CN111058077A - Electrolyte for micro-arc oxidation of black ceramic membrane, preparation method of electrolyte and micro-arc oxidation method - Google Patents
Electrolyte for micro-arc oxidation of black ceramic membrane, preparation method of electrolyte and micro-arc oxidation method Download PDFInfo
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Abstract
The invention belongs to the technical field of surface treatment of magnesium alloy materials, and discloses an electrolyte for micro-arc oxidation of a black ceramic membrane, a preparation method of the electrolyte and a micro-arc oxidation method. The invention provides a process technical method for obtaining a black appearance on a magnesium alloy surface, which comprises the steps of preparing an electrolyte synthesized by a first coloring liquid and a second coloring liquid in an optimal ratio, setting key technical parameters, and obtaining a black ceramic film with the thickness of about 15-30 mu m on the magnesium alloy surface by adopting a two-step micro-arc oxidation method of constant voltage and constant current. The method has the advantages of good process repeatability, good electrolyte stability, recycling, uniform color of the obtained black ceramic membrane, good corrosion resistance and wear resistance, and further widening the application range of the magnesium alloy in electronic products.
Description
Technical Field
The invention relates to a surface treatment method of a magnesium alloy material, in particular to a method for coloring the surface of the magnesium alloy material by using a micro-arc oxidation technology.
Background
The magnesium alloy has great application value in the fields of light-weight structure automobiles, electronic products and the like as a circulating type and ultra-light green environment-friendly material which has the greatest development potential in the 21 st century, but the magnesium alloy has poor corrosion resistance and is easy to wear, which is the biggest obstacle restricting the commercial development of the magnesium alloy. The surface treatment is one of the simplest and most effective methods for improving the corrosion resistance and the abrasion resistance of the magnesium alloy, and is also a common treatment method for surface decoration.
The magnesium alloy surface coloring technology is widely applied to the traditional anodic oxidation coloring, but the technology has the following defects: (1) the prepared anodic oxide film has poor binding force with a matrix, is easy to fall off and has poor corrosion resistance; (2) the coloring process is carried out by two steps of coloring after anodic oxidation, the coloring quality depends on the quality of an anodic oxide film, the process is complicated, the production rate is reduced, and the cost is increased.
The micro-arc oxidation coloring technology is a valve metal surface coloring technology which is started in recent years, and has the following advantages: (1) the prepared ceramic membrane is firmly combined with a matrix, has high hardness and good corrosion resistance and wear resistance; (2) the process is simple, the production efficiency is high, and the method is popularized in the fields of electronic products and the like. However, the magnesium alloy ceramic membrane prepared by the technology is mainly white and grey-white ceramic membranes, and the research on black ceramic membranes is relatively less, so that the application of the magnesium alloy ceramic membrane in the fields of electronics, automobiles and the like is limited.
In the prior art for preparing the black ceramic membrane on the surface of the magnesium alloy by utilizing the micro-arc oxidation technology, the following defects are present: (1) the micro-arc oxidation process mostly adopts a one-stage process method with constant electrical parameters, but a porous layer with uneven distribution and cracks are generated seriously at the later stage due to micro-arc discharge, the surface of the film layer is rough, and the protective performance to a matrix is not good, for example, a method for preparing a magnesium alloy black micro-arc oxidation film is disclosed in the patent with the application number of CN201710335350.7, a black ceramic film is prepared by utilizing the one-stage process method with constant voltage, and the surface of the film layer is accompanied by cracks. (2) At present, most reports in microarc oxidation electrolyte for preparing black ceramic membranes are that metal oxides such as vanadium salt, tungsten salt and the like with black color development characteristics are provided, but the vanadium salt, the tungsten salt and the like have high toxicity and cause certain pollution to the environment; copper salt is easy to precipitate in a strong alkaline environment, and the stability of the coloring solution is influenced by the traditional micro-arc oxidation process.
Disclosure of Invention
The invention provides an electrolyte for micro-arc oxidation of a black ceramic membrane, a preparation method thereof and a micro-arc oxidation method, compared with the existing micro-arc oxidation technology, the use of toxic black chromogenic metal is avoided, the invention improves the stability of a coloring liquid by optimizing the solution preparation mode and adopting a step-by-step preparation method under a specific process to obtain more saturated blackening of an oxide membrane, thereby solving the problem of non-uniformity of the distribution of coloring ions on the surface of a magnesium alloy; by optimizing the micro-arc oxidation mode and adopting the constant-voltage-first-constant-current method, the problems of porosity and cracks of the film layer caused by the traditional one-stage constant-current parameter method are solved, the film layer is more compact, and the corrosion resistance and the wear resistance of the matrix can be obviously improved.
An electrolyte for micro-arc oxidation of a black ceramic membrane, a preparation method thereof and a micro-arc oxidation method comprise the following specific steps:
(1) preparing electrolyte:
preparing a first coloring liquid, then preparing a second coloring liquid, and adjusting the pH value of the mixed liquid of the first coloring liquid and the second coloring liquid to obtain a coloring electrolyte.
The preparation method comprises the following specific steps:
a, pouring deionized water into an oxidation tank, sequentially adding sodium silicate, sodium fluoride and phosphate according to the volume of the added deionized water, controlling the mass ratio to be 6-8: 3-5: 1, and performing high-speed homogenizer dispersion treatment for 10-15 min in an ice-water bath environment at 0 ℃ to prepare a first coloring liquid;
dissolving sodium potassium tartrate and copper salt in deionized water according to the mass ratio of 1: 1-2, and performing magnetic stirring dispersion treatment for 10-15 min in a constant-temperature water bath environment at the temperature of 20-40 ℃ to prepare a second coloring liquid;
c, adding the second coloring liquid into the first coloring liquid, controlling the volume ratio of deionized water of the second coloring liquid to deionized water of the first coloring liquid to be 1:1, performing dispersion treatment in a high-speed homogenizer in an ice water bath, cooling the temperature of the mixed solution to 0 ℃, adding a certain amount of potassium hydroxide or sodium hydroxide into the mixed solution, and adjusting the pH value of the mixed solution to be 8-13 to obtain the coloring mixed solution. The preparation method ensures that copper ions are not easy to generate copper hydroxide precipitation in strong alkaline solution, so that the components of the electrolyte are more uniformly distributed, the stability of the electrolyte is good, and a film layer with uniform color is obtained on the metal surface.
Understandably, when the mass ratio of the sodium silicate, the sodium fluoride and the phosphate in the first coloring liquid is controlled to be 6-8: 3-5: 1 in the step a, the micro-arc oxidation film has the fastest film forming rate, and the film layer is most uniform and compact. The sodium silicate in the proportion maximally reduces the arcing voltage of the micro-arc oxidation film, so that the film forming efficiency is highest, the surface appearance of the film layer is more uniform and porous due to the sodium fluoride, and the compactness of the film layer is improved due to the phosphate. The first coloring liquid is subjected to dispersion treatment in ice-water bath at 0 ℃, so that the problem that water glass is solidified due to large heat release during dissolution can be avoided, and the stability of the solution is improved.
Understandably, when the mass ratio of the potassium sodium tartrate to the copper salt in the step b is controlled to be 1: 1-2, the potassium sodium tartrate and the copper salt are subjected to a complex reaction, so that copper ions are not subjected to copper hydroxide precipitation in a strong alkaline solution, and the dispersing capacity of the electrolyte is improved. And the second coloring liquid is subjected to dispersion treatment at the temperature of 20-40 ℃, so that the solubility of the sodium potassium tartrate and the copper salt can be improved, the complex reaction is enhanced, and the deposition amount of copper in the film layer is increased.
Understandably, in the step c, potassium hydroxide or sodium hydroxide is used as a pH regulator of the electrolyte, and when the pH value of the solution is 8-13, the film forming efficiency is high, the compactness of the film layer is good, and the stability of the electrolyte is strong, so that the film layer with uniform color is obtained on the metal surface.
(2) Adopting a direct current pulse power supply to carry out two-section type micro-arc oxidation treatment:
connecting a magnesium alloy sample subjected to polishing and cleaning treatment by using an aluminum sheet, fixing the magnesium alloy sample on an anode rod in an oxidation tank to be used as an anode in a micro-arc oxidation process, using a stainless steel plate as a cathode in the micro-arc oxidation process, and using the coloring mixed solution obtained in the step (1) as an oxidation electrolyte; firstly, carrying out constant-pressure micro-arc oxidation treatment in the first step, then cooling the coloring electrolyte to 0 ℃ through ice-water bath, then carrying out constant-current micro-arc oxidation treatment in the second step, taking out a sample after the two-step micro-arc oxidation treatment, washing the sample with distilled water, and then putting the sample into a drying oven at the temperature of 40-60 ℃ for heat preservation for 0.5-1 h to prepare a magnesium alloy sample with a black ceramic membrane formed on the surface, wherein the thickness of the black ceramic membrane is 15-30 mu m.
It can be understood that in the two-step constant-voltage-constant-current-after-constant-current micro-arc oxidation treatment in the step (2), the first step of constant-voltage micro-arc oxidation is firstly carried out to prepare the black base membrane mainly containing magnesium oxide, copper oxide and forsterite, and then the second step of constant-current micro-arc oxidation is carried out to repeatedly melt and regrow the oxide membrane at the micropores, so that the large-diameter micropores formed in the first step of constant-voltage stage are repaired, the magnesium oxide, the copper oxide and the forsterite in the membrane are continuously melted and sintered into a whole, a blackened ceramic layer with a more saturated structure is obtained, the corrosion of a corrosion medium can be blocked, and the corrosion resistance of the ceramic layer is also obviously improved due to the addition of the forsterite.
Preferably, in the step (1), the coloring electrolyte comprises 10-30 g/L sodium silicate, 5-20 g/L sodium fluoride, 3-8 g/L potassium sodium tartrate, 1-5 g/L phosphate, 3-8 g/L copper salt, 2-12 g/L alkali pH regulator and deionized water. The copper salt is any one of copper pyrophosphate, copper phosphate, copper carbonate and copper sulfate; the phosphate is any one of sodium phosphate, sodium trimetaphosphate, sodium hexametaphosphate, sodium tripolyphosphate and sodium polyphosphate; the alkaline pH regulator is sodium hydroxide or potassium hydroxide.
Preferably, in the step (2), a magnesium alloy substrate with a brand number of AZ91 or AZ31 can be selected, the magnesium alloy is cut into a sample with a length x width x height of 10mm x 2mm, SiC sand paper of 400, 500, 800, 1000, 1500 meshes is sequentially adopted on a pre-grinding machine to gradually grind and remove a surface passivation film, acetone is used for cleaning for 5min to remove oil stains, then distilled water is used for ultrasonic cleaning for 5min to remove surface impurities, and finally ethanol is used for cleaning and dewatering.
Preferably, in the micro-arc oxidation treatment in the step (2), the cathode is two pieces of stainless steel, and the two pieces of stainless steel are placed on two sides of the magnesium alloy substrate as the anode and keep a symmetrical distance of 15-20 cm.
Preferably, in the two-step micro-arc oxidation treatment in the step (2), the first step is constant voltage micro-arc oxidation treatmentThe technological parameters of the oxidation treatment are as follows: the oxidation voltage is 300-400V, the oxidation time is 5-30 min, the frequency is 500-600 Hz, and the duty ratio is 50-60%; the second step of constant current micro-arc oxidation treatment comprises the following process parameters: the oxidation current is 0.5-2A/dm2The oxidation time is 5-15 min, the frequency is 300-400 Hz, and the duty ratio is 40-50%.
The invention has the beneficial effects that: the electrolyte prepared in steps is added, the technological parameters adaptive to the electrolyte are set to carry out two-step micro-arc oxidation treatment on the magnesium alloy, and the two steps must cooperate to form a black ceramic membrane mainly containing magnesium oxide, copper oxide and forsterite on the surface of the magnesium alloy, so that the black degree of the black ceramic membrane is more saturated, and the surface color is more uniform.
The first coloring liquid and the second coloring liquid added in the invention have reasonable proportion, the stability of the electrolyte is good, the electrolyte can be recycled, and meanwhile, a double-micro-arc oxidation treatment method of constant voltage and constant current is adopted to obtain a black ceramic membrane with controllable thickness and more compactness and uniformity; the process has good repeatability and high production efficiency, and is beneficial to industrial production.
Drawings
FIG. 1 is a macro topography of a black ceramic film formed on the surface of the magnesium alloy in examples 1-3.
FIG. 2 is an XRD spectrum of a black ceramic film formed on the surface of the magnesium alloy in example 1.
FIG. 3 shows polarization curves of the magnesium alloy AZ91 without any treatment and the magnesium alloy modified in examples 1-3 after being soaked in 3.5% NaCl solution for 0.5 h.
FIG. 4 is a graph showing the friction coefficient curves of the AZ91 magnesium alloy without any treatment and the magnesium alloys obtained by modification in examples 1 to 3.
FIG. 5 is an SEM topography of black ceramic films formed on the surfaces of the magnesium alloys of example 3 and comparative example 3.
Detailed Description
The invention will be further described with reference to specific embodiments and drawings, without limiting the scope of the invention.
Example 1:
(1) after AZ91 magnesium alloy wires are cut into samples with the length multiplied by the width multiplied by the height of 10mm multiplied by 2mm, SiC sand paper with 400 meshes, 500 meshes, 800 meshes, 1000 meshes and 1500 meshes is sequentially adopted on a pre-grinding machine to gradually grind and remove surface oxidation films, acetone is used for cleaning for 5min to remove oil stains, then distilled water is used for ultrasonic cleaning for 5min to remove surface impurities, ethanol is used for cleaning and removing water, and finally the samples are dried for standby.
(2) Pouring 1L of deionized water into an oxidation tank, sequentially adding 24g of sodium silicate, 12g of sodium fluoride and 4g of sodium hexametaphosphate, and performing high-speed homogenizer dispersion treatment for 10-15 min in an ice-water bath environment at 0 ℃ to obtain a first coloring liquid; pouring 1L of deionized water into a beaker, sequentially adding 8g of sodium potassium tartrate and 8g of copper pyrophosphate, carrying out magnetic stirring hydrolysis treatment for 10-15 min in a constant-temperature water bath environment at 20-40 ℃ to obtain a second coloring liquid, then pouring the second coloring liquid into an oxidation tank to mix the first coloring liquid with the second coloring liquid, carrying out dispersion treatment on the mixture solution by a high-speed homogenizer under ice water bath to reduce the temperature of the mixture solution to 0 ℃, and adding 9g of potassium hydroxide under a stirring state to obtain a coloring mixed solution, wherein the pH value of the coloring mixed solution is 11.
(3) Connecting the AZ91 magnesium alloy sample subjected to surface treatment in the step (1) by using an aluminum sheet, fixing the aluminum sheet on an anode rod in an oxidation tank to be used as an anode of direct-current pulse micro-arc oxidation equipment, completely soaking the aluminum sheet in the coloring mixed solution prepared in the step (2), using a stainless steel sheet as a cathode of the direct-current pulse micro-arc oxidation equipment, and firstly performing first-step micro-arc oxidation treatment under constant pressure, wherein the process parameters are as follows: the oxidation voltage is 300V, the oxidation time is 10min, the frequency is 600Hz, and the duty ratio is 50%; after treatment, the temperature of the coloring electrolyte is cooled to 0 ℃ by adopting an ice-water bath, and then the second constant-current micro-arc oxidation treatment is carried out, wherein the process parameters are as follows: the oxidation current is 2A/dm2The oxidation time is 10min, the frequency is 400Hz, and the duty ratio is 40 percent; and taking out a magnesium alloy sample after the two-step micro-arc oxidation treatment, washing the magnesium alloy sample with distilled water, and then putting the magnesium alloy sample into a drying oven at 40 ℃ for heat preservation for 30min to prepare the magnesium alloy matrix with the surface generating the black ceramic membrane with the thickness of 23 mu m.
Example 2:
(1) after AZ91 magnesium alloy wires are cut into samples with the length multiplied by the width multiplied by the height of 10mm multiplied by 2mm, SiC sand paper with 400 meshes, 500 meshes, 800 meshes, 1000 meshes and 1500 meshes is sequentially adopted on a pre-grinding machine to gradually grind and remove surface oxidation films, acetone is used for cleaning for 5min to remove oil stains, then distilled water is used for ultrasonic cleaning for 5min to remove surface impurities, ethanol is used for cleaning and removing water, and finally the samples are dried for standby.
(2) Pouring 1L of deionized water into an oxidation tank, sequentially adding 30g of sodium silicate, 15g of sodium fluoride and 5g of sodium trimetaphosphate, and performing high-speed homogenizer dispersion treatment for 10-15 min in an ice-water bath environment at 0 ℃ to obtain a first coloring solution; pouring 1L of deionized water into a beaker, sequentially adding 10g of potassium sodium tartrate and 10g of copper phosphate, carrying out magnetic stirring hydrolysis treatment for 10-15 min in a constant-temperature water bath environment at 20-40 ℃ to obtain a second coloring solution, then pouring the second coloring solution into an oxidation tank to mix the first coloring solution with the second coloring solution, carrying out dispersion treatment on the second coloring solution by using a high-speed homogenizer under ice water bath to reduce the temperature of the mixed solution to 0 ℃, and then adding 10g of sodium hydroxide under a stirring state to obtain a coloring mixed solution, wherein the pH value of the coloring mixed solution is 10.
(3) Connecting the AZ91 magnesium alloy sample subjected to surface treatment in the step (1) by using an aluminum sheet, fixing the aluminum sheet on an anode rod in an oxidation tank to be used as an anode of direct-current pulse micro-arc oxidation equipment, completely soaking the aluminum sheet in the coloring mixed solution prepared in the step (2), using a stainless steel sheet as a cathode of the direct-current pulse micro-arc oxidation equipment, and firstly performing first-step micro-arc oxidation treatment under constant pressure, wherein the process parameters are as follows: the oxidation voltage is 350V, the oxidation time is 10min, the frequency is 600Hz, and the duty ratio is 50%; then cooling the coloring electrolyte to 0 ℃ by ice-water bath, and then carrying out the second step of micro-arc oxidation treatment under constant current, wherein the process parameters are as follows: the oxidation current is 0.5A/dm2The oxidation time is 10min, the frequency is 400Hz, and the duty ratio is 40 percent; and taking out a magnesium alloy sample after the two-step micro-arc oxidation treatment, washing the magnesium alloy sample with distilled water, and then putting the magnesium alloy sample into a drying oven at 40 ℃ for heat preservation for 30min to prepare the magnesium alloy matrix with the surface generating the black ceramic membrane with the thickness of 24 mu m.
Example 3:
(1) after AZ91 magnesium alloy wires are cut into samples with the length multiplied by the width multiplied by the height of 10mm multiplied by 2mm, SiC sand paper with 400 meshes, 500 meshes, 800 meshes, 1000 meshes and 1500 meshes is sequentially adopted on a pre-grinding machine to gradually grind and remove surface oxidation films, acetone is used for cleaning for 5min to remove oil stains, then distilled water is used for ultrasonic cleaning for 5min to remove surface impurities, ethanol is used for cleaning and removing water, and finally the samples are dried for standby.
(2) Pouring 1L of deionized water into an oxidation tank, sequentially adding 32g of sodium silicate, 20g of sodium fluoride and 4g of sodium phosphate, and performing high-speed homogenizer dispersion treatment for 10-15 min in an ice-water bath environment at 0 ℃ to obtain a first coloring liquid; pouring 1L of deionized water into a beaker, sequentially adding 10g of sodium potassium tartrate and 12g of copper carbonate, carrying out magnetic stirring hydrolysis treatment for 10-15 min in a constant-temperature water bath environment at 20-40 ℃ to obtain a second coloring solution, then pouring the second coloring solution into an oxidation tank to mix the first coloring solution with the second coloring solution, carrying out dispersion treatment on the second coloring solution by using a high-speed homogenizer under an ice water bath to reduce the temperature of the mixed solution to 0 ℃, and then adding 12g of potassium hydroxide under a stirring state to obtain a coloring mixed solution, wherein the pH value of the coloring mixed solution is 12.
(3) Connecting the AZ91 magnesium alloy sample subjected to surface treatment in the step (1) by using an aluminum sheet, fixing the aluminum sheet on an anode rod in an oxidation tank to be used as an anode of direct-current pulse micro-arc oxidation equipment, completely soaking the aluminum sheet in the coloring mixed solution prepared in the step (2), using a stainless steel sheet as a cathode of the direct-current pulse micro-arc oxidation equipment, and firstly performing first-step micro-arc oxidation treatment under constant pressure, wherein the process parameters are as follows: the oxidation voltage is 400V, the oxidation time is 8min, the frequency is 500Hz, and the duty ratio is 50%; then cooling the coloring electrolyte to 0 ℃ by ice-water bath, and then carrying out the second step of micro-arc oxidation treatment under constant current, wherein the process parameters are as follows: the oxidation current is 1A/dm2The oxidation time is 8min, the frequency is 400Hz, and the duty ratio is 40 percent; and taking out a magnesium alloy sample after the two-step micro-arc oxidation treatment, washing the magnesium alloy sample with distilled water, and then putting the magnesium alloy sample into a drying oven at 40 ℃ for heat preservation for 30min to prepare the magnesium alloy matrix with the surface generating the black ceramic membrane with the thickness of 26 mu m.
Comparative example 1:
comparative example 1 is different from example 3 in that the coloring electrolyte solution in step (2) is prepared in the following manner: pouring 1L of deionized water into an oxidation tank, and sequentially adding 32g of sodium silicate, 20g of sodium fluoride, 4g of sodium phosphate and 12g of potassium hydroxide for mixing to prepare a first coloring liquid; pouring 1L of deionized water into a beaker, sequentially adding 10g of sodium potassium tartrate and 12g of copper carbonate for mixing to prepare a second coloring liquid, and then pouring the second coloring liquid into an oxidation tank to mix the second coloring liquid with the first coloring liquid to prepare a coloring mixed liquid. The other operations were the same as in example 3.
In the preparation method of comparative example 1, the thickness of the black ceramic film obtained by micro-arc oxidation of the surface of the magnesium alloy is 14 μm, the surface color distribution is not uniform, and the compactness is general.
Comparative example 2:
the difference between comparative example 2 and example 3 is that the process of micro-arc oxidation in step (3) is as follows: performing one-stage constant-pressure micro-arc oxidation treatment on the coloring mixed solution prepared in the step (2), wherein the process parameters are as follows: the oxidation voltage is 400V, the oxidation time is 8min, the frequency is 500Hz, and the duty ratio is 50%.
In comparative example 2, the thickness of the black ceramic film obtained by micro-arc oxidation on the surface of the magnesium alloy by the one-stage constant-pressure micro-arc oxidation process was 10 μm, and the surface had large holes and cracks and poor compactness.
Comparative example 3:
comparative example 3 is different from example 3 in that the process of micro-arc oxidation in step (3) is as follows: in the synergistic embodiment 3, the coloring mixed solution prepared in the step (2) is subjected to two-stage constant-current micro-arc oxidation treatment, and the first-stage constant-current micro-arc oxidation treatment is firstly carried out, wherein the process parameters are as follows: the oxidation current is 0.5A/dm2The oxidation time is 8min, the frequency is 500Hz, and the duty ratio is 50 percent; then cooling the coloring electrolyte to 0 ℃ by ice-water bath, and then carrying out second-stage constant-current micro-arc oxidation treatment, wherein the process parameters are as follows: the oxidation current is 1A/dm2The oxidation time is 8min, the frequency is 400Hz, and the duty ratio is 40%.
Comparative example 3 the black ceramic film obtained by micro-arc oxidation on the surface of the magnesium alloy in the micro-arc oxidation mode has a thickness of 16 μm, a large number of protrusions and uneven-sized holes on the surface, and a general compactness.
Performance analysis:
FIG. 1 is a macro topography of a black ceramic film formed on the surface of the magnesium alloy in examples 1-3. It can be seen that by the method of the present invention, a black ceramic film can be obtained on the surface of the magnesium alloy, which is distinguished from the off-white morphology prepared by the conventional method.
FIG. 2 is an XRD spectrum of a black ceramic film formed on the surface of the magnesium alloy in example 1. The graph shows that the black ceramic film generated on the surface of the magnesium alloy mainly consists of phases of magnesium oxide, copper oxide and forsterite.
FIG. 3 shows polarization curves obtained by testing the magnesium alloy AZ91 without any treatment and the magnesium alloy modified in examples 1-3 after being soaked in NaCl solution with a mass concentration of 3.5% for 0.5h, and the results of the polarization curve fitting are shown in Table 1.
TABLE 1
As can be seen by combining FIG. 3 and Table 1, the corrosion potential of the magnesium alloy sample obtained after the micro-arc oxidation modification is significantly higher than that of the magnesium alloy substrate, and the corrosion current density and the corrosion rate are lower than those of the substrate, which indicates that the corrosion resistance of the substrate magnesium alloy can be greatly improved by the black ceramic film obtained on the surface of the magnesium alloy after the micro-arc oxidation.
FIG. 4 is a graph showing the friction coefficients of AZ91 magnesium alloy without any treatment and the magnesium alloys obtained by modification in examples 1 to 3, and the average friction coefficients are shown in Table 2.
TABLE 2
| Base body | Example 1 | Example 2 | |
|
| Average coefficient of friction | 0.65 | 0.27 | 0.31 | 0.24 |
As can be seen by combining FIG. 4 and Table 2, the friction coefficient of the magnesium alloy sample obtained after the micro-arc oxidation modification is obviously lower than that of the original matrix, which shows that the roughness of the black ceramic membrane obtained on the surface of the magnesium alloy after the micro-arc oxidation is reduced, the structure is more compact and uniform, and the wear resistance of the matrix magnesium alloy can be greatly improved.
FIG. 5 is an SEM topography of black ceramic films formed on the surfaces of the magnesium alloys of example 3 and comparative example 3. As can be seen from fig. 5, the black ceramic film obtained in example 3 had no cracks on the surface, reduced the number of pores, reduced the pore diameter, and better film density. The black ceramic film obtained in comparative example 3 has a large number of holes on the surface, a large pore diameter and a general compactness, which indicates that the black ceramic film prepared under the process conditions of the present invention has a more compact and uniform structure.
Table 3 shows comparative analysis of corrosion resistance of example 3 and comparative examples 1 to 3. As can be seen from table 3, the corrosion potential of the black ceramic film prepared by the synergistic effect of the preparation process and the micro-arc oxidation process in example 3 of the present invention is higher than that of the black ceramic film prepared by the conventional method, and the corrosion current density and corrosion rate are lower than those of the comparative example, which indicates that the black ceramic film prepared under the process conditions of the present invention has better corrosion resistance.
TABLE 3
Table 4 shows comparative analyses of the abrasion resistance of example 3 and comparative examples 1 to 3. From table 4, it can be seen that the black ceramic film prepared by the synergistic effect of the preparation process and the micro-arc oxidation process in example 3 of the present invention has a lower friction coefficient than the black ceramic film prepared by the conventional method, which indicates that the black ceramic film prepared by the process of the present invention has a reduced roughness, a more compact and uniform structure, and a better wear resistance.
TABLE 4
| Example 3 | Comparative example 1 | Comparative example 2 | Comparative example 3 | |
| Average coefficient of friction | 0.24 | 0.40 | 0.51 | 0.49 |
In the examples, specific conditions are not specified, and the reaction is carried out under conventional conditions. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially. The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Obvious improvements, changes and modifications to some technical features in the foregoing embodiments can be made by those skilled in the art without departing from the technical idea of the present invention, and the technical scope of the present invention is not limited to the contents of the specification, but must be determined from the scope of the claims.
Claims (10)
1. The electrolyte for micro-arc oxidation of the black ceramic membrane is characterized by comprising the following components in parts by weight: the electrolyte comprises 10-30 g/L sodium silicate, 5-20 g/L sodium fluoride, 3-8 g/L potassium sodium tartrate, 1-5 g/L phosphate, 3-8 g/L copper salt, 2-12 g/L alkali pH regulator and deionized water.
2. The electrolyte for micro-arc oxidation of a black ceramic membrane according to claim 1, wherein the copper salt is any one of copper pyrophosphate, copper phosphate, copper carbonate, and copper sulfate; the phosphate is any one of sodium phosphate, sodium trimetaphosphate, sodium hexametaphosphate, sodium tripolyphosphate and sodium polyphosphate; the alkaline pH regulator is sodium hydroxide or potassium hydroxide.
3. The method for preparing the electrolyte for micro-arc oxidation of the black ceramic membrane according to claim 1, wherein the preparation steps are as follows:
(1) dissolving sodium silicate, sodium fluoride and phosphate in deionized water according to a mass ratio, and performing dispersion hydrolysis treatment to prepare a first coloring liquid;
(2) dissolving sodium potassium tartrate and copper salt in deionized water according to a mass ratio, and dissolving in a constant-temperature water bath environment to prepare a second coloring liquid;
(3) and adding the second coloring liquid into the first coloring liquid, controlling the volume ratio of deionized water of the second coloring liquid to deionized water of the first coloring liquid to be 1:1, cooling the mixed solution to 0 ℃ in an ice water bath, adding an alkali pH regulator into the mixed solution, and regulating the pH value of the mixed solution to be 8-13 to obtain the coloring electrolyte.
4. The preparation method of the electrolyte for the micro-arc oxidation black ceramic membrane according to claim 3, wherein the mass ratio of the sodium silicate, the sodium fluoride and the phosphate in the step (1) is 6-8: 3-5: 1; the dispersion treatment was carried out in an ice-water bath at 0 ℃.
5. The preparation method of the electrolyte for the micro-arc oxidation black ceramic membrane according to claim 3, wherein the mass ratio of the potassium sodium tartrate to the copper salt in the step (2) is 1: 1-2; and (3) carrying out dissolving treatment in a constant-temperature water bath environment at the temperature of 20-40 ℃.
6. A preparation method of a magnesium alloy micro-arc oxidation black ceramic membrane is characterized by comprising the following steps:
taking the magnesium alloy after polishing and cleaning as an anode in the micro-arc oxidation process, taking a stainless steel plate as a cathode in the micro-arc oxidation process, soaking the anode in the coloring electrolyte according to any one of claims 1-5, performing two-stage micro-arc oxidation treatment by using a direct-current pulse power supply, performing constant-voltage micro-arc oxidation treatment, and performing constant-current micro-arc oxidation treatment to obtain the magnesium alloy with the black ceramic film formed on the surface.
7. The method for preparing a magnesium alloy micro-arc oxidation black ceramic membrane according to claim 6, wherein in the two-stage micro-arc oxidation treatment, the process parameters of the first step of constant-pressure micro-arc oxidation treatment are as follows: the oxidation voltage is 300-400V, the oxidation time is 5-30 min, the frequency is 500-600 Hz, and the duty ratio is 50-60%.
8. The method for preparing a magnesium alloy micro-arc oxidation black ceramic membrane according to claim 7, wherein in the two-stage micro-arc oxidation treatment, the process parameters of the second constant-current micro-arc oxidation treatment are as follows: the oxidation current is 0.5-2A/dm2The oxidation time is 5-15 min, the frequency is 300-400 Hz, and the duty ratio is 40-50%.
9. The method for preparing the magnesium alloy micro-arc oxidation black ceramic membrane according to claim 6, wherein after the first constant-voltage micro-arc oxidation treatment, the temperature of the coloring electrolyte is cooled to 0 ℃ by using an ice water bath, then the second constant-current micro-arc oxidation treatment is carried out, the sample is taken out after the two micro-arc oxidation treatments, and the sample is placed in a drying oven at the temperature of 40-60 ℃ for heat preservation for 0.5-1 h, so that the magnesium alloy with the black ceramic membrane formed on the surface is prepared.
10. The method for preparing the magnesium alloy micro-arc oxidation black ceramic membrane according to claim 6, which is characterized in that: the thickness of the black ceramic film obtained on the surface of the magnesium alloy is 15-30 mu m.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112342591A (en) * | 2020-10-19 | 2021-02-09 | 四川轻化工大学 | Electrolyte solution for magnesium alloy surface micro-arc oxidation and preparation method of black coating |
| CN112458512A (en) * | 2020-11-19 | 2021-03-09 | 西安交通大学 | Preparation method of magnesium alloy micro-arc oxidation black super-hydrophobic film layer |
| CN112941594A (en) * | 2021-01-28 | 2021-06-11 | 常州大学 | Method for realizing magnesium alloy surface yellowing treatment |
| CN113430616A (en) * | 2021-06-16 | 2021-09-24 | 常州大学 | Preparation method of black ceramic film on titanium alloy surface |
| CN113622010A (en) * | 2021-08-31 | 2021-11-09 | 日照微弧技术有限公司 | Aluminum alloy surface black ceramic membrane and preparation method thereof |
| CN114703530A (en) * | 2022-04-28 | 2022-07-05 | 徐州工程学院 | Method for compositely constructing samarium-doped hydroxyapatite gradient coating on surface of magnesium alloy by utilizing electrophoresis/micro-arc oxidation technology |
| CN115807257A (en) * | 2022-08-24 | 2023-03-17 | 重庆大学 | Dynamic monitoring method for micro-arc ceramic oxidation electroplating process |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101092694A (en) * | 2007-08-15 | 2007-12-26 | 李克清 | Method for processing surface of magnesium alloy |
| CN101245485A (en) * | 2008-03-21 | 2008-08-20 | 哈尔滨工程大学 | Surface treating method for magnesium lithium alloy |
| CN101476146A (en) * | 2008-12-29 | 2009-07-08 | 中国科学院长春应用化学研究所 | Method for preparing black ceramic membrane by magnesium alloy differential arc oxidation |
| CN103469280A (en) * | 2013-09-24 | 2013-12-25 | 重庆研镁科技有限公司 | Magnesium alloy micro-arc oxidation electrolyte and technology for carrying out black ceramic processing on magnesium alloy surface by using electrolyte |
| US20150083598A1 (en) * | 2013-09-26 | 2015-03-26 | AHC Oberflächentechnik GmbH | Plasma-Chemical Method For Production Of Black Oxide-Ceramic Layers And Correspondingly Coated Object |
| CN104894628A (en) * | 2015-06-25 | 2015-09-09 | 江苏科技大学 | Method for using stage voltage boosting to prepare magnesium alloy micro-arc oxidation ceramic layer |
| CN105714354A (en) * | 2016-03-21 | 2016-06-29 | 南京工程学院 | Electrolyte used for preparing N-doped micro-arc oxidation ceramic layer |
| CN107419315A (en) * | 2017-05-12 | 2017-12-01 | 深圳市粤辉煌环保技术有限公司 | A kind of preparation method of magnesium alloy black micro-arc oxidation films |
-
2020
- 2020-01-19 CN CN202010059104.5A patent/CN111058077B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101092694A (en) * | 2007-08-15 | 2007-12-26 | 李克清 | Method for processing surface of magnesium alloy |
| CN101245485A (en) * | 2008-03-21 | 2008-08-20 | 哈尔滨工程大学 | Surface treating method for magnesium lithium alloy |
| CN101476146A (en) * | 2008-12-29 | 2009-07-08 | 中国科学院长春应用化学研究所 | Method for preparing black ceramic membrane by magnesium alloy differential arc oxidation |
| CN103469280A (en) * | 2013-09-24 | 2013-12-25 | 重庆研镁科技有限公司 | Magnesium alloy micro-arc oxidation electrolyte and technology for carrying out black ceramic processing on magnesium alloy surface by using electrolyte |
| US20150083598A1 (en) * | 2013-09-26 | 2015-03-26 | AHC Oberflächentechnik GmbH | Plasma-Chemical Method For Production Of Black Oxide-Ceramic Layers And Correspondingly Coated Object |
| CN104894628A (en) * | 2015-06-25 | 2015-09-09 | 江苏科技大学 | Method for using stage voltage boosting to prepare magnesium alloy micro-arc oxidation ceramic layer |
| CN105714354A (en) * | 2016-03-21 | 2016-06-29 | 南京工程学院 | Electrolyte used for preparing N-doped micro-arc oxidation ceramic layer |
| CN107419315A (en) * | 2017-05-12 | 2017-12-01 | 深圳市粤辉煌环保技术有限公司 | A kind of preparation method of magnesium alloy black micro-arc oxidation films |
Non-Patent Citations (1)
| Title |
|---|
| 寇钢 等: "AZ镁合金黑色微弧氧化陶瓷层的显色、摩擦学和腐蚀特性", 《硅酸盐学报》 * |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112342591A (en) * | 2020-10-19 | 2021-02-09 | 四川轻化工大学 | Electrolyte solution for magnesium alloy surface micro-arc oxidation and preparation method of black coating |
| CN112342591B (en) * | 2020-10-19 | 2021-11-23 | 四川轻化工大学 | Electrolyte solution for magnesium alloy surface micro-arc oxidation and preparation method of black coating |
| CN112458512A (en) * | 2020-11-19 | 2021-03-09 | 西安交通大学 | Preparation method of magnesium alloy micro-arc oxidation black super-hydrophobic film layer |
| CN112941594A (en) * | 2021-01-28 | 2021-06-11 | 常州大学 | Method for realizing magnesium alloy surface yellowing treatment |
| CN113430616A (en) * | 2021-06-16 | 2021-09-24 | 常州大学 | Preparation method of black ceramic film on titanium alloy surface |
| CN113430616B (en) * | 2021-06-16 | 2022-08-26 | 常州大学 | Preparation method of black ceramic film on titanium alloy surface |
| CN113622010A (en) * | 2021-08-31 | 2021-11-09 | 日照微弧技术有限公司 | Aluminum alloy surface black ceramic membrane and preparation method thereof |
| CN114703530A (en) * | 2022-04-28 | 2022-07-05 | 徐州工程学院 | Method for compositely constructing samarium-doped hydroxyapatite gradient coating on surface of magnesium alloy by utilizing electrophoresis/micro-arc oxidation technology |
| CN114703530B (en) * | 2022-04-28 | 2023-08-25 | 徐州工程学院 | Method for compositely constructing samarium-doped hydroxyapatite gradient coating on magnesium alloy surface by utilizing electrophoresis/micro-arc oxidation technology |
| CN115807257A (en) * | 2022-08-24 | 2023-03-17 | 重庆大学 | Dynamic monitoring method for micro-arc ceramic oxidation electroplating process |
| CN115807257B (en) * | 2022-08-24 | 2023-09-26 | 重庆大学 | Dynamic monitoring method for micro-arc ceramic oxidation electroplating process |
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