CN114990660A - Variable-angle different-color anodic oxidation method - Google Patents

Abstract

The invention discloses a variable-angle different-color anodic oxidation method, which comprises the steps of adjusting the membrane pores of an anodic oxide membrane on the surface of a part to be processed from an upper drift diameter structure to a lower drift diameter structure into a variable-diameter structure; and arranging an electrolytic coloring deposition layer in the membrane hole, wherein the part of the membrane hole above the upper surface of the electrolytic coloring deposition layer at least comprises two sections of hole sections with different inner diameters. The method can effectively control the processing process, intervene in the color expression of the final product, realize the color-variable effect of a vertical and small-angle light color system and a parallel and large-angle observation system, and the product after multicolor treatment can meet the special visual demand of the existing subdivided high-end market. Meanwhile, the product can pass through a good sealing process of the subsequent process, the performance index of the product can meet important corrosion resistance tests and weather resistance tests, and the product obtained by the method can achieve the corrosion resistance and the weather resistance which are equal to those of common oxidation or electrolytic coloring.

Description

Variable-angle different-color anodic oxidation method

Technical Field

The invention relates to the technical field of metal surface treatment, in particular to a variable-angle and different-color anodic oxidation method.

Background

Anodic oxidation electrolytic coloring of aluminum and aluminum alloy articles is one of the important methods in the surface treatment of aluminum and aluminum alloys. The aluminum alloy is placed in proper electrolyte to be used as anode for electrifying treatment, an anodic oxide film with the thickness of several to dozens of micrometers is generated on the surface, and the surface of the oxide film is in a porous honeycomb shape. In the last 60 years, people began to use the porosity of oxide films and combined anodic oxidation and electrodeposition technologies to invent electrolytic coloring technologies. The aluminum alloy anodic oxidation electrolytic coloring technology originally originates from Europe, and is widely applied to various aspects such as automobiles, aviation, shipbuilding, machinery, buildings, daily life and the like due to simple and convenient operation, simple process and low cost.

The principle of anodic oxidation electrolytic coloring is that a porous type anodic oxide film includes regular and controllable micropores, and very fine metal and/or oxide particles are deposited at the bottom of the pores by electrolytic coloring, and different colors can be obtained due to the scattering effect of light. The shade of the colour is related to the number of deposited particles, i.e. to the colouring time and to the applied voltage. Generally, the electrolytic colouring colour resemblance is from champagne, light to dark bronze to black, the hue not being exactly the same, which is related to the size distribution of the precipitated particles. At present, the electrolytic coloring is only bronze, black, golden yellow and purplish red. Aluminum or aluminum alloy trim strips for automobiles are usually subjected to anodic oxidation electrolytic coloring treatment to obtain a finish layer having a specific color difference on the surface thereof.

However, in the prior art, the texture of the common aluminum or aluminum alloy decorative strip for the automobile is derived from the natural color of metal or the appearance obtained after the common electrolytic coloring treatment, so that the appearance only has relatively monotonous champagne color, bronze color, black color and other colors, the final finished product of the aluminum or aluminum alloy decorative strip for the automobile has a single visual effect, and the requirement of people on the color diversity of the product cannot be met.

Disclosure of Invention

The invention provides a variable-angle different-color anodic oxidation method.

The invention provides the following scheme:

a variable-angle heterochromatic anodic oxidation method comprises the following steps:

adjusting the film hole of the anodic oxide film on the surface of the part to be processed into a diameter-variable structure from an upper drift diameter structure and a lower drift diameter structure;

an electrolytic coloring deposition layer is arranged in the membrane hole, and the part of the membrane hole, which is positioned above the upper surface of the electrolytic coloring deposition layer, at least comprises two sections of hole sections with different inner diameters, so that light waves irradiating on the electrolytic coloring deposition layer generate film interference in the reflection process, and the aim of displaying different colors when a user observes from different angles is further achieved.

Preferably: the pore of the anodic oxide film is adjusted into a reducing structure from an upper drift diameter structure and a lower drift diameter structure, and the pore of the anodic oxide film comprises the following components:

placing the part to be treated in a first solution, wherein the first solution comprises a first acid substance and a second acid substance; the second acid substance can be subjected to electrolytic reaction to generate larger membrane pores compared with the first acid substance by oxidation; the first acid substance is an acid substance used in the electrolytic oxidation forming process of the anodic oxide film;

and alternately introducing alternating current and direct current into the first solution to perform electrolytic machining so as to adjust the membrane hole of the anodic oxide membrane from an upper drift diameter structure to a lower drift diameter structure.

Preferably: the first acid comprises a sulfuric acid solution, and the electrolytic oxidation comprises:

and carrying out electrolytic oxidation 1320-1800 seconds on the part to be treated by using 180-210 g/L sulfuric acid at the temperature of 15-20 ℃ and the voltage of 13-17 volts so as to form the anodic oxide film on the surface of the part to be treated.

Preferably: the second acid species comprises a phosphoric acid solution; and alternately introducing alternating current and direct current into the first solution to perform electrolytic machining to adjust the oxide film barrier layer contained in the anodic oxide film, and adjusting the film hole of the anodic oxide film into a reducing structure with a large bottom and a small top from an upper drift diameter structure and a lower drift diameter structure.

Preferably: the first solution includes a Phoenix IM1 coloring additive, the second acid species being provided by the Phoenix IM1 coloring additive.

Preferably: the concentration of the Phoenix IM1 coloring additive contained in the first solution is 35-45 g/L, and the concentration of the sulfuric acid solution is 30-40 g/L;

to alternating current and direct current of letting in the first solution carry out the electrolytic machining right the oxide film barrier layer that anodic oxide film contains adjusts, will anodic oxide film's membrane hole is by the big-end-up reducing structure of latus rectum structure adjustment down, includes:

adjusting the temperature of the first solution to 17-21 ℃, switching to 2-5V alternating current for electrolytic machining for 8-12 minutes after electrolytic machining is carried out for 2-3 minutes by adopting 10-15V direct current, and switching back to 10-15V direct current for electrolytic machining for 4-10 minutes.

Preferably: the electrolytic coloring deposition layer is arranged in the film hole and comprises:

placing the part to be treated in a second solution, wherein the second solution comprises a sulfuric acid solution with the concentration of 16-22 g/L, stannous sulfate with the concentration of 16-22 g/L and a stabilizer with the concentration of 20-35 g/L;

adjusting the temperature of the second solution to be 20-28 ℃, and carrying out electrolytic machining for 2-6 minutes by adopting 10-18V alternating current to obtain the electrolytic coloring deposition layer.

Preferably: the hole sealing processing is carried out after the electrolytic coloring deposition layer is arranged in the film hole, and the hole sealing processing comprises the following steps:

washing the part to be treated, placing the washed part into a conventional closed tank solution, and carrying out primary hole sealing, wherein the primary hole sealing comprises treating the part at the temperature of 30 ℃ for 15-30 minutes by using a Phoenix 531 hole sealing agent; the concentration of the Phoenix 531 hole sealing agent is 2-8 g/l;

carrying out secondary hole sealing processing on the part to be processed after the primary hole sealing processing, wherein the secondary hole sealing processing comprises processing for 15-20 minutes at the temperature of 90-100 ℃ by adopting a Phoenix 595 sealing agent; the concentration of the Phoenix 595 hole sealing agent is 20g/L-45 g/L;

and (4) boiling and cleaning the part to be treated after the second hole sealing processing by hot water at 80 ℃ and then hanging the part to be treated.

Preferably: before the anodic oxide film on the surface of the part to be processed is subjected to electrolytic oxidation, after the part to be processed is sequentially subjected to degreasing and electrochemical polishing, the part to be processed is subjected to electrolytic oxidation so that the anodic oxide film is formed on the surface of the part to be processed.

Preferably: the degreasing and electrochemical polishing treatment of the part to be treated in sequence comprises the following steps:

washing the part to be treated with a phosphatized alkaline degreasing agent at 40-60 ℃ for 4-7 minutes;

the degreased part to be processed is subjected to electrochemical polishing for 10 to 20 minutes in binary mixed acid with the concentration of 600-800 g/L phosphoric acid and the concentration of 340-420 g/L sulfuric acid at the temperature of between 58 and 65 ℃ under the voltage of between 35 and 45V;

the part to be treated after electrochemical polishing is subjected to film removing for 30 to 40 seconds at the temperature of 28 to 32 ℃ by using a sodium hydroxide solution with the concentration of 20 to 35 g/L;

and (3) removing ash from the part to be treated after the membrane is removed in a sulfuric acid solution with the concentration of 170-200 g/L at 15-20 ℃ for 100-140 seconds.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the variable-angle different-color anodic oxidation method can be realized, and in an implementation mode, the method can comprise the steps of adjusting the membrane pores of the anodic oxide membrane on the surface of the part to be processed from an upper drift diameter structure to a lower drift diameter structure to be of a variable-diameter structure; an electrolytic coloring deposition layer is arranged in the membrane hole, and the part of the membrane hole, which is positioned above the upper surface of the electrolytic coloring deposition layer, at least comprises two sections of hole sections with different inner diameters, so that light waves irradiating on the electrolytic coloring deposition layer generate film interference in the reflection process, and the aim of displaying different colors when a user observes from different angles is further achieved. The variable-angle heterochromatic multicolor anodic oxidation method provided by the embodiment of the application can effectively control the processing process, intervene in the color expression of the final product, realize vertical and small-angle light colors, and parallel and large-angle observation into the variable color effect of a dark color system, and the product after polychromization treatment can meet the special visual requirements of the existing subdivided high-end market. Meanwhile, the product can pass through the sealing process (pore filling or composite coating covering) with good post-procedure, the performance index can meet important corrosion resistance test and weather resistance test, and the product obtained by the method provided by the application can achieve the same corrosion resistance and weather resistance as common oxidation or electrolytic coloring.

Of course, it is not necessary for any product in which the invention is practiced to achieve all of the above-described advantages at the same time.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of a Keller model of an aluminum alloy oxide film provided by an embodiment of the present invention;

FIG. 2 is a microstructure model of an aluminum alloy oxide film provided by an embodiment of the present invention;

FIG. 3 is a microstructure model (electrolytically colored porous layer salt-precipitated state) of an aluminum alloy oxide film provided by an embodiment of the present invention;

FIG. 4 is a microstructure model of an aluminum alloy oxide film provided by an embodiment of the present invention (the film pore structure after oxidation is changed by a treatment method provided by the present application);

FIG. 5 is a microstructure model of an aluminum alloy oxide film provided by an embodiment of the present invention (the hole wall salt deposition position after coloring by the method provided by the present application);

FIG. 6 is a schematic diagram of the principle of polychromization of a light display provided by an embodiment of the present invention.

In the figure: the film comprises a metal substrate 1, a barrier layer 2, a film hole 3, a hole wall 4, a honeycomb 5, an electrolytic coloring deposition layer 6, a thin film layer 7 formed by tin salt deposition hole walls after the bottom aperture of an anodic oxide film is enlarged, an amorphous transparent film layer 8 in a porous layer main closed area of the anodic oxide film, a refractive index n and a film thickness d.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

Examples

The embodiment of the invention provides a variable-angle different-color anodic oxidation method, which comprises the following steps:

adjusting the film hole 3 of the anodic oxide film on the surface of the part to be processed into a reducing structure from an upper drift diameter structure and a lower drift diameter structure;

an electrolytic coloring deposition layer 6 is arranged in the membrane hole, and the part of the membrane hole 3 above the upper surface of the electrolytic coloring deposition layer at least comprises two sections of hole sections with different inner diameters, so that light waves irradiating on the electrolytic coloring deposition layer generate film interference in the reflection process, and the purpose that a user observes from different angles to present different colors is further achieved.

According to the variable-angle different-color anodic oxidation method provided by the embodiment of the application, the step of changing the pore structure is added between the electrolytic oxidation step (generating the anodic oxide film) and the electrolytic coloring step (coloring after the anodic oxide film is generated), so that the pore structure can be changed into the variable-diameter structure from the upper and lower drift diameter structures. The variable diameter structure in the embodiment of the present application means that the inside of the membrane hole includes at least two hole sections with different diameters, for example, as shown in fig. 4 and 5, wherein the hole section at the bottom has a larger inner diameter and the hole section at the top has a smaller inner diameter.

In the anodic oxidation electrolytic machining process, by adding a stable and controllable secondary electrolytic process, the traditional anodic oxidation (namely electrolytic machining) process is primary electrolysis, the method provided by the embodiment of the application has the main key point that the secondary electrolytic section is added, and for the subsequent electrolytic coloring machining, namely the three electrolytic processes in the method, the electrolytic coloring belongs to the secondary electrolytic process for the traditional coloring oxidation electrolytic machining. The anodic oxide film is formed into a single porous layer structure (the oxide film structure is theorized into a porous hexagonal column model according to a Keller model, as shown in figures 1, 2 and 3) and is further differentiated into a new thin film layer due to obvious difference in microstructure size, wherein in the theoretical model for explaining the mechanism, practically, each film layer structure is composed of an oxide layer which is fine and does not contain electrolyte ions and an alumina gel plasmid sublayer aggregate which contains the electrolyte ions, and a product which is subjected to electrolytic coloring and subsequent sealing treatment can visually present different color appearance effects at different angles under the sunlight due to the principle of film-like interference.

It can be understood that, in practical applications, the adjustment of the film hole structure may be implemented by using a variety of methods, for example, in one implementation manner, the embodiment of the present application may provide that the adjusting of the film hole of the anodic oxide film from the upper and lower drift diameter structures to the reducing diameter structure includes:

placing the part to be treated in a first solution, wherein the first solution comprises a first acid substance and a second acid substance; the second acid substance can be subjected to electrolytic reaction to generate larger membrane pores compared with the first acid substance by oxidation; the first acid substance is an acid substance used in the electrolytic oxidation formation process of the anodic oxide film;

and alternately introducing alternating current and direct current into the first solution to perform electrolytic machining so as to adjust the membrane hole of the anodic oxide membrane from an upper drift diameter structure to a lower drift diameter structure.

After the formation of the anodic oxide film, the structure of the film pores may be changed by performing secondary electrolytic processing in the first solution. The first acid substance is used for realizing primary electrolytic oxidation processing of the part to be processed so as to form an anodic oxide film on the surface of the part to be processed. When the second acid substance and the first acid substance are used together for electrolytic processing, the inside of the film hole of the anodic oxide film obtained by processing the first acid substance can show different dissolution and growth speeds, and finally the film hole is processed into a reducing structure.

Adjusting a hole bottom barrier layer in a dilute sulfuric acid solution containing an additive of a second acid substance, promoting the growth of a new oxide film through an electric field in a DC-AC-DC switching mode, influencing the one-time electrolytic oxidation and the further dissolution (field dissolution) of the oxide film generated by the first-stage presoaking, and realizing the co-promotion interaction of microscopic growth and dissolution by the interaction of the two processes, thereby realizing the stable and controllable adjustment effect and preparing for finally generating a metal film; the process can also shorten the first section, namely, the first section directly starts from the alternating current section (namely, alternating current-direct current), and then the direct current section is switched, the effect can also be achieved, the scheme of switching twice is verified on the repeatability of the color, the procedure is the key for controlling the color, the stability of multicolor products is ensured, and the industrialization and the commercialization of new processes are realized.

The first acid and the second acid provided in the embodiments of the present application may be selected variously, for example, in one implementation, the embodiments of the present application may provide that the first acid includes a sulfuric acid solution, and the electrolytic oxidation includes:

and (3) carrying out electrolytic oxidation 1320-1800 seconds on the part to be treated by using 180-210 g/L sulfuric acid at the temperature of 15-20 ℃ and the voltage of 13-17 volts so as to form the anodic oxide film on the surface of the part to be treated.

The second acid species comprises a phosphoric acid solution; and alternately introducing alternating current and direct current into the first solution to perform electrolytic machining to adjust the oxide film barrier layer contained in the anodic oxide film, and adjusting the film hole of the anodic oxide film into a reducing structure with a large bottom and a small top from an upper drift diameter structure and a lower drift diameter structure.

The first solution includes a Phoenix IM1 coloring additive, the second acid species being provided by the Phoenix IM1 coloring additive.

The concentration of the Phoenix IM1 coloring additive contained in the first solution is 35-45 g/L, and the concentration of the sulfuric acid solution is 30-40 g/L;

to alternating current and direct current of letting in the first solution carry out the electrolytic machining right the oxide film barrier layer that anodic oxide film contains adjusts, will anodic oxide film's membrane hole is by the big-end-up reducing structure of latus rectum structure adjustment down, includes:

adjusting the temperature of the first solution to 17-21 ℃, switching to 2-5V alternating current for electrolytic machining for 8-12 minutes after electrolytic machining is carried out for 2-3 minutes by adopting 10-15V direct current, and switching back to 10-15V direct current for electrolytic machining for 4-10 minutes.

The colored sedimentary deposit of electrolysis that this application embodiment provided can adopt the colored technology of electrolysis to set up in the diaphragm orifice, it is specific set up the colored sedimentary deposit of electrolysis in the diaphragm orifice, include:

placing the part to be treated in a second solution, wherein the second solution comprises a sulfuric acid solution with the concentration of 16-22 g/L, stannous sulfate with the concentration of 16-22 g/L and a stabilizer with the concentration of 20-35 g/L;

adjusting the temperature of the second solution to be 20-28 ℃, and carrying out electrolytic processing for 2-6 minutes by adopting 10-18V alternating current to obtain the electrolytic coloring deposition layer.

In order to improve the strength of the formed final product, the embodiment of the present application may further provide that the hole sealing process is performed after the electrolytic coloring deposition layer is disposed in the film hole, and includes:

washing the part to be treated, placing the washed part into a conventional closed tank solution, and carrying out primary hole sealing, wherein the primary hole sealing comprises treating the part at the temperature of 30 ℃ for 15-30 minutes by using a Phoenix 531 hole sealing agent; the concentration of the Phoenix 531 hole sealing agent is 2-8 g/l;

carrying out secondary hole sealing processing on the part to be processed after the primary hole sealing processing, wherein the secondary hole sealing processing comprises processing for 15-20 minutes at the temperature of 90-100 ℃ by adopting a Phoenix 595 sealing agent; the concentration of the Phoenix 595 hole sealing agent is 20g/L-45 g/L;

and (4) boiling and cleaning the part to be treated after the second hole sealing processing by hot water at 80 ℃ and then hanging the part to be treated.

Further, before the anodic oxide film on the surface of the component to be processed is subjected to electrolytic oxidation, after the component to be processed is sequentially subjected to degreasing and electrochemical polishing, the component to be processed is subjected to electrolytic oxidation so that the anodic oxide film is formed on the surface of the component to be processed.

The degreasing and electrochemical polishing treatment of the part to be treated in sequence comprises the following steps:

washing the part to be treated with a phosphatized alkaline degreasing agent at 40-60 ℃ for 4-7 minutes;

subjecting the degreased part to be treated to electrochemical polishing for 10-20 minutes in binary mixed acid with the concentration of 600-800 g/L phosphoric acid and the concentration of 340-420 g/L sulfuric acid at the temperature of 58-65 ℃ under the voltage of 35-45V;

the part to be treated after electrochemical polishing is subjected to film removing for 30-40 seconds at 28-32 ℃ by using a sodium hydroxide solution with the concentration of 20-35 g/L;

and (3) removing ash from the part to be treated after the membrane is removed in a sulfuric acid solution with the concentration of 170-200 g/L at 15-20 ℃ for 100-140 seconds.

The performance of the anodic oxide film is mainly determined by the sealing quality of the oxidation micropores, or the corrosion resistance of the film material (such as a sprayed varnish layer) of the oxide film and the outer organic and inorganic composite film layers of the oxide film, and only the multi-color process is described without being described in detail;

the scheme provided by the application relates to several common sense theories:

film interference: if a light wave is irradiated to the thin film, the light wave is reflected by the upper interface and the lower interface of the thin film due to different refractive indexes, and a new light wave is formed due to mutual interference, which is called thin film interference.

② conditions for generating thin film interference:

a. the disturbance directions of the two trains of waves are consistent, or parallel components with consistent directions exist. If orthogonal, it must be non-coherent superimposed.

b. Frequency identity is another condition of coherence. If the two trains of waves have different frequencies, the two trains of waves are necessarily incoherently superposed.

c. A stable phase difference, a stable interference pattern can be obtained.

③ the phase difference: the phase relation depends on the different optical paths of the two reflected lights, namely the optical path difference; and the optical path length depends on the film thickness, optical constants, and wavelength; the formula is summarized as follows: 2nd ═ i +1/2 λ (2 is because the lower surface reflects light through the film twice, n is the refractive index, d is the film thickness, i is an integer, and λ is the wavelength of the light).

The variable-angle heterochromatic multicolor anodic oxidation method provided by the embodiment of the application can effectively control the processing process, intervene in the color expression of the final product, realize vertical and small-angle light colors, and parallel and large-angle observation into the variable color effect of a dark color system, and the product after polychromization treatment can meet the special visual requirements of the existing subdivided high-end market.

Meanwhile, the sealing process (pore channel filling or composite coating covering) with good post-procedure performance can be carried out, the performance index can meet the important corrosion resistance test and weather resistance test (ISO 9227 plus 2017-neutral salt spray corrosion test (NSS); DIN 50018-AHT 2.0S-condensate water alternating climate; PV 1200 plus 2004-climate alternating stability), and the product obtained by the method provided by the application can achieve the corrosion resistance and the weather resistance which are equal to the corrosion resistance and the weather resistance of common oxidation or electrolytic coloring.

In practical application, the method provided by the embodiment of the application can comprise the following steps:

the method provided by the embodiment of the application can be used for further electrochemically polishing and brightening the semi-finished product of the aluminum or the aluminum alloy before anodic oxidation on the basis of polishing the outer surface by a front-sequence machine (the front process of the outer decoration of the automobile industry needs mechanical polishing), so that the defect of fine polishing texture generated on the surface in the mechanical polishing process is reduced, and a good foundation is laid for the subsequent generation of a good oxide film surface; then oxidizing to generate a porous oxide film layer formed by the porous layer and the barrier layer, and then entering dilute sulfuric acid tank liquor containing specific additives, wherein the Phoenix IM1 coloring additive is used for pore-expanding adjustment, the main effective component in the Phoenix IM1 coloring additive is acid substances such as phosphoric acid and the like which can be subjected to electrolytic reaction to generate film pores larger than sulfuric acid oxidation, and then electrolytic coloring is carried out, and the metal deposition layer at the bottom pore-expanding film layer part is generally only 0.05-0.3 mu m, thereby forming the metal film optical condition of the interference effect.

Firstly, washing the preorder semi-finished product for 4-7 min by using an alkaline phosphatizing degreasing agent at the temperature of 40-60 ℃;

secondly, electrochemical polishing is carried out for 10min to 20min in binary mixed acid of phosphoric acid (600g/L to 800g/L) and sulfuric acid (340g/L to 420g/L) at the temperature of 58 ℃ to 65 ℃ by introducing the voltage of 35V to 45V

Thirdly, removing the membrane for 30 to 40 seconds at the temperature of between 28 and 32 ℃ by using 20 to 35g/L of sodium hydroxide solution;

fourthly, 170g/L to 200g/L of sulfuric acid is used for ash removal and light extraction for 100s to 140s at the temperature of 15 ℃ to 20 ℃;

fifthly, anodizing for 1320-1800 s with 180g/L-210g/L sulfuric acid at 15-20 ℃ and 13-17V;

sixthly, adjusting an oxide film barrier layer (an anodic oxide film comprises an oxide film porous layer and an oxide film barrier layer) in a sulfuric acid solution at the temperature of 17-21 ℃ and the temperature of 30-40 g/L, wherein the sulfuric acid solution is added with a specific additive (the Phoenix IM1 coloring additive is used in the method, and mainly phosphoric acid and the like which can generate acid substances with film holes larger than those of sulfuric acid oxidation), switching to 2-5V alternating current for energizing for 8-12 min after 10-15V direct current electrolytic processing is adopted for 2-3 min, and then switching back to 10-15V direct current electrolytic processing for 4-10 min;

seventhly, carrying out electrolytic coloring (salt precipitation) treatment, wherein the temperature of the bath solution is 20-28 ℃, the sulfuric acid concentration is 16-22 g/L, the stannous sulfate concentration is 16-22 g/L, and the stabilizing agent is 20-35 g/L; performing electrolytic machining for 2-6 minutes by adopting 10V-18V alternating current;

after washing, putting the mixture into a conventional (cold/medium temperature) closed tank solution for primary hole sealing treatment, wherein a Phoenix 531 hole sealing agent is taken as an example (the concentration is 2g/L-8g/L, the PH is 5 (6.5,400 ppm) and F-1000 ppm), and the mixture is treated for 15min-30min at the temperature of 30 ℃;

ninthly, performing further secondary hole sealing on the part, wherein a Phoenix 595 sealing agent is adopted as an example (the concentration is 20g/L-45g/L, and the PH is less than 5 and less than 6), and the part is treated for 15min-20min at the temperature of 90-100 ℃;

the red (R) is boiled and cleaned by 80 ℃ hot water and then hung down to finish the whole process flow.

The following is a verification of the color change of the product obtained by the method provided by the present application through a specific example.

The preparation of degreasing, polishing, anodizing, etc. of the aluminum or aluminum alloy semi-finished product before anodizing may be performed in the manner described above.

The parameters of the reaming procedure are increased after the anodic oxide film is formed by electrolytic oxidation as follows: the temperature of the reaming tank solution is 20 ℃, the concentration of the Phoenix IM1 coloring additive is 40g/L, and the concentration of sulfuric acid is 38 g/L; DC voltage 12 volts, soft start (voltage from 0 to 12V) time 20S, duration 2 min; DC switching AC time 45S, AC voltage 3V, soft start (voltage from 0 to 3V) time 20S, duration 10 min; the sequence control of the rectifier is not switched again at intervals, alternating current is converted into direct current, the direct current voltage is 12 volts, the soft start (voltage is increased from 0 to 12V) time is 20S, and the duration is 5min30S to 6 min;

the parameters of the subsequent electrolytic coloring process are as follows: the temperature of the coloring bath solution is 22 ℃, wherein the temperature of the coloring bath solution is 20g/L, the stannous sulfate is 18g/L, the stabilizer is 26g/L (can also be replaced by 25g/L Phoenix EB223+96g/L Phoenix EB 224), the alternating current electrolytic voltage is 12 volts, the soft start time (the voltage is increased from 0 to 12V) is 20S, and the duration is 2min 30S;

then sealing treatment is carried out, the conventional temperature resistance of the sample is good, and the sample can pass a 1H test at 100 ℃; can pass the routine quick check (aluminum blue) staining test; can pass the (chemical reagent) corrosion resistance test at pH 12.5; the paint can pass the EN ISO 9227 salt spray test stably, and the surface has no appearance change caused by corrosion after the test.

By matching different time lengths, the ground color and the outer surface layer of the color can be changed, so that the final multicolor effect is changed, and the color is changed from purple black to green. When the formed product is observed, the product is observed at a small angle to be green, and the product is observed at a large angle to be purple black.

According to the above description, not only for the above gradient, but also various color combinations (e.g., purple-green gradient, blue-violet gradient, green-blue gradient, yellow-violet gradient, and green-yellow gradient) such as changing purple into blue can be realized by adjusting the above parameters, which are not listed here.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. A variable angle heterochromatic anodization method, comprising:

adjusting the film hole of the anodic oxide film on the surface of the part to be processed into a diameter-variable structure from an upper drift diameter structure and a lower drift diameter structure;

an electrolytic coloring deposition layer is arranged in the membrane hole, and the part of the membrane hole, which is positioned above the upper surface of the electrolytic coloring deposition layer, at least comprises two sections of hole sections with different inner diameters, so that light waves irradiating on the electrolytic coloring deposition layer generate film interference in the reflection process, and the aim of displaying different colors when a user observes from different angles is further achieved.

2. The method of claim 1, wherein the step of adjusting the pores of the anodized film from an upper and a lower diameter structure to a variable diameter structure comprises:

placing the part to be treated in a first solution, wherein the first solution comprises a first acid substance and a second acid substance; the second acid substance can be subjected to electrolytic reaction to generate larger membrane pores compared with the first acid substance by oxidation; the first acid substance is an acid substance used in the electrolytic oxidation forming process of the anodic oxide film;

and alternately introducing alternating current and direct current into the first solution to perform electrolytic machining so as to adjust the membrane hole of the anodic oxide membrane from an upper drift diameter structure to a lower drift diameter structure.

3. The method of claim 2, wherein the first acid comprises a sulfuric acid solution, and the electrolytic oxidation comprises:

and (3) carrying out electrolytic oxidation 1320-1800 seconds on the part to be treated by using 180-210 g/L sulfuric acid at the temperature of 15-20 ℃ and the voltage of 13-17 volts so as to form the anodic oxide film on the surface of the part to be treated.

4. The method of claim 3, wherein the second acid species comprises a phosphoric acid solution; and alternately introducing alternating current and direct current into the first solution to perform electrolytic machining to adjust the oxide film barrier layer contained in the anodic oxide film, and adjusting the film hole of the anodic oxide film into a reducing structure with a large bottom and a small top from an upper drift diameter structure and a lower drift diameter structure.

5. The variable angle allochromatic multicolor anodizing method of claim 4, wherein the first solution comprises a Phoenix IM1 coloring additive, and the second acid species is provided by the Phoenix IM1 coloring additive.

6. The variable angle allochromatic multicolor anodizing method of claim 5, wherein the concentration of said Phoenix IM1 coloring additive contained in said first solution is 35-45 g/L, and the concentration of said sulfuric acid solution is 30-40 g/L;

to alternating current and direct current of letting in the first solution carry out the electrolytic machining right the oxide film barrier layer that anodic oxide film contains adjusts, will anodic oxide film's membrane hole is by the big-end-up reducing structure of latus rectum structure adjustment down, includes:

adjusting the temperature of the first solution to 17-21 ℃, switching to 2-5V alternating current for electrolytic machining for 8-12 minutes after electrolytic machining is carried out for 2-3 minutes by adopting 10-15V direct current, and switching back to 10-15V direct current for electrolytic machining for 4-10 minutes.

7. The method of claim 6, wherein the disposing of an electrolytically colored deposit within the film hole comprises:

placing the part to be treated in a second solution, wherein the second solution comprises a sulfuric acid solution with the concentration of 16-22 g/L, stannous sulfate with the concentration of 16-22 g/L and a stabilizer with the concentration of 20-35 g/L;

adjusting the temperature of the second solution to be 20-28 ℃, and carrying out electrolytic processing for 2-6 minutes by adopting 10-18V alternating current to obtain the electrolytic coloring deposition layer.

8. The variable-angle different-color anodic oxidation method according to claim 1, wherein the hole sealing process is performed after an electrolytic coloring deposition layer is disposed in the film hole, and comprises the following steps:

washing the part to be treated, placing the washed part into a conventional closed tank solution, and carrying out primary hole sealing, wherein the primary hole sealing comprises treating the part at the temperature of 30 ℃ for 15-30 minutes by using a Phoenix 531 hole sealing agent; the concentration of the Phoenix 531 hole sealing agent is 2-8 g/l;

carrying out secondary hole sealing processing on the part to be processed after the primary hole sealing processing, wherein the secondary hole sealing processing comprises processing for 15-20 minutes at the temperature of 90-100 ℃ by adopting a Phoenix 595 sealing agent; the concentration of the Phoenix 595 hole sealing agent is 20g/L-45 g/L;

and (4) boiling and cleaning the part to be treated after the second hole sealing processing by hot water at 80 ℃ and then hanging the part to be treated.

9. The method of claim 1, wherein before the anodic oxide film on the surface of the workpiece is electrolytically oxidized, the workpiece is sequentially degreased and electrochemically polished, and then is electrolytically oxidized to form the anodic oxide film on the surface of the workpiece.

10. The method of claim 9, wherein the degreasing and electrochemical polishing of the part to be treated comprises:

washing the part to be treated with a phosphatized alkaline degreasing agent at 40-60 ℃ for 4-7 minutes;

subjecting the degreased part to be treated to electrochemical polishing for 10-20 minutes in binary mixed acid with the concentration of 600-800 g/L phosphoric acid and the concentration of 340-420 g/L sulfuric acid at the temperature of 58-65 ℃ under the voltage of 35-45V;

the part to be treated after electrochemical polishing is subjected to film removing for 30 to 40 seconds at the temperature of 28 to 32 ℃ by using a sodium hydroxide solution with the concentration of 20 to 35 g/L;

and (3) removing ash from the part to be treated after the membrane is removed in a sulfuric acid solution with the concentration of 170-200 g/L at 15-20 ℃ for 100-140 seconds.

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