Aluminum alloy non-phosphating polishing liquid, preparation method and polishing process thereof

Abstract

The present invention relates to the field of C23F technology, and more specifically, to a non-phosphating polishing liquid for aluminum alloy, a preparation method and a polishing process thereof. The non-phosphating polishing liquid for aluminum alloy comprises, by weight, 20-40 parts of sulfuric acid, 0.01-0.1 parts of sulfate, 1-5 parts of organic acid salt, and 0.05-0.1 parts of surfactant. The present application adopts the theory of chemical polishing mucosal layer, and abandons toxic and harmful components under the condition of meeting the appearance requirements of customers for gloss, flow marks, roughness, etc., and adopts chemical components without chromic acid, phosphoric acid, and nitric acid to develop an aluminum alloy chemical polishing liquid, which has good environmental protection, good stability, and can maintain good polishing performance for a long time. In addition, the LC4 workpiece obtained by using the polishing liquid is not only free of scratches, lines, orange peel, matte and other problems, but also has a neat surface of the workpiece and good bright effect.

Description

Technical Field

[0001] The present invention relates to the technical field of C23F, and more specifically to an aluminum alloy non-phosphating polishing liquid, a preparation method and a polishing process thereof. Background Art

[0002] With the widespread application of aluminum alloy materials, the amount of chemical polishing liquid used in the surface treatment process has also greatly increased. CN202010717578 obtains a chemical polishing liquid by using phosphoric acid, ammonium polyphosphate and other phosphoric acids, sulfuric acid, nitric acid, etc. CN201210200515 also provides an aluminum alloy chemical polishing liquid, including phosphoric acid, sulfuric acid, ammonium salts, etc. However, with the strong attention paid by the country and the people to environmental protection, the chemical polishing liquid using chromic acid, phosphoric acid and nitric acid as basic components in traditional production cannot meet the increasing requirements of environmental protection. It is necessary to develop a chemical polishing liquid that does not contain chromic acid, phosphoric acid, nitric acid and the like that causes harm to humans and the environment. Summary of the invention

[0003] In view of some problems existing in the prior art, the first aspect of the present invention provides an aluminum alloy non-phosphating polishing liquid, which comprises, by weight, 20-40 parts of sulfuric acid, 0.01-0.1 parts of sulfate, 1-5 parts of organic acid salt, and 0.05-0.1 parts of surfactant.

[0004] In one embodiment, the aluminum alloy non-phosphating polishing liquid further includes 0.1-0.3 parts by weight of a corrosion inhibitor.

[0005] In a preferred embodiment, the aluminum alloy non-phosphating polishing liquid comprises, by weight, 32 parts of sulfuric acid, 0.06 parts of sulfate, 1.5 parts of organic acid salt, 0.08 parts of surfactant, and 0.2 parts of corrosion inhibitor.

[0006] The concentration of sulfuric acid described in the present application is not particularly limited and can be routinely selected by those skilled in the art.

[0007] Preferably, the concentration of the sulfuric acid is 98 wt %.

[0008] In one embodiment, the sulfate salts are sodium sulfate and potassium sulfate.

[0009] Preferably, the weight ratio of sodium sulfate to potassium sulfate is (0.8-1.8):1, more preferably 1.5:1.

[0010] In one embodiment, the organic acid salt is selected from one or more of organic acid ammonium salt, organic acid copper salt, organic acid molybdenum salt, and organic acid lithium salt.

[0011] Preferably, the organic acid salt is ammonium acetate and copper acetate; further preferably, the weight ratio of ammonium acetate to copper acetate is 1:(1-2), more preferably 1:1.5.

[0012] In one embodiment, the corrosion inhibitor is selected from one or more of benzoic acid, sulfonic acid, molybdate, siloxane ketone, methylthiourea, ethylthiourea, propylthiourea, diisopropylthiourea, phenylthiourea, benzotriazole, methylbenzotriazole, and imidazole compounds.

[0013] Preferably, the corrosion inhibitor is phenylthiourea and benzotriazole; further preferably, the weight ratio of phenylthiourea to benzotriazole is 1:(3-6), more preferably 1:5.

[0014] The applicant found in the experiment that the polishing liquid of the present application had no flow marks when polishing within 60 seconds, but the polishing effect was poor, and there were some flow marks when polishing within 2 minutes. When the applicant added a corrosion inhibitor to avoid over-corrosion of the workpiece, it was unexpectedly found that when the corrosion inhibitor included phenylthiourea and benzotriazole, especially when the weight ratio of phenylthiourea and benzotriazole was 1: (3-6), it not only had a good corrosion inhibition effect, but also could avoid some flow marks on the workpiece after polishing in the present application. The applicant believes that the possible reason is that the hydrogen bonding force between phenylthiourea and benzotriazole forms a macromolecular aromatic structure bridged by alkyl and five-membered rings, which destroys the gas-liquid system in the polishing liquid system to a certain extent, avoiding the generation of gas defects during high-temperature polishing.

[0015] In one embodiment, the surfactant is selected from one or more of polyether carboxylates, polyethylene glycol, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0016] Preferably, the surfactant comprises polyether carboxylate.

[0017] Preferably, the polyether carboxylate is a linear alkyl polyoxyethylene ether carboxylate, further preferably, the linear alkyl polyoxyethylene ether carboxylate has a degree of polymerization of 7-12, further preferably, the polyether carboxylate comprises a polyether carboxylate with a degree of polymerization of 7 and a polyether carboxylate with a degree of polymerization of 12, and the weight ratio is (5-8): (0.3-0.6), more preferably 6.2:0.5.

[0018] The degree of polymerization in this application refers to the number of ethylene oxide chain segments.

[0019] In the prior art, small molecule phosphoric acid is used to utilize the dissolution difference between the raised and recessed parts of the aluminum alloy to achieve the polishing effect. However, it contains elemental phosphorus. The applicant found in the experiment that when conventional surfactants such as sodium dodecylbenzene sulfonate, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, etc. are used to improve the adsorption permeability of the chemical polishing solution and the sample, when the chemical polishing solution of the present application does not include phosphoric acid organic acid, the polishing effect needs to be improved. The applicant unexpectedly found in the experiment that when the polyether carboxylate includes a polyether carboxylate with a degree of polymerization of 7 and a polyether carboxylate with a degree of polymerization of 12, especially when the weight ratio is (5-8): (0.3-0.6), the leveling and polishing effect is significantly improved in the absence of phosphoric acid. The applicant believes that the possible reason is that the specific mosaic structure formed by the two specific polyether carboxylates with different degrees of polymerization avoids the organic acid salt in the present application from being adsorbed on the raised part of the sample, affecting the diffusion of aluminum ions, thereby affecting the leveling and polishing effect.

[0020] In one embodiment, the surfactant further comprises alkylphenol polyoxyethylene ether.

[0021] Preferably, the cloud point of the alkylphenol polyoxyethylene ether is 60-65°C.

[0022] Preferably, the alkylphenol polyoxyethylene ether is nonylphenol polyoxyethylene (10) ether, which is purchased from Xingtai Xinlanxing Technology Co., Ltd.

[0023] Preferably, the weight ratio of the alkylphenol polyoxyethylene ether to the polyether carboxylate is (0.1-1):1, more preferably 0.5:1.

[0024] The applicant unexpectedly discovered in the experiment that the present application has a low content of sulfuric acid while ensuring environmental protection requirements, and does not contain other inorganic acids such as nitric acid and phosphoric acid. The polishing efficiency is low during polishing, and polishing is required for more than 4.5 minutes to achieve a better polishing effect. The applicant unexpectedly discovered that when the surfactant also includes alkylphenol polyoxyethylene ether, especially when its cloud point is 60-65°C and the alkyl segment is a nonyl segment, the polishing efficiency is improved, and a better polishing effect can be achieved by polishing at a lower polishing temperature of 85-95°C for 2 minutes. The applicant believes that the possible reason is that the alkylphenol polyoxyethylene ether with a specific cloud point increases the probability of collision between some micelles in the chemical polishing liquid. No slight shaking is required during the polishing operation. The polishing liquid has suitable ion diffusion and fluidity, which avoids the formation of undulating waveforms in the raised part and achieves an ideal polishing effect.

[0025] In addition, the applicant unexpectedly discovered that the use of the corrosion inhibitor and surfactant in the present application can further achieve the brightness requirements for the hard LC4 aluminum alloy workpiece in a shorter time. This may be due to their interaction, which improves the stability of the polishing liquid to a certain extent and increases the polishing activity of sulfuric acid.

[0026] The second aspect of the present invention provides a method for preparing the aluminum alloy non-phosphating polishing liquid, comprising: mixing the various components of the aluminum alloy non-phosphating polishing liquid to obtain.

[0027] The third aspect of the present invention provides a polishing process, comprising: after degreasing and cleaning the polishing workpiece, placing it in the aluminum alloy non-phosphating polishing liquid, and polishing it at 85-95° C. for 2-5 minutes.

[0028] In one embodiment, the polishing process comprises: after degreasing and cleaning the polishing workpiece, placing it in the aluminum alloy non-phosphating polishing liquid, polishing at 90° C. for 2 minutes, and then repeatedly washing it with water and drying it.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This application is based on the theory of chemical polishing mucous film layer. While meeting customers' requirements for appearance such as gloss, flow marks, and roughness, toxic and harmful ingredients are abandoned, and a chemical polishing liquid for aluminum alloy is developed using chemical ingredients without chromic acid, phosphoric acid, or nitric acid. The liquid has good environmental protection and stability, and can maintain good polishing performance for a long time. In addition, the LC4 workpiece obtained using the polishing liquid not only has no scratches, lines, orange peel, matte, and other problems, but also has a neat surface and a good bright effect. DETAILED DESCRIPTION

[0031] The present invention is described below by specific implementation methods, but is not limited to the specific embodiments given below.

[0032] Example

[0033] Example 1

[0034] Embodiment 1 of the present invention provides a phosphating-free polishing liquid for aluminum alloy, which comprises, by weight, 20 parts of 98wt% sulfuric acid, 0.01 parts of sulfate, 1 part of organic acid salt, 0.05 parts of surfactant, and 0.1 parts of corrosion inhibitor.

[0035] The sulfate is sodium sulfate and potassium sulfate, with a weight ratio of 0.8:1; the organic acid salt is ammonium acetate and copper acetate, with a weight ratio of 1:1; the surfactant is sodium tridecyl alcohol polyether-12 carboxylate, sodium tridecyl alcohol polyether-7 carboxylate, nonylphenol polyoxyethylene (10) ether; the weight ratio of sodium tridecyl alcohol polyether-12 carboxylate and sodium tridecyl alcohol polyether-7 carboxylate is 5:0.3; the total weight ratio of nonylphenol polyoxyethylene (10) ether and sodium tridecyl alcohol polyether-12 carboxylate and sodium tridecyl alcohol polyether-7 carboxylate is 0.1:1; nonylphenol polyoxyethylene (10) ether is purchased from Xingtai Xinlanxing Technology Co., Ltd. The corrosion inhibitor is phenylthiourea and benzotriazole, with a weight ratio of 1:3.

[0036] The preparation method of the aluminum alloy non-phosphating polishing liquid is to mix the various components of the aluminum alloy non-phosphating polishing liquid to obtain the aluminum alloy non-phosphating polishing liquid.

[0037] The polishing process includes: removing oil and cleaning the polishing workpiece LC4 aluminum alloy, placing it in the aluminum alloy non-phosphating polishing liquid, polishing at 90° C. for 2 minutes, and then repeatedly washing it with water and drying it to obtain the product.

[0038] Example 2

[0039] Embodiment 2 of the present invention provides a phosphating-free polishing liquid for aluminum alloy, which comprises, by weight, 40 parts of 98wt% sulfuric acid, 0.1 parts of sulfate, 5 parts of organic acid salt, 0.1 parts of surfactant, and 0.3 parts of corrosion inhibitor.

[0040] The sulfate is sodium sulfate and potassium sulfate, with a weight ratio of 1.8:1; the organic acid salt is ammonium acetate and copper acetate, with a weight ratio of 1:2; the surfactant is sodium tridecyl alcohol polyether-12 carboxylate, sodium tridecyl alcohol polyether-7 carboxylate, nonylphenol polyoxyethylene (10) ether; the weight ratio of sodium tridecyl alcohol polyether-12 carboxylate and sodium tridecyl alcohol polyether-7 carboxylate is 8:0.6; the total weight ratio of nonylphenol polyoxyethylene (10) ether and sodium tridecyl alcohol polyether-12 carboxylate and sodium tridecyl alcohol polyether-7 carboxylate is 1:1; nonylphenol polyoxyethylene (10) ether is purchased from Xingtai Xinlanxing Technology Co., Ltd. The corrosion inhibitor is phenylthiourea and benzotriazole, with a weight ratio of 1:6.

[0041] The preparation method of the aluminum alloy non-phosphating polishing liquid is to mix the various components of the aluminum alloy non-phosphating polishing liquid to obtain the aluminum alloy non-phosphating polishing liquid.

[0042] The polishing process includes: removing oil and cleaning the polishing workpiece LC4 aluminum alloy, placing it in the aluminum alloy non-phosphating polishing liquid, polishing at 90° C. for 2 minutes, and then repeatedly washing it with water and drying it to obtain the product.

[0043] Example 3

[0044] Embodiment 3 of the present invention provides a phosphating-free polishing liquid for aluminum alloy, which comprises, by weight, 32 parts of 98wt% sulfuric acid, 0.06 parts of sulfate, 1.5 parts of organic acid salt, 0.08 parts of surfactant, and 0.2 parts of corrosion inhibitor.

[0045] The sulfate is sodium sulfate and potassium sulfate, with a weight ratio of 1.5:1; the organic acid salt is ammonium acetate and copper acetate, with a weight ratio of 1:1.5; the surfactant is sodium tridecyl alcohol polyether-12 carboxylate, sodium tridecyl alcohol polyether-7 carboxylate, nonylphenol polyoxyethylene (10) ether; the weight ratio of sodium tridecyl alcohol polyether-12 carboxylate and sodium tridecyl alcohol polyether-7 carboxylate is 6.2:0.5; the total weight ratio of nonylphenol polyoxyethylene (10) ether and sodium tridecyl alcohol polyether-12 carboxylate and sodium tridecyl alcohol polyether-7 carboxylate is 0.5:1; nonylphenol polyoxyethylene (10) ether is purchased from Xingtai Xinlanxing Technology Co., Ltd. The corrosion inhibitor is phenylthiourea and benzotriazole, with a weight ratio of 1:5.

[0046] The preparation method of the aluminum alloy non-phosphating polishing liquid is to mix the various components of the aluminum alloy non-phosphating polishing liquid to obtain the aluminum alloy non-phosphating polishing liquid.

[0047] The polishing process includes: removing oil and cleaning the polishing workpiece LC4 aluminum alloy, placing it in the aluminum alloy non-phosphating polishing liquid, polishing at 90° C. for 2 minutes, and then repeatedly washing it with water and drying it to obtain the product.

[0048] Example 4

[0049] Example 4 of the present invention provides an aluminum alloy non-phosphating polishing liquid, and its specific implementation method is the same as that of Example 3, except that the surfactant is OP-10 purchased from Shandong Dengnuo New Material Technology Co., Ltd.

[0050] The specific implementation method of the preparation method of the aluminum alloy non-phosphating polishing liquid is the same as that of Example 3.

[0051] The specific implementation method of the polishing process is the same as that of Example 3.

[0052] Example 5

[0053] Example 5 of the present invention provides a phosphating-free polishing liquid for aluminum alloy, and its specific implementation manner is the same as that of Example 3, except that the surfactant is polyethylene glycol 400.

[0054] The specific implementation method of the preparation method of the aluminum alloy non-phosphating polishing liquid is the same as that of Example 3.

[0055] The specific implementation method of the polishing process is the same as that of Example 3.

[0056] Example 6

[0057] Example 6 of the present invention provides an aluminum alloy non-phosphating polishing liquid, and its specific implementation manner is the same as that of Example 3, except that the corrosion inhibitor is 4-hydroxyazobenzene 4'-sulfonic acid.

[0058] The specific implementation method of the preparation method of the aluminum alloy non-phosphating polishing liquid is the same as that of Example 3.

[0059] The specific implementation method of the polishing process is the same as that of Example 3.

[0060] Performance Evaluation

[0061] 1. Appearance: Observe whether there are flow marks on the surface of the aluminum alloy after polishing.

[0062] 2. Brightness: Observe whether the brightness of the aluminum alloy is uniform after polishing.

[0063] Table 1

[0064] brightness Appearance Example 1 Uniform No flow marks Example 2 Uniform No flow marks Example 3 Uniform No flow marks Example 4 Uneven No flow marks Example 5 Uneven No flow marks Example 6 Uneven Some traces

Claims

1. A phosphorus-free polishing liquid for aluminum alloy, characterized in that: In parts by weight, it comprises 20-40 parts of sulfuric acid, 0.01-0.1 parts of sulfate, 1-5 parts of organic acid salt, 0.05-0.1 parts of surfactant, and 0.1-0.3 parts by weight of corrosion inhibitor; The surfactant includes polyether carboxylates and alkylphenol polyoxyethylene ethers; The weight ratio of the alkylphenol polyoxyethylene ether to the polyether carboxylate is (0.1-1):1; The polyether carboxylate is a linear alkyl polyoxyethylene ether carboxylate; The polyether carboxylate comprises a polyether carboxylate with a degree of polymerization of 7 and a polyether carboxylate with a degree of polymerization of 12, with a weight ratio of (5-8): (0.3-0.6); The corrosion inhibitors are phenylthiourea and benzotriazole; The weight ratio of the phenylthiourea to benzotriazole is 1:(3-6).

2. The aluminum alloy phosphorus-free polishing liquid according to claim 1, characterized in that: The cloud point of the alkylphenol polyoxyethylene ether is 60-65°C.

3. The aluminum alloy phosphorus-free polishing liquid according to claim 1, characterized in that: The organic acid salt is selected from one or more of organic acid ammonium salt, organic acid copper salt, organic acid molybdenum salt and organic acid lithium salt.

4. A method for preparing the phosphorus-free aluminum alloy polishing liquid according to any one of claims 1 to 3, characterized in that: include: The phosphorus-free polishing liquid for aluminum alloy is obtained by mixing various components.

5. A polishing process, characterized in that: include: The polishing workpiece is cleaned and degreased, and then placed in the aluminum alloy phosphorus-free polishing liquid according to any one of claims 1 to 3, and polished at 85 to 95° C. for 2 to 5 minutes to obtain the polishing workpiece.