surface of the aluminum-containing object. The step (b) is to perform an anodizing treatment on the aluminum-containing object after the step (a), thereby forming an aluminum oxide film with a plurality of nanopores on the surface of the aluminum-containing object. In the present invention, when implementing the step (b), it is completed by providing N periodic current signals. Each periodic current signal includes a first predetermined time, a second predetermined time, a third predetermined time, and a fourth predetermined time; the first predetermined time is a constant current signal with a first current value; the second predetermined time is a decreasing current signal that gradually decreases from the first current value to a second current value; the third predetermined time is a constant current signal with the second current value; the fourth predetermined time is a rapidly increasing current signal that rapidly increases from the second current value to the first current value. The second object of the present invention is to provide a colorized aluminum-containing object obtained by the method for colorizing an aluminum-containing object described above. The alumin-containing article colorization of the present invention includes an alumin-containing article and an alumina film. The alumina film has N film bodies sequentially stacked on the surface of the alumin-containing article, and a plurality of photonic crystals distributed in each film body. Each photonic crystal sequentially has a first pore structure, a second pore structure, a plurality of third pore structures, and a fourth pore structure along a first direction. The first direction is the direction from these film bodies towards the surface of the alumin-containing article. The first pore structure of each photonic crystal is a nano-pore with an equal pore diameter extending along the first direction. The second pore structure of each photonic crystal communicates with the corresponding first pore structure and is a nano-pore with a decreasing pore diameter that gradually shrinks along the first direction. The third pore structures of each photonic crystal extend along the first direction and are spaced apart from each other along a second direction perpendicular to the first direction. The fourth pore structure of each photonic crystal extends along the first direction. The effect of the present invention is that when performing the anodizing treatment, since the second predetermined time of each cycle is a decreasing current signal, the alumina film of the colorized alumin-containing article obtained can have good stability, and the colorized alumin-containing article can present different colors at different viewing angles. Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals. Referring to FIGS. 1 and 5, an embodiment of the method for colorizing an alumin-containing article of the present invention is composed of the following steps: a step (a), a step (a'), a step (b), and a step (c). Step (a) is to perform a first pretreatment on a surface 611 of an alumin-containing article 6 to remove contaminants on the surface 611 of the alumin-containing article 6. In step (a) of this embodiment of the present invention, the first pretreatment sequentially includes polishing, degreasing, and sandblasting. Step (a') is to sequentially perform a second pretreatment on the alumin-containing article 6 after sandblasting, including degreasing, alkali washing, pre-acid washing, chemical polishing, and post-acid washing. Step (b) is to perform an anodizing treatment on the alumin-containing article 6 after step (a), thereby forming an alumina film 60 with a plurality of nano-pores on the surface 611 of the alumin-containing article 6. When implementing step (b), it is completed by providing N periodic current signals to the alumin-containing article 6. Each periodic current signal is as shown in FIG. 8 and includes a first predetermined time pt1, a second predetermined time pt2, a third predetermined time pt3, and a fourth predetermined time pt4. Specifically, the first predetermined time pt1 is a constant current signal with a first current value; the second predetermined time pt2 is a decreasing current signal that gradually decreases from the first current value to a second current value; the third predetermined time pt3 is a constant current signal with the second current value; the fourth predetermined time pt4 is a sudden increase current signal that rapidly increases from the second current value to the first current value. Step (c) is to perform an etching process on different regions of the alumina film 60 after step (b) to increase the pore diameter of the nanopores in the alumina film 60, so that the pore diameters of the nanopores increased after the etching process in different regions of the alumina film 60 are different. The etching process applicable to this embodiment of the present invention may be chemical wet etching, but is not limited to this etching method. In step (c) of this embodiment of the present invention, a segmented wet etching process is performed on the alumina film 60 after step (b) using an automated wet etching system 100 as shown in FIG. 2. Referring to FIG. 2, the automated wet etching system 100 of the present invention is used for an operator (not shown in the figure) to perform step (c) of the foregoing method. In a first embodiment of the automated wet etching system 100, it includes a base 1, a liquid storage container 2, a lifting device 3, and a control device 4. The liquid storage container 2 is used to contain an etchant 5 as shown in FIGS. 3 and 4. The lifting device 3 is used to fix the aluminum-containing object 6 after performing step (b). The lifting device 3 is used to hold the aluminum-containing object 6 and can drive the aluminum-containing object 6 to move up and down relative to the liquid storage container 2 along a height direction Z to different height positions, so that the aluminum-containing object 6 can be segmentedly immersed in the etchant 5 at different height positions for etching. The control device 4 is signal-connected to the lifting device 3 and is used for the operator to input a segmented wet etching condition of step (c) in the control device 4. The segmented wet etching condition includes a moving distance, a moving speed, and a stationary time of the lifting device 3. Referring to FIG. 3, step (c) of this embodiment of the present invention sequentially includes the following sub-steps: a first sub-step (c1), a first sub-step (c2), a first sub-step (c3), and a first sub-step (c4). The first sub-step (c1) is to completely immerse the aluminum-containing object 6 with the aluminum oxide film 60 formed after step (b) in the etchant 5 in the liquid storage container 2 of the automated wet etching system 100 and keep it stationary for a first time t1. The first sub-step (c2) of this embodiment of the present invention is to continuously move the aluminum-containing object 6 after the first sub-step (c1) upward along the height direction Z at a first moving speed V1 for a second time t2. During the second time t2, the top edge of the aluminum oxide film 60 is gradually exposed outside the etchant 5, and when the second time t2 is reached, the distance from the top edge of the aluminum oxide film 60 to the liquid level of the etchant 5 is a first distance L1 as shown in the first sub-step (c3) of FIG. 3. After the first sub-step (c2) is implemented, as shown in the first sub-step (c3) of FIG. 3, a part of the aluminum oxide film 60 is still immersed in the etchant 5. The first sub-step (c3) of this embodiment of the present invention is to continuously move the aluminum-containing object 6 after the first sub-step (c2) upward along the height direction Z at a second moving speed V2 for a third time t3. During the third time t3, the part of the aluminum oxide film 60 immersed in the etchant 5 is gradually exposed outside the etchant 5, and when the third time t3 is reached, the distance from the top edge of the aluminum oxide film 60 to the liquid level of the etchant 5 is the first distance L1 plus a second distance L2 as shown in the first sub-step (c4) of FIG. 3. After the first sub-step (c3) is implemented, as shown in the first sub-step (c4) of FIG. 3, there is still a remaining area of the aluminum oxide film 60 immersed in the etchant 5. The first sub-step (c4) of this embodiment of the present invention is to continuously move the aluminum-containing object 6 after the first sub-step (c3) upward along the height direction Z at a third moving speed V3 for a fourth time t4. During the fourth time t4, the remaining area of the aluminum oxide film 60 immersed in the etchant 5 is gradually exposed outside the etchant 5, and when the fourth time t4 is reached, the remaining area of the aluminum oxide film 60 completely leaves the liquid level of the etchant 5, and the distance from the top edge of the aluminum oxide film 60 to the liquid level of the etchant 5 is the first distance L1 plus the second distance L2 and a third height L3 (not shown in the figure). Referring to FIG. 4, step (c) of another embodiment of the present invention sequentially includes the following sub-steps: a first sub-step (c1), a second sub-step (c2), and a third sub-step (c3). The sub-step (c1) of this another embodiment of the present invention is the same as the sub-step (c1) of this embodiment, and will not be elaborated here. The sub-step (c2) of this another embodiment of the present invention is to move the aluminum-containing object 6 after the sub-step (c1) upward in the height direction Z, so that the top edge of the aluminum oxide film 60 is exposed outside the etchant 5. The distance from the top edge of the aluminum oxide film 60 to the liquid surface of the etchant 5 is a first distance L1, and a partial area of the aluminum oxide film 60 that is not exposed outside the liquid surface of the etchant 5 is continuously and statically immersed in the etchant 5 for a second time t2. The sub-step (c3) of this another embodiment of the present invention is to move the aluminum-containing object 6 after the sub-step (c2) upward in the height direction Z, so that the partial area of the aluminum oxide film 60 is exposed outside the etchant 5. The distance from the partial area of the aluminum oxide film 60 to the liquid surface of the etchant 5 is the first distance L1 plus a second distance L2, and a remaining area of the aluminum oxide film 60 that is not exposed outside the liquid surface of the etchant 5 is continuously and statically immersed in the etchant 5 for a third time t3. After reaching the third time t3, the aluminum-containing object 6 after the sub-step (c3) is moved upward in the height direction Z, so that the remaining area of the aluminum oxide film 60 completely leaves the liquid surface of the etchant 5 (not shown in the figure), and the distance of the remaining area of the aluminum oxide film 60 in the height direction Z is a third distance L3. In the sub-step (c1) and the sub-step (c2) of still another embodiment of the present invention, the aluminum-containing object 6 formed with the aluminum oxide film 60 is also etched by jet flow of the etchant 5. In the sub-step (c1) and the sub-step (c2) of yet another embodiment of the present invention, the aluminum-containing object 6 formed with the aluminum oxide film 60 can also rotate in the etchant 5. A colorized aluminum-containing object obtained by the step (b) of the colorization method of this embodiment of the present invention is shown in FIGS. 5 and 6, and it includes an aluminum-containing object 6 and an aluminum oxide film 60. The alumina film 60 has N film bodies 621 sequentially stacked on the surface 611 of the aluminum-containing object 6, and a plurality of photonic crystals 622 distributed in each film body 621. That is to say, as can be seen from FIG. 5, each film body 621 has a plurality of photonic crystals 622 distributed inside it, and each photonic crystal 622 sequentially has a first pore structure 6221, a second pore structure 6222, a plurality of third pore structures 6223, and a fourth pore structure 6224 along a first direction X. The first direction X is, as shown in FIGS. 5 and 6, the direction from the film body 621 towards the surface 611 of the aluminum-containing object 6. It should be noted that the photonic crystals 622 in each film body 621 respectively correspond to the periodic current signals in step (b). Therefore, the first pore structure 6221, the second pore structure 6222, the third pore structure 6223, and the fourth pore structure 6224 of each photonic crystal 622 in each film body 621 respectively correspond to the current signals at the first predetermined time pt1, the second predetermined time pt2, the third predetermined time pt3, and the fourth predetermined time pt4 of the respective periodic current signals. Further referring to FIGS. 6 and 7 in detail, the current signal based on the first predetermined time pt1 of each periodic current signal is a constant current signal having a first current value; therefore, the first pore structure 6221 of each photonic crystal 622 is a nano-pore with an equal pore diameter extending along the first direction X. In addition, the current signal based on the second predetermined time pt2 of each periodic current signal is a decreasing current signal gradually decreasing from the first current value to the second current value; therefore, the second pore structure 6222 of each photonic crystal 622 communicates with the corresponding first pore structure 6221, and is a nano-pore with a decreasing pore diameter gradually shrinking along the first direction X. The current signal based on the third predetermined time pt3 of each periodic current signal is a constant current signal having a second current value; therefore, the third pore structures 6223 of each photonic crystal 622 are arranged at intervals along the first direction X and along a second direction Y perpendicular to the first direction X. The third pore structures 6223 of each photonic crystal 622 do not communicate with the corresponding second pore structures 6222. Each of the third pore structures 6223 of each photonic crystal 622 is a nano-pore with an equal pore diameter, and the pore diameter of the nano-pores of each third pore structure 6223 is smaller than the pore diameter of the nano-pores of each first pore structure 6221. Moreover, the current signal at the fourth predetermined time pt4 based on each periodic current signal is a rapidly increasing current signal that rapidly rises from the second current value to the first current value; thus, the fourth hole structure 6224 of each photonic crystal 622 extends along the first direction X and is a nano-hole with a rapidly increasing aperture that rapidly increases along the first direction X. As shown in FIG. 7, the first hole structure 6221 and the fourth hole structure 6224 of each photonic crystal 622 in the first direction X are respectively in communication with the fourth hole structure 6224 and the first hole structure 6221 of two adjacent photonic crystals 622, the fourth hole structure 6224 of each photonic crystal 622 is in communication with the corresponding third hole structures 6223, and the first layer of film body 621 completed by the first periodic current signal after performing step (b) and its corresponding photonic crystal 622 are the farthest from the surface 611 of the aluminum-containing object 6, while the Nth layer of film body 621 completed by the Nth periodic current signal after performing step (b) and its corresponding photonic crystal 222 are in direct contact with the surface 611 of the aluminum-containing object 6. Integrating the above description, it can be seen that in step (b) of this embodiment of the present invention, after the Nth film body 621 is formed after performing the Nth time, the colorized aluminum-containing object obtained by the method of step (b) of the colorization method of this embodiment of the present invention has a decreasing current signal at the second predetermined time pt2 of each periodic current signal when performing step (b), which can avoid the high resistance problem that is not desirable when the background art uses a pulsed voltage signal to convert from a positive voltage value to a negative voltage value, and can also provide an inclined slope (that is, the second hole structure 6222 of each photonic crystal 622) between the nano-holes in the alumina film 60 and the entity (each film body 621). Therefore, the stability of the alumina film 60 obtained after anodic treatment can be improved, and the colorized aluminum-containing object can exhibit different colors at different viewing angles due to the aforementioned inclined slope. Regarding the relevant analysis results of being able to exhibit different colors at different viewing angles, it will be described in the following specific examples in conjunction with the color images shown in FIGS. 8 to 18 later. <Specific Example 1 (E1)> A specific example 1 (E1) of the colorization method of the aluminum-containing object of the present invention and the colorized aluminum-containing object obtained by the method are described in detail as follows. In this specific example 1 (E1) of the present invention, a circular aluminum alloy object with an outer diameter of 48 mm and a concentric circle shape is used for the colorization method. First, a first pretreatment is performed on an aluminum alloy object of Specific Example 1 (E1). Specifically, after rough polishing the aluminum alloy object of Specific Example 1 (E1) with diamond polishing liquid having a particle size of 1 - 10 μm and a polishing pad for 5 to 50 minutes, then fine polishing the aluminum alloy object with polishing liquid and a flannel pad for 30 to 200 minutes to complete the polishing of the first pretreatment. After completing the polishing of the first pretreatment, immerse the aluminum alloy object of Specific Example 1 (E1) in a degreasing liquid containing 1 to 10 vol% at 40 to 70˚C and perform ultrasonic oscillation cleaning for 1 to 10 minutes, then wash with pure water, blow dry, and then place in an oven at 75 to 100˚C to dry for 20 to 30 minutes to complete the degreasing of the first pretreatment. After completing the degreasing of the first pretreatment, the aluminum alloy object of Specific Example 1 (E1) is surface blasted using alumina balls (ball diameter 40 to 500 μm) at a pressure of 1 to 5 kg / cm 2 . Next, a second pretreatment is performed on the aluminum alloy object of Specific Example 1 (E1). Specifically, first immerse the aluminum alloy object in a degreasing liquid containing 1 to 10 vol% at 40 to 70˚C and perform ultrasonic oscillation cleaning for 1 to 10 minutes, then wash with pure water and complete the degreasing of the second pretreatment. Immerse the aluminum alloy object after completing the degreasing of the second pretreatment in an alkaline solution containing 1 to 10 wt.% of sodium hydroxide (NaOH) at 40 to 70˚C for 30 to 120 seconds, then wash with pure water to complete the alkali washing of the second pretreatment. Immerse the aluminum alloy object after completing the alkali washing of the second pretreatment in an acidic solution containing nitric acid (HNO 3 ) at 20 to 50˚C for 1 to 5 minutes and then wash with pure water to complete the pre-acid washing of the second pretreatment; wherein, the acidic solution is composed of a solution with a volume ratio of nitric acid: deionized water of 1 to 5: 9 to 5. Immerse the aluminum alloy object after completing the pre-acid washing of the second pretreatment in a phosphoric acid (H 3 PO 4 ) solution at 50 to 85˚C and a concentration of 50 to 85 wt.% for 10 to 300 seconds, then wash with pure water and complete the chemical polishing of the second pretreatment. Immerse the aluminum alloy object after completing the chemical polishing of the second pretreatment in an acid pickling solution for 1 to 5 minutes, then wash with pure water and complete the post-acid washing of the second pretreatment. Subsequently, an anodizing treatment is performed on the aluminum alloy object of Specific Example 1 (E1). Preferably, use sulfuric acid (H 2 SO 4) An electrolyte solution, with the above-mentioned aluminum alloy object as the anode and a lead plate as the cathode, provides a periodic current signal to the aluminum alloy object 30 to 300 times at a temperature of -5 to 10 °C to perform anodic treatment on it, and an alumina film with nanopores is formed on the surface of the aluminum alloy object. More preferably, the total time of each cycle is between 200 and 1800 seconds; the first predetermined time pt1 of each cycle and its corresponding current density (J1) are respectively between 30 and 300 seconds and between 1 and 5 mA / cm 2 ; the second predetermined time pt2 of each cycle and its corresponding current density decay rate (J2) are respectively between 10 and 150 seconds and between 0.027 and 0.09 mA·cm -2 ·s -1 ; the third predetermined time pt3 of each cycle and its corresponding current density (J3) are respectively between 150 and 1350 seconds and between 0.1 and 1 mA / cm 2 . The periodic current signal of the specific example 1 (E1) of the present invention is summarized in Table 1 below and shown in Figure 8. Table 1. Finally, the aluminum alloy object after anodic treatment is fixed on the holding module (31) shown in Figure 2, and a segmented wet etching treatment is applied to the alumina film on the surface of the aluminum alloy object of the specific example 1 (E1) through the automated wet etching system 100. Specifically, the segmented wet etching treatment of the specific example 1 (E1) of the present invention adopts a three-stage wet etching treatment at room temperature. The storage container 2 contains a phosphoric acid solution with a concentration between 1 and 35 wt% as the etchant 5, and the three-stage wet etching treatment is input by the operator into the control device (4) with the three-stage wet etching conditions of the specific example 1 (E1). The etchant in the specific example 1 (E1) of the present invention is a phosphoric acid solution with a concentration of 5 wt%. More preferably, the moving rates of the sub-step (c2) and sub-step (c3) of the specific example 1 (E1) of the present invention are between 0.01 and 2.00 mm / s. The three-stage wet etching conditions of the specific example 1 (E1) of the present invention are summarized in Table 2 below. Table 2. As can be seen from the SEM image shown in Figure 9, the alumina film obtained by oxidation after the anodic treatment of the specific example 1 (E1) of the present invention has multiple film bodies, and each film body has multiple photonic crystals. In addition, as is clearly visible from FIGS. 10 and 11, the top view image of the specific example 1 (E1) of the present invention after the anodizing treatment shows green, while the inclined view (45-degree angle) image shows purple. This proves that when the anodizing treatment is performed in the present invention, the second predetermined time pt2 of each cycle is a decreasing current signal, enabling the colored aluminum-containing object produced thereby to exhibit different colors at different viewing angles. Further referring to FIG. 12, it is clearly visible that the top view image of the specific example 1 (E1) of the present invention after the three-stage wet etching treatment shows a two-color gradient of green - blue-violet from top to bottom. <Specific Example 2 (E2)> A specific example 2 (E2) of the method for coloring the aluminum-containing object 6 of the present invention and the colored aluminum-containing object produced by the method are substantially the same as the specific example 1 (E1), except for the detailed conditions of the anodizing treatment and its segmented wet etching treatment in the specific example 2 (E2). More preferably, the total time of each cycle of the anodizing treatment in the specific example 2 (E2) of the present invention is between 200 and 2100 seconds; the first predetermined time pt1 of each cycle is between 40 and 360 seconds and between 1 and 5 mA / cm 2 and between; the third predetermined time pt3 of each cycle is between 200 and 1800 seconds. In addition, the wet etching treatment of the specific example 2 (E2) of the present invention further includes a step (c4). More preferably, the moving rates of the secondary step (c2), the secondary step (c3), and the secondary step (c4) in the specific example 2 (E2) of the present invention are between 0.01 and 2.00 mm / s. The detailed conditions of the anodizing treatment and its segmented wet etching treatment in the specific example 2 (E2) of the present invention are respectively summarized in Table 3. (and FIG. 13) and Table 4. Table 3. Table 4. As is clearly visible from FIGS. 14 and 15, the top view image of the specific example 2 (E2) of the present invention after the anodizing treatment shows orange, while the inclined view (45-degree angle) image shows green. Further referring to FIG. 16, it is clearly visible that the top view image of the specific example 2 (E2) of the present invention after the four-stage wet etching treatment shows a three-color gradient of orange-red - yellow-green - blue from top to bottom. <Specific Example 3 (E3)> A specific example 3 (E3) of the colorization method of the aluminum-containing object of the present invention and the colorization obtained by the method are substantially the same as specific example 2 (E2). The difference lies in that in the wet etching treatment of specific example 3 (E3), the aluminum alloy object with an aluminum oxide film formed thereon is also etched by the jet flow of the etching agent 5. As can be clearly seen from FIG. 17, the top-down perspective image of specific example 3 (E3) of the present invention after performing the four-stage wet jet etching treatment presents a multi-color gradient of orange - left yellow (right orange red) - blue green. <Specific Example 4 (E4)> A specific example 4 (E4) of the colorization method of the aluminum-containing object of the present invention and the colorization obtained by the method are substantially the same as specific example 3 (E3). The difference lies in that in the wet etching treatment of specific example 4 (E4), the aluminum alloy object with an aluminum oxide film formed thereon can also rotate in the etching agent 5. As can be clearly seen from FIG. 18, the perspective image from above of specific example 4 (E4) of the present invention after performing the four-stage wet rotary jet etching treatment presents a uniform gradient color change. Integrating the detailed descriptions of these specific examples (E1, E2, E3, E4), it can be known that the present invention not only enables the colorized aluminum-containing object obtained to present different colors at different viewing angles because the second predetermined time pt2 in each cycle is a decreasing current signal when performing anodic treatment, but also the aluminum oxide film after each anodic treatment can be subjected to segmented wet etching treatment, segmented wet jet etching treatment, and segmented wet rotary jet etching treatment by the automated wet etching system 100 shown in FIG. 2, so as to present segmented colors, colors with gradient distribution, multi-color gradients, or uniform gradient color changes in a single object, and can simplify the manufacturing process more than the technical solution proposed in the prior case 1 in the background art. The following details the first embodiment of the automated wet etching system 100 for implementing, for example, the aforementioned specific example 1 (E1) and specific example 2 (E2). For the convenience of subsequent description, a first horizontal direction X1, a second horizontal direction Y1 perpendicular to the first horizontal direction X1, and a vertical direction Z perpendicular to the first horizontal direction X1 and the second horizontal direction Y1 of the automated wet etching system 100 are defined (that is, the height direction Z, which will be described as the vertical direction Z hereinafter). The first horizontal direction X1 is taken as the front-rear direction. The direction indicated by the arrow in FIG. 2 is the front, and the reverse direction is the rear. The second horizontal direction Y1 is taken as the left-right direction. The direction indicated by the arrow in FIG. 2 is the left, and the reverse direction is the right. The vertical direction Z is the up-down direction. The direction indicated by the arrow in FIG. 2 is the up, and the reverse direction is the down. The base 1 includes a base body 11, a bracket 12 disposed at the top of the base body 11, and a frame 13 disposed at the top of the base body 11. The liquid storage container 2 is disposed at the top of the base body 11 of the base 1 and in front of the bracket 12, forming an etching tank for at least partially accommodating the etchant 5. The lifting device 3 is disposed on the bracket 12 of the base 1. Referring to FIGS. 19, 20, and 21, the aluminum-containing object 6 (or the object to be etched) is in the shape of a cube. The aluminum-containing object 6 has a top surface 61 and a back surface 62 vertically connected to the rear end of the top surface 61. A threaded hole 63 adjacent to the top surface 61 is formed by the back surface 62 of the aluminum-containing object 6 being recessed forward. The lifting device 3 includes a holding module 31 and a lifting module 33. The holding module 31 is disposed at the bottom end of the lifting module 33 for holding the aluminum-containing object 6. The lifting module 33 is disposed on the bracket 12 of the base 1 for driving the holding module 31 and the aluminum-containing object 6 held by the holding module 31 to move up and down in the vertical direction Z. The holding module 31 includes a hanging plate 310 connected to the bottom end of the lifting module 33, a holding member 311, and a fastening assembly 312. The hanging plate 310 has a top surface 313, a front surface 314 vertically connected to the front end of the top surface 313, a back surface 315 vertically connected to the rear end of the top surface 313, a stopping plane 316 vertically connected to the bottom end of the front surface 314 and spaced below the top surface 313 in the vertical direction Z, and a stopping vertical surface 317 vertically connected to the rear end of the stopping plane 316 and spaced in front of the back surface 315 in the first horizontal direction X1. The stopping plane 316 faces downward to stop the top surface 61 of the aluminum-containing object 6. The stopping vertical surface 317 faces forward to stop the back surface 62 of the aluminum-containing object 6. When the stopping plane 316 is configured to stop the aluminum-containing object 6, the aluminum-containing object 6 partially protrudes from the bottom end of the stopping vertical surface 317. Thereby, the overlapping range of the aluminum-containing object 6 and the hanging plate 310 in the first horizontal direction X1 can be reduced, so that most of the volume of the aluminum-containing object 6 protrudes from the bottom end of the stopping vertical surface 317 and does not overlap with the hanging plate 310. The stopping plane 316 and the stopping vertical surface 317 together define a positioning groove 318 for positioning the aluminum-containing object 6. A through hole 319 extending between the back surface 315 and the stopping vertical surface 317 and communicating with the positioning groove 318 is formed in the hanging plate 310. Two threaded holes 320 spaced in the second horizontal direction Y1 are formed by the top surface 313 of the hanging plate 310 being recessed downward. In this first embodiment, the holding member 311 is a screw extending in the first horizontal direction X1. The holding member 311 is used to pass through the through hole 319 of the hanging plate 310 and be screwed into the threaded hole 63 of the aluminum-containing object 6 to lock the aluminum-containing object 6 to the hanging plate 310 and hold the aluminum-containing object 6. The fastening assembly 312 includes two screws 321 spaced apart along the second horizontal direction Y1. Each screw 321 extends along the vertical direction Z for passing through the lifting module 33 and screwing into the corresponding screw holes 320 of the hanging plate 310 to lock the hanging plate 310 to the lifting module 33. The lifting module 33 is an electric cylinder. The lifting module 33 includes a lifting frame 331 capable of lifting and moving along the vertical direction Z. The lifting frame 331 has a flat plate 332 located at the bottom end for abutting against the top surface 313 of the hanging plate 310. Two through holes 333 spaced apart along the second horizontal direction Y1 are formed in the flat plate 332. Each through hole 333 is for a corresponding screw 321 to pass through, so that the screw 321 can lock the hanging plate 310 to the bottom surface of the flat plate 332. Referring to FIG. 2, the control device 4 is disposed on the frame 13 of the machine base 1 and electrically connected to the lifting module 33 of the lifting device 3. The control device 4 includes a control panel 41 for an operator to operate. The operator can input a segmented wet etching condition on the control panel 41 to control the distance and speed of the lifting frame 331 of the lifting module 33 moving along the vertical direction Z and the stationary time when the lifting frame 331 stops moving. Thereby, the lifting frame 331 can drive the aluminum-containing object 6 to perform segmented etching through the holding module 31. Referring to FIGS. 19 and 21, when assembling the hanging plate 310 of the holding module 31 to the flat plate 332 of the lifting frame 331, first abut the top surface 313 of the hanging plate 310 against the bottom surface of the flat plate 332 so that the screw holes 320 of the hanging plate 310 are respectively aligned with the through holes 333 of the flat plate 332. Subsequently, pass each screw 321 through the corresponding through hole 333 and screw it into the corresponding screw hole 320, then the hanging plate 310 can be locked to the bottom surface of the flat plate 332 and assembled on the flat plate 332. When disassembling the hanging plate 310 of the holding module 31 from the flat plate 332, loosen each screw 321. When each screw 321 disengages from the corresponding screw hole 320, the hanging plate 310 can be disassembled from the flat plate 332. The screw 321 of the fastening assembly 312 can lock or detach the hanging plate 310, so that the hanging plate 310 is detachably assembled and connected to the flat plate 332 of the lifting frame 331. Referring to FIGS. 19, 20 and 21, when assembling the aluminum-containing object 6 to the hanging plate 310, first place the top of the aluminum-containing object 6 in the positioning groove 318 of the hanging plate 310, so that the top surface 61 and the back surface 62 of the aluminum-containing object 6 respectively abut against the stopping plane 316 and the stopping vertical surface 317 of the hanging plate 310, and the screw hole 63 of the aluminum-containing object 6 is aligned with the through hole 319 of the hanging plate 310. Then, pass the holding member 311 through the through hole 319 and screw it into the screw hole 63, so that the aluminum-containing object 6 can be locked to the hanging plate 310. By the stopping plane 316 stopping the top surface 61 of the aluminum-containing object 6, after the holding member 311 locks the aluminum-containing object 6 to the hanging plate 310, it can prevent the aluminum-containing object 6 from rotating on the two-dimensional plane formed by the second horizontal direction Y1 and the vertical direction Z relative to the hanging plate 310. By the stopping vertical surface 317 stopping the back surface 62 of the aluminum-containing object 6, after the holding member 311 locks the aluminum-containing object 6 to the hanging plate 310, it can prevent the aluminum-containing object 6 from rotating on the two-dimensional plane formed by the first horizontal direction X1 and the second horizontal direction Y1 relative to the hanging plate 310, and from rotating on the two-dimensional plane formed by the first horizontal direction X1 and the vertical direction Z. Thereby, the holding module 31 can firmly lock the aluminum-containing object 6 to the hanging plate 310 and hold the aluminum-containing object 6 through one holding member 311, so as to reduce the number of components and the manufacturing cost of the holding module 31. The following will detail the method of performing segmented wet etching treatment on the aluminum-containing object 6 by the automated wet etching system 100: Referring to FIG. 2, first, the operator inputs segmented wet etching conditions on the control panel 41 to control the distance and speed of the lifting frame 331 of the lifting module 33 moving along the vertical direction Z and the stationary time when the lifting frame 331 stops moving. The segmented wet etching conditions of this first embodiment take the three-stage wet etching conditions as an example, so that the automated wet etching system 100 performs three-stage wet etching treatment on the aluminum-containing object 6. Of course, the aforementioned segmented wet etching conditions are not limited to three stages and can be set to four stages or more according to requirements. Referring to FIGS. 20 and 22, next, the control device 4 (shown in FIG. 2) controls the lifting module 33 to actuate, causing the lifting frame 331 to drive the holding module 31 and the aluminum-containing object 6 held by the holding module 31 to move downward along the vertical direction Z. When the aluminum-containing object 6 moves downward to the height position shown in FIG. 22 and is completely immersed in the etchant 5, the lifting frame 331 stops moving downward, so that the aluminum-containing object 6 can be stationary and immersed in the etchant 5 for a predetermined time. At this time, the entire section 600 of the aluminum-containing object 6 taken along the vertical direction Z is etched by the etchant 5. Due to the blocking of the blocking plane 316, most of the volume of the aluminum-containing object 6 protrudes from the bottom end of the blocking vertical surface 317 and does not overlap with the hanging plate 310. Therefore, when the entire section 600 of the aluminum-containing object 6 is completely immersed in the etchant 5, the volume of the hanging plate 310 immersed in the etchant 5 along with the aluminum-containing object 6 can be reduced. Referring to FIGS. 22 and 23, when the aluminum-containing object 6 is immersed in the etchant 5 for a predetermined time, the lifting frame 331 drives the holding module 31 and the aluminum-containing object 6 held by the holding module 31 to move upward along the vertical direction Z. When the aluminum-containing object 6 moves upward to the height position shown in FIG. 23, the lifting frame 331 stops moving upward, so that the aluminum-containing object 6 can be stationary and immersed in the etchant 5 for a predetermined time. The distance that the aluminum-containing object 6 moves upward is, for example, half of the height of the aluminum-containing object 6, so that the upper half section 601 of the aluminum-containing object 6 is exposed above the etchant 5, and the lower half section 602 of the aluminum-containing object 6 is immersed in the etchant 5 and etched by the etchant 5. Referring to FIGS. 23 and 24, when the lower half section 602 of the aluminum-containing object 6 is immersed in the etchant 5 for a predetermined time, the lifting frame 331 drives the holding module 31 and the aluminum-containing object 6 held by the holding module 31 to move upward along the vertical direction Z. When the aluminum-containing object 6 moves upward to the height position shown in FIG. 24, the distance that the aluminum-containing object 6 moves upward is, for example, half of the height of the aluminum-containing object 6, so that the lower half section 602 of the aluminum-containing object 6 is exposed above the etchant 5. Subsequently, the lifting frame 331 continues to drive the holding module 31 and the aluminum-containing object 6 held by the holding module 31 to move upward along the vertical direction Z, so that the aluminum-containing object 6 returns to the height position shown in FIG. 20. At this time, the segmented wet etching process of the aluminum-containing object 6 is completed. By driving the holding module 31 and the aluminum-containing object 6 to lift and move to different height positions by the lifting module 33, the aluminum-containing object 6 can be segmented and immersed in the etchant 5 at different height positions for etching, so that the upper half section 601 and the lower half section 602 of the aluminum-containing object 6 can respectively exhibit different etching effects. Referring to FIGS. 20 and 21, since the lifting module 33 is an electric cylinder, the lifting module 33 can drive the aluminum-containing object 6 to move up and down steplessly through the holding module 31, and can also accurately control the moving distance and speed, so that the aluminum-containing object 6 can be precisely positioned at different height positions. By arranging the holding module 31 at the bottom end of the lifting module 33, it is possible to avoid the lifting frame 331 colliding with the liquid storage container 2 during the process of driving the holding module 31 to move up and down. In addition, the holding module 31 holds the aluminum-containing object 6 by means of the cooperation of the hanging plate 310 and the holding member 311, which can reduce the space occupied by the holding module 31 on the two-dimensional plane formed by the first horizontal direction X1 and the second horizontal direction Y1. When the holding module 31 drives the aluminum-containing object 6 to penetrate into the liquid storage container 2, the holding module 31 can penetrate into the liquid storage container 2 along with the aluminum-containing object 6 without colliding with the liquid storage container 2, and can also reduce the volume of the holding module 31 immersed in the etching agent 5. Furthermore, by extending the holding member 311 along the first horizontal direction X1 and passing through the hanging plate 310 and locking the aluminum-containing object 6, the length of the holding member 311 can be designed to be shorter and can play the role of holding the aluminum-containing object 6. Referring to FIG. 25, it is a second embodiment of the automated wet etching system 100 of the present invention. Its overall structure is substantially the same as that of the first embodiment, except for the aluminum-containing object 6 and the holding module 31. Referring to FIGS. 25, 26 and 27, the aluminum-containing object 6 is in a circular ring shape. A plurality of spaced-apart jacks 64 are formed by the back surface 62 of the aluminum-containing object 6 being recessed forward. A plurality of mounting through holes 322 extending between the front surface 314 and the back surface 315 and spaced apart are formed on the hanging plate 310 of the holding module 31. The mounting through holes 322 respectively correspond to the positions of the jacks 64. The holding module 31 includes a plurality of holding members 311 respectively installed in the mounting through holes 322. Each holding member 311 is a pin extending along the first horizontal direction X1 and partially protruding from the front surface 314 of the hanging plate 310 for inserting into the corresponding jack 64 of the aluminum-containing object 6. Each holding member 311 is configured such that when inserted into the corresponding jack 64 of the aluminum-containing object 6, the back surface 62 of the aluminum-containing object 6 is spaced apart from the front surface 314 of the hanging plate 310. Thereby, it can prevent the back surface 62 of the aluminum-containing object 6 from fitting against the front surface 314 of the hanging plate 310 to ensure that the back surface 62 can be etched by the etching agent 5 when the aluminum-containing object 6 is immersed in the etching agent 5 (as shown in FIG. 20). An interference fit is provided between each holding member 311 and the corresponding jack 64. Thereby, it can prevent the aluminum-containing object 6 from detaching from the holding member 311 during the process of the holding module 31 driving the aluminum-containing object 6 to move up and down. The holding module 31 of this second embodiment provides another way to hold the aluminum-containing object 6, which is suitable for holding aluminum-containing objects with an outer peripheral surface in a circular ring shape or an arc shape and without a planar shape, and is suitable for holding aluminum-containing objects that are too thin to be processed to form screw holes. Referring to FIG. 28, it is a third embodiment of the automated wet etching system 100. The difference from the first embodiment lies in the aluminum-containing object 6', the liquid supply device 2' and the lifting device 7. The third embodiment is used to implement, for example, the aforementioned specific example 4 (E4). In the third embodiment, the liquid supply device 2' is disposed at the top of the base body 11 of the base 1 and in front of the support 12 for supplying the etching agent 5. The lifting device 7 includes a holding module and a lifting module 71 connected to each other. The holding module is a holding and rotating module 70 in this embodiment for holding an aluminum-containing object 6' and driving the aluminum-containing object 6' to rotate to different angular positions. The lifting module 71 is disposed on the support 12 of the base 1 and connected to the holding and rotating module 70 for driving the holding and rotating module 70 and the aluminum-containing object 6' to move relative to the liquid supply device 2' and align the aluminum-containing object 6' with the liquid supply device 2', so that the aluminum-containing object 6' can be etched by the etching agent 5 supplied by the liquid supply device 2' in segments at different angular positions. Referring to FIGS. 28, 29 and 30, the aluminum-containing object 6' has a shape such as an annular shape. The aluminum-containing object 6' has an inner peripheral surface 61' and an outer peripheral surface 62' opposite to the inner peripheral surface 61'. A perforation 63' is formed on the inner peripheral surface 61' of the aluminum-containing object 6'. The liquid supply device 2' includes a liquid storage container 21 with an upward opening. The liquid storage container 21 forms an etching tank for containing the etching agent 5 for the aluminum-containing object 6' to be contained so that the aluminum-containing object 6' can be immersed in the etching agent 5. Referring to FIGS. 29, 30, 31 and 32, the holding and rotating module 70 includes a carrier 72, a first holding wheel 73, a second holding wheel 74, a third holding wheel 75, an electric motor 76, a transmission mechanism 77, and a cylinder 78. The carrier 72 is upright and forms an accommodation space 721, a first pivot hole 722, a second pivot hole 723, a first accommodation hole 724, and a second accommodation hole 725. The accommodation space 721 is adjacent to the bottom end of the carrier 72. The first pivot hole 722 and the second pivot hole 723 are adjacent to the bottom end of the carrier 72 and are spaced apart from each other left and right along the second horizontal direction Y1. The first pivot hole 722 and the second pivot hole 723 each extend along the first horizontal direction X1. The first accommodation hole 724 communicates with the front end of the accommodation space 721 and is located above the first pivot hole 722 and the second pivot hole 723. The second accommodation hole 725 communicates with the front end of the accommodation space 721 and the rear end of the first pivot hole 722. The axis of the first holding wheel 73 extends along the first horizontal direction X1 for holding the aluminum-containing object 6'. The first holding wheel 73 includes a wheel body 731 and an elastic washer group 732. The wheel body 731 has a holding section 733 located in front of the carrier 72, a pivot section 734 extending rearward from the holding section 733 and pivotally connected to the first pivot hole 722 rotatably, and a connecting shaft section 735 extending rearward from the pivot section 734 and passing through the second accommodation hole 725 and the accommodation space 721. A circumferential groove 736 for accommodating the elastic washer group 732 is formed by radially recessing the outer peripheral surface of the holding section 733 of the wheel body 731. The circumferential groove 736 is used for accommodating a part of the aluminum-containing object 6'. The holding section 733 has two stop conical surfaces 737 respectively located on the opposite front and rear sides of the circumferential groove 736 for stopping the aluminum-containing object 6'. The elastic washer group 732 has a plurality of elastic washers 738 sleeved on the holding section 733 and accommodated in the circumferential groove 736. The elastic washer 738 is made of an elastic material such as silicone or rubber, for example, and is used to contact the aluminum-containing object 6', whereby damage to the aluminum-containing object 6' can be avoided when the first holding wheel 73 holds the aluminum-containing object 6'. The structure of the second holding wheel 74 is similar to that of the first holding wheel 73. The axis of the second holding wheel 74 extends along the first horizontal direction X1 for holding the aluminum-containing object 6'. The second holding wheel 74 includes a wheel body 741 and an elastic washer group 742. The wheel body 741 has a holding section 743 located in front of the carrier 72, and a pivot section 744 extending rearward from the holding section 743 and pivotally connected to the second pivot hole 723 rotatably. A circumferential groove 745 for accommodating the elastic washer group 742 is formed by radially recessing the outer peripheral surface of the holding section 743 of the wheel body 741. The circumferential groove 745 is used for accommodating a part of the aluminum-containing object 6'. The holding section 743 has two stop conical surfaces 746 respectively located on the opposite front and rear sides of the circumferential groove 745 for stopping the aluminum-containing object 6'. The elastic washer group 742 has a plurality of elastic washers 747 sleeved on the holding section 743 and accommodated in the circumferential groove 745. The elastic washer 747 is made of an elastic material such as silicone or rubber, for example, and is used to contact the aluminum-containing object 6', whereby damage to the aluminum-containing object 6' can be avoided when the second holding wheel 74 holds the aluminum-containing object 6'. By the pivot section 734 of the first holding wheel 73 and the pivot section 744 of the second holding wheel 74 being pivotally connected to the first pivot hole 722 and the second pivot hole 723 rotatably respectively, the first holding wheel 73 and the second holding wheel 74 are arranged at intervals left and right along the second horizontal direction Y1. Referring to FIGS. 30, 31, 32 and 33, the structure of the third holding wheel 75 is similar to that of the first holding wheel 73. The axis of the third holding wheel 75 extends along the first horizontal direction X1 for holding the aluminum-containing object 6'. The third holding wheel 75 includes a wheel body 751 and an elastic washer group 752. A circumferential groove 753 for accommodating the elastic washer group 752 is formed by radially recessing the outer peripheral surface of the wheel body 751. The circumferential groove 753 is used for accommodating a part of the aluminum-containing object 6'. The wheel body 751 has two stop conical surfaces 754 located on opposite sides before and after the circumferential groove 753 respectively for stopping the aluminum-containing object 6'. A pivot hole 755 is formed in the wheel body 751 of the third holding wheel 75. The elastic washer group 752 has a plurality of elastic washers 756 sleeved on the wheel body 751 and accommodated in the circumferential groove 753. The elastic washer 756 is made of an elastic material such as silicone or rubber, etc., for contacting the aluminum-containing object 6'. Thereby, damage to the aluminum-containing object 6' can be avoided when the third holding wheel 75 holds the aluminum-containing object 6'. Referring to FIGS. 32 and 34, in this third embodiment, the first holding wheel 73 and the second holding wheel 74 are each a supporting wheel for passing through the perforation 63' of the aluminum-containing object 6' and supporting the inner peripheral surface 61' of the aluminum-containing object 6' through the elastic washer groups 732 and 742. The third holding wheel 75 is spaced above the first holding wheel 73 and the second holding wheel 74 in the vertical direction Z and is between the first holding wheel 73 and the second holding wheel 74, such that the first holding wheel 73, the second holding wheel 74 and the third holding wheel 75 are arranged in a triangle. The third holding wheel 75 is a pressing wheel that can be lifted and lowered in the vertical direction Z. The elastic washer group 752 of the third holding wheel 75 is used for contacting the top of the outer peripheral surface 62' of the aluminum-containing object 6' and can press the aluminum-containing object 6' towards the first holding wheel 73 and the second holding wheel 74, such that the first holding wheel 73, the second holding wheel 74 and the third holding wheel 75 can stably hold the aluminum-containing object 6' in a three-point positioning manner. Referring to FIGS. 30, 31 and 32, the motor 76 is a stepping motor disposed at the front end of the carrier 72. The motor 76 has a driving shaft 761 accommodated in the first accommodation hole 724. The transmission mechanism 77 includes a first pulley 771 accommodated in the accommodation space 721 and the first accommodation hole 724, a second pulley 772 accommodated in the accommodation space 721 and the second accommodation hole 725, and a transmission belt 773 wound between the first pulley 771 and the second pulley 772. The first pulley 771 is sleeved and fixed on the driving shaft 761 of the motor 76. The second pulley 772 is sleeved and fixed on the connecting shaft section 735 of the first holding wheel 73. When the driving shaft 761 of the motor 76 rotates, it will drive the first holding wheel 73 to rotate through the transmission mechanism 77. Thereby, the first holding wheel 73 is the driving wheel for driving the aluminum-containing object 6' to rotate among the three holding wheels or the two supporting wheels, while the second holding wheel 74 and the third holding wheel 75 are both idler wheels. Referring to FIGS. 30, 33 and 34, the cylinder 78 is disposed at the front end of the carrier 72 and includes a sliding frame 781 that can move up and down along the vertical direction Z. The sliding frame 781 has a shaft 782 extending along the first horizontal direction X1. The shaft 782 passes through the pivot hole 755 of the third holding wheel 75 and is pivotally connected to the third holding wheel 75. The cylinder 78 is used to drive the third holding wheel 75 between an initial position away from the first holding wheel 73 and the second holding wheel 74 (as shown in FIG. 34), and a pressing position close to the first holding wheel 73 and the second holding wheel 74 and pressing against the top of the outer peripheral surface 62' of the aluminum-containing object 6' (as shown in FIG. 35). Referring to FIG. 29, the lifting module 71 is an electric cylinder. The lifting module 71 includes a lifting frame 711 that can move up and down along the vertical direction Z and is connected to the rear end of the carrier 72 of the holding and rotating module 70. The lifting frame 711 of the lifting module 71 is used to drive the holding and rotating module 70 and the aluminum-containing object 6' held by the holding and rotating module 70 to move up and down along the vertical direction Z, so that the aluminum-containing object 6' can be placed in the liquid storage container 21 and immersed in the etching agent 5. Referring to FIGS. 28 and 31, the control device 4 is disposed on the frame 13 of the machine base 1 and is electrically connected to the lifting module 71 of the lifting device 7, the motor 76 of the holding and rotating module 70, and the cylinder 78. The control device 4 includes a control panel 41 for the operator to operate. The operator can input a segmented wet etching condition on the control panel 41 to control the rotation angle and rotation speed of the drive shaft 761 of the motor 76 and the stationary time when the drive shaft 761 stops rotating, and control the operation of the lifting module 71 and the cylinder 78. Thereby, the motor 76 can drive the aluminum-containing object 6' to perform segmented etching through the transmission mechanism 77 and the first holding wheel 73. The following will detail the method of performing segmented wet etching treatment on the aluminum-containing object 6' by the automated wet etching system 100: Referring to FIGS. 28, 30 and 34, first, the operator assembles and hangs the aluminum-containing object 6' on the first holding wheel 73 and the second holding wheel 74 of the holding and rotating module 70, so that the first holding wheel 73 and the second holding wheel 74 pass through the through hole 63' of the aluminum-containing object 6' and support the inner peripheral surface 61' of the aluminum-containing object 6' through the elastic washer groups 732 and 742. Thereby, the first holding wheel 73 and the second holding wheel 74 can stably support the aluminum-containing object 6' to prevent the aluminum-containing object 6' from rotating and shaking relative to one of the first holding wheel 73 and the second holding wheel 74. Subsequently, the operator inputs segmented wet etching conditions on the control panel 41 to control the rotation angle and rotation speed of the drive shaft 761 of the electric motor 76 and the stationary time when the drive shaft 761 stops rotating. The segmented wet etching conditions of this third embodiment take the four-segment wet etching conditions as an example, enabling the automated wet etching system 100 to perform four-segment wet etching on the aluminum-containing object 6'. Of course, the foregoing segmented wet etching conditions are not limited to four segments and can be adjusted according to requirements. Referring to FIGS. 28, 35, and 36, then, the control device 4 controls the cylinder 78 to actuate, causing the sliding carriage 781 to drive the third holding wheel 75 to move downward in the vertical direction Z. When the third holding wheel 75 moves down to the pressing position shown in FIG. 35, the elastic washer group 752 of the third holding wheel 75 contacts the top of the outer peripheral surface 62' of the aluminum-containing object 6' and presses the aluminum-containing object 6' toward the first holding wheel 73 and the second holding wheel 74, such that the inner peripheral surface 61' of the aluminum-containing object 6' abuts tightly against the elastic washer group 732 of the first holding wheel 73 (as shown in FIG. 32) and the elastic washer group 742 of the second holding wheel 74. Thereby, the elastic washer group 732 of the first holding wheel 73, the elastic washer group 742 of the second holding wheel 74, and the elastic washer group 752 of the third holding wheel 75 firmly hold the aluminum-containing object 6' in a three-point positioning manner. Referring to FIGS. 28 and 37, thereafter, the control device 4 controls the lifting module 71 to actuate, causing the lifting frame 711 to drive the holding and rotating module 70 and the aluminum-containing object 6' held by the holding and rotating module 70 to move downward in the vertical direction Z. When the aluminum-containing object 6' moves down to a preset height position shown in FIG. 37 and is partially accommodated in the liquid storage container 21 and immersed in the etching agent 5, the lifting frame 711 stops moving downward, such that a first segment 64' of the lower half of the aluminum-containing object 6' can be stationary and immersed in the etching agent 5 for a predetermined time and be etched by the etching agent 5. Referring to FIGS. 28, 31, 37 and 38, when the first section 64' of the aluminum-containing object 6' is immersed in the etching agent 5 for a predetermined time, the control device 4 controls the motor 76 to actuate, causing the drive shaft 761 to drive the first pulley 771 to rotate in a rotational direction R. During the rotation of the first pulley 771, the second pulley 772 is driven to rotate synchronously in the rotational direction R through the transmission belt 773. During the rotation of the second pulley 772, the first holding wheel 73 is driven to rotate synchronously in the rotational direction R. During the rotation of the first holding wheel 73, the aluminum-containing object 6' is driven to rotate synchronously in the rotational direction R by the frictional force between the elastic washer 738 and the inner peripheral surface 61' of the aluminum-containing object 6'. When the aluminum-containing object 6' rotates to an angular position shown in FIG. 38, the drive shaft 761 of the motor 76 stops rotating, so that a second section 65' of the aluminum-containing object 6' located in the lower half can be stationary and immersed in the etching agent 5 for a predetermined time and be etched by the etching agent 5. The rotational angle of the aluminum-containing object 6' rotating to the aforementioned angular position is, for example, 90 degrees, such that the upper half of the first section 64' is exposed above the etching agent 5 while the lower half is still immersed in the etching agent 5. That is to say, the second section 65' includes the area of the lower half of the first section 64'. Referring to FIGS. 31, 36 and 38, by means of the blocking conical surfaces 737 of the first holding wheel 73, the blocking conical surfaces 746 of the second holding wheel 74 and the blocking conical surfaces 754 of the third holding wheel 75 blocking the front and rear ends of the aluminum-containing object 6', it is possible to prevent the aluminum-containing object 6' from shaking back and forth during the rotation in the rotational direction R, so that the first holding wheel 73, the second holding wheel 74 and the third holding wheel 75 can stably drive the aluminum-containing object 6' to rotate. Referring to FIGS. 28, 38 and 39, when the second section 65' of the aluminum-containing object 6' is immersed in the etching agent 5 for a predetermined time, the control device 4 controls the motor 76 to actuate again, causing the motor 76 to drive the aluminum-containing object 6' to rotate in the rotational direction R through the transmission mechanism 77 and the first holding wheel 73. When the aluminum-containing object 6' rotates to another angular position shown in FIG. 39, the drive shaft 761 of the motor 76 stops rotating, so that a third section 66' of the aluminum-containing object 6' located in the lower half can be stationary and immersed in the etching agent 5 for a predetermined time and be etched by the etching agent 5. The rotational angle of the aluminum-containing object 6' rotating to the aforementioned another angular position is also 90 degrees, such that the upper half of the second section 65' is exposed above the etching agent 5 while the lower half is still immersed in the etching agent 5. That is to say, the third section 66' includes the area of the lower half of the second section 65'. Referring to FIGS. 39 and 40, when the third section 66' of the aluminum-containing object 6' is immersed in the etching agent 5 for a predetermined time, the electric motor 76 will drive the aluminum-containing object 6' to rotate 90 degrees again through the transmission mechanism 77 and the first holding wheel 73 to another angular position shown in FIG. 40, so that a fourth section 67' of the aluminum-containing object 6' is immovably immersed in the etching agent 5 for a predetermined time and is etched by the etching agent 5. Referring to FIGS. 28, 35 and 40, when the fourth section 67' of the aluminum-containing object 6' is immersed in the etching agent 5 for a predetermined time, the control device 4 will control the lifting module 71 to act, so that the lifting frame 711 drives the holding and rotating module 70 and the aluminum-containing object 6' held by the holding and rotating module 70 to move upward in the vertical direction Z and reset to an initial height position shown in FIG. 35. Referring to FIGS. 28 and 34, subsequently, the control device 4 will control the cylinder 78 to act, so that the sliding frame 781 drives the third holding wheel 75 to move upward in the vertical direction Z and reset to the initial position shown in FIG. 34. At this time, the elastic washer group 752 of the third holding wheel 75 (shown in FIG. 31) moves away from the outer peripheral surface 62' of the aluminum-containing object 6' and is spaced from it by a certain distance, and the operator can conveniently and quickly remove the aluminum-containing object 6' from the first holding wheel 73 and the second holding wheel 74, that is, the segmented wet etching treatment of the aluminum-containing object 6' is completed. Referring to FIGS. 34 and 35, by means of the first holding wheel 73 and the second holding wheel 74 passing through the through hole 63' of the aluminum-containing object 6' and supporting at the top of the inner peripheral surface 61', the first holding wheel 73 and the second holding wheel 74 can suspend the aluminum-containing object 6'. Thereby, the first holding wheel 73 and the second holding wheel 74 can also have the effect of firmly supporting the aluminum-containing object 6' to avoid the situation that the aluminum-containing object 6' rotates and shakes relative to one of the first holding wheel 73 and the second holding wheel 74. In addition, it can ensure that when the aluminum-containing object 6' moves down to the preset height position, it can be partially immersed in the etching agent 5. Moreover, it can also avoid the situation that the first holding wheel 73 and the second holding wheel 74 are blocked by the top of the liquid storage container 21 and cannot move down. On the other hand, by means of the third holding wheel 75 and the cylinder 78 being arranged above the first holding wheel 73 and the second holding wheel 74, the structural complexity of the holding and rotating module 70 can be reduced, and it can also avoid the interference between the third holding wheel 75 and the cylinder 78 and the liquid storage container 21 and affect the lifting of the holding and rotating module 70. Referring to FIG. 41, it is a fourth embodiment of the automated wet etching system 100 of the present invention, and its overall structure is substantially the same as that of the third embodiment, the difference lies in the liquid supply device 2', in addition to rotation, jet etching such as the aforementioned specific example 3 (E3) can be simultaneously implemented. Referring to FIGS. 42 and 43, in this fourth embodiment, the liquid supply device 2' further includes a pump 22, a liquid suction pipe 23, and a flexible pipe 24. The pump 22 is disposed at the top of the base body 11 of the base 1 and on one side of the liquid storage container 21. The pump 22 is electrically connected to the control device 4 (shown in FIG. 28) and can be controlled by the control device 4 to operate. The liquid suction pipe 23 is connected between the liquid storage container 21 and the pump 22. The liquid suction pipe 23 is configured to suck the etching agent 5 contained in the liquid storage container 21 when the pump 22 operates. One end of the flexible pipe 24 is connected to the pump 22, and the flexible pipe 24 has a nozzle 241 opposite to the pump 22 and accommodated in the liquid storage container 21. The nozzle 241 can correspond to the position of the aluminum-containing object 6' and is configured to jet the etching agent 5 sucked by the pump 21 onto the aluminum-containing object 6' when the pump 21 operates. When the lifting frame 711 of the lifting module 71 drives the aluminum-containing object 6' to move downward to the preset height position shown in FIG. 42 through the holding and rotating module 70, the section of the aluminum-containing object 6' in the lower half corresponds to the position of the nozzle 241 of the flexible pipe 24 and is located behind the nozzle 241. By controlling the operation of the pump 22 by the control device 4, the pump 22 sucks the etching agent 5 contained in the liquid storage container 21 through the liquid suction pipe 23, and jets the sucked etching agent 5 onto the section of the aluminum-containing object 6' through the nozzle 241 of the flexible pipe 24 to perform jet etching on the first section 64'. The liquid storage container 21 is used to accommodate the etching agent 5 jetted out by the nozzle 241 for the liquid suction pipe 23 to suck. The holding and rotating module 70 drives the aluminum-containing object 6' to rotate to different angular positions in the manner described in the third embodiment, so that the aluminum-containing object 6' can be etched by the etching agent 5 jetted by the nozzle 241 in segments at different angular positions. The liquid supply device 2' of this fourth embodiment performs jet etching on the aluminum-containing object 6' through the nozzle 241, and can achieve the same etching effect as the third embodiment in a shorter time compared with the immersion etching of the third embodiment. Thereby, the etching processing time of the aluminum-containing object 6' can be greatly shortened to improve the speed and efficiency of the etching processing. Since the etching processing time of the aluminum-containing object 6' is short, the aluminum-containing object 6' can maintain better structural strength after the etching processing. In addition, by the pump 22 sucking the etching agent 5 in the liquid storage container 21 through the liquid suction pipe 23 and jetting the etching agent 5 through the nozzle 241 of the flexible pipe 24, and the liquid storage container 21 accommodating the etching agent 5 jetted out by the nozzle 241 and supplying it for the liquid suction pipe 23 to suck, the liquid supply device 2' can continuously recycle and use the etching agent 5. Moreover, since the flexible pipe 24 has the function of being able to bend and adjust, the operator can correspondingly adjust the jet position, angle, and direction of the nozzle 241 according to the jet requirements for different aluminum-containing objects, thereby increasing the flexibility in use. It should be noted that the holding and rotating module 70 of the third embodiment and the fourth embodiment may also have the following implementation aspects according to requirements: One implementation aspect: The holding and rotating module 70 omits the second holding wheel 74, the outer diameter of the first holding wheel 73 is close to the aperture diameter of the perforation 63' of the aluminum-containing object 6', and the aluminum-containing object 6' is supported by a single first holding wheel 73. Another implementation aspect: The holding and rotating module 70 omits the second holding wheel 74, and the first holding wheel 73 and the third holding wheel 75 are held on the inner peripheral surface 61' of the aluminum-containing object 6' in an inner clamping manner. Another implementation aspect: The holding and rotating module 70 omits the second holding wheel 74, and the first holding wheel 73 and the third holding wheel 75 are held on the outer peripheral surface 62' of the aluminum-containing object 6' in an outer clamping manner. Another implementation aspect: The first holding wheel 73 and the second holding wheel 74 are held on the outer peripheral surface 62' of the aluminum-containing object 6' and are adjacent to the bottom end of the outer peripheral surface 62', so that the first holding wheel 73, the second holding wheel 74 and the third holding wheel 75 hold the aluminum-containing object 6' in an outer clamping manner. Another implementation aspect: The first holding wheel 73 and the second holding wheel 74 are held on the outer peripheral surface 62' of the aluminum-containing object 6' and are adjacent to the top end of the outer peripheral surface 62', and the third holding wheel 75 is held at the top end of the inner peripheral surface 61' of the aluminum-containing object 6'. Another implementation aspect: The third holding wheel 75 is held at the bottom end of the inner peripheral surface 61' of the aluminum-containing object 6', so that the first holding wheel 73, the second holding wheel 74 and the third holding wheel 75 hold the aluminum-containing object 6' in an inner clamping manner. In summary, the colorization method of the aluminum-containing object of the present invention and its product can not only present different colors at different viewing angles, but also present segmented colors, gradually distributed colors, multi-color gradients or uniform gradual color changes in a single object, so it can indeed achieve the purpose of the present invention. However, the above are only examples of the present invention, and the scope of implementation of the present invention cannot be limited thereby. All simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification still fall within the scope covered by the patent of the present invention. 1: Machine base 100: Automated wet etching system 11: Base body 12: Bracket 13: Frame 2’: Liquid supply device 2, 21: Liquid storage container 22: Pump 23: Liquid extraction pipe 24: Flexible pipe 241: Nozzle 3: Lifting device 31: Holding module 310: Hanging plate 311: Holder 312: Fastening assembly 313: Top surface 314: Front surface 315: Back surface 316: Stopping plane 317: Stopping vertical surface 318: Positioning groove 319: Perforation 320: Screw hole 321: Screw 322: Mounting through hole 33: Lifting module 331: Lifting frame 332: Flat plate 333: Through hole 4: Control device 41: Control panel 5: Etchant 6, 6’: Aluminum-containing object 600: Whole section 60: Aluminum oxide film 601: Upper half section 602: Lower half section 61: Top surface 61’: Inner peripheral surface 611: Surface 62: Back surface 62’: Outer peripheral surface 621: Film body 622: Photonic crystal 6221: First hole structure 6222: Second hole structure 62223: Third hole structure 6224: Fourth hole structure 63: Screw hole 63’: Perforation 64: Jack 64’: First section 65’: Second section 66’: Third section 67’: Fourth section 7: Lifting device 70: Holding and rotating module 71: Lifting module 711: Lifting frame 72: Carrying frame 721: Accommodating space 722: First pivot hole 723: Second pivot hole 724: First accommodating hole 725: Second accommodating hole 73: First holding wheel 731: Wheel body 732: Elastic washer group 733: Holding section 734: Pivot section 735: Connecting shaft section 736: Annular groove 737: Stopping conical surface 738: Elastic washer 74: Second holding wheel 741: Wheel body 742: Elastic washer group 743: Holding section 744: Pivoting section 745: Annular groove 746: Stopping conical surface 747: Elastic washer 75: Third holding wheel 751: Wheel body 752: Elastic washer group 753: Annular groove 754: Stopping conical surface 755: Pivot hole 756: Elastic washer 76: Motor 761: Driving shaft 77: Transmission mechanism 771: First pulley 772: Second pulley 773: Transmission belt 78: Cylinder 781: Sliding frame 782: Shaft rod R: Rotation direction X: First direction X1: First horizontal direction Y: Second direction Y1: Second horizontal direction Z: Height direction (vertical direction) Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: FIG. 1 is; FIG. 1 is a flowchart illustrating an embodiment of the method for colorizing an aluminum-containing object of the present invention; FIG. 2 is a three-dimensional view illustrating a first embodiment of an automated wet etching system used in the etching process of step (c) of the method of the present invention and a three-dimensional view of an aluminum-containing object, illustrating the configuration relationship among a machine base, a liquid storage container, a lifting device, and a control device; FIG. 3 is a schematic diagram of an element manufacturing process, illustrating an implementation aspect of the method of this embodiment during the etching process of step (c); FIG. 4 is a schematic diagram of an element manufacturing process, illustrating another implementation aspect of the method of this embodiment during the etching process of step (c); FIG. 5 is a schematic diagram illustrating a plurality of nanopores of a photonic crystal in an aluminum oxide film obtained after implementing step (b) of this embodiment of the present invention; FIG. 6 is a partial enlarged schematic diagram of FIG. 5, illustrating the contours of the nanopores of each photonic crystal; FIG. 7 is a schematic diagram of an element manufacturing process, illustrating an implementation aspect of this embodiment of the present invention during the implementation of step (b); FIG. 8 is a graph of current density versus time, illustrating the periodic current density signal during the anodization process of step (b) in a specific example (E1) of the method for colorizing an aluminum-containing object of the present invention; FIG. 9 is a scanning electron microscope (SEM) cross-sectional image diagram, illustrating the microstructure of the aluminum oxide film obtained after the anodization process of step (b) in the specific example (E1) of the method for colorizing an aluminum-containing object of the present invention; FIG. 10 is a top-view image diagram, illustrating the color display of the aluminum-containing object after the anodization process of the specific example 1 (E1) of the present invention from a top view; FIG. 11 is an inclined-view image diagram, illustrating the color display of the aluminum-containing object after the anodization process of the specific example 1 (E1) of the present invention at an inclined angle (45 degrees); FIG. 12 is a top-view image diagram, illustrating the color display of the aluminum-containing object after the wet etching process of the specific example 1 (E1) of the present invention from a top view; FIG. 13 is a graph of current density versus time, illustrating the periodic current density signal during the anodization process of step (b) in a specific example (E2) of the method for colorizing an aluminum-containing object of the present invention; FIG. 14 is a top-view image diagram, illustrating the color display of the aluminum-containing object after the anodization process of the specific example 2 (E2) of the method for colorizing an aluminum-containing object of the present invention from a top view; FIG. 15 is an inclined-view image diagram, illustrating the color display of the aluminum-containing object after the anodization process of the specific example 2 (E2) of the present invention at an inclined angle (45 degrees); FIG. 16 is a top-view image diagram, illustrating the color display of the aluminum-containing object after the wet etching process of the specific example 2 (E2) of the present invention from a top view;FIG. 17 is a top - view image diagram showing the color - display situation of an aluminum - containing object after wet etching treatment in a specific example 3 (E3) of implementing the colorization method of the aluminum - containing object of the present invention from a top - view angle; FIG. 18 is a top - view image diagram showing the color - display situation of an aluminum - containing object after wet etching treatment in a specific example 4 (E4) of implementing the colorization method of the aluminum - containing object of the present invention from a top - view angle; FIG. 19 is a three - dimensional exploded view of the lifting device of the first embodiment of the automated wet - etching system and the aluminum - containing object; FIG. 20 is an incomplete front - view of the first embodiment of the automated wet - etching system and the aluminum - containing object; FIG. 21 is an incomplete side - view of the lifting device of the first embodiment of the automated wet - etching system and the aluminum - containing object; FIG. 22 is an incomplete front - view of the first embodiment of the automated wet - etching system and the aluminum - containing object, showing that the lifting device drives the aluminum - containing object to move downward so that the aluminum - containing object is completely immersed in the etching agent in the liquid - storage container; FIG. 23 is an incomplete front - view of the first embodiment of the automated wet - etching system and the aluminum - containing object, showing that the lifting device drives the aluminum - containing object to move upward so that the aluminum - containing object is partially immersed in the etching agent in the liquid - storage container; FIG. 24 is an incomplete front - view of the first embodiment of the automated wet - etching system and the aluminum - containing object, showing that the lifting device drives the aluminum - containing object to move upward so that the aluminum - containing object is exposed from the etching agent in the liquid - storage container; FIG. 25 is a three - dimensional view of a lifting device of a second embodiment of the automated wet - etching system and the aluminum - containing object; FIG. 26 is a three - dimensional exploded view of the lifting device of the second embodiment of the automated wet - etching system and the aluminum - containing object; FIG. 27 is an incomplete side - view of the lifting device of the second embodiment of the automated wet - etching system and the aluminum - containing object; FIG. 28 is a three - dimensional view of a third embodiment of the automated wet - etching system and the aluminum - containing object, showing the configuration relationship among the machine base, the liquid - supply device, the lifting device, and the control device; FIG. 29 is an incomplete three - dimensional view of the third embodiment of the automated wet - etching system and the aluminum - containing object; FIG. 30 is a three - dimensional exploded view of a holding and rotating module of the third embodiment of the automated wet - etching system and the aluminum - containing object; FIG. 31 is a cross - sectional view of the holding and rotating module of the third embodiment of the automated wet - etching system; FIG. 32 is a cross - sectional view of the holding and rotating module of the third embodiment of the automated wet - etching system; FIG. 33 is a cross - sectional view of the holding and rotating module of the third embodiment of the automated wet - etching system; FIG. 34 is an incomplete front - view of the third embodiment of the automated wet - etching system and the aluminum - containing object, showing that a first holding wheel and a second holding wheel support the aluminum - containing object, and a third holding wheel is in an initial position; FIG. 35 is an incomplete front - view of the third embodiment of the automated wet - etching system and the aluminum - containing object, showing that the third holding wheel is in a pressing position, and the first holding wheel, the second holding wheel, and the third holding wheel hold the aluminum - containing object; FIG. 36 is an incomplete cross - sectional view of the holding and rotating module of the third embodiment of the automated wet - etching system and the aluminum - containing objectFIG. 37 is an incomplete front view of the third embodiment of the automated wet etching system and the aluminum-containing object, illustrating that the lifting device drives the aluminum-containing object downward so that a part of the aluminum-containing object is immersed in the etching agent in the liquid storage container; FIG. 38 is an incomplete front view of the third embodiment of the automated wet etching system and the aluminum-containing object, illustrating that the holding and rotating module drives the aluminum-containing object to rotate to an angular position; FIG. 39 is an incomplete front view of the third embodiment of the automated wet etching system and the aluminum-containing object, illustrating that the holding and rotating module drives the aluminum-containing object to rotate to another angular position; FIG. 40 is an incomplete front view of the third embodiment of the automated wet etching system and the aluminum-containing object, illustrating that the holding and rotating module drives the aluminum-containing object to rotate to another angular position; FIG. 41 is an incomplete perspective view of a fourth embodiment of the automated wet etching system and the aluminum-containing object, illustrating the connection relationship between the liquid storage container, a pump, a liquid suction pipe, and a flexible pipe; FIG. 42 is an incomplete perspective view of the fourth embodiment of the automated wet etching system and the aluminum-containing object; and FIG. 43 is an incomplete sectional view of the fourth embodiment of the automated wet etching system and the aluminum-containing object, illustrating that a nozzle of the flexible pipe jets the etching agent onto the aluminum-containing object.;

Claims

1. A method for coloring an aluminum-containing object, comprising the following steps: a step (a) of applying a first pretreatment to an aluminum-containing object to remove contaminants from a surface of the aluminum-containing object; and a step (b) of applying an anodizing treatment to the aluminum-containing object after step (a) to form an aluminum oxide film having a plurality of nanopores on the surface of the aluminum-containing object; wherein, Step (b) is performed by providing 30 to 300 periodic current signals, each periodic current signal including a first predetermined time, a second predetermined time, a third predetermined time, and a fourth predetermined time; wherein, the first predetermined time is a fixed current signal having a first current value; wherein, the second predetermined time is a decreasing current signal gradually decreasing from the first current value to a second current value; wherein, the third predetermined time is a fixed current signal having the second current value; wherein, the fourth predetermined time is a rapidly increasing current signal rapidly rising from the second current value to the first current value; wherein, the first predetermined time of each cycle is between 30 and 300 seconds, and the current density corresponding to the first predetermined time of each cycle is between 1 and 5 mA / cm²; wherein, the second predetermined time of each cycle is between 10 and 150 seconds, and the current density deceleration rate corresponding to the second predetermined time of each cycle is between 0.027 and 0.09 mA·cm⁻²·s⁻¹. The third predetermined time of each cycle is between 150 and 1350 seconds, and the current density corresponding to the third predetermined time of each cycle is between 0.1 and 1 mA / cm2; and the fourth predetermined time of each cycle is less than 1 second.

2. The method for colorizing aluminum-containing objects as described in claim 1, wherein, In step (a), the first pretreatment sequentially includes polishing, degreasing, and sandblasting.

3. The method for colorizing aluminum-containing articles as described in claim 2, wherein, Between step (a) and step (b) there is a step (a') which is to sequentially apply a second pretreatment to the sandblasted aluminum-containing object, including degreasing, alkaline washing, pre-acid washing, chemical polishing and post-acid washing.

4. A colored aluminum-containing object, comprising: an aluminum-containing object; an alumina film formed by the anodizing process described in step (b) of claim 1, the alumina film having 30 to 300 film bodies sequentially stacked on a surface of the aluminum-containing object, and a plurality of photonic crystals distributed in each film body, wherein each photonic crystal sequentially has a first pore structure, a second pore structure, a plurality of third pore structures, and a fourth pore structure along a first direction, the first direction being a direction from the film bodies toward the surface of the aluminum-containing object; wherein... The first aperture structure of each photonic crystal is formed by a constant current signal having the first current value, and is a nano-aperture with a constant aperture extending along the first direction; wherein, the second aperture structure of each photonic crystal is formed by a decreasing current signal that gradually decreases from the first current value to the second current value, and is a nano-aperture with a decreasing aperture that connects to the corresponding first aperture structure and gradually shrinks along the first direction. In this embodiment, the third hole structures of each photonic crystal are formed by a constant current signal having the second current value, and extend along the first direction and are spaced apart from each other along a second direction perpendicular to the first direction. The third hole structures of each photonic crystal are not connected to their respective second hole structures. Each third hole structure of each photonic crystal is a nano-hole with a uniform aperture, and the aperture of the nano-hole of each third hole structure is smaller than the aperture of the nano-hole of each first hole structure. In this embodiment, the fourth hole structure of each photonic crystal is formed by a rapidly increasing current signal that rises rapidly from the second current value to the first current value, and extends along the first direction. The fourth hole structure of each photonic crystal is a nano-hole with a rapidly increasing aperture that increases rapidly along the first direction.

5. The colored aluminum-containing article as described in claim 4, wherein, The first hole structure and the fourth hole structure of each photonic crystal in the first direction are connected to the fourth hole structure and the first hole structure of the two adjacent photonic crystals, respectively.

6. The colored aluminum-containing article as described in claim 4, wherein, The fourth pore structure of each photonic crystal is connected to its corresponding third pore structure.

Images