A polishing liquid for aluminum alloy surface treatment

Abstract

The present invention relates to a polishing liquid, and in particular to a polishing liquid for aluminum alloy surface treatment. The polishing liquid for aluminum alloy surface treatment provided by the present invention adopts an alkaline polishing liquid instead of an acidic polishing liquid, thereby avoiding the pollution such as toxic yellow gas generated in the polishing liquid, and also reducing the water pollution generated by phosphate ions and other problems. The polishing liquid for aluminum alloy surface treatment of the present invention is characterized in that the polishing liquid is formulated from the following components: sodium hydroxide, sodium nitrate, a corrosion inhibitor, a surfactant, magnesium sulfate, and the balance is water. Among them, the corrosion inhibitor is composed of glycerol and sodium tungstate, and the surfactant is composed of sodium gluconate and sodium dodecyl sulfate. The reflectivity of the 6060 aluminum alloy after polishing with the polishing liquid of the present invention is 96-99.8%, and the weight loss per unit area of ​​the aluminum alloy plate surface after polishing is 7.8-11.6 g / m 2 , the polishing effect is excellent and the polishing process is environmentally friendly.

Description

Technical Field

[0001] The invention relates to a polishing liquid, in particular to a polishing liquid for aluminum alloy surface treatment. Background Art

[0002] Aluminum alloy products are widely used in optical instruments, electronic product housings, lamps and other fields. In order to improve the surface finish of aluminum alloys, the surface of aluminum alloys needs to be polished. Chemical polishing is simple to operate and has low production costs, while acidic polishing liquid has good polishing performance and strong stability, and is widely used in industry. However, the acidic polishing liquid contains more nitric acid, which easily produces yellow gas during the polishing process, causing air pollution. At the same time, phosphate ions will be discharged, causing water pollution. Replacing the acidic polishing liquid with an alkaline polishing liquid can reduce environmental pollution.

[0003] At present, alkaline polishing liquid still has problems such as poor polishing effect, large alloy weight loss, and high polishing temperature. For example, although the polishing liquid in patent document CN106702389A is environmentally friendly, the polishing effect and high polishing temperature need to be further improved. The polishing liquid in patent document CN104109482A uses silica sol to improve the control effect of aluminum alloy surface roughness, but the surface brightness of the aluminum alloy is not good. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a polishing liquid for aluminum alloy surface treatment. The aluminum alloy polished by the polishing liquid of the present invention has the advantages of good polishing effect, less alloy weight loss during the polishing process, and low polishing temperature.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A polishing liquid for aluminum alloy surface treatment is characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0007] Wherein, the corrosion inhibitor is composed of propylene glycol and sodium tungstate.

[0008] Among them, the surfactant is composed of sodium gluconate and sodium dodecyl sulfate.

[0009] Preferably, based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 120-150 g / L.

[0010] Preferably, based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 60-90 g / L.

[0011] Preferably, based on the total amount of the polishing liquid, the concentration of the glycerol is 20-30 g / L.

[0012] Preferably, based on the total amount of the polishing liquid, the concentration of the sodium tungstate is 10-20 g / L.

[0013] Preferably, based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 0.5-1.5 g / L.

[0014] Preferably, based on the total amount of the polishing liquid, the concentration of the sodium dodecyl sulfate is 0.5-1.0 g / L.

[0015] Preferably, based on the total amount of the polishing liquid, the concentration of magnesium sulfate is 0.3-1.0 g / L.

[0016] Preferably, the polishing liquid for aluminum alloy surface treatment is used as follows: the aluminum alloy is soaked in anhydrous ethanol for 2 minutes, washed with deionized water, the washed aluminum alloy is placed in the polishing liquid, and chemically polished at a temperature of 30-45°C for 12-20 seconds; the polished aluminum alloy is placed in an acid solution for neutralization, washed with deionized water, and dried after washing to obtain a polished aluminum alloy.

[0017] Preferably, the aluminum alloy is 6060 aluminum alloy.

[0018] Preferably, the chemical polishing is performed at a temperature of 40° C. for 15 seconds.

[0019] The reaction of sodium hydroxide and aluminum alloy can improve the surface finish of aluminum alloy, and sodium nitrate can selectively dissolve the protruding parts of aluminum alloy and smooth the surface of aluminum alloy. When the concentration of sodium hydroxide is 132g / L and the concentration of sodium nitrate is 75g / L, the polishing effect of aluminum alloy is higher.

[0020] The corrosion inhibitor composed of glycerol and sodium tungstate can play a good role in corrosion inhibition and improve the polishing effect. The combination of glycerol and sodium tungstate can reduce the weight loss of aluminum alloy. After adding sodium tungstate with a concentration of 10-20g / L, the glycerol concentration can reach 20g / L to meet the corrosion inhibition requirements. However, too high a concentration of glycerol will not only reduce the reaction rate, but also slightly reduce the polishing effect. When the concentration of glycerol is 25g / L and the concentration of sodium tungstate is 18g / L, the polishing effect of aluminum alloy is higher and the weight loss is less.

[0021] The surfactant composed of sodium gluconate and sodium dodecyl sulfate can improve the polishing effect and reduce the weight loss. Too high a concentration of sodium gluconate or sodium dodecyl sulfate will produce more foam, which is not conducive to polishing. Too low a concentration will reduce the material transfer between the polishing liquid and the reaction product, reduce the roughness of the aluminum alloy surface, and reduce the polishing effect. When the ratio of the concentration of sodium gluconate to the concentration of sodium dodecyl sulfate is 1:1.2, the polishing effect is better and the weight loss is less.

[0022] Magnesium sulfate has a leveling effect. Magnesium ions will expand at the protrusions, which will accelerate the dissolution rate of the protrusions on the surface of the aluminum alloy, improve the brightness of the polishing, and is beneficial to the polishing effect of the aluminum alloy. However, if the concentration of magnesium sulfate is too low, the leveling effect will be reduced. If the concentration of magnesium sulfate is too high, it will react with hydroxide ions, which will also reduce the polishing effect and accelerate the weight loss of the aluminum alloy. When the concentration of magnesium sulfate is 0.5g / L, the polishing effect is better and the weight loss is less.

[0023] Aluminum alloy polishing effect and weight loss test: soak the 6060 aluminum alloy in anhydrous ethanol for 2 minutes, wash it with deionized water, put the washed 6060 aluminum alloy into the polishing liquid of the present invention, and perform chemical polishing at a temperature of 40°C for 15 seconds; put the polished 6060 aluminum alloy into an acid solution for neutralization, wash it with deionized water, and dry it after washing to obtain the polished 6060 aluminum alloy. According to the test, the reflectivity of the polished 6060 aluminum alloy is 96-99.8%, and the weight loss per unit area of ​​the surface of the polished aluminum alloy plate is 7.8-11.6g / m 2 The degree of pitting is determined according to the number of pitting, such as very few, less, less, and more, to indicate the surface finish of the aluminum alloy. The pitting on the surface of the polished 6060 aluminum alloy is very few or less.

[0024] Beneficial effects of the present invention:

[0025] 1. The polishing liquid for aluminum alloy surface treatment provided by the present invention adopts an alkaline polishing liquid instead of an acidic polishing liquid, thereby avoiding pollution such as toxic yellow gas generated in the polishing liquid and also reducing problems such as water pollution generated by phosphate ions.

[0026] 2. The corrosion inhibitor composed of propylene glycol and sodium tungstate can play a good role in corrosion inhibition and improve the polishing effect. The combined use of propylene glycol and sodium tungstate can reduce the weight loss of aluminum alloy. The appropriate concentration can ensure that the polishing effect of aluminum alloy is higher and the weight loss is less.

[0027] 3. The surfactant composed of sodium gluconate and sodium dodecyl sulfate can improve the polishing effect and reduce the weight loss. When the concentration of magnesium sulfate is 0.5g / L, the polishing effect is better and the weight loss is less.

[0028] 4. When the concentration of sodium hydroxide in the polishing liquid is 132g / L, the concentration of sodium nitrate is 75g / L, the concentration of glycerol is 25g / L, the concentration of sodium tungstate is 18g / L, the ratio of sodium gluconate to sodium dodecyl sulfate is 1:1.2, and the concentration of magnesium sulfate is 0.5g / L, the polishing liquid has better polishing effect and weight loss effect on aluminum alloy. DETAILED DESCRIPTION

[0029] The above contents of the present invention are further described in detail below by means of specific embodiments in the form of examples, but the specific embodiments are essentially considered to be illustrative rather than restrictive.

[0030] Embodiment 1: A polishing liquid for aluminum alloy surface treatment, characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0031] Wherein, the corrosion inhibitor is composed of propylene glycol and sodium tungstate.

[0032] Among them, the surfactant is composed of sodium gluconate and sodium dodecyl sulfate.

[0033] Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 120 g / L.

[0034] Based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 90 g / L.

[0035] Based on the total amount of the polishing liquid, the concentration of the glycerol is 20 g / L, and the concentration of the sodium tungstate is 20 g / L.

[0036] Based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 0.5 g / L and the concentration of the sodium dodecyl sulfate is 1.0 g / L.

[0037] Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 0.3 g / L.

[0038] The aluminum alloy is 6060 aluminum alloy.

[0039] Embodiment 2: A polishing liquid for aluminum alloy surface treatment, characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0040] Wherein, the corrosion inhibitor is composed of propylene glycol and sodium tungstate.

[0041] Among them, the surfactant is composed of sodium gluconate and sodium dodecyl sulfate.

[0042] Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 150 g / L.

[0043] Based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 60 g / L.

[0044] Based on the total amount of the polishing liquid, the concentration of the glycerol is 30 g / L, and the concentration of the sodium tungstate is 10 g / L.

[0045] Based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 1.5 g / L and the concentration of the sodium dodecyl sulfate is 0.5 g / L.

[0046] Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 1.0 g / L.

[0047] The aluminum alloy is 6060 aluminum alloy.

[0048] Embodiment 3: A polishing liquid for aluminum alloy surface treatment, characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0049] Wherein, the corrosion inhibitor is composed of propylene glycol and sodium tungstate.

[0050] Among them, the surfactant is composed of sodium gluconate and sodium dodecyl sulfate.

[0051] Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 132 g / L.

[0052] Based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 75 g / L.

[0053] Based on the total amount of the polishing liquid, the concentration of the glycerol is 20 g / L, and the concentration of the sodium tungstate is 20 g / L.

[0054] Based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 0.5 g / L and the concentration of the sodium dodecyl sulfate is 1.0 g / L.

[0055] Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 0.3 g / L.

[0056] The aluminum alloy is 6060 aluminum alloy.

[0057] Embodiment 4: A polishing liquid for aluminum alloy surface treatment, characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0058] Wherein, the corrosion inhibitor is composed of propylene glycol and sodium tungstate.

[0059] Among them, the surfactant is composed of sodium gluconate and sodium dodecyl sulfate.

[0060] Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 132 g / L.

[0061] Based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 75 g / L.

[0062] Based on the total amount of the polishing liquid, the concentration of the glycerol is 25 g / L, and the concentration of the sodium tungstate is 18 g / L.

[0063] Based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 0.5 g / L and the concentration of the sodium dodecyl sulfate is 1.0 g / L.

[0064] Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 0.3 g / L.

[0065] The aluminum alloy is 6060 aluminum alloy.

[0066] Embodiment 5: A polishing liquid for aluminum alloy surface treatment, characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0067] Wherein, the corrosion inhibitor is composed of propylene glycol and sodium tungstate.

[0068] Among them, the surfactant is composed of sodium gluconate and sodium dodecyl sulfate.

[0069] Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 132 g / L.

[0070] Based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 75 g / L.

[0071] Based on the total amount of the polishing liquid, the concentration of the glycerol is 25 g / L, and the concentration of the sodium tungstate is 18 g / L.

[0072] Based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 0.5 g / L and the concentration of the sodium dodecyl sulfate is 0.6 g / L.

[0073] Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 0.5 g / L.

[0074] The aluminum alloy is 6060 aluminum alloy.

[0075] Comparative Example 1: A polishing liquid for aluminum alloy surface treatment, characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0076] Among them, the corrosion inhibitor is composed of sodium silicate and gelatin.

[0077] Among them, the surfactant is composed of sodium gluconate and sodium dodecyl sulfate.

[0078] Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 120 g / L.

[0079] Based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 90 g / L.

[0080] Based on the total amount of the polishing liquid, the concentration of the sodium silicate is 20 g / L, and the concentration of the gelatin is 20 g / L.

[0081] Based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 0.5 g / L and the concentration of the sodium dodecyl sulfate is 1.0 g / L.

[0082] Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 0.3 g / L.

[0083] The aluminum alloy is 6060 aluminum alloy.

[0084] Comparative Example 2: A polishing liquid for aluminum alloy surface treatment, characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0085] Wherein, the corrosion inhibitor is composed of propylene glycol and sodium tungstate.

[0086] The surfactant is composed of alkylphenol polyoxyethylene ether and sodium citrate.

[0087] Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 120 g / L.

[0088] Based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 90 g / L.

[0089] Based on the total amount of the polishing liquid, the concentration of the glycerol is 20 g / L, and the concentration of the sodium tungstate is 20 g / L.

[0090] Based on the total amount of the polishing liquid, the concentration of the alkylphenol polyoxyethylene ether is 0.5 g / L and the concentration of the sodium citrate is 1.0 g / L.

[0091] Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 0.3 g / L.

[0092] The aluminum alloy is 6060 aluminum alloy.

[0093] Comparative Example 3: A polishing liquid for aluminum alloy surface treatment, characterized in that the polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water.

[0094] Wherein, the corrosion inhibitor is composed of propylene glycol and sodium tungstate.

[0095] Among them, the surfactant is composed of sodium gluconate and sodium dodecyl sulfate.

[0096] Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 200 g / L.

[0097] Based on the total amount of the polishing liquid, the concentration of the sodium nitrate is 50 g / L.

[0098] Based on the total amount of the polishing liquid, the concentration of the glycerol is 5 g / L, and the concentration of the sodium tungstate is 5 g / L.

[0099] Based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 4 g / L and the concentration of the sodium dodecyl sulfate is 6 g / L.

[0100] Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 6 g / L.

[0101] The aluminum alloy is 6060 aluminum alloy.

[0102] The aluminum alloy was polished using the polishing liquids of Examples 1-5 and Comparative Examples 1-3, and the polishing effect and weight loss of the polished aluminum alloy were tested, specifically: the 6060 aluminum alloy was soaked in anhydrous ethanol for 2 minutes, washed with deionized water, and the washed 6060 aluminum alloy was placed in the polishing liquid of the present invention, and chemically polished at a temperature of 40°C for 15 seconds; the polished 6060 aluminum alloy was placed in an acid solution for neutralization, washed with deionized water, and dried after washing to obtain the polished 6060 aluminum alloy. After testing, the reflectivity of the 6060 aluminum alloy polished with the polishing liquid of the present invention was 96-99.8%, and the weight loss per unit area of ​​the surface of the polished aluminum alloy plate was 7.8-11.6 g / m 2 , and according to the number of pits, the degree of extremely few, less, less, more, more, etc. is determined to indicate the surface finish of the aluminum alloy. The pits on the surface of the 6060 aluminum alloy polished with the polishing liquid of the present invention are extremely few and less. The specific test results of Examples 1-5 and Comparative Examples 1-3 are shown in Table 1.

[0103] Table 1 Effect of different polishing fluids on polishing effect of 6060 aluminum alloy

[0104] Polishing liquid Reflectivity / % <![CDATA[Weight loss / g / m 2 > Pits on the alloy surface Example 1 96 10.9 less Example 2 96.3 11.6 less Example 3 97.6 10.8 less Example 4 98.4 9.1 Very rare Example 5 99.8 7.8 Very rare Comparative Example 1 86.3 13.9 many Comparative Example 2 84.8 13.7 More Comparative Example 3 86.1 13.1 many

[0105] It can be seen from Table 1 that the use of the polishing liquid of the present invention can obtain an excellent polishing effect and can reduce the weight loss of the aluminum alloy to a large extent.

[0106] The reflectivity of the 6060 aluminum alloy after being polished by the polishing liquid of the present invention is 96-99.8%, and the weight loss per unit area of ​​the surface of the aluminum alloy plate after being polished is 7.8-11.6 g / m 2 , the polishing effect is excellent and the polishing process is environmentally friendly.

[0107] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. Without departing from the scope of the present invention, all improvements and modifications made should be within the protection scope of the present invention.

Claims

1. A polishing liquid for aluminum alloy surface treatment, characterized in that: The polishing liquid is prepared from the following components: sodium hydroxide, sodium nitrate, corrosion inhibitor, surfactant, magnesium sulfate, and the balance is water; wherein the corrosion inhibitor is composed of propylene glycol and sodium tungstate; the surfactant is composed of sodium gluconate and sodium dodecyl sulfate; based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 120-150 g / L, the concentration of the sodium nitrate is 60-90 g / L; the concentration of the propylene glycol is 20-30 g / L, the concentration of the sodium tungstate is 10-20 g / L; the concentration of the sodium gluconate is 0.5-1.5 g / L, the concentration of the sodium dodecyl sulfate is 0.5-1.0 g / L; the concentration of the magnesium sulfate is 0.3-1.0 g / L.

2. The polishing liquid for aluminum alloy surface treatment according to claim 1, characterized in that: Based on the total amount of the polishing liquid, the concentration of the sodium hydroxide is 132 g / L, and the concentration of the sodium nitrate is 75 g / L.

3. The polishing liquid for aluminum alloy surface treatment according to claim 1, characterized in that: Based on the total amount of the polishing liquid, the concentration of the glycerol is 25 g / L, and the concentration of the sodium tungstate is 18 g / L.

4. The polishing liquid for aluminum alloy surface treatment according to claim 1, characterized in that: Based on the total amount of the polishing liquid, the concentration of the sodium gluconate is 0.5 g / L, and the concentration of the sodium dodecyl sulfate is 0.6 g / L.

5. The polishing liquid for aluminum alloy surface treatment according to claim 1, characterized in that: Based on the total amount of the polishing liquid, the concentration of the magnesium sulfate is 0.5 g / L.

6. The polishing liquid for aluminum alloy surface treatment according to claim 1, characterized in that: The aluminum alloy is 6060 aluminum alloy.

7. The polishing liquid for aluminum alloy surface treatment according to claim 1, characterized in that: The polishing liquid for aluminum alloy surface treatment is used as follows: the aluminum alloy is soaked in anhydrous ethanol for 2 minutes, washed with deionized water, the washed aluminum alloy is placed in the polishing liquid, and chemically polished at a temperature of 30-45°C for 12-20 seconds; the polished aluminum alloy is placed in an acid solution for neutralization, washed with deionized water, and dried after washing to obtain a polished aluminum alloy.

8. The polishing liquid for aluminum alloy surface treatment according to claim 7, characterized in that: Chemical polishing was performed at a temperature of 40°C for 15 seconds.