Aluminum alloy products, their preparation methods and applications

Abstract

This invention belongs to the field of material processing technology, specifically relating to an aluminum alloy product and its preparation method and application. The aluminum alloy product includes: an aluminum alloy substrate and an oxide layer and a decorative composite layer sequentially covering the surface of the aluminum alloy substrate, as well as a sealing material located within the micropores of the oxide layer and / or on the surface of the oxide layer; the decorative composite layer includes, from the inside out, an underlayer, a transition layer, and a decorative layer; wherein the material of the underlayer is a metal oxide. The preparation method includes: (1) oxidizing the aluminum alloy substrate to obtain an oxidized part; (2) sealing the oxidized part to obtain a sealed part; (3) polishing the sealed part to obtain a polished sealed part; (4) plating the polished sealed part, forming an underlayer, a transition layer, and a decorative layer sequentially from the inside out on the surface of the polished sealed part. It has excellent corrosion resistance and high bonding strength between the layers.

Description

Technical Field

[0001] This invention belongs to the field of materials processing technology, specifically relating to an aluminum alloy product, its preparation method, and its application. Background Technology

[0002] With the advancement of technology, the trend towards thinner and lighter electronic products has become mainstream. Due to its lightweight nature, aluminum is widely used, leading to increasingly higher demands for surface finish. Currently, anodizing is the primary method for improving the decorative properties of aluminum alloy surfaces; however, the high-gloss finish achieved through anodizing cannot meet the latest market requirements.

[0003] To achieve better surface decoration effects, metal PVD decoration technology is usually used. Currently, the conventional aluminum alloy PVD processes are: A) directly plating PVD onto the aluminum alloy; B) first electroplating the aluminum alloy surface, and then plating PVD onto the electroplated layer; C) first performing ordinary anodizing treatment on the aluminum alloy, without sealing the pores during this process, and then plating PVD onto the anodized layer.

[0004] In process A, the adhesion between PVD and aluminum alloy is poor, the PVD layer is prone to peeling off, and its corrosion resistance is poor. In process B, the adhesion between the electroplated layer and aluminum alloy is limited, and the PVD layer is not only easily corroded but also easily peels off. In process C, the ordinary anolyte film is not sealed, resulting in localized micro-cracks. After bonding with the PVD coating, some of the metal in the PVD comes into direct contact with the aluminum alloy, easily creating a potential difference. This makes the material susceptible to corrosion during corrosive tests such as salt spray and artificial sweat.

[0005] Therefore, there is an urgent need to provide an aluminum alloy product that is corrosion resistant and has high interlayer bonding strength. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of poor corrosion resistance and easy PVD layer peeling caused by low interlayer bonding strength in existing aluminum alloy products. It provides an aluminum alloy product, its preparation method, and its applications. Compared with existing aluminum alloy products, the interlayer bonding strength of the aluminum alloy product in this invention is significantly improved, and its corrosion resistance is excellent.

[0007] To achieve the above objectives, the first aspect of the present invention provides an aluminum alloy article, wherein the aluminum alloy article comprises: an aluminum alloy substrate and an oxide layer and a decorative composite layer sequentially covering the surface of the aluminum alloy substrate, and a sealing material located in the micropores of the oxide layer and / or located on the surface of the oxide layer; the decorative composite layer comprises, from the inside to the outside, an underlayer, a transition layer and a decorative layer; wherein the material of the underlayer is a metal oxide.

[0008] A second aspect of the present invention provides a method for preparing an aluminum alloy article, wherein the method includes:

[0009] (1) The aluminum alloy substrate is oxidized to obtain an oxidized part;

[0010] (2) The oxidized part is sealed to obtain a sealed part;

[0011] (3) Polish the sealing part to obtain a polished sealing part;

[0012] (4) The polished sealing part is plated, and an underlayer, a transition layer and a decorative layer are formed sequentially from the inside to the outside on the surface of the polished sealing part.

[0013] The third aspect of the present invention provides an aluminum alloy article obtained by the method of the second aspect.

[0014] The fourth aspect of this invention provides an application of the aluminum alloy articles described in the first or third aspect in mobile phones, watches, tablets, and laptops.

[0015] Through the above technical solution, the aluminum alloy product, its preparation method, and its application provided by the present invention achieve the following beneficial effects:

[0016] Compared with existing aluminum alloy products, the aluminum alloy products of this invention have significantly improved interlayer bonding strength and excellent corrosion resistance.

[0017] In this invention, an oxidation treatment is applied to the aluminum alloy substrate, followed by a sealing and polishing process. The polished sealed part is then coated with a layer, forming an underlayer, a transition layer, and a decorative layer sequentially from the inside out on the surface of the polished sealed part. This sealing treatment effectively reduces microcracks on the sealed part, preventing galvanic corrosion caused by direct contact between the decorative composite layer and the aluminum alloy substrate after subsequent PVD decorative film coating. The aluminum alloy product provided by this invention exhibits excellent corrosion and wear resistance, strong interlayer adhesion, and good density. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the aluminum alloy product prepared in Example 1 of the present invention.

[0019] Explanation of reference numerals in the attached figures

[0020] 1. Aluminum alloy substrate; 2. Oxide film; 3-1. Undercoat layer.

[0021] 3-2, Transition Layer; 3-3, Decorative Layer; 4, Anti-fingerprint Protective Layer Detailed Implementation

[0022] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0023] The first aspect of the present invention provides an aluminum alloy article, wherein the aluminum alloy article comprises: an aluminum alloy substrate and an oxide layer and a decorative composite layer sequentially covering the surface of the aluminum alloy substrate, and a sealing material located in the micropores of the oxide layer and / or located on the surface of the oxide layer; the decorative composite layer comprises, from the inside to the outside, an underlayer, a transition layer and a decorative layer; wherein the material of the underlayer is a metal oxide.

[0024] This invention does not impose any particular limitation on the aluminum alloy substrate; for example, any type of wrought aluminum alloy, such as the 5-series, 6-series, or 7-series, can be used. During the production process, the cleanliness of the aluminum alloy substrate surface varies, and degreasing, oil removal, and water washing can be performed on the surface of the aluminum alloy substrate as needed to improve the cleanliness of the aluminum alloy substrate surface.

[0025] According to the present invention, the materials of the transition layer and the decorative layer are each independently selected from at least one of elemental metals, metal oxides and carbonitrides.

[0026] The present invention employs a technical solution combining a base layer, a transition layer, and a decorative layer, which can significantly improve the bonding strength between the decorative composite layer and the oxide layer.

[0027] According to the present invention, preferably, the material of the underlayer is selected from at least one of alumina, titanium oxide and niobium oxide, and more preferably alumina.

[0028] According to the present invention, preferably, the material of the transition layer is selected from at least one of chromium, titanium, niobium and zirconium, and more preferably chromium.

[0029] According to the present invention, preferably, the material of the decorative layer is selected from at least one of chromium carbide, silicon carbide, silicon carbonitride, chromium carbonitride, chromium nitride, titanium nitride, titanium carbonitride, titanium carbide, titanium aluminum nitrogen, chromium aluminum nitrogen, zirconium nitride, and titanium oxide, and more preferably at least one of chromium carbide, chromium carbonitride, and chromium nitride.

[0030] According to the present invention, the thickness of the decorative composite layer is 0.5-4 μm.

[0031] According to the present invention, in the decorative composite layer, the thickness of the underlayer is 50-300 nm.

[0032] According to the present invention, in the decorative composite layer, the thickness of the transition layer is 50-300 nm.

[0033] According to the present invention, in the decorative composite layer, the thickness of the decorative layer is 500-3000 nm.

[0034] In this invention, when the thickness of the decorative composite layer is within the aforementioned range, the corrosion resistance and wear resistance of the product can be improved. By individually or simultaneously adjusting the thickness of the underlayer, the transition layer, and the decorative layer to within the aforementioned range, the corrosion resistance and wear resistance of the product can be improved.

[0035] According to the present invention, the oxide layer is one of a conventional anodized layer, a hard anodized layer, and a ceramic anodized layer.

[0036] In this invention, the term "ordinary anodized layer" refers to the process of placing an aluminum alloy substrate in a sulfuric acid solution or a mixed solution of sulfuric acid and organic acid, and performing anodizing at a voltage of 10-20V to form an aluminum alloy oxide layer.

[0037] In this invention, the so-called hard anodized layer refers to an aluminum alloy substrate placed in a sulfuric acid solution or a mixed solution of sulfuric acid and organic acid, and anodized under low temperature and high pressure to form a dense / high-hardness aluminum alloy oxide layer.

[0038] In this invention, the ceramic anodized layer refers to an aluminum alloy substrate placed in a mixed solution of organic acid and organic acid salt, and anodized under high temperature and high pressure to form a translucent aluminum alloy oxide layer with a glaze-like texture.

[0039] According to the present invention, the oxide layer is obtained by sealing and further polishing after being formed by the above method.

[0040] According to the present invention, the hardness of the oxide layer is 150-500 HV. When the hardness of the oxide layer is within the above range, it is beneficial for the decorative composite layer coated thereon to have better hardness, wear resistance and corrosion resistance.

[0041] According to the present invention, the surface roughness of the oxide layer is 0.02-0.08 μm, thereby increasing the bonding force between the decorative composite layer and the oxide layer.

[0042] According to the present invention, the surface gloss of the oxide layer is 100-500 GU.

[0043] According to the present invention, the thickness of the oxide layer is 4-30 μm. When the thickness of the oxide layer is within the above range, the decorative composite layer can have better hardness, wear resistance, and corrosion resistance.

[0044] According to the present invention, the sealing material is at least one of nickel hydroxide, hydrated aluminum oxide, and aluminum fluoride.

[0045] According to the present invention, the content of the sealing material per unit area of ​​the oxide layer is ≥2wt%.

[0046] According to the present invention, the surface gloss of the aluminum alloy product is 100-600 GU, and the surface roughness is 0.04-0.08 μm.

[0047] According to the present invention, the aluminum alloy product further includes an anti-fingerprint protective layer disposed on the outer surface of the decorative composite layer.

[0048] According to the present invention, the anti-fingerprint protective layer is made of fluorinated siloxane.

[0049] According to the present invention, the thickness of the anti-fingerprint protective layer is 5-500 nm.

[0050] A second aspect of the present invention provides a method for preparing an aluminum alloy article, wherein the method includes:

[0051] (1) The aluminum alloy substrate is oxidized to obtain an oxidized part;

[0052] (2) The oxidized part is sealed to obtain a sealed part;

[0053] (3) Polish the sealing part to obtain a polished sealing part;

[0054] (4) The polished sealing part is plated, and an underlayer, a transition layer and a decorative layer are formed sequentially from the inside to the outside on the surface of the polished sealing part.

[0055] According to the present invention, an oxide layer is formed on the surface of the aluminum alloy substrate through the oxidation treatment to obtain the oxidized part. Preferably, the hardness of the oxide layer is 150-500 HV. When the hardness of the oxide layer is within the above range, the hardness, wear resistance, and corrosion resistance of the PVD coating can be improved.

[0056] According to the present invention, the thickness of the oxide layer in the oxide-treated part is 7-31 μm.

[0057] In this invention, the method of oxidation treatment is not particularly limited, as long as the hardness and thickness of the oxide layer in the oxidized part obtained after oxidation treatment can meet the above-mentioned requirements. As a preferred technical solution, the oxidation treatment method is anodizing.

[0058] According to the present invention, the oxidizing solution used in the oxidation treatment comprises sulfuric acid and optionally an organic acid. Preferably, the concentration of the sulfuric acid is 50-250 g / L. Preferably, the concentration of the organic acid is 0-20 g / L.

[0059] According to the present invention, the organic acid is selected from at least one of oxalic acid, malonic acid, succinic acid and malic acid.

[0060] According to the present invention, the oxidation solution adopts a combination of sulfuric acid and organic acid, which is beneficial to improving the hardness of the oxide layer.

[0061] According to the present invention, the conditions for the oxidation treatment include: a temperature of 10-30°C, an oxidation voltage of 8-20V, and an oxidation time of 20-80min.

[0062] According to the present invention, the surface micropores of the sealing member and / or the surface of the sealing member are provided with a sealing material. Preferably, the sealing material is at least one selected from nickel hydroxide, hydrated aluminum oxide, and aluminum fluoride.

[0063] In this invention, the method of sealing is not particularly limited. For example, the oxidized part can be brought into contact with a sealing agent for sealing treatment. After sealing is completed, a sealing material is formed in the micropores of the oxide layer of the oxidized part and / or on the surface of the oxide layer to obtain the sealed part.

[0064] According to the present invention, the main component of the sealing agent is selected from at least one of nickel acetate, nickel nitrate, nickel sulfate, and nickel fluoride. The sealing agent is preferably in solution form. In the present invention, the sealing agent can be obtained in-house or from conventionally available commercially available products.

[0065] According to the present invention, the conditions for the sealing treatment include: the concentration of the sealing agent used in the sealing treatment is 5-15 g / L, the temperature of the sealing treatment is 85-95°C, and the sealing treatment time is 20-60 min.

[0066] According to the present invention, after the polishing treatment, the thickness of the resulting polished sealing part is less than that of the sealing part. Preferably, the thickness difference between the sealing part and the polished sealing part is 1-3 μm.

[0067] According to the present invention, the polished sealing member contains a sealing material, specifically, the polished sealing member has a sealing material in the micropores on its surface and / or on its surface, wherein the content of the sealing material per unit area of ​​the polished sealing member is ≥2wt%.

[0068] According to the present invention, the surface roughness of the polished sealing component is 0.02-0.08 μm. By controlling the surface roughness of the polished sealing component to be within the above-mentioned range, the adhesion between the decorative composite layer and the oxide layer can be increased.

[0069] According to the present invention, the surface gloss of the polished sealing part is 100-500 GU. By adjusting the surface gloss of the polished sealing part to be within the above range, the gloss of the aluminum alloy product obtained after subsequent application of the decorative composite layer can reach 100-600 GU.

[0070] In this invention, the polishing method is not particularly limited, as long as the content of the sealing material, surface roughness and surface gloss of the polished sealing part obtained after polishing can meet the above requirements.

[0071] According to the present invention, the total thickness of the base layer, the transition layer and the decorative layer is 0.5-4 μm by performing the plating.

[0072] According to the present invention, the thickness of the underlayer is 50-300 nm by performing the coating.

[0073] According to the present invention, the thickness of the transition layer is 50-300 nm by performing the coating.

[0074] According to the present invention, the thickness of the decorative layer is 500-3000 nm by performing the plating.

[0075] According to the present invention, the coating is preferably applied using a PVD (Polydioxanone) process. Preferred conditions for the PVD process include: a vacuum degree of 6 × 10⁻⁶. -3 -10×10 -3 Pa, operating voltage is 500-800V, and coating time is 1800-3600s.

[0076] In this invention, the material of the underlayer formed by the plating is a metal oxide; the materials of the transition layer and the decorative layer formed by the plating are each independently selected from at least one of elemental metals, metal oxides, and carbonitrides. As a preferred embodiment of this invention, the material of the underlayer is selected from at least one of alumina, titanium oxide, and niobium oxide, preferably alumina; the material of the transition layer is selected from at least one of chromium, titanium, niobium, and zirconium, preferably chromium; the material of the decorative layer is selected from at least one of chromium carbide, silicon carbide, silicon carbonitride, chromium carbonitride, chromium nitride, titanium nitride, titanium carbonitride, titanium carbide, titanium aluminum nitride, chromium aluminum nitride, zirconium nitride, and titanium oxide, preferably at least one of chromium carbide, chromium carbonitride, and chromium nitride.

[0077] According to the present invention, the surface roughness of the aluminum alloy substrate is 0.02-0.08 μm.

[0078] According to the present invention, the surface gloss of the aluminum alloy substrate is 100-700 GU. When the surface gloss of the aluminum alloy substrate is within the above range, its surface is smooth and has a mirror effect.

[0079] In this invention, surface roughness is evaluated using Ra (i.e., “profile arithmetic mean deviation”).

[0080] According to the present invention, the method further includes: spraying the product obtained in step (4) with a coating.

[0081] In this invention, the method of spraying is not particularly limited. As a preferred technical solution, the spraying process employs an anti-fingerprint treatment process. In this invention, the anti-fingerprint treatment process refers to an anti-fingerprint treatment process, the specific process of which is well known to those skilled in the art and will not be described in detail here.

[0082] According to the present invention, preferably, the conditions of the AF treatment process include: the amount of spraying liquid used in the AF treatment process is 19-21 g / min, and the pressure of the AF treatment process is 0.8-1 kg / cm². 2 .

[0083] According to the present invention, the active ingredient in the spraying liquid includes at least one of trifluoropropyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, and perfluoropolyether.

[0084] In this invention, the spraying liquid can be obtained by self-production or by using conventional commercially available products.

[0085] The third aspect of the present invention provides an aluminum alloy article obtained by the method of the second aspect.

[0086] According to the present invention, the aluminum alloy articles obtained by the method of the second aspect have the same structural composition, parameters and properties as the aluminum alloy articles described in the first aspect of the present invention, and will not be repeated here.

[0087] The fourth aspect of this invention provides an application of the aluminum alloy articles described in the first or third aspect in mobile phones, watches, tablets, and laptops.

[0088] The present invention will be described in detail below through examples. Unless otherwise specified, all reagents used in the following examples are commercially available industrial products.

[0089] The following examples and comparative examples involve test methods for performance parameters:

[0090] (1) Water Cross-Section Test: Soak in pure water at 100℃ for 30 minutes, then let stand for 2 hours. Then, use a cross-section cutter and 3M tape to test the adhesion of the above experimental samples and observe the area of ​​film peeling off. The water cross-section test requires an adhesion of ≥4B to be qualified. 5B - The edge of the cross-section is smooth, and there is no paint peeling off at the edge and intersection of the cross-section; 4B - There are small pieces of paint peeling off at the intersection of the cross-section, and the total peeling area is less than 5%; 3B - There are small pieces of paint peeling off at the edge and intersection of the cross-section, and the total peeling area is between 5-15%; 2B - There are large areas of paint peeling off at the edge and intersection of the cross-section, and the total peeling area is between 15-35%; 1B - There are large areas of paint peeling off at the edge and intersection of the cross-section, and the total peeling area is between 35-65%; 0B - There are large areas of paint peeling off at the edge and intersection of the cross-section, and the total peeling area is greater than 65%.

[0091] (2) Vibration abrasion resistance test: The sample is mounted on the counterweight assembly and placed in the vibration friction testing equipment for testing. The wear area of ​​the film is observed, whether there is any exposure of the substrate, and whether the coating has peeled off (the area of ​​the peeled-off part is 1mm). 2 (4 or fewer are allowed).

[0092] (3) Salt spray test: salt concentration 5wt%, test temperature 35℃, pH value of spray solution (35℃) 6.8, spray pressure 0.1MPa, spray method is continuous spraying, spray volume 1.5mL / h (funnel area 80cm²) 2 After 48 hours, the sample surface is removed and observed for discoloration, pitting corrosion, or area corrosion to assess its corrosion resistance. No rust, discoloration, corrosion, or peeling should occur after the test.

[0093] (4) Method for detecting layer thickness: slice and mount the sample, and then measure the coating thickness with a metallographic microscope.

[0094] (5) Hardness testing method: The material hardness tester and the product surface hardness assessment were carried out using an HV-1000 hardness tester. The test pressure was 50g and the loading time was 10s. Five points were measured on the oxide layer, and the highest and lowest points were removed and the average value was taken.

[0095] (6) Roughness detection method: Use a roughness meter to measure the surface roughness of the product at a speed of 0.25 mm / s.

[0096] (7) Gloss test method: Use a gloss meter to measure the gloss at the midpoint of the material, with the light-transmitting aperture of the gloss meter aligned with the center of the material.

[0097] Example 1

[0098] (1) The raw material is subjected to CNC machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel; polishing liquid is an abrasive liquid containing polishing wax and silica). Then, it is degreased with an oil remover, neutralized with a neutralizing agent, and washed with water to obtain the aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.06μm, and the surface gloss is 690GU.

[0099] (2) The aluminum alloy substrate was placed in an oxidizing solution of 250 g / L sulfuric acid. The oxidation conditions included a temperature of 18°C, an oxidation voltage of 13 V, and an oxidation time of 40 min. The hardness of the oxide layer in the resulting oxidized part was 270 HV, and the thickness of the oxide layer was 13 μm.

[0100] (3) The anodized parts were sealed with DX-500 (main component is nickel acetate) as the sealing agent at a concentration of 10 g / L. The sealing temperature was 93℃ and the sealing time was 30 min. The sealing material in the resulting sealed parts was nickel hydroxide and hydrated aluminum oxide.

[0101] (4) The sealing part was polished using a silica wet polishing solution for 5 minutes to obtain a polished sealing part. After polishing, the thickness difference between the sealed part and the polished sealing part was 2 μm, the surface roughness of the polished sealing part was 0.04 μm, and the surface gloss was 200 GU. The content of sealing material per unit area of ​​the polished sealing part was 4 wt% (nickel hydroxide content).

[0102] (5) The polished sealing parts are subjected to PVD treatment. The process conditions include: placing the polished sealing parts in a PVD furnace, evacuating to 0.006 Pa, using an ion source for ion cleaning at a voltage of 500 V, and a coating time of 2700 s. The total thickness of the base layer, transition layer, and decorative layer formed by the coating is 2 μm, of which the thickness of the base layer is 100 nm and the thickness of the transition layer is 300 nm. The raw material for the base layer is an aluminum target; the material for the base layer is alumina. The raw material for the transition layer is a chromium target; the material for the transition layer is chromium. The raw material for the decorative layer is acetylene and a chromium target; the material for the decorative layer is chromium carbide. The raw materials referred to in this invention refer to the raw materials used in the PVD treatment process to form the base layer, transition layer, and decorative layer respectively; the materials referred to in this invention refer to the materials of the base layer, transition layer, and decorative layer formed after the PVD treatment process.

[0103] (6) The PVD-treated workpiece is then coated with an AF process. The process conditions include: the dosage of Dongxing AF solution (the active ingredient is perfluoropolyether) is 20 g / min, and the pressure is 1 kg / cm². 2The resulting fingerprint protective layer (made of fluorinated siloxane) has a thickness of 100nm.

[0104] The final product has Figure 1 The structure is shown. The final product was tested, and the test results are shown in Table 1.

[0105] Example 2

[0106] (1) The raw material is subjected to CNC machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel. The polishing liquid is an abrasive slurry containing polishing wax and silica); then it is degreased with a degreasing agent, neutralized with a neutralizing agent, and washed with water to obtain the aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.06μm, and the surface gloss is 690GU.

[0107] (2) The aluminum alloy substrate was placed in an oxidation solution consisting of 150 g / L sulfuric acid and 10 g / L oxalic acid. The oxidation conditions included a temperature of 12°C, an oxidation voltage of 14 V, and an oxidation time of 40 min. The hardness of the oxide layer in the resulting oxidized part was 280 HV, and the thickness of the oxide layer was 10 μm.

[0108] (3) The anodized parts were sealed with DX-500 (main component is nickel acetate) as the sealing agent at a concentration of 10 g / L. The sealing temperature was 93℃ and the sealing time was 30 min. The sealing material in the resulting sealed parts was nickel hydroxide and hydrated aluminum oxide.

[0109] (4) The sealing part was polished using a silica wet polishing solution for 5 minutes to obtain a polished sealing part. After polishing, the thickness difference between the sealed part and the polished sealing part was 2 μm; the surface roughness of the polished sealing part was 0.06 μm; and the surface gloss of the polished sealing part was 150 GU. The content of sealing material per unit area of ​​the polished sealing part was 4 wt% (nickel hydroxide content).

[0110] (5) PVD treatment is performed on the polished sealing parts. The process conditions include: placing the product in a PVD furnace, evacuating to 0.006 Pa, performing ion cleaning using an ion source at a voltage of 500 V, and a coating time of 2700 s. The total thickness of the substrate, transition layer, and decorative layer formed by the coating is 2 μm, of which the substrate thickness is 100 nm and the transition layer thickness is 300 nm. The substrate material is an aluminum target; the substrate material is alumina. The transition layer material is a chromium target; the transition layer material is chromium. The decorative layer material is acetylene and a chromium target; the decorative layer material is chromium carbide.

[0111] (6) The PVD-treated workpiece is then coated with an AF process. The process conditions include: the dosage of Dongxing AF solution (the active ingredient is perfluoropolyether) is 20 g / min, and the pressure is 1 kg / cm². 2 The resulting fingerprint protective layer (made of fluorinated siloxane) has a thickness of 100nm.

[0112] The final product was tested, and the test results are shown in Table 1.

[0113] Example 3

[0114] (1) The raw material is subjected to CNC (Computer Numerical Control) machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel; polishing liquid is an abrasive liquid containing polishing wax and silica); then degreasing is performed using a degreasing agent, followed by neutralization with a neutralizing agent, and finally washing with water to obtain the aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.02μm, and the surface gloss is 100GU.

[0115] (2) The aluminum alloy substrate was placed in an oxidizing solution of 220 g / L sulfuric acid. The oxidation conditions included a temperature of 22°C, an oxidation voltage of 11 V, and an oxidation time of 35 min. The hardness of the oxide layer in the resulting oxidized part was 150 HV, and the thickness of the oxide layer was 7 μm.

[0116] (3) The anodized parts were sealed with DX-500 (main component is nickel acetate) as the sealing agent at a concentration of 10 g / L. The sealing temperature was 93℃ and the sealing time was 30 min. The sealing material in the resulting sealed parts was nickel hydroxide and hydrated aluminum oxide.

[0117] (4) The sealing part was polished using a silica wet polishing solution for 5 minutes to obtain a polished sealing part. After polishing, the thickness difference between the sealed part and the polished sealing part was 2 μm; the surface roughness of the polished sealing part was 0.02 μm; and the surface gloss of the polished sealing part was 100 GU. The content of sealing material per unit area of ​​the polished sealing part was 4 wt% (nickel hydroxide content).

[0118] (5) PVD treatment is performed on the polished sealing parts. The process conditions include: placing the product in a PVD furnace, evacuating to 0.006 Pa, ion cleaning using an ion source at 500 V, and a coating time of 2700 s. The total thickness of the base layer, transition layer, and decorative layer formed by the coating is 2 μm, of which the thickness of the base layer is 50 nm and the thickness of the transition layer is 50 nm. The raw material for the base layer is an aluminum target; the material for the base layer is alumina. The raw material for the transition layer is a chromium target; the material for the transition layer is chromium. The raw material for the decorative layer is acetylene and a chromium target; the material for the decorative layer is chromium carbide.

[0119] (6) The PVD-treated workpiece is then coated with an AF process. The process conditions include: the dosage of Dongxing AF solution (the active ingredient is perfluoropolyether) is 20 g / min, and the pressure is 1 kg / cm². 2 The thickness of the fingerprint protection layer (made of fluorinated siloxane) is 100nm.

[0120] The final product was tested, and the test results are shown in Table 1.

[0121] Example 4

[0122] (1) The raw material is subjected to CNC (Computer Numerical Control) machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel; polishing liquid is an abrasive liquid containing polishing wax and silica); then degreasing is performed using a degreasing agent, followed by neutralization with a neutralizing agent, and finally washing with water to obtain the aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.08μm, and the surface gloss is 700GU.

[0123] (2) The aluminum alloy substrate was placed in an oxidizing solution of 250 g / L sulfuric acid. The oxidation conditions included a temperature of 12°C, an oxidation voltage of 18 V, and an oxidation time of 60 min. The hardness of the oxide layer in the resulting oxidized part was 500 HV, and the thickness of the oxide layer was 30 μm.

[0124] (3) The anodized parts were sealed with DX-500 (main component is nickel acetate) as the sealing agent at a concentration of 10 g / L. The sealing temperature was 93℃ and the sealing time was 30 min. The sealing material in the resulting sealed parts was nickel hydroxide and hydrated aluminum oxide.

[0125] (4) The sealing part was polished using a silica wet polishing solution for 5 minutes to obtain a polished sealing part. After polishing, the thickness difference between the sealed part and the polished sealing part was 2 μm; the surface roughness of the polished sealing part was 0.08 μm; and the surface gloss of the polished sealing part was 200 GU. The content of sealing material per unit area of ​​the polished sealing part was 4 wt% (nickel hydroxide content).

[0126] (5) PVD treatment is performed on the polished sealing parts. The process conditions include: placing the product in a PVD furnace, evacuating to 0.006 Pa, ion cleaning using an ion source at 500 V, and a coating time of 2700 s. The total thickness of the base layer, transition layer, and decorative layer formed by the coating is 2 μm, of which the thickness of the base layer is 300 nm and the thickness of the transition layer is 300 nm. The raw material for the base layer is an aluminum target; the material for the base layer is alumina. The raw material for the transition layer is a chromium target; the material for the transition layer is chromium. The raw material for the decorative layer is acetylene and a chromium target; the material for the decorative layer is chromium carbide.

[0127] (6) The PVD-treated workpiece is then coated with an AF process. The process conditions include: the dosage of Dongxing AF solution (the active ingredient is perfluoropolyether) is 20 g / min, and the pressure is 1 kg / cm². 2 The thickness of the fingerprint protection layer (made of fluorinated siloxane) is 100nm.

[0128] The final product was tested, and the test results are shown in Table 1.

[0129] Example 5

[0130] The aluminum alloy product was prepared according to the method of Example 1, except that the surface roughness of the aluminum alloy substrate in step (1) was 0.1 μm and the surface gloss of the aluminum alloy substrate was 90 GU. All other conditions were the same as in Example 1.

[0131] The final product was tested, and the test results are shown in Table 1.

[0132] Example 6

[0133] Aluminum alloy products were prepared according to the method of Example 1, except that in step (4), a silica wet polishing solution was used for wet polishing for 10 min. After polishing, the surface roughness of the polished sealing part was 0.02 μm; the surface gloss of the polished sealing part was 600 GU; and the content of sealing material per unit area of ​​the polished sealing part was 1.5 wt% (nickel hydroxide content). All other conditions were the same as in Example 1.

[0134] The final product was tested, and the test results are shown in Table 1.

[0135] Example 7

[0136] The aluminum alloy product was prepared according to the method of Example 1, except that in step (5), the total thickness of the underlayer, transition layer and decorative layer after PVD treatment was 4.5 μm, of which the thickness of the underlayer was 40 nm and the thickness of the transition layer was 400 nm.

[0137] The final product was tested, and the test results are shown in Table 1.

[0138] Comparative Example 1

[0139] (1) The raw material is subjected to CNC machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel. The polishing liquid is an abrasive slurry containing polishing wax and silica). Then, it is degreased with an oil remover, neutralized with a neutralizing agent, and washed with water to obtain the aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.06μm; the surface gloss of the aluminum alloy substrate is 690GU.

[0140] (2) The aluminum alloy substrate is subjected to PVD treatment. The process conditions include: placing the product in a PVD furnace, evacuating to 0.006 Pa, performing ion cleaning using an ion source at a voltage of 500 V, and a coating time of 2700 s. The total thickness of the substrate, transition layer, and decorative layer formed by the coating is 2 μm, of which the substrate thickness is 100 nm and the transition layer thickness is 300 nm. The substrate material is an aluminum target; the substrate material is alumina. The transition layer material is a chromium target; the transition layer material is chromium. The decorative layer material is acetylene and a chromium target; the decorative layer material is chromium carbide.

[0141] The final product was tested, and the test results are shown in Table 1.

[0142] Comparative Example 2

[0143] (1) The raw material is subjected to CNC machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel. The polishing liquid is an abrasive slurry containing polishing wax and silica). Then, it is degreased with an oil remover, neutralized with a neutralizing agent, and washed with water to obtain the aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.06μm; the surface gloss of the aluminum alloy substrate is 690GU.

[0144] (2) The aluminum alloy substrate was placed in an oxidizing solution of 200 g / L sulfuric acid. The oxidation conditions included a temperature of 18°C, an oxidation voltage of 14 V, and an oxidation time of 40 min. The hardness of the oxide layer in the resulting oxidized part was 275 HV, and the thickness of the oxide layer was 12 μm.

[0145] (3) The anodized parts are subjected to PVD treatment. The process conditions include: placing the anodized parts in a PVD furnace, evacuating to 0.006 Pa, performing ion cleaning using an ion source at a voltage of 500 V, and a coating time of 2700 s. The total thickness of the substrate, transition layer, and decorative layer formed by the coating is 2 μm, of which the substrate thickness is 100 nm and the transition layer thickness is 300 nm. The substrate material is an aluminum target; the substrate material is alumina. The transition layer material is a chromium target; the transition layer material is chromium. The decorative layer material is acetylene and a chromium target; the decorative layer material is chromium carbide.

[0146] The final product was tested, and the test results are shown in Table 1.

[0147] Comparative Example 3

[0148] (1) The raw materials are subjected to CNC machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel. The polishing liquid is an abrasive liquid containing polishing wax and silica); then degreasing is performed using an oil remover, followed by neutralization with a neutralizing agent, and then water washing to obtain an aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.06μm; the surface gloss of the aluminum alloy substrate is 690GU.

[0149] (2) The above aluminum alloy substrate is immersed in the electroplating solution, and after a zinc immersion for 1 minute, the zinc is removed, followed by a second zinc immersion for 30 seconds, then a copper layer of 2 μm is plated, and a nickel layer of 2 μm is plated on the copper layer.

[0150] (3) The workpiece obtained in step (2) is subjected to PVD treatment. The process conditions include: placing the workpiece in a PVD furnace, evacuating to 0.006 Pa, performing ion cleaning using an ion source at a voltage of 500 V, and a coating time of 2700 s. The total thickness of the substrate, transition layer, and decorative layer formed by the coating is 2 μm, of which the substrate thickness is 100 nm and the transition layer thickness is 300 nm. The substrate material is an aluminum target; the substrate material is alumina. The transition layer material is a chromium target; the transition layer material is chromium. The decorative layer material is acetylene and a chromium target; the decorative layer material is chromium carbide.

[0151] The final product was tested, and the test results are shown in Table 1.

[0152] Comparative Example 4

[0153] (1) The raw material is subjected to CNC machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel. The polishing liquid is an abrasive slurry containing polishing wax and silica). Then, it is degreased with an oil remover, neutralized with a neutralizing agent, and washed with water to obtain the aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.06μm; the surface gloss of the aluminum alloy substrate is 690GU.

[0154] (2) The aluminum alloy substrate was placed in an oxidation solution consisting of 150 g / L sulfuric acid and 10 g / L oxalic acid. The oxidation conditions included a temperature of 12°C, an oxidation voltage of 14 V, and an oxidation time of 40 min. The hardness of the oxide layer in the resulting oxidized part was 280 HV, and the thickness of the oxide layer was 10 μm.

[0155] (3) The anodized parts were sealed using DX-500 as the sealing agent at a concentration of 10 g / L, at a sealing temperature of 93°C, and for 30 min. The sealing material in the resulting sealed parts was nickel hydroxide and hydrated aluminum oxide. The content of the sealing material per unit area of ​​the sealed parts was 4 wt%. The surface roughness of the sealed parts was 0.1 μm, and the surface gloss was 80 GU.

[0156] (4) The sealing parts are subjected to PVD treatment. The process conditions include: placing the sealing parts in a PVD furnace, evacuating to 0.006 Pa, performing ion cleaning using an ion source at a voltage of 500 V, and a coating time of 2700 s. The total thickness of the substrate, transition layer, and decorative layer obtained by coating is 2 μm, of which the substrate thickness is 100 nm and the transition layer thickness is 300 nm. The substrate material is an aluminum target; the substrate material is alumina. The transition layer material is a chromium target; the transition layer material is chromium. The decorative layer material is acetylene and a chromium target; the decorative layer material is chromium carbide.

[0157] The final product was tested, and the test results are shown in Table 1.

[0158] Comparative Example 5

[0159] (1) The raw material is subjected to CNC machining, grinding (sandpaper from 400# to 1200# in sequence), and polishing (using dry or wet polishing methods; polishing consumables include: cloth wheel, nylon wheel, and buff wheel; polishing liquid is an abrasive liquid containing polishing wax and silica). Then, it is degreased with an oil remover, neutralized with a neutralizing agent, and washed with water to obtain the aluminum alloy substrate. The surface roughness of the aluminum alloy substrate is 0.06μm, and the surface gloss is 690GU.

[0160] (2) The aluminum alloy substrate was placed in an oxidizing solution of 250 g / L sulfuric acid. The oxidation conditions included a temperature of 18°C, an oxidation voltage of 13 V, and an oxidation time of 40 min. The hardness of the oxide layer in the resulting oxidized part was 270 HV, and the thickness of the oxide layer was 13 μm.

[0161] (3) The anodized parts were sealed with DX-500 (main component is nickel acetate) as the sealing agent at a concentration of 10 g / L. The sealing temperature was 93℃ and the sealing time was 30 min. The sealing material in the resulting sealed parts was nickel hydroxide and hydrated aluminum oxide.

[0162] (4) The sealing part was polished using a silica wet polishing solution for 5 minutes to obtain a polished sealing part. After polishing, the thickness difference between the sealed part and the polished sealing part was 2 μm, the surface roughness of the polished sealing part was 0.04 μm, and the surface gloss was 200 GU. The content of sealing material per unit area of ​​the polished sealing part was 4 wt% (nickel hydroxide content).

[0163] (5) The polished sealing parts are subjected to PVD treatment. The process conditions include: placing the polished sealing parts in a PVD furnace, evacuating to 0.006 Pa, using an ion source for ion cleaning at a voltage of 500 V, and a coating time of 2700 s. The total thickness of the base layer, transition layer, and decorative layer formed by the coating is 2 μm, wherein the thickness of the base layer is 100 nm and the thickness of the transition layer is 300 nm. The raw material for the base layer is a chromium target; the material for the base layer is chromium. The raw material for the transition layer is a chromium target; the material for the transition layer is chromium. The raw material for the decorative layer is acetylene and a chromium target; the material for the decorative layer is chromium carbide. The raw materials referred to in this invention refer to the raw materials used in the PVD treatment process to form the base layer, transition layer, and decorative layer respectively; the materials referred to in this invention refer to the materials of the base layer, transition layer, and decorative layer formed after the PVD treatment process.

[0164] (6) The PVD-treated workpiece is then coated with an AF process. The process conditions include: the dosage of Dongxing AF solution (the active ingredient is perfluoropolyether) is 20 g / min, and the pressure is 1 kg / cm². 2 The resulting fingerprint protective layer (made of fluorinated siloxane) has a thickness of 100nm.

[0165] The final product was tested, and the test results are shown in Table 1.

[0166] Table 1

[0167]

[0168]

[0169] Note: In Table 1, the vibration wear resistance test time is 2 hours, and the salt spray test time is 48 hours.

[0170] As shown in Table 1, the process of anodizing and sealing the aluminum alloy substrate, followed by polishing, and then depositing a PVD layer (first depositing a base layer, then a transition layer, and finally a decorative film) can make the aluminum alloy product have good film density, good interlayer bonding, excellent corrosion resistance and wear resistance, and its overall performance is better than that of comparative examples 1-5.

[0171] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An aluminum alloy product, characterized in that, The aluminum alloy product includes: an aluminum alloy substrate and an oxide layer and a decorative composite layer sequentially covering the surface of the aluminum alloy substrate, as well as a sealing material located in the micropores of the oxide layer and / or on the surface of the oxide layer; the decorative composite layer includes, from the inside to the outside, an underlayer, a transition layer and a decorative layer. The material of the base layer is selected from at least one of alumina, titanium oxide and niobium oxide; The material of the transition layer is selected from at least one of chromium, titanium, niobium and zirconium; The material of the decorative layer is selected from at least one of chromium carbide, silicon carbide, silicon carbonitride, chromium carbonitride, chromium nitride, titanium nitride, titanium carbonitride, titanium carbide, titanium aluminum nitrogen, chromium aluminum nitrogen, zirconium nitride, and titanium oxide; The oxide layer after sealing is polished, and the surface gloss of the polished oxide layer is 100-500 GU.

2. The aluminum alloy product according to claim 1, wherein, The thickness of the decorative composite layer is 0.5-4 μm; And / or, the thickness of the substrate layer is 50-300 nm; And / or, the thickness of the transition layer is 50-300 nm; And / or, the thickness of the decorative layer is 500-3000 nm.

3. The aluminum alloy product according to claim 1 or 2, wherein, The oxide layer is one of the following: ordinary anodized layer, hard anodized layer, and ceramic anodized layer; And / or, the hardness of the oxide layer is 150-500 HV; And / or, the surface roughness of the oxide layer is 0.02-0.08 μm; And / or, the thickness of the oxide layer is 4-30 μm.

4. In the aluminum alloy product according to claim 1 or 2, the content of the sealing agent per unit area of ​​the oxide layer is ≥2wt%; And / or, the sealing material is selected from at least one of nickel hydroxide, hydrated aluminum oxide and aluminum fluoride; And / or, the surface gloss of the aluminum alloy product is 100-600 GU, and the surface roughness is 0.04-0.08 μm.

5. The aluminum alloy product according to claim 3, wherein the content of the sealing agent per unit area of ​​the oxide layer is ≥2wt%; And / or, the sealing material is selected from at least one of nickel hydroxide, hydrated aluminum oxide and aluminum fluoride; And / or, the surface gloss of the aluminum alloy product is 100-600 GU, and the surface roughness is 0.04-0.08 μm.

6. The aluminum alloy article according to any one of claims 1, 2 and 5, wherein, The aluminum alloy product also includes an anti-fingerprint protective layer disposed on the outer surface of the decorative composite layer.

7. The aluminum alloy product according to claim 6, wherein, The anti-fingerprint protective layer is made of fluorinated siloxane; And / or, the thickness of the anti-fingerprint protective layer is 5-500nm.

8. The aluminum alloy product according to claim 3, wherein, The aluminum alloy product also includes an anti-fingerprint protective layer disposed on the outer surface of the decorative composite layer.

9. The aluminum alloy product according to claim 8, wherein, The anti-fingerprint protective layer is made of fluorinated siloxane; And / or, the thickness of the anti-fingerprint protective layer is 5-500nm.

10. The aluminum alloy product according to claim 4, wherein, The aluminum alloy product also includes an anti-fingerprint protective layer disposed on the outer surface of the decorative composite layer.

11. The aluminum alloy article according to claim 10, wherein, The anti-fingerprint protective layer is made of fluorinated siloxane; And / or, the thickness of the anti-fingerprint protective layer is 5-500nm.

12. A method for preparing an aluminum alloy product, characterized in that, The method includes: (1) The aluminum alloy substrate is oxidized to obtain an oxidized part; (2) The oxidized part is sealed to obtain a sealed part; (3) Polish the sealing part to obtain a polished sealing part; (4) The polished sealing part is plated, and an underlayer, a transition layer and a decorative layer are formed sequentially from the inside to the outside on the surface of the polished sealing part; The material of the base layer is selected from at least one of alumina, titanium dioxide and niobium oxide; The material of the transition layer is selected from at least one of chromium, titanium, niobium and zirconium; The material of the decorative layer is selected from at least one of chromium carbide, silicon carbide, silicon carbonitride, chromium carbonitride, chromium nitride, titanium nitride, titanium carbonitride, titanium carbide, titanium aluminum nitrogen, chromium aluminum nitrogen, zirconium nitride, and titanium oxide; The surface gloss of the polished sealing part is 100-500 GU.

13. The method according to claim 12, wherein, The hardness of the oxide layer in the oxide-treated part is 150-500 HV; And / or, the thickness of the oxide layer in the oxidized part is 7-31 μm.

14. The method according to claim 12 or 13, wherein, The oxidation treatment method is anodizing; And / or, the oxidizing solution used in the oxidation treatment contains sulfuric acid and optionally an organic acid; And / or, the conditions for the oxidation treatment include: a temperature of 10-30℃, an oxidation voltage of 8-20V, and an oxidation time of 20-80min.

15. The method according to claim 14, wherein, The concentration of the sulfuric acid is 50-250 g / L; And / or, the concentration of the organic acid is 0-20 g / L; And / or, the organic acid is selected from at least one of oxalic acid, malonic acid, succinic acid and malic acid.

16. The method according to claim 12 or 13, wherein, The sealing conditions include: the concentration of the sealing agent used in the sealing treatment is 5-15 g / L, the sealing temperature is 85-95℃, and the sealing time is 20-60 min.

17. The method according to claim 12 or 13, wherein, After the polishing process, the thickness difference between the sealing part and the polished sealing part is 1-3 μm; And / or, the polished sealing member contains a sealing agent, wherein the content of the sealing agent per unit area of ​​the polished sealing member is ≥2 wt%; And / or, the surface roughness of the polished sealing part is 0.02-0.08 μm.

18. The method according to claim 12 or 13, wherein, The total thickness of the base layer, the transition layer, and the decorative layer is 0.5-4 μm; And / or, the thickness of the substrate layer is 50-300 nm; And / or, the thickness of the transition layer is 50-300 nm; And / or, the thickness of the decorative layer is 500-3000 nm.

19. The method according to claim 12 or 13, wherein, The coating is applied using a PVD process.

20. The method according to claim 19, wherein, The conditions for the PVD processing include: a vacuum degree of 6 × 10⁻⁶. -3 -10×10 -3 Pa, operating voltage is 500-800V, and coating time is 1800-3600s.

21. The method according to claim 12 or 13, wherein, The surface roughness of the aluminum alloy substrate is 0.02-0.08 μm; And / or, the surface gloss of the aluminum alloy substrate is 100-700 GU.

22. The method according to claim 12 or 13, wherein, The method further includes: spraying the product obtained in step (4).

23. The method according to claim 22, wherein, The spraying treatment uses the AF process.

24. The method according to claim 23, wherein, The conditions for the AF treatment process include: the amount of spraying liquid used in the AF treatment process is 19-21 g / min, and the pressure of the AF treatment process is 0.8-1 kg / cm². 2 .

25. An aluminum alloy article obtained by the method of any one of claims 12-24.

26. The application of the aluminum alloy articles according to any one of claims 1-11 or claim 25 in mobile phones, watches, tablets and laptops.

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