Preparation method of a metal surface cleaning agent

Abstract

The present invention provides a preparation method of a metal surface cleaning agent. The steps are as follows: (1) Mix polyolamine and polyol at a mixing temperature of 5-10°C and stir evenly; (2) Continue stirring, keep the temperature stable, slowly add perchloric acid, and stir evenly; (3) Continue stirring, and simultaneously add a mercapto sulfonyl ionic compound and a pyridinium salt compound. After slowly heating to room temperature, continue stirring for 1-2 h to obtain the cleaning agent. The mercapto sulfonyl ionic compound and the pyridinium salt compound in the cleaning agent can effectively improve the state of the metal surface.

Description

Technical Field

[0001] The present invention relates to a preparation method of a metal surface cleaning agent, and particularly relates to the field of aluminum alloy surface cleaning. Technical Background

[0002] In nature, aluminum is the most abundant metallic element, accounting for 8.3% of the earth's crust content. Aluminum and aluminum alloy products have the advantages of low specific gravity, good electrical and thermal conductivity, high specific strength, high temperature resistance, corrosion resistance to various media, fatigue resistance, and good reflection performance to light and heat. They are typical light alloy materials and are widely used in civil, construction, machinery manufacturing, science and technology, military, electronic and electrical, transportation, aerospace, and chemical industry fields. With the continuous development of science and technology and industrial technology, higher requirements and standards have been put forward for the surface quality of aluminum and aluminum alloy workpieces, especially in terms of the surface gloss and flatness of the workpieces. Therefore, in order to make aluminum and aluminum alloy workpieces meet the usage standards of industrial production and life, usually the surface of aluminum and aluminum alloy workpieces needs to achieve the decorative effects of sand surface or mirror surface.

[0003] However, aluminum and aluminum alloys have low hardness and poor wear resistance. During the manufacturing and production of aluminum and aluminum alloy materials, mechanical damage is caused to the workpieces, and defects such as pores, scratches, bruises, scratches, and abrasions are generated on the surface of aluminum and aluminum alloy workpieces. Due to the existence of these surface defects, the aesthetics and application value of aluminum and aluminum alloy workpieces are greatly affected, reducing the surface flatness and brightness of aluminum and aluminum alloy workpieces. Moreover, the existence of these defects particularly affects the chemical stability of the workpieces, especially the corrosion resistance. Local corrosion often occurs preferentially at the surface defects of the workpieces, greatly shortening the service life of the workpieces. Therefore, solving the surface defect problem of aluminum and aluminum alloy products is the top priority for the continuous development of the aluminum and aluminum alloy industry. In order to eliminate these surface defects and obtain higher surface brightness and better decorative effects, usually the surface of aluminum and aluminum alloy workpieces is treated.

[0004] According to different action principles and process characteristics, polishing techniques can be divided into three categories: mechanical polishing, electro-chemical polishing (electrolytic polishing), and chemical polishing. Surface polishing treatment technology can be used either as the final treatment of the surface of aluminum and aluminum alloy workpieces or as a pre-treatment process for anodizing and electroplating of aluminum and aluminum alloys. Each polishing method has its own advantages and disadvantages. Different polishing methods result in different polishing effects on aluminum and aluminum alloys after treatment, which are mainly reflected in four aspects: polishing process, polishing cost, surface finish of the workpiece, and impact on the atmospheric environment.

[0005] Mechanical polishing is a process in which, under the action of external force, very fine polishing paste applied on the polishing disc and the surface of the workpiece to be processed produce grinding and rolling, removing the raised parts of the machined surface of the workpiece, making the uneven surface become flat and smooth. However, during the mechanical polishing process, due to factors such as extrusion and heat on the workpiece surface, a new crystal deformation layer will be formed on the workpiece surface, damaging the surface structure of the workpiece. As a result, there are still problems with the polished aluminum alloy workpieces, not meeting the product usage requirements. For example, the surface finish of the polished workpiece is insufficient, the corrosion resistance is poor, and stress corrosion or intergranular corrosion is likely to occur. Although the surface of the workpiece after mechanical polishing can obtain sufficient flatness and brightness, if such a workpiece is directly subjected to the anodizing process, a high-quality film layer with excellent decorative effects cannot be obtained. In addition, mechanical polishing can only be used to polish workpieces with simple external structures. For decorative materials, precision components, and optical components with high requirements for workpiece surface performance and complex shapes, relying solely on mechanical polishing cannot achieve the required specular reflectivity and surface flatness of the workpiece.

[0006] For example, CN105081941A discloses a mechanical polishing process for the inner wall of a stainless steel storage tank, which includes the following steps:

[0007] 1) Rough polishing: Use a 60# - 100# diamond grinding wheel to grind, polish, or abrade the surface of the workpiece to remove burrs, scratches, rust marks, oxide scales, excess weld bead height, weld tumors, weld slag, etc. on the surface, remove the surface oxide layer, and expose the metallic luster.

[0008] 2) Fine polishing: Use an 80# diamond grinding wheel and a thousand - leaf wheel to further process the surface after rough polishing, remove the scratches left during rough polishing, and produce a smooth to moderately bright surface.

[0009] 3) Precision polishing: Use 240# - 320# fiber wheels and cloth wheels coated with polishing paste to polish the surface of the stainless steel storage tank, further reducing the surface roughness of the stainless steel to achieve the purpose of micro - flatness.

[0010] 4) Polishing inspection: Use the center - line average method for inspection. During inspection, move the roughness detector horizontally on the surface of the stainless steel storage tank and record the peak - valley change amplitude.

[0011] Chemical polishing is similar to electro - chemical polishing. Both rely on the etching action of special chemical reagents on the workpiece surface

[0012] Selective dissolution is carried out on the uneven area. Under certain temperature and time conditions, the oxide layer and crystal deformation layer on the surface are etched away to eliminate surface scratches and achieve etching and leveling. After chemical polishing, the surface glossiness of the workpiece is improved, the surface roughness is reduced, the chemical stability is enhanced, and the reflection ability of light and heat is increased, etc. However, compared with electrochemical polishing, the equipment investment in chemical polishing is less. It does not require power supply equipment and corresponding fixtures. Its equipment is simple, the operation is simple, the production efficiency is high, and it can effectively process thin tubes, parts with deep holes, small-sized and complex-shaped parts. Since most aluminum and aluminum alloy applications have no special requirements, as long as they meet the requirements for surface glossiness and flatness in daily industry and life, the use of chemical polishing process is completely sufficient. The materials applicable to chemical polishing are not only for aluminum and aluminum alloy products. Other materials such as copper, nickel, titanium and their alloy products, and even workpieces such as steel and silver can improve the surface finish of the materials by using chemical polishing or electrochemical polishing process.

[0013] As disclosed in CN102277575A, an aluminum product chemical polishing solution and its preparation method are provided, which relate to a chemical polishing solution. A nitrate-improved "three-acid" polishing process is provided, which not only has the advantages of less yellow smoke, low pollution, and no nitric acid, but also the polishing quality can reach the level of the traditional "three-acid" process, and can reduce the environmental pollution caused by the release of nitrogen oxides. The raw material composition is sulfuric acid, phosphoric acid, boric acid, passivator, anti-fog brightener, citric acid, tartaric acid and water. The specific steps are as follows: add each solid raw material into water, after dissolution, add phosphoric acid and sulfuric acid in sequence. After the solution cools down, transfer it to a volumetric flask for volume fixing. Usage method: heat the aluminum product chemical polishing solution to 95 - 110 °C; immerse the dry and clean aluminum product to be polished into the aluminum product chemical polishing solution, take it out after processing for 30 - 100 s; immerse the taken-out aluminum product to be polished into nitric acid for brightening for 25 - 120 s, and then wash it to complete the polishing of the aluminum product.

[0014] Electrochemical polishing (also known as electrolytic polishing or electropolishing) is a surface finishing technique in which the anode of a metal workpiece dissolves in a certain electrolyte solution, thereby reducing the surface roughness, increasing the brightness, and producing a metallic luster on its surface. The specific process is as follows: The workpiece to be treated is used as the anode, and an insoluble metal is used as the cathode (usually a lead plate or a stainless steel plate). Then, both the anode and the cathode are placed in the electrolytic bath solution, and the DC power supply is turned on to start polishing. During the polishing process, selective anodic dissolution occurs on the surface of aluminum and aluminum alloy workpieces, resulting in a workpiece surface with a higher gloss and a flatter surface. Electrochemical polishing technology has been developed for several decades, and it can improve the properties of the metal surface without changing the properties of the workpiece itself. After electrochemical polishing, metals and alloys become smoother, brighter, and more corrosion-resistant. This process dissolves the particles generated by mechanical polishing.

[0015] For example, CN110846710A discloses an electrochemical polishing method for the surface of copper materials, which includes the following steps: preparing a polishing solution; immersing the copper material to be polished in the polishing solution and turning on the power supply for polishing; wherein, preparing the polishing solution includes: calculating the dosage of each solute according to the total volume of the solution to be prepared, and the solutes include phosphoric acid, glycerol, thiourea, and polyoxyethylene alkanolamide; according to the calculation results, weighing phosphoric acid and glycerol and introducing them into a corrosion-resistant container, adding water to reach the total volume, and stirring to dissolve to obtain a first intermediate solution; according to the calculation results, weighing thiourea and adding it to the first intermediate solution, and stirring to dissolve to obtain a second intermediate solution; according to the calculation results, measuring polyoxyethylene alkanolamide and adding it to the second intermediate solution, and stirring evenly to obtain the polishing solution. The present invention can improve the surface roughness of copper precision parts from Ra0.4μm to Ra0.2μm to meet the usage requirements of vacuum electronic devices.

[0016] Compared with chemical polishing and mechanical polishing, electrochemical polishing has the following advantages: (1) It can obtain a high surface finish; (2) It can obtain a high polishing accuracy; (3) The operating environment is good, and the metal loss is small; (4) The energy consumption is low; (5) It can process workpieces of any shape and size; (6) The polishing speed is independent of the physical and mechanical properties of the metal; (7) It can greatly improve the production efficiency; (8) It can improve the physical and mechanical properties, physicochemical properties, and service performance of the surface of metal parts; (9) It is relatively easy to master the operation technology; (10) It has a wide range of applications. Summary of the Invention

[0017] Based on the above introduction of polishing, the present invention provides a preparation method of a metal surface cleaning agent, which, as an electrolytic solution for electrochemical polishing, can effectively polish a metal substrate to obtain a metal surface with low roughness, high flatness, corrosion resistance, and good stability.

[0018] A preparation method of a metal surface cleaning agent, the cleaning agent preparation method is as follows:

[0019] (1) Mix polyolamine and polyol, the mixing temperature is 5 - 10 °C, and stir evenly;

[0020] (2) Continue to stir, keep the temperature stable, slowly add perchloric acid, and stir evenly;

[0021] (3) Continue to stir, and at the same time add a mercapto sulfonyl ionic compound and a pyridinium salt compound, slowly heat up to room temperature, and then continue to stir for 1 - 2 h to obtain the cleaning agent.

[0022] The polyol is selected from one of dipropylene glycol, glycerol or butanediol.

[0023] The polyolamine is selected from one of diisopropanolamine, triisopropanolamine or triethanolamine.

[0024] The mercapto sulfonyl ionic compound is selected from one of sodium thiazolinyl dithiopropane sulfonate, sodium dimethyldithiocarbonyl propane sulfonate, 3-(benzothiazol-2-ylmercapto)-propane sulfonate.

[0025] The pyridinium salt compound is selected from one of 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, or 3-(4-tert-butyl-1-pyridyl)propane sulfonate, or 3-(1-pyridyl)propane sulfonate.

[0026] The content of the polyol is 30 - 65 vol.%, the content of perchloric acid is 3 - 5 vol.%, the content of the polyolamine is 10 - 15 ml / L, the content of the mercapto sulfonyl ionic compound is 3 - 5 g / L, and the pyridinium salt compound is 1.5 - 3 g / L.

[0027] The metal is stainless steel, aluminum alloy or titanium alloy, preferably aluminum alloy.

[0028] The metal is used as the anode, an inert metal is used as the cathode, the cleaning agent is used as the electrolyte, and a power supply is applied between the metal and the inert technology to clean the anode metal.

[0029] The power supply is first a DC power supply and then a pulsed power supply. The pulse is first a millisecond-level pulse and then a microsecond-level pulse.

[0030] The cleaning process is as follows:

[0031] (1) Turn on the DC power supply: the current density is 3 - 5 A / cm 2 , the polishing time is 5 - 7 min, the temperature is 20 - 25 °C, and the electrode spacing is 15 - 20 mm;

[0032] (2) Intermittent step: Turn off the power supply, start stirring, with a stirring speed of 200 - 300 rpm, a stirring temperature of 17 - 23 °C, and a stirring time of 2 - 3 min.

[0033] (3) Turn on the millisecond pulse power supply: The forward pulse current density is 2 - 3 mA / cm 2 , the forward pulse width is 100 - 150 ms, the forward duty cycle is 10 - 15%, the number of pulses is 5 - 10, the reverse pulse current density is 2 - 3 mA / cm 2 , the pulse width is 150 - 170 ms, the reverse duty cycle is 10 - 15%, the number of pulses is 1, the temperature is 20 - 25 °C, and the time is 2 - 3 min;

[0034] (4) Intermittent step: Turn off the power supply, start stirring, with a stirring speed of 200 - 300 rpm, a stirring temperature of 17 - 23 °C, and a stirring time of 2 - 3 min.

[0035] (5) Turn on the microsecond pulse power supply: The forward pulse current density is 1 - 2 mA / cm 2 , the forward pulse width is 50 - 100 μs, the forward duty cycle is 10 - 15%, the number of pulses is 10 - 15, the reverse pulse current density is 1 - 2 mA / cm2, the reverse pulse width is 50 - 100 μs, the reverse duty cycle is 10 - 15%, the number of pulses is 1, the temperature is 13 - 15 °C, and the time is 0.5 - 1 min.

[0036] (6) Post - treatment: Turn off the power supply, wash with absolute ethanol, purge and dry in an inert atmosphere. The inert atmosphere is nitrogen or argon, the temperature is 35 - 40 °C, and the time is 1 - 2 h.

[0037] Regarding the cleaning solution of the present invention, its composition is polyol, perchloric acid, polyolamine, mercapto sulfonyl ionic compound, pyridinium salt compound, and the balance is made up with deionized water. It is a standard deionized water cleaning system. Generally speaking, the composition of the polishing solution is relatively complex, and different types of polishing solutions are applicable to different materials. There is no definite formula, and most of them need to be explored through experiments. However, the types of components contained therein can be roughly divided into three parts: polishing base liquid, oxidant, and various additives. The oxidant is the most important component among them. Electrochemical polishing solutions are mainly divided into three categories, namely acid-acid systems, such as combinations of concentrated sulfuric acid and concentrated phosphoric acid; acid-alcohol systems, such as combinations of concentrated sulfuric acid and methanol / ethanol; and alcohol-salt systems, such as combinations of ethylene glycol and chloride salts. Each polishing solution system cannot meet all requirements and has certain advantages and disadvantages. There is no completely ideal polishing solution system. For the acid-acid system, most use strong acids such as concentrated sulfuric acid and concentrated phosphoric acid. Although the polishing quality is good and the polishing efficiency is high, the corrosiveness is strong, the reaction process is not easy to control, and it is easy to be dangerous during use. For the acid-alcohol system, alcohols are generally volatile and not easy to store, and alcohols and acids easily react to form esters, and the operation process has high requirements for the environment, etc. For the alcohol-salt system, although most of them have no pollution to the environment, due to their low corrosiveness and oxidizing property, the polishing efficiency is low, the production cost is high, and the polishing process has high requirements for polishing devices, etc. The present invention mainly adopts a polyol-perchloric acid system, and perchloric acid is used as the oxidant, which is the most important component in the polishing solution. It can dissolve metal alloys and generate soluble salts, and also form a passivation film on the surface of the specimen. Polyol is used as a solvent to dissolve the soluble salts generated by the anode. At the same time, the carboxyl groups and hydroxyl groups contained in them can also play a corrosion inhibition role. Compared with monohydric alcohols such as methanol, the solvent selected in the present invention is a polyol, which is one of dipropylene glycol, glycerol or butanediol, and the polyhydroxyl groups show better slow-release effects.

[0038] The polyol and polyolamine are added simultaneously. The polyolamine is selected from one of diisopropanolamine, triisopropanolamine or triethanolamine. The polyolamine is weakly basic and can be a complexing agent or a leveling agent. It can produce a mucous membrane on the surface, adsorb on the surface, help polishing, and make the surface gradually flat.

[0039] The mercapto sulfonyl ionic compound and the pyridinium salt compound have a synergistic leveling and brightening technical effect. The mercapto sulfonyl ionic compound is selected from one of sodium thiazolinyl dithiopropane sulfonate, sodium dimethyldithiocarbonyl propane sulfonate, 3-(benzothiazol-2-ylmercapto)-propane sulfonate; the pyridinium salt compound is selected from one of 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, or 3-(4-tert-butyl-1-pyridyl)propane sulfonate, or 3-(1-pyridyl)propane sulfonate. The structural formulas of the three pyridinium salts are as follows:

[0040] ; ;

[0041] In theory, during the metal polishing process, when the metal immersed in the electrolyte is energized, at the anode, it loses electrons, and the metal dissolves in the electrolyte in the form of ions. The reaction formula is Al → 3Al 3+ + 3e; In this process, it is hoped that the aluminum ions can leave the surface as soon as possible; after the metal loses electrons, under the action of the electric field force, the OH- ions perform electromigration movement, causing a large number of local OH- ions to accumulate near the metal anode, and a hydrolysis deposition reaction occurs, that is, Al 3+ + 3OH - → Al(OH)3. In this process, it is hoped that hydrolysis does not occur. Based on the above theory, the pyridinium salts described in the present invention all have a C=N structure and are amphoteric compounds. Under current conditions, one end of the anion will adsorb on the anode surface to neutralize the anions therein, and the metal ions released during the polishing dissolution process, such as aluminum ions, will significantly form a repulsive effect with the nitrogen-containing positive charge, accelerating Al 3+ The metal ions enter the electrolyte from the surface of the dissolved metal, and the repelled aluminum ions are very easy to undergo hydrolysis with water, thereby forming hydroxide particles, which affects the polishing effect. In order to prevent excessive hydrolysis of aluminum ions, the metal ions (Al 3+ ) entering the solution will combine with C-S=O and N=C-S in the mercapto sulfonyl group. The unshared electron pairs in the functional group fill the empty orbitals of the metal ions to achieve a strong adsorption effect with the metal ions, thereby avoiding the deposition of metals. In addition, the mercapto sulfonyl ionic compound and the pyridinium salt compound have a rich cyclic structure, and their adsorption conjugation effect is significant, forming a mucosal structure on the surface, controlling rapid corrosion at the convex part and slow corrosion at the concave part, and finally obtaining a leveling and brightening effect. Neither of them can be lacking. If the pyridinium salts are lacking, the metal ions cannot effectively move and diffuse away from the metal surface. If the mercapto sulfonyl ionic compound is lacking, the metal ions cannot effectively avoid hydrolysis, as shown in Figure 1 and Figure 2 shown.

[0042] Another important reason for the excellent surface treatment effect obtained by treating the metal surface with the cleaning agent of the present invention is the electrochemical electrolysis parameters. In the prior art, the mainly used electrochemical polishing power supply is a DC power supply or a pulse power supply. There are few treatment methods of first DC and then pulse, and even fewer electrochemical treatment processes of first millisecond level and then micron level.

[0043] In the present invention, the substrate to be processed is used as the anode, and the cleaning agent obtained in the above preparation process is added, and then anodic electrochemical polishing is carried out. The metal to be processed is stainless steel, aluminum alloy or titanium alloy, preferably aluminum alloy. The metal can be subjected to various surface pretreatments, including but not limited to degreasing, pickling and activation, sandblasting, grinding, polishing and other treatments.

[0044] First, direct current electrolytic polishing is carried out on the substrate. In the initial stage of direct current electrolytic polishing, due to the different roughness of the part surface, that is, the unevenness and roughness of the metal surface, the electrolyte is adsorbed on the metal surface and an oxidation reaction occurs. The thickness of the viscous liquid film formed at the convex part is smaller than that formed at the concave part. Moreover, due to the greater impact of the power line and the liquid stirring action on the viscous liquid film at the convex part, and the convex part is closer to the cathode, the electric field strength is large, and it is easy to lose electrons according to the principle of tip discharge, forming a highly concentrated positive charge at the convex part. Since the anions around the anode preferentially act on the cations at the convex part, the dissolution rate of the metal at the convex part is faster than that at the concave part. For direct current electrolytic polishing, it has an obvious and relatively fast flattening effect on the obvious concave-convex structure on the metal surface. The whole process appears rough and fast. Although it lacks fineness, the efficiency is relatively high, as shown in the appendix Figure 3 as shown.

[0045] Direct current electrolytic conditions: current density 3 - 5 A / cm 2 , the polishing time is 5 - 7 min, the temperature is 20 - 25 °C, and the electrode spacing is 15 - 20 mm; among them, the current density has the greatest influence on the process of direct current electrolytic polishing and is the energy source for polishing. Too large or too small current density will have an adverse effect on polishing. When the current density is too small, the polished surface is always in the dissolution stage, the surface roughness is large, there is no metallic luster, and the polishing effect is small. When the current density is too large, the reaction is intense, more heat is generated, the oxidizing property of perchloric acid increases with the increase of temperature, more surface material is etched away, and the surface brightness increases. At the same time, more oxygen is evolved on the anode surface. Due to the agitation of the gas, uneven polishing and over-polishing phenomena will occur on the surface. In addition, the inter-electrode distance during electrochemical polishing is larger than that during electrolytic machining, mainly to ensure that the metal dissolves more evenly during polishing and achieve a better polishing effect. When the inter-electrode distance is too small, the diffusion of reactants is inconvenient, the temperature of the polishing solution rises rapidly, and the heat dissipation is poor. When the inter-electrode distance is too large, the current density decreases and the polishing effect is not obvious. Finally, the optimized reaction conditions are current density 3 - 5 A / cm 2 , the polishing time is 5 - 7 min, the temperature is 20 - 25 °C, and the electrode spacing is 15 - 20 mm. Overall, compared with pulse electrolysis, the direct current electrolytic polishing has a larger current density and a longer time, and can obtain a flat surface more quickly.

[0046] The roughness of the metal surface treated by direct current electro-polishing is approximately 5 - 10 μm. The polishing precision is significantly insufficient. The main reason may be that the direct current voltage is constant, it is difficult to remove the polishing products and heat, and the products accumulate on the anode surface, increasing the surface roughness of the workpiece, thereby resulting in very poor surface quality.

[0047] Then perform pulse treatment:

[0048] (2)Turn on the millisecond pulse power supply: The forward pulse current density is 2 - 3 mA / cm 2 , the forward pulse width is 100 - 150 ms, the forward duty cycle is 10 - 15%, the number of pulses is 5 - 10, the reverse pulse current density is 2 - 3 mA / cm 2 , the pulse width is 150 - 170 ms, the reverse duty cycle is 10 - 15%, the number of pulses is 1, the temperature is 20 - 25 °C, and the time is 2 - 3 min.

[0049] (3)Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 200 - 300 rpm, the stirring temperature is 17 - 23 °C, and the stirring time is 2 - 3 min.

[0050] (4)Turn on the microsecond pulse power supply: The forward pulse current density is 1 - 2 mA / cm[[ID=I7]] 2 , the forward pulse width is 50 - 100 μs, the forward duty cycle is 10 - 15%, the number of pulses is 10 - 15, the reverse pulse current density is 1 - 2 mA / cm2, the reverse pulse width is 50 - 100 μs, the reverse duty cycle is 10 - 15%, the number of pulses is 1, the temperature is 13 - 15 °C, and the time is 0.5 - 1 min.

[0051] The surface roughness after polishing by pulsed current electro-chemical polishing is significantly reduced compared to direct current electro-chemical polishing. The reason is that theoretically, a pressure wave will be generated in the electrode gap at the moment of power-on. Due to the action of the pressure wave, bubbles will be generated in the electrode gap, and the anode surface will be corroded. At the moment of power-off, the bubbles suddenly expand and merge, and the anode products are washed away. In this way, the phenomenon of poor surface roughness caused by the inability to remove surface products in time is effectively reduced. Generally, the narrower the pulse width and the higher the frequency of the pulsed current, the more beneficial it is to improve the flow field. Because the smaller the pulse width and the higher the frequency, the faster the electrolyte renewal speed in the gap, and the more obvious the impact effect of the pressure wave, which is more conducive to improving the surface quality.

[0052] Based on the above considerations, the present invention adopts a periodic commutation pulse power supply. The periodic commutation pulse is to add one or more reverse pulses after a group of forward pulses, which can further accelerate the migration of anode products, and thus obtain a high polishing effect. During the pulse stage, relatively high current is first used for anode polishing in milliseconds for a relatively long time, and the surface roughness of the metal obtained is about 400 - 600 nm. Then, relatively low current is used for anode polishing in microseconds for a short time, and the surface roughness of the metal obtained is about 50 - 150 nm. Compared with directly performing periodic commutation pulse electrochemical treatment in microseconds, to obtain the same polishing effect, the polishing time can be shortened by 3 / 4, and the polishing effect is greatly satisfied. The polishing effect is as shown in the attached Figure 4 figure.

[0053] Advantageous technical effects

[0054] (1) By effectively configuring the cleaning solution, especially the mercapto sulfonyl ionic compound and pyridinium salt compound therein, the present invention has a direct impact on the roughness, high flatness, and glossiness of the metal surface treatment.

[0055] (2) By treating the metal surface with DC + millisecond pulse + microsecond pulse, on the premise of ensuring low roughness, high gloss, and low corrosion amount of the metal surface, the present invention effectively reduces the man-hour consumption and reduces the loss amount. Description of the drawings

[0056] Attached Figure 1 Aluminum alloy diagram after the treatment of Comparative Example 1 of the present invention.

[0057] Attached Figure 2 Aluminum alloy diagram after the treatment of Comparative Example 2 of the present invention.

[0058] Attached Figure 3 Aluminum alloy diagram after the treatment of Comparative Example 3 of the present invention.

[0059] Attached Figure 4 Aluminum alloy diagram after the treatment of Example 2 of the present invention. Detailed implementation manners

[0060] The preparation methods of the cleaning agents in Examples 1 - 3 and the comparative examples of the present invention are as follows:

[0061] (1) Mix polyol amine and polyol, with the mixing temperature being 5 - 10 °C, and stir evenly;

[0062] (2) Continue stirring, keep the temperature stable, slowly add perchloric acid, and stir evenly;

[0063] (3) Continue stirring, and simultaneously add mercapto sulfonyl ionic compound and pyridinium salt compound, slowly heat up to room temperature, and then continue stirring for 1 - 2 h to obtain the cleaning agent.

[0064] If it does not contain the above components, partial adaptive deletion is performed.

[0065] Example 1

[0066] A preparation method of a metal surface cleaning agent. The cleaning agent obtained by the above method includes polyol, perchloric acid, polyolamine, mercapto sulfonyl ionic compound, and pyridinium salt compound. The content of polyol is 30 vol.%, the content of perchloric acid is 3 vol.%, the content of the polyolamine is 10 ml / L, the content of the mercapto sulfonyl ionic compound is 3 g / L, the pyridinium salt compound is 1.5 g / L, and the balance is deionized water.

[0067] The polyol is selected from dipropylene glycol.

[0068] The polyolamine is selected from diisopropanolamine.

[0069] The mercapto sulfonyl ionic compound is selected from sodium thiazolinyl dithiopropane sulfonate.

[0070] The pyridinium salt compound is selected from 3-(4-tert-butyl-1-pyridyl) propanesulfonate.

[0071] Using the metal as the anode, an inert metal as the cathode, and the cleaning agent as the electrolyte, a power supply is applied between the metal anode and the inert metal cathode to clean the anode metal.

[0072] The cleaning process is as follows:

[0073] (1) Turn on the DC power supply: the current density is 3 A / cm 2 , the polishing time is 5 min, the temperature is 20 °C, and the electrode spacing is 15 mm.

[0074] (2) Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 200 rpm, the stirring temperature is 17 °C, and the stirring time is 2 min.

[0075] (3) Turn on the millisecond pulse power supply: the forward pulse current density is 2 mA / cm 2 , the forward pulse width is 100 ms, the forward duty cycle is 10%, the number of pulses is 5, the reverse pulse current density is 2 mA / cm 2 , the pulse width is 150 ms, the reverse duty cycle is 10%, the number of pulses is 1, the temperature is 20 °C, and the time is 2 min.

[0076] (4) Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 200 rpm, the stirring temperature is 17 °C, and the stirring time is 2 min.

[0077] (5) Turn on the microsecond pulse power supply: the forward pulse current density is 1 mA / cm2 The forward pulse width is 50 μs, the forward duty cycle is 10%, the number of pulses is 10, and the reverse pulse current density is 1 mA / cm 2 The pulse width is 50 μs, the forward duty cycle is 10%, the number of pulses is 1, the temperature is 13 °C, and the time is 0.5 min.

[0078] There is post-treatment: turn off the power supply, wash with absolute ethanol, purge and dry in an inert atmosphere. The inert atmosphere is nitrogen or argon, the temperature is 35 °C, and the time is 1 h.

[0079] Example 2

[0080] A preparation method of a metal surface cleaning agent. The cleaning agent obtained by the above method includes polyol, perchloric acid, polyolamine, mercapto sulfonyl ionic compound, and pyridinium salt compound. The content of polyol is 55 vol.%, the content of perchloric acid is 4 vol.%, the content of the polyolamine is 12.5 ml / L, the content of the mercapto sulfonyl ionic compound is 4 g / L, the pyridinium salt compound is 2 g / L, and the balance is deionized water.

[0081] The polyol is selected from one of glycerol.

[0082] The polyolamine is selected from one of triisopropanolamine.

[0083] The mercapto sulfonyl ionic compound is selected from one of sodium dimethyldithiocarbonyl propane sulfonate.

[0084] The pyridinium salt compound is selected from 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide.

[0085] Using the metal as the anode, an inert metal as the cathode, and the cleaning agent as the electrolyte, a power supply is applied between the metal anode and the inert metal cathode for cleaning the anode metal.

[0086] The cleaning process is as follows:

[0087] (1) Turn on the DC power supply: the current density is 4 A / cm 2 The polishing time is 6 min, the temperature is 23 °C, and the electrode spacing is 17 mm.

[0088] (2) Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 250 rpm, the stirring temperature is 20 °C, and the stirring time is 2.5 min.

[0089] (3) Turn on the millisecond pulse power supply: the forward pulse current density is 2.5 mA / cm 2 The forward pulse width is 125 ms, the forward duty cycle is 12.5%, the number of pulses is 8, and the reverse pulse current density is 2.5 mA / cm2 , the reverse pulse width is 160 ms, the reverse duty cycle is 12.5%, the number of pulses is 1, the temperature is 23 °C, and the time is 2.5 min.

[0090] (4) Intermittent step: Turn off the power supply, start stirring, the stirring speed is 250 rpm, the stirring temperature is 20 °C, and the stirring time is 2.5 min.

[0091] (5) Turn on the microsecond pulse power supply: The forward pulse current density is 1.5 mA / cm 2 , the forward pulse width is 75 μs, the forward duty cycle is 12.5%, the number of pulses is 13, the reverse pulse current density is 1.5 mA / cm2, the reverse pulse width is 75 μs, the reverse duty cycle is 12.5%, the number of pulses is 1, the temperature is 14 °C, and the time is 0.75 min.

[0092] There is post-treatment: Turn off the power supply, wash with absolute ethanol, purge and dry in an inert atmosphere. The inert atmosphere is nitrogen or argon, the temperature is 38 °C, and the time is 1.5 h.

[0093] Example 3

[0094] A preparation method of a metal surface cleaning agent. The cleaning agent obtained by the above method includes polyol, perchloric acid, polyolamine, mercapto sulfonyl ionic compound, and pyridinium salt compound. The content of polyol is 65 vol.%, the content of perchloric acid is 5 vol.%, the content of the polyolamine is 15 ml / L, the content of the mercapto sulfonyl ionic compound is 5 g / L, the pyridinium salt compound is 3 g / L, and the balance is deionized water.

[0095] The polyol is selected from one of butanediols.

[0096] The polyolamine is selected from one of triethanolamines.

[0097] The mercapto sulfonyl ionic compound is selected from one of sodium 3-(benzothiazole-2-mercapto)-propane sulfonate.

[0098] The pyridinium salt compound is selected from one of 3-(1-pyridyl) propanesulfonate.

[0099] Using the metal as the anode, an inert metal as the cathode, and the cleaning agent as the electrolyte, apply a power supply between the metal anode and the inert metal cathode to clean the anode metal;

[0100] The cleaning process is as follows:

[0101] (1) Turn on the DC power supply: The current density is 5 A / cm 2 , the polishing time is 7 min, the temperature is 25 °C, and the electrode spacing is 20 mm.

[0102] (2)Intermittent step: Turn off the power supply, start stirring, the stirring speed is 300 rpm, the stirring temperature is 23 °C, and the stirring time is 3 min.

[0103] (3)Turn on the millisecond pulse power supply: The forward pulse current density is 3 mA / cm 2 , the forward pulse width is 150 ms, the forward duty cycle is 15%, the number of pulses is 10, the reverse pulse current density is 3 mA / cm 2 , the pulse width is 170 ms, the reverse duty cycle is 15%, the number of pulses is 1, the temperature is 25 °C, and the time is 3 min.

[0104] (4)Intermittent step: Turn off the power supply, start stirring, the stirring speed is 200 - 300 rpm, the stirring temperature is 17 - 23 °C, and the stirring time is 2 - 3 min.

[0105] (5)Turn on the microsecond pulse power supply: The forward pulse current density is 2 mA / cm 2 , the forward pulse width is 100 μs, the forward duty cycle is 15%, the number of pulses is 15, the reverse pulse current density is 2 mA / cm2, the reverse pulse width is 100 μs, the reverse duty cycle is 15%, the number of pulses is 1, the temperature is 15 °C, and the time is 1 min.

[0106] There is post - treatment: Turn off the power supply, wash with absolute ethanol, purge and dry in an inert atmosphere. The inert atmosphere is nitrogen or argon, the temperature is 40 °C, and the time is 2 h.

[0107] Comparative Example 1

[0108] A preparation method of a metal surface cleaning agent. The cleaning agent obtained by the above method includes polyol, perchloric acid, and a polyolamine compound. The content of the polyol is 55 vol.%, the content of perchloric acid is 4 vol.%, the content of the polyolamine is 12.5 ml / L, and the balance is deionized water.

[0109] The polyol is selected from one of glycerol.

[0110] The polyolamine is selected from one of triisopropanolamine.

[0111] The mercapto sulfonyl ionic compound is selected from one of sodium dimethyldithiocarbonyl propane sulfonate.

[0112] The pyridinium salt compound is 1 - ethyl - 3 - methylpyridinium bis(trifluoromethylsulfonyl)imide.

[0113] Using the metal as the anode, an inert metal as the cathode, and the cleaning agent as the electrolyte, apply a power supply between the metal anode and the inert metal cathode to clean the anode metal.

[0114] The cleaning process is as follows:

[0115] (1)Turn on the DC power supply: the current density is 4 A / cm 2 , the polishing time is 6 min, the temperature is 23 °C, and the electrode spacing is 17 mm.

[0116] (2)Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 250 rpm, the stirring temperature is 20 °C, and the stirring time is 2.5 min.

[0117] (3)Turn on the millisecond pulse power supply: the forward pulse current density is 2.5 mA / cm 2 , the forward pulse width is 125 ms, the forward duty cycle is 12.5%, the number of pulses is 8, the reverse pulse current density is 2.5 mA / cm 2 , the reverse pulse width is 160 ms, the reverse duty cycle is 12.5%, the number of pulses is 1, the temperature is 23 °C, and the time is 2.5 min.

[0118] (4)Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 250 rpm, the stirring temperature is 20 °C, and the stirring time is 2.5 min.

[0119] (5)Turn on the microsecond pulse power supply: the forward pulse current density is 1.5 mA / cm 2 , the forward pulse width is 75 μs, the forward duty cycle is 12.5%, the number of pulses is 13, the reverse pulse current density is 1.5 mA / cm2, the reverse pulse width is 75 μs, the reverse duty cycle is 12.5%, the number of pulses is 1, the temperature is 14 °C, and the time is 0.75 min.

[0120] There is post-treatment: turn off the power supply, wash with absolute ethanol, purge and dry in an inert atmosphere. The inert atmosphere is nitrogen or argon, the temperature is 38 °C, and the time is 1.5 h.

[0121] Comparative Example 2

[0122] A preparation method of a metal surface cleaning agent. The cleaning agent obtained by the above method includes polyol, perchloric acid, polyolamine, and mercapto sulfonyl ionic compound. The content of polyol is 55 vol.%, the content of perchloric acid is 4 vol.%, the content of the polyolamine is 12.5 ml / L, the content of the mercapto sulfonyl ionic compound is 4 g / L, and the balance is deionized water.

[0123] The polyol is selected from one of glycerol.

[0124] The polyolamine is selected from one of triisopropanolamine.

[0125] The mercapto sulfonyl ionic compound is selected from one of sodium dimethyldithiocarbonyl propane sulfonate.

[0126] Using the metal as the anode, an inert metal as the cathode, and the cleaning agent as the electrolyte, a power supply is applied between the metal anode and the inert metal cathode to clean the anode metal.

[0127] The cleaning process is as follows:

[0128] (1) Turn on the DC power supply: the current density is 4 A / cm 2 , the polishing time is 6 min, the temperature is 23 °C, and the electrode spacing is 17 mm.

[0129] (2) Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 250 rpm, the stirring temperature is 20 °C, and the stirring time is 2.5 min.

[0130] (3) Turn on the millisecond pulse power supply: the forward pulse current density is 2.5 mA / cm 2 , the forward pulse width is 125 ms, the forward duty cycle is 12.5%, the number of pulses is 8, the reverse pulse current density is 2.5 mA / cm 2 , the reverse pulse width is 160 ms, the reverse duty cycle is 12.5%, the number of pulses is 1, the temperature is 23 °C, and the time is 2.5 min.

[0131] (4) Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 250 rpm, the stirring temperature is 20 °C, and the stirring time is 2.5 min.

[0132] (5) Turn on the microsecond pulse power supply: the forward pulse current density is 1.5 mA / cm 2 , the forward pulse width is 75 μs, the forward duty cycle is 12.5%, the number of pulses is 13, the reverse pulse current density is 1.5 mA / cm2, the reverse pulse width is 75 μs, the reverse duty cycle is 12.5%, the number of pulses is 1, the temperature is 14 °C, and the time is 0.75 min.

[0133] There is post-treatment: Turn off the power supply, wash with absolute ethanol, purge and dry in an inert atmosphere. The inert atmosphere is nitrogen or argon, the temperature is 38 °C, and the time is 1.5 h.

[0134] Comparative Example 3

[0135] A preparation method of a metal surface cleaning agent. The cleaning agent obtained by the above method comprises polyol, perchloric acid, polyolamine, mercapto sulfonyl ionic compound, and pyridinium salt compound. The content of polyol is 55 vol.%, the content of perchloric acid is 4 vol.%, the content of the polyolamine is 12.5 ml / L, the content of the mercapto sulfonyl ionic compound is 4 g / L, the pyridinium salt compound is 2 g / L, and the balance is deionized water.

[0136] The polyol is selected from one of glycerol.

[0137] The polyolamine is selected from one of triisopropanolamine.

[0138] The mercapto sulfonyl ionic compound is selected from one of sodium dimethyldithiocarbony propane sulfonate.

[0139] The pyridinium salt compound is selected from 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide.

[0140] Using the metal as the anode, an inert metal as the cathode, and the cleaning agent as the electrolyte, a power supply is applied between the metal anode and the inert metal cathode to clean the anode metal.

[0141] The cleaning process is as follows:

[0142] (1) Turn on the DC power supply: the current density is 4 A / cm 2 , the polishing time is 10 min, the temperature is 23 °C, and the electrode spacing is 17 mm.

[0143] (2) Post-treatment: Turn off the power supply, wash with absolute ethanol, purge and dry in an inert atmosphere. The inert atmosphere is nitrogen or argon, the temperature is 38 °C, and the time is 1.5 h.

[0144] Comparative Example 4

[0145] A preparation method of a metal surface cleaning agent. The cleaning agent obtained by the above method comprises polyol, perchloric acid, polyolamine, mercapto sulfonyl ionic compound, and pyridinium salt compound. The content of polyol is 55 vol.%, the content of perchloric acid is 4 vol.%, the content of the polyolamine is 12.5 ml / L, the content of the mercapto sulfonyl ionic compound is 4 g / L, the pyridinium salt compound is 2 g / L, and the balance is deionized water.

[0146] The polyol is selected from one of glycerol.

[0147] The polyolamine is selected from one of triisopropanolamine.

[0148] The mercapto sulfonyl ionic compound is selected from one of sodium dimethyldithiocarbonyl propane sulfonate.

[0149] The pyridinium salt compound is selected from 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide.

[0150] Using the metal as the anode, an inert metal as the cathode, and the cleaning agent as the electrolyte, a power supply is applied between the metal anode and the inert metal cathode to clean the anode metal.

[0151] The cleaning process is as follows:

[0152] (1) Turn on the millisecond pulse power supply: the forward pulse current density is 2.5 mA / cm 2 , the forward pulse width is 125 ms, the forward duty cycle is 12.5%, the number of pulses is 8, the reverse pulse current density is 2.5 mA / cm 2 , the reverse pulse width is 160 ms, the reverse duty cycle is 12.5%, the number of pulses is 1, the temperature is 23 °C, and the time is 13 min.

[0153] (2) Intermittent step: Turn off the power supply, turn on the stirring, the stirring speed is 250 rpm, the stirring temperature is 20 °C, and the stirring time is 2.5 min.

[0154] (3) Turn on the microsecond pulse power supply: the forward pulse current density is 1.5 mA / cm 2 , the forward pulse width is 75 μs, the forward duty cycle is 12.5%, the number of pulses is 13, the reverse pulse current density is 1.5 mA / cm2, the reverse pulse width is 75 μs, the reverse duty cycle is 12.5%, the number of pulses is 1, the temperature is 14 °C, and the time is 7.4 min.

[0155] Post-treatment: Turn off the power supply, wash with absolute ethanol, purge and dry in an inert atmosphere. The inert atmosphere is nitrogen or argon, the temperature is 38 °C, and the time is 1.5 h.

[0156] Surface roughness: Detect by selecting 3 different areas on the surface of the specimen with an RSE3000 surface roughness meter, and take the average value of the roughness of the 3 measured areas as the test result.

[0157] Surface glossiness: Using aluminum as the specimen, detect the 45 o reflection angle, and measure the surface glossiness of the specimen according to the standard of GB8807-88.

[0158] Table 1

[0159]

[0160] As shown in the above table, in Example 2 of the present invention, by using base liquid + mercapto sulfonyl + pyridinium salt, the surface roughness of the aluminum alloy obtained is 53 nm, and the glossiness is 81.3%. The corrosion amount of the product is small. In comparison, under the same electrolysis parameters, if the electrolyte is changed, for example, mercapto sulfonyl + pyridinium salt is deleted in Comparative Example 1, and pyridinium salt is deleted in Comparative Example 2, it can be seen that the electrolyte has an obvious impact on the glossiness and roughness of the product, which is an order of magnitude of ten. This is mainly because the additives have an obvious impact on the migration and diffusion of the generated oxide particles in the electroplating solution. In Comparative Examples 3-4, the electrolytes are the same, but the electrolysis parameters are different. If only direct current electrolysis is used, the polishing degree and glossiness cannot meet the industrial requirements of low roughness and high metallic luster. Compared with directly performing pulse treatment, the millisecond and microsecond pulse times of Comparative Example 3 are adjustable. By adjusting the time parameters of Comparative Example 3, the same surface roughness effect as that of Example 2 is obtained. Although a high mirror effect can be obtained, the time used, loss consumption, and equipment burden are significantly higher than those of Example 2 of the present invention.

[0161] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A preparation method of a metal surface cleaning agent, characterized in that The preparation method of the cleaning agent is as follows: (1) Mix polyolamine and polyol at a mixing temperature of 5 - 10 °C and stir evenly; (2) Continue stirring, keep the temperature stable, slowly add perchloric acid, and stir evenly; (3) Continue stirring, and simultaneously add a mercapto sulfonyl ionic compound and a pyridinium salt compound. After slowly heating to room temperature, continue stirring for 1 - 2 h to obtain the cleaning agent; The content of the polyol is 30 - 65 vol.%, the content of perchloric acid is 3 - 5 vol.%, the content of the polyolamine is 10 - 15 ml / L, the content of the mercapto sulfonyl ionic compound is 3 - 5 g / L, and the content of the pyridinium salt compound is 1.5 - 3 g / L; The metal is aluminum alloy.

2. The preparation method of a metal surface cleaning agent according to claim 1, characterized in that The polyol is selected from one of dipropylene glycol, glycerol or butanediol; the polyolamine is selected from one of diisopropanolamine, triisopropanolamine or triethanolamine; the mercapto sulfonyl ionic compound is selected from one of sodium thiazolinyl dithiopropane sulfonate, sodium dimethyldithiocarbonyl propane sulfonate, sodium 3-(benzothiazol-2-ylthio)-propane sulfonate; the pyridinium salt compound is selected from one of 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, or 3-(4-tert-butyl-1-pyridyl)propanesulfonate, or 3-(1-pyridyl)propanesulfonate.

3. The preparation method of a metal surface cleaning agent as described in claim 1, characterized in that The metal is used as the anode, an inert metal is used as the cathode, the cleaning agent is used as the electrolyte, and a power supply is applied between the metal and the inert metal for cleaning the anode metal.

4. The preparation method of a metal surface cleaning agent according to claim 3, characterized in that The power supply is first a DC power supply and then a pulse power supply. The pulse is first a millisecond-level pulse and then a microsecond-level pulse.

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