A method for preparing a ceramic film on an aluminum-nickel alloy surface

Abstract

The application provides a preparation method of an aluminum-nickel alloy surface ceramic film, which comprises the following steps: firstly, performing surface degreasing pretreatment on the aluminum-nickel alloy; then, performing micro-arc oxidation treatment in an alkaline electrolyte solution comprising a phosphate, a borate and a film-forming modifier; and optimizing the film-forming electric parameters, so that a dark ceramic film mainly composed of aluminum oxide-nickel oxide and containing metal nickel nanoparticle reinforcement can be obtained. The method can obtain a ceramic film with good bonding force, dense structure, high hardness, excellent wear resistance and corrosion resistance on the surface of the aluminum-nickel alloy, and is suitable for surface strengthening treatment of aluminum-nickel alloy parts.

Description

Technical Field

[0001] This invention belongs to the field of aluminum-nickel alloy surface treatment, and particularly relates to a method for preparing a ceramic film on the surface of aluminum-nickel alloy. Background Technology

[0002] Aluminum alloys are widely used in aerospace, machinery, automotive, electronics, and home appliances. However, the heat resistance and high-temperature strength of many mature aluminum alloy systems are not ideal. With continuous technological advancements, increasingly higher performance requirements are being placed on aluminum alloy products (such as pistons, cylinders, and cables). For example, with the continuous expansion of the domestic power grid, the requirements for the transmission efficiency and heat resistance of aluminum alloy cables are constantly increasing. Ordinary aluminum stranded wire has poor heat resistance, making it difficult to meet the output requirements of ultra-high-capacity circuits. Therefore, developing aluminum alloys with good conductivity, mechanical properties, and heat resistance is of great significance. Generally, appropriate amounts of alloying elements such as Zr, Ni, and Sc can be added to improve the high-temperature strength, thermal stability, and corrosion resistance of aluminum alloys.

[0003] AlNi alloys, especially those with near-eutectic or eutectic compositions (nickel content ~6%), possess excellent casting properties, making them suitable for large-scale production of various structural parts or as powder raw materials for 3D printing. They are applicable to the manufacture of structural components such as engine pistons and cylinder blocks. Furthermore, the high-melting-point Al3Ni precipitate phase in AlNi alloys can significantly improve their high-temperature strength, making them suitable for manufacturing heat-resistant aluminum alloy wires and structural components. However, the wear resistance and corrosion resistance of these AlNi alloys are not ideal. To meet the requirements of use in harsh environments such as high-temperature wear and corrosion, protective films can be prepared using surface coating processes to improve their surface properties. Currently, there are very few research reports on surface strengthening treatments for AlNi alloys. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention proposes a ceramic film on the surface of an aluminum-nickel alloy, which can significantly improve the hardness, wear resistance, corrosion resistance and heat insulation performance of the aluminum-nickel alloy surface.

[0005] A second aspect of the present invention provides a method for preparing a ceramic film on an aluminum-nickel alloy surface.

[0006] A third aspect of the present invention proposes the application of a ceramic film on the surface of an aluminum-nickel alloy in the appearance modification and / or surface strengthening of the aluminum-nickel alloy.

[0007] According to a first aspect of the present invention, a ceramic film on an aluminum-nickel alloy surface is provided, comprising aluminum oxide, nickel oxide and metallic nickel nanoparticles.

[0008] In some embodiments of the present invention, the thickness of the ceramic film is 25 μm to 40 μm.

[0009] In some embodiments of the present invention, the nickel nanoparticles are spherical or near-spherical with a particle size of 10 nm to 60 nm.

[0010] In some preferred embodiments of the present invention, the thickness of the ceramic film is 30 μm to 35 μm.

[0011] In this invention, the ceramic film formed on the surface of the aluminum-nickel alloy is gray, brown, light brown, or brownish-yellow, preferably brownish-yellow, and can be used for decoration.

[0012] According to a second aspect of the present invention, a method for preparing the ceramic film on the surface of the aluminum-nickel alloy described in the first aspect is provided, comprising the following steps: performing micro-arc oxidation treatment on the pretreated aluminum-nickel alloy substrate in an alkaline electrolyte to obtain the ceramic film on the surface of the aluminum-nickel alloy.

[0013] In this invention, an aluminum-nickel alloy substrate can grow in situ a brown ceramic film mainly composed of aluminum oxide and nickel oxide, and reinforced with metallic nickel nanoparticles, under the high temperature action of a micro-arc oxidation discharge arc.

[0014] In some embodiments of the present invention, the mass fraction of nickel in the aluminum-nickel alloy matrix is ​​4% to 12%.

[0015] In this invention, an appropriate amount of nickel content can not only improve the casting performance and heat resistance of aluminum-nickel alloys, but also help to obtain a uniform and consistent micro-arc oxidation ceramic film. If the content is lower than the above range, it will result in a low content of nickel oxide and metallic nickel nanoparticle reinforcing phase in the micro-arc oxidation ceramic film of aluminum-nickel alloys, resulting in a light film color and unsatisfactory wear resistance and corrosion resistance. If the content is higher than the above range, it will result in difficulties in forming micro-arc oxidation films of aluminum-nickel alloys and poor film uniformity.

[0016] In some embodiments of the present invention, the aluminum-nickel alloy matrix contains a modifier, including but not limited to strontium, sodium salts, and rare earth elements, which can refine the Al / Al3Ni eutectic structure in the matrix during the smelting process, thereby obtaining a uniform matrix structure.

[0017] In some embodiments of the present invention, the pretreatment is to perform mechanical polishing and degreasing pretreatment on the surface of the aluminum-nickel alloy substrate to obtain a clean surface.

[0018] In some embodiments of the present invention, the mechanical polishing is performed using 240# to 1000# wet sandpaper.

[0019] In some embodiments of the present invention, the degreasing pretreatment is performed by ultrasonic cleaning with alcohol for 5 to 15 minutes.

[0020] In some embodiments of the present invention, the alkaline electrolyte includes phosphate, borate, film-forming modifier and solvent.

[0021] In some embodiments of the present invention, the concentration of phosphate in the alkaline electrolyte is 8 g / L to 16 g / L.

[0022] In some embodiments of the present invention, the concentration of borate in the alkaline electrolyte is 6 g / L to 15 g / L.

[0023] In this invention, an electrolyte with phosphate and borate as the main components within the aforementioned concentration range is used for micro-arc oxidation of aluminum-nickel alloys. The electrolyte components essentially do not enter the membrane, resulting in a relatively dense ceramic membrane mainly composed of aluminum oxide and nickel oxide, with a nickel nanoparticle reinforcing phase. If the concentration of phosphate and borate is too low, it leads to a low film formation rate and a long processing cycle; if the concentration is too high, the cost of the electrolyte will be high, which is not conducive to actual production. Furthermore, if silicates, commonly used in micro-arc oxidation, are used as the electrolyte, a porous mullite phase transformed from silicates will be introduced into the membrane, resulting in a significant decrease in the overall membrane density, wear resistance, and corrosion resistance.

[0024] In some embodiments of the present invention, the concentration of the film-forming modifier in the alkaline electrolyte is 2 g / L to 6 g / L.

[0025] In this invention, if the concentration of the film-forming modifier is too low, it will lead to the problem that the improvement of film uniformity is not obvious. If the concentration of the film-forming modifier is too high, it will lead to the decrease of electrolyte stability and the shortening of service life, which is not conducive to actual production.

[0026] In some embodiments of the present invention, the pH value of the alkaline electrolyte is 11 to 13.

[0027] In this invention, the pH value of the electrolyte is controlled by adding alkaline substances, including but not limited to sodium hydroxide and potassium hydroxide.

[0028] In some embodiments of the present invention, the solvent is water.

[0029] In some preferred embodiments of the present invention, the phosphate is a soluble phosphate, including but not limited to sodium phosphate, sodium metaphosphate, potassium phosphate, and sodium dihydrogen phosphate.

[0030] In some preferred embodiments of the present invention, the borate is a soluble borate, which includes, but is not limited to, lithium borate, potassium borate, sodium tetraborate, and potassium metaborate, and is preferably sodium tetraborate.

[0031] In some preferred embodiments of the present invention, the film-forming modifier is selected from at least one of oxaloacetic acid, disodium oxaloacetate, hexamethyltetraamine, and glycerol.

[0032] In this invention, the film-forming modifier containing this component is added to the electrolyte and can be adsorbed on or near the surface of the sample immersed in the electrolyte, inhibiting the charge transfer of charged particles in the electrolyte on the surface, thereby improving the uniformity of the discharge arc distribution on the substrate surface during micro-arc oxidation, suppressing the phenomenon of local ablation caused by large-size arcs on the film surface during micro-arc oxidation film formation, and thus improving the uniformity and density of the micro-arc oxidation ceramic film on the surface of aluminum-nickel alloy.

[0033] In some preferred embodiments of the present invention, the micro-arc oxidation treatment employs a bipolar pulsed micro-arc oxidation power supply with a forward current density of 3 A / dm². 2 ~12A / dm 2 The negative current density is 2A / dm 2 ~5A / dm 2 The frequencies of both positive and negative pulses are 400Hz to 2000Hz, and the duty cycles are both 15% to 30%; the ratio of positive to negative pulses is 2 to 4:1.

[0034] In some preferred embodiments of the present invention, the micro-arc oxidation treatment time is 40 min to 80 min.

[0035] In some preferred embodiments of the present invention, the micro-arc oxidation treatment employs a bipolar pulsed micro-arc oxidation power supply with a forward current density of 8 A / dm². 2 ~10A / dm 2 The negative current density is 2A / dm 2 ~5A / dm 2 The frequencies of both positive and negative pulses are 400Hz to 800Hz, and the duty cycles are both 15% to 30%; the ratio of positive to negative pulses is 2 to 4:1.

[0036] In this invention, electrical parameters such as current density, frequency, duty cycle, and ratio of positive to negative pulses are optimized to ensure that a micro-arc oxidation ceramic film with high structural density and good uniformity is obtained.

[0037] According to a third aspect of the present invention, the application of the ceramic film on the surface of the aluminum-nickel alloy described in the first aspect is proposed in the appearance modification and / or surface strengthening of aluminum-nickel alloys.

[0038] In this invention, the surface of the micro-arc oxidation ceramic film layer has a uniformly distributed nickel oxide, which can present a specific color and meet the surface decoration requirements of certain aluminum-nickel alloy electronic products, industrial parts, etc.

[0039] The beneficial effects of this invention are as follows:

[0040] The aluminum-nickel alloy surface ceramic film of the present invention is dark in color, which has a good decorative effect, is easy to identify, and has good film adhesion, high hardness, and excellent wear resistance and corrosion resistance.

[0041] This invention provides an efficient and environmentally friendly surface treatment process for surface strengthening of aluminum-nickel alloy parts, which helps to expand the application of aluminum-nickel alloys in industrial production. Attached Figure Description

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0043] Figure 1 The macroscopic morphology of the aluminum-nickel alloy surface ceramic film sample prepared in Example 4 of this invention;

[0044] Figure 2 The image shows the SEM morphology of the ceramic film on the surface of the aluminum-nickel alloy prepared in Example 4 of this invention.

[0045] Figure 3 The local morphology and elemental analysis of the ceramic film on the surface of the aluminum-nickel alloy prepared in Example 4 of this invention;

[0046] Figure 4 The image shows the XRD pattern of the ceramic film prepared on the surface of the aluminum-nickel alloy substrate in Example 4 of this invention. Detailed Implementation

[0047] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. The aluminum-nickel alloy matrix described in the present invention can be a commercially available aluminum-nickel alloy or a self-made aluminum-nickel alloy, ensuring that the nickel mass fraction is 4% to 12%.

[0048] Example 1

[0049] This embodiment prepares a ceramic film on the surface of an Al-6wt.%Ni alloy. The specific process is as follows:

[0050] (1) Using commercial pure aluminum with a purity of not less than 99.5% and Al-20wt.%Ni master alloy (size <20mm×20mm×20mm) as raw materials, weigh them at a mass ratio of 7:3. Then place them in an electromagnetic induction heating furnace for rapid heating. After melting at 700℃~800℃ for 1~2h, after refining treatment such as stirring with a quartz rod and degassing with hexachloroethane, quickly pour the clean melt into a metal mold made of low carbon steel and cool it to obtain an Al-6wt.%Ni alloy ingot with a relatively uniform structure.

[0051] (2) The Al-6wt.%Ni alloy ingot was wire-cut to prepare a sample with a size of 20mm×20mm×4mm as the substrate. The sample was then polished alternately with 240#, 400#, 600#, 800# and 1000# sandpaper. Each type of sandpaper was used for polishing for 3-5 minutes. Then, the sample was ultrasonically cleaned with alcohol for 10 minutes for degreasing.

[0052] (3) Using 2L of deionized water as the solvent, prepare an electrolyte with a pH of approximately 13, consisting of 10g / L trisodium phosphate, 10g / L sodium tetraborate, and 2g / L sodium hydroxide, and add 5g / L disodium oxalate as a film-forming modifier. Continuously stir the electrolyte using a magnetic stirrer at a rate of 1500–2500 r / min to promote uniform dispersion of the substances in the electrolyte.

[0053] (4) Using a bipolar DC pulse power supply, the pretreated Al-6wt.%Ni sample from (2) was subjected to micro-arc oxidation treatment in the electrolyte obtained in (3). The process parameters for micro-arc oxidation treatment were: forward current 9A / dm 2 Negative current density 3A / dm 2 The frequencies of both positive and negative pulses were 600 Hz, the duty cycles of both pulses were 25%, the ratio of positive to negative pulses was 2:1, and the micro-arc oxidation treatment time was 60 min. Finally, a uniform light brown ceramic film was obtained on the Al-6wt.%Ni alloy surface.

[0054] Example 2

[0055] This embodiment prepares a ceramic film on the surface of an Al-6wt.%Ni alloy modified with Sr. The specific process is as follows:

[0056] (1) Using commercially pure aluminum particles with a purity of not less than 99.5% and Al-20wt.%Ni master alloy blocks (size <20mm×20mm×20mm) as raw materials, weigh them at a mass ratio of 7:3, and add Al-10Sr master alloy as a modifier, controlling the mass fraction of Sr element added in the whole melt to be 0.1%. Place it in an electromagnetic induction heating furnace and melt it at 700℃~800℃ for 1~2h. After refining treatment such as stirring with a quartz rod and degassing with hexachloroethane, quickly pour the clean melt into a metal mold made of low carbon steel and cool it to obtain a uniform and fine Al-6wt.%Ni alloy ingot.

[0057] (2) The Sr-modified Al-6wt.%Ni alloy ingot was wire-cut to prepare a sample with a size of 20mm×20mm×4mm as the substrate. The sample was then polished alternately with 240#, 400#, 600#, 800# and 1000# sandpaper, with each type of sandpaper polishing for 3-5 minutes. Then, the sample was ultrasonically cleaned with alcohol for 10 minutes for degreasing.

[0058] (3) Weigh 2L of deionized water as solvent, and prepare an alkaline electrolyte with a pH of approximately 13, consisting of 10g / L trisodium phosphate, 10g / L sodium tetraborate, and 2g / L sodium hydroxide. Add 5g / L disodium oxalate as a film-forming modifier. Then, use a magnetic stirrer to continuously stir the electrolyte at a stirring rate of 1500–2500 r / min to promote uniform dispersion of the substances in the electrolyte.

[0059] (4) A bipolar DC pulse power supply was used to perform micro-arc oxidation treatment on the pretreated Al-6wt.%Ni sample from (2) in the electrolyte obtained in (3). The oxidation process parameters were as follows: forward current was 9A / dm 2 The negative current density is 3A / dm 2 The frequency of the positive and negative pulses was 600 Hz, the duty cycle of the positive and negative pulses was 25%, the ratio of positive to negative pulses was 2:1, and the micro-arc oxidation treatment time was 60 min. Finally, a uniform and consistent brownish-yellow ceramic film was obtained on the surface of the Sr-modified Al-6wt.%Ni alloy.

[0060] Example 3

[0061] This embodiment prepares a ceramic film on the surface of an Al-6wt.%Ni alloy. The specific process is as follows:

[0062] (1) Using commercial pure aluminum particles with a purity of not less than 99.5% and Al-20wt.%Ni master alloy blocks (size <20mm×20mm×20mm) as raw materials, weigh them at a mass ratio of 7:3 and place them in an electromagnetic induction heating furnace to melt at 700℃~800℃ for 1~2h. After refining treatment such as stirring with a quartz rod and degassing with hexachloroethane, the clean melt is quickly poured into a metal mold made of low carbon steel and cooled to obtain an Al-6wt.%Ni alloy ingot with a relatively uniform structure.

[0063] (2) The Al-6wt.%Ni alloy ingot was wire-cut to prepare a sample with a size of 20mm×20mm×4mm as the substrate. The sample was then polished alternately with 240#, 400#, 600#, 800# and 1000# sandpaper. Each type of sandpaper was used for polishing for 3-5 minutes. Then, the sample was ultrasonically cleaned with acetone for 10 minutes for degreasing.

[0064] (3) Weigh 2L of deionized water as solvent, and prepare an alkaline electrolyte with a pH of approximately 13, consisting of 15g / L trisodium phosphate, 10g / L sodium tetraborate, and 2g / L sodium hydroxide. Add 4g / L oxaloacetic acid as a film-forming modifier. Then, use a magnetic stirrer to continuously stir the electrolyte at a stirring rate of 1500–2500 r / min to promote uniform dispersion of the substances in the electrolyte.

[0065] (4) A bipolar DC pulse power supply was used to perform micro-arc oxidation treatment on the pretreated Al-6wt.%Ni sample from (2) in the electrolyte obtained in (3). The oxidation process parameters were as follows: forward current 10A / dm 2 The negative current density is 4 A / dm 2 The frequency of the positive and negative pulses was 600 Hz, the duty cycle of the positive and negative pulses was 25%, the ratio of positive to negative pulses was 2:1, and the oxidation time was 60 min. Finally, a uniform light brown ceramic film was obtained on the surface of the Al-6wt.%Ni alloy.

[0066] Example 4

[0067] This embodiment prepares a ceramic film on the surface of an Al-10wt.%Ni alloy. The specific process is as follows:

[0068] (1) Using commercial pure aluminum particles with a purity of not less than 99.5% and Al-20wt.%Ni intermediate alloy blocks (size <20mm×20mm×20mm) as raw materials, weigh them at a mass ratio of 1:1 and place them in an electromagnetic induction heating furnace to melt at 700℃~800℃ for 1~2h. After refining treatment such as stirring with a quartz rod and degassing with hexachloroethane, the clean melt is quickly poured into a metal mold made of low carbon steel and cooled to obtain an Al-10wt.%Ni alloy ingot with a relatively uniform structure.

[0069] (2) The Al-10wt.%Ni alloy ingot was wire-cut to prepare a sample with a size of 20mm×20mm×4mm as the substrate. The sample was then polished alternately with 240#, 400#, 600#, 800# and 1000# sandpaper. Each type of sandpaper was used for polishing for 3-5 minutes. Then, the sample was ultrasonically cleaned with alcohol for 10 minutes for degreasing.

[0070] (3) Weigh 2L of deionized water as solvent, and prepare an alkaline electrolyte with a pH of approximately 13, consisting of 10g / L trisodium phosphate, 10g / L sodium tetraborate, and 2g / L sodium hydroxide. Add 5g / L disodium oxalate as a film-forming modifier. Then, use a magnetic stirrer to continuously stir the electrolyte at a stirring rate of 1500–2500 r / min to promote uniform dispersion of the substances in the electrolyte.

[0071] (4) A bipolar DC pulse power supply was used to perform micro-arc oxidation treatment on the pretreated Al-10wt.%Ni sample from (2) in the electrolyte obtained in (3). The oxidation process parameters were as follows: forward current was 9A / dm 2 The negative current density is 3A / dm 2 The frequency of the positive and negative pulses was 600 Hz, the duty cycle of the positive and negative pulses was 25%, the ratio of positive to negative pulses was 2:1, and the oxidation time was 60 min. Finally, a uniform brown ceramic film was obtained on the surface of the Al-10wt.%Ni alloy.

[0072] Comparative Example 1

[0073] Except for the composition of the electrolyte in the micro-arc oxidation treatment, the steps and parameters in this comparative example are the same as those in Example 1. The electrolyte used in this comparative example contains 20 g / L sodium silicate and 2 g / L sodium hydroxide, with 5 g / L disodium oxalate added as a film-forming modifier.

[0074] Comparative Example 2

[0075] In this comparative micro-arc oxidation treatment, no film-forming modifier was added to the electrolyte, and the remaining steps and parameters were the same as in Example 1.

[0076] Comparative Example 3

[0077] The matrix of this comparative example is Al-1wt.Ni%, and the remaining steps and parameters are the same as those in Example 1.

[0078] Comparative Example 4

[0079] The electrical parameters for micro-arc oxidation in this comparative example are: forward current 15 A / dm². 2 The negative current density is 3A / dm 2 The duty cycle of both positive and negative pulses is 40%. The remaining steps and parameters are the same as in Example 1.

[0080] Test case

[0081] The products of the examples and comparative examples were characterized and their performance was tested.

[0082] The macroscopic appearance and color of the film can be observed with the naked eye. The macroscopic morphology of the aluminum-nickel alloy surface ceramic film sample prepared in Example 4 of this invention is shown in [the figure]. Figure 1 .

[0083] from Figure 1 It can be seen that the film is brown in color due to the presence of some nickel oxide doping, and the color uniformity is good, indicating that the film has good uniformity.

[0084] Film thickness: tested using an eddy current thickness gauge;

[0085] Surface roughness: The surface roughness of the membrane is tested using a surface roughness meter to evaluate the uniformity of the membrane. The lower the surface roughness, the better the surface uniformity of the membrane.

[0086] Microstructure and elemental analysis: The microstructure of the film is observed using a scanning electron microscope, and the elemental composition of the film is analyzed locally using its built-in energy dispersive spectrometer.

[0087] The SEM morphology of the aluminum-nickel alloy surface ceramic film sample prepared in Example 4 of this invention is shown in the figure. Figure 2 ,from Figure 2 It can be seen that the film has good flatness. Although there are fine short cracks on the film surface near the discharge channel, the overall structure of the film is relatively dense, which is beneficial to reducing surface roughness and having good wear resistance and corrosion resistance.

[0088] The local morphology of the aluminum-nickel alloy surface ceramic film sample prepared in Example 4 of this invention is shown in [the figure]. Figure 3 It can be seen that the metallic nickel nanoparticles are incorporated into the ceramic film, especially with a large amount of enrichment on the film surface. These metallic nickel nanoparticles can serve as a reinforcing phase for the ceramic film on the substrate surface, increasing the film's hardness, corrosion resistance, and wear resistance.

[0089] Phase structure: analyzed using X-ray diffraction;

[0090] The XRD patterns of the aluminum-nickel alloy substrate and the ceramic film prepared on its surface in Example 4 of this invention are shown below. Figure 4 ,from Figure 4 It can be seen that the phase structure of the film mainly contains aluminum oxide and nickel oxide. Since aluminum oxide and nickel oxide are high-performance ceramic structures, the entire micro-arc oxidation film can exhibit good hardness, wear resistance and corrosion resistance.

[0091] Corrosion resistance: The ceramic membrane sample was tested using a Shanghai Chenhua CHI660E electrochemical workstation with a 3.5% (w / w) NaCl solution as the etching solution. The corrosion current density I of the membrane was calculated using Tafel's Slope software. corr To evaluate the corrosion resistance of the membrane samples;

[0092] Wear resistance: The wear resistance of the film was tested using a UMT-Tribolab multifunctional mechanical characterization system. The friction pair was a WC-6Co cemented carbide ball with a diameter of 6 mm. The load was 10 N, and the ball was subjected to reciprocating linear friction motion. The friction distance of a single pass was 10 mm, and the wear time was 10 min. The wear resistance of the film was evaluated by measuring the weight loss of the sample before and after wear using an analytical balance.

[0093] The results of the above tests are shown in Table 1 below:

[0094] Table 1

[0095]

[0096] Results Analysis: The table shows that by using appropriate electrolyte composition and electrical parameter ranges during the preparation of the micro-arc oxidation film on the Al-Ni alloy surface, a film with a relatively smooth and uniform surface can be obtained, resulting in good corrosion resistance and wear resistance. In particular, the addition of certain special film-forming modifiers to the electrolyte is beneficial for improving the corrosion resistance and wear resistance of the micro-arc oxidation film on the Al-Ni alloy surface. Furthermore, refining the microstructure of the Al-Ni alloy substrate through modification treatment can also effectively improve the surface smoothness, corrosion resistance, and wear resistance of the obtained micro-arc oxidation film. Additionally, when the Ni content in the Al-Ni alloy substrate reaches a high value, a nickel nanoparticle reinforcing phase can be formed on the surface of the obtained micro-arc oxidation film, further enhancing the wear resistance of the film.

[0097] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A ceramic film on the surface of an aluminum-nickel alloy, characterized in that, The membrane material includes aluminum oxide, nickel oxide, and metallic nickel nanoparticles; The method for preparing the ceramic film on the surface of the aluminum-nickel alloy includes the following steps: The pretreated aluminum-nickel alloy substrate was subjected to micro-arc oxidation in an alkaline electrolyte to obtain a ceramic film on the surface of the aluminum-nickel alloy. The nickel mass fraction in the aluminum-nickel alloy matrix is ​​4%–12%; the alkaline electrolyte includes phosphate, borate, film-forming modifier, and solvent; the micro-arc oxidation treatment uses a bipolar pulsed micro-arc oxidation power supply with a forward current density of 3 A / dm³. 2 ~12 A / dm 2 The negative current density is 2 A / dm 2 ~5 A / dm 2 The duty cycle of both positive and negative pulses in the micro-arc oxidation treatment is 15%~30%. The film-forming modifier is selected from at least one of oxaloacetic acid, disodium oxaloacetate, hexamethyltetraamine, and glycerol.

2. The ceramic film on the surface of the aluminum-nickel alloy according to claim 1, characterized in that, The thickness of the membrane is 25 μm to 40 μm.

3. The method for preparing the ceramic film on the surface of an aluminum-nickel alloy according to any one of claims 1 to 2, characterized in that, The process includes the following steps: micro-arc oxidation treatment of the pretreated aluminum-nickel alloy substrate in an alkaline electrolyte to obtain a ceramic film on the surface of the aluminum-nickel alloy. The nickel mass fraction in the aluminum-nickel alloy matrix is ​​4%–12%; the alkaline electrolyte includes phosphate, borate, film-forming modifier, and solvent; the micro-arc oxidation treatment uses a bipolar pulsed micro-arc oxidation power supply with a forward current density of 3 A / dm³. 2 ~12 A / dm 2 The negative current density is 2 A / dm 2 ~5 A / dm 2 The duty cycle of both positive and negative pulses in the micro-arc oxidation treatment is 15%~30%.

4. The preparation method according to claim 3, characterized in that, The concentration of the film-forming modifier in the alkaline electrolyte is 2 g / L to 6 g / L.

5. The preparation method according to claim 3, characterized in that, The concentration of phosphate in the alkaline electrolyte is 8 g / L to 16 g / L; the concentration of borate in the alkaline electrolyte is 6 g / L to 15 g / L.

6. The preparation method according to claim 3, characterized in that, The frequencies of the positive and negative pulses in the micro-arc oxidation treatment are both 400 Hz to 2000 Hz; the ratio of positive to negative pulses is 2 to 4:

1.

7. The application of the ceramic film on the surface of aluminum-nickel alloy as described in any one of claims 1 to 2 in the appearance modification and / or surface strengthening of aluminum-nickel alloys.

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