Aluminum alloy micro-arc oxidation film layer with high plasma fluorination environment resistance and preparation method of aluminum alloy micro-arc oxidation film layer

Abstract

The invention belongs to the technical field of aluminum alloy surface treatment, and discloses an aluminum alloy micro-arc oxidation film layer with high plasma fluorination environment resistance and a preparation method thereof.The aluminum alloy serves as a matrix, the micro-arc oxidation film layer with high plasma fluorination environment resistance is formed on the surface of the matrix, the thickness of the film layer is 10-50 micrometers, the porosity is 3-5%, and the thickness of the film layer is 10-50 micrometers. The pore diameter is 0.5-1 [mu] m, and the alpha-Al2O3 accounts for 60-80%. According to the film layer, generation of more compact Al2O3 is promoted by adding zircon salt and yttrium salt, the structure and performance of the film layer are improved through introduced zirconium and yttrium elements, and the film layer has the advantages of being high in hardness, low in porosity, high in corrosion resistance and high in wear resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy surface treatment, and in particular to a micro-arc oxidation film layer of an aluminum alloy with high resistance to plasma fluorination environment and a preparation method thereof. Background Art

[0002] Aluminum alloys have been widely used in aerospace, automotive, electronic equipment, nuclear chemical, and semiconductor manufacturing due to their advantages such as low density, high strength, and good processing properties. However, in some special harsh environments, such as process links with strong acids, bases, strong oxidizing chemicals, and harsh plasma fluorination environments, aluminum alloys are still subject to corrosion. In particular, in the manufacturing of semiconductor chips, processes such as plasma etching often use fluorine-containing gases. Components such as reaction chambers need to have high resistance to plasma fluorination environments to ensure the stability and service life of the equipment, prevent the material from being corroded and releasing impurities such as metal ions, polluting the semiconductor manufacturing process environment, and affecting the performance and quality of the chip.

[0003] Although many processes are used to improve the corrosion resistance of aluminum alloy semiconductors during manufacturing, such as chemical vapor deposition (CVD), physical vapor deposition (PVD), and anodizing, the surface of the aluminum alloy film is still susceptible to corrosion and damage in harsh corrosive environments, seriously affecting the service life and performance of its substrate. Micro-arc oxidation technology is a surface treatment technology that grows a ceramic film in situ on the metal surface. It can significantly improve the hardness, wear resistance, corrosion resistance and other properties of the metal surface. It is also green and environmentally friendly, with little pollution to the environment. However, since the Al2O3 phase formed in the traditional micro-arc oxidation film layer of aluminum alloy is mainly γ-Al2O3 phase, and a small amount of ɑ-Al2O3 phase and mullite phase are detected, the density is not enough to ensure that the aluminum alloy can serve in harsh fluorinated environments. At the same time, the main method to improve the corrosion resistance of aluminum alloys in harsh environments is generally to prepare a high-density insulating oxide composite film layer on the aluminum alloy surface, and fill the gaps in the film layer with organic resin to achieve a sealing effect. However, since organic coatings are prone to bubbling, aging and other problems, the bonding strength and wear resistance with the metal oxide film layer cannot meet the use requirements in harsh environments. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a micro-arc oxidation film layer of aluminum alloy with high resistance to plasma fluorination environment and a preparation method thereof, which meets the protection and use requirements of aluminum alloy products in harsh environments such as plasma fluorination.

[0005] The technical solution adopted in the present invention is:

[0006] The application discloses a micro-arc oxidation film layer with high plasma fluorination environment resistance of an aluminum alloy, and the film layer is formed on the surface of an aluminum alloy base body and has a thickness of 10-50 microns, a porosity of 3-5%, a pore size of 0.5-1 micron and an alpha-Al2O3 proportion of 60-80%.

[0007] The application discloses a micro-arc oxidation film layer with high plasma fluorination environment resistance of an aluminum alloy, and the film layer is formed on the surface of an aluminum alloy base body and has a thickness of 10-50 microns, a porosity of 3-5%, a pore size of 0.5-1 micron and an alpha-Al2O3 proportion of 60-80%.

[0008] Step 1, surface pretreatment of the aluminum alloy base body; the base body is processed into a shape of 50mm*50mm*2mm, and the base body is pretreated; the pretreatment includes polishing, surface alkali washing, oil removal, ash removal and cleaning, and drying for standby; in the oil removal process, the base body is immersed into an oil removal agent, and ultrasonic treatment is carried out for 5-10 minutes, and then the base body is blown dry for standby;

[0009] Step 2, preparation of a micro-arc oxidation film layer electrolyte; aluminum acid sodium, sodium hydroxide, citric acid, ethylenediaminetetraacetic acid disodium, zirconium salt, yttrium salt, triethanolamine and water are used to form a basic electrolyte, and then aluminum oxide nanoparticles are added into the basic electrolyte, and stirring is carried out to uniformly disperse the aluminum oxide nanoparticles;

[0010] Step 3, the aluminum alloy base body is placed into the micro-arc oxidation film layer electrolyte, and high-voltage pulse mode is adopted to perform micro-arc oxidation on the aluminum alloy base body, so that a micro-arc oxidation film layer is formed on the surface of the aluminum alloy base body.

[0011] The component content of the electrolyte is as follows: aluminum acid sodium 15-25g / L, sodium hydroxide 1-2g / L, citric acid 2-5g / L, ethylenediaminetetraacetic acid disodium 5-10g / L, zirconium salt 5-10g / L, yttrium salt 2-5g / L, aluminum oxide nanoparticles 5-10g / L, triethanolamine 20-50ml and water 95g / L.

[0012] The zirconium salt is analytically pure, and the zirconium salt is one or more of potassium fluorozirconate, zirconium nitrate, zirconium sulfate or zirconium chloride.

[0013] The yttrium salt is an analytically pure yttrium-containing compound, and the yttrium-containing compound is one or more of yttrium acetate, yttrium nitrate, yttrium chloride or yttrium sulfate.

[0014] The temperature of the micro-arc oxidation electrolyte is 15-50 DEG C, and the specific conditions of the high-voltage pulse are as follows: pulse frequency 100-1000Hz, pulse voltage 350-600V, duty cycle 50 / 30, current density 1-4A / dm 2 , oxidation time 10-60min; and the micro-arc oxidation film layer is formed.

[0015] Compared with the prior art, the application has the following advantages:

[0016] 1. The micro-arc oxidation film layer with high resistance to plasma fluorination environment is prepared on the surface of the aluminum alloy, so that the high corrosion resistance of the aluminum alloy substrate is realized.

[0017] 2. The micro-arc oxidation film layer with high resistance to plasma fluorination environment is prepared on the surface of the aluminum alloy, so that the high corrosion resistance of the aluminum alloy substrate is realized.

[0018] 3. The preparation method is simple and feasible, and the aluminum alloy micro-arc oxidation film layer with zirconium and yttrium elements can be prepared by reasonably controlling the composition of the micro-arc oxidation electrolyte and the process parameters of the micro-arc oxidation treatment. DETAILED DESCRIPTION

[0019] The application will be further described in detail below in combination with specific embodiments, but the protection scope of the application is not limited to these embodiments.

[0020] The technical scheme of the application is a micro-arc oxidation film layer with high resistance to plasma fluorination environment of aluminum alloy, which is formed on the surface of the aluminum alloy substrate and has a thickness of 10-50 μm, a porosity of 3-5%, a pore size of 0.5-1 μm, and an α-Al2O3 content of 60-80%.

[0021] The preparation method of the micro-arc oxidation film layer with high resistance to plasma fluorination environment of aluminum alloy comprises the following steps:

[0022] Step 1: surface pretreatment of the aluminum alloy substrate; the substrate is processed into a shape of 50 mm×50 mm×2 mm, and the substrate is pretreated, including polishing, surface alkali washing, oil removal, ash removal, cleaning, and drying for standby; the substrate is immersed in an oil removal agent (commercial product) during the oil removal process, and is ultrasonically treated for 5-10 min, and then is blown dry for standby;

[0023] Step 2: preparation of the micro-arc oxidation film layer electrolyte; aluminum sodium, sodium hydroxide, citric acid, disodium ethylenediaminetetraacetate, zirconium salt, yttrium salt, triethanolamine, and water are added to the basic electrolyte to form an electrolyte, and the electrolyte is stirred to make the particles uniformly dispersed;

[0024] Step 3, the aluminum alloy substrate is put into the micro-arc oxidation film electrolyte, and the aluminum alloy substrate is micro-arc oxidized in a high-voltage pulse mode to form a micro-arc oxidation film layer on the surface of the aluminum alloy substrate.

[0025] The component content of the electrolyte is: sodium aluminate 15-25 g / L, sodium hydroxide 1-2 g / L, citric acid 2-5 g / L, disodium ethylenediaminetetraacetate 5-10 g / L, zirconium salt 5-10 g / L, yttrium salt 2-5 g / L, aluminum oxide nanoparticles 5-10 g / L, triethanolamine 20-50 ml, and water 95 g / L.

[0026] The zirconium salt is analytical pure, and the zirconium salt is one or more of potassium fluorozirconate, zirconium nitrate, zirconium sulfate or zirconium chloride.

[0027] The yttrium salt is an yttrium-containing compound of analytical purity, and the yttrium-containing compound is one or more of yttrium acetate, yttrium nitrate, yttrium chloride or yttrium sulfate.

[0028] The temperature of the micro-arc oxidation electrolyte is 15-50℃, and the specific conditions of the high-voltage pulse are: pulse frequency 100-1000 Hz, pulse voltage 350-600 V, duty cycle 50 / 30, current density 1-4 A / dm 2 , oxidation time 10-60 min; form a micro-arc oxidation film layer.

[0029] Example 1:

[0030] Step 1: The aluminum alloy substrate is processed into a shape of 50mm x 50mm x 2mm, and is pretreated, polished and polished, surface alkali washing, oil removal, ash removal and cleaning, and drying for standby. In the oil removal process, the sample is immersed in the oil removal agent for ultrasonic treatment for 5 min, and then dried for standby.

[0031] Step 2: Preparation of micro-arc oxidation film electrolyte with high plasma fluorination environment performance: sodium aluminate 15 g / L, sodium hydroxide 2 g / L, citric acid 5 g / L, disodium ethylenediaminetetraacetate 10 g / L, potassium fluorozirconate 5 g / L, yttrium acetate 5 g / L, aluminum oxide nanoparticles 5 g / L, triethanolamine 50 ml, and stirring to disperse uniformly.

[0032] Step 3: The aluminum alloy is put into the micro-arc oxidation electrolyte, and the aluminum alloy is micro-arc oxidized in a high-voltage pulse mode, and the specific conditions are: the temperature of the micro-arc oxidation electrolyte is 15℃, the pulse frequency is 500 Hz, the pulse voltage is 500 V, the duty cycle is 50 / 30, the current density is 2 A / dm 2 , and the oxidation time is 45 min.

[0033] The micro-arc oxidation film layer with high plasma fluorination environment resistance formed in step 3 has a thickness of 30 μm, a porosity of 3-5%, a pore size of 0.5-1 μm, and an α-Al2O3 proportion of 61%.

[0034] Example 2

[0035] Step 1: The aluminum alloy substrate is processed into a shape of 50 mm x 50 mm x 2 mm, pretreated, polished, and then subjected to surface alkali washing, oil removal, ash removal, and cleaning, and dried for standby. In the oil removal process, the sample is immersed in the oil removal agent for ultrasonic treatment for 8 min, and then blown dry for standby.

[0036] Step 2: Preparation of the micro-arc oxidation film layer electrolyte with high plasma fluorination environment resistance: sodium aluminate 25 g / L, sodium hydroxide 1 g / L, citric acid 3 g / L, ethylenediaminetetraacetic acid disodium 5 g / L, zirconium sulfate 6 g / L, yttrium sulfate 2 g / L, aluminum oxide nanoparticles 5 g / L, and triethanolamine 25 ml, which are uniformly dispersed by stirring.

[0037] Step 3: The aluminum alloy is placed into the micro-arc oxidation electrolyte, and the aluminum alloy is subjected to micro-arc oxidation in a high-voltage pulse mode. The specific conditions are as follows: the temperature of the micro-arc oxidation electrolyte is 30°C, the pulse frequency is 300 Hz, the pulse voltage is 600 V, the duty cycle is 50 / 30, the current density is 3 A / dm 2 , and the oxidation time is 30 min.

[0038] The micro-arc oxidation film layer with high plasma fluorination environment resistance formed in step 3 has a thickness of 25 μm, a porosity of 3-5%, a pore size of 0.5-1 μm, and an α-Al2O3 proportion of 80%.

[0039] Example 3

[0040] Step 1: The aluminum alloy substrate is processed into a shape of 50 mm x 50 mm x 2 mm, pretreated, polished, and then subjected to surface alkali washing, oil removal, ash removal, and cleaning, and dried for standby. In the oil removal process, the sample is immersed in the oil removal agent for ultrasonic treatment for 8 min, and then blown dry for standby.

[0041] Step 2: Preparation of the micro-arc oxidation film layer electrolyte with high plasma fluorination environment resistance: sodium aluminate 20 g / L, sodium hydroxide 2 g / L, citric acid 2 g / L, ethylenediaminetetraacetic acid disodium 7 g / L, zirconium nitrate 5 g / L, yttrium nitrate 3 g / L, aluminum oxide nanoparticles 10 g / L, and triethanolamine 35 ml, which are uniformly dispersed by stirring.

[0042] Step 3: the aluminum alloy is put into a micro-arc oxidation electrolyte, and the aluminum alloy is subjected to micro-arc oxidation in a high-voltage pulse mode, and the specific conditions are that the temperature of the micro-arc oxidation electrolyte is 45 DEG C, the pulse frequency is 700 Hz, the pulse voltage is 550 V, the duty cycle is 50 / 30, the current density is 2.5 A / dm 2 , and the oxidation time is 50 min.

[0043] The micro-arc oxidation film layer with high plasma fluorination environment resistance prepared in step 3 has a thickness of 45 mu m, a porosity of 3-5%, a pore size of 0.5-1 mu m, and an alpha-Al2O3 proportion of 62%.

[0044] In the preparation of the micro-arc oxidation film layer with high plasma fluorination environment resistance on the surface of the aluminum alloy, it is found that with the increase of the zirconium salt and the yttrium salt, the diffraction peak of the alpha-Al2O3 phase in the film layer is enhanced, which indicates that the addition of the two metal salts promotes the reaction of Al and O, generates more and denser Al2O3, and helps to improve the density and corrosion resistance of the ceramic film layer.

[0045] The aluminum alloy micro-arc oxidation film layer containing zirconium and yttrium elements prepared in examples 1, 2 and 3 is subjected to performance testing, and the results show that the thickness, hardness, porosity and other performance indicators of the film layer meet the requirements, and the corrosion resistance in the plasma fluorination environment is obviously better than that of the traditional aluminum alloy micro-arc oxidation film layer.

Claims

1. A micro-arc oxidation film layer on aluminum alloy with high resistance to plasma fluorination environment, characterized in that: The film layer is based on aluminum alloy and forms a micro-arc oxidation film layer with high resistance to plasma fluorination environment on the surface of the substrate. The film layer has a thickness of 10 to 50 μm, a porosity of 3 to 5%, a pore size of 0.5 to 1 μm, and an α-Al2O3 ratio of 60 to 80%.

2. The micro-arc oxidation film layer of aluminum alloy with high resistance to plasma fluorination environment according to claim 1, characterized in that: The preparation method comprises the following steps: Step 1: Surface pretreatment of the aluminum alloy substrate: Process the substrate into a shape of 50mm×50mm×2mm, and pretreat the substrate, including grinding and polishing, surface alkaline cleaning and degreasing, dust removal and cleaning, and drying for standby use; During the degreasing process, the substrate is immersed in the degreasing agent, ultrasonically treated for 5 to 10 minutes, and then blown dry for later use; Step 2, preparing the electrolyte of the micro-arc oxidation film layer; adding aluminum oxide nanoparticles to the basic electrolyte formed by sodium aluminate, sodium hydroxide, citric acid, disodium ethylenediaminetetraacetic acid, zirconium salt, yttrium salt, triethanolamine and water, and stirring to uniformly disperse them; Step 3: Place the aluminum alloy substrate into the micro-arc oxidation film electrolyte, and perform micro-arc oxidation on the aluminum alloy substrate using a high voltage pulse method to form a micro-arc oxidation film on the surface of the aluminum alloy substrate.

3. The micro-arc oxidation film layer of aluminum alloy with high resistance to plasma fluorination environment according to claim 2, characterized in that: The components of the electrolyte are: 15-25 g / L of sodium aluminate, 1-2 g / L of sodium hydroxide, 2-5 g / L of citric acid, 5-10 g / L of disodium ethylenediaminetetraacetic acid, 5-10 g / L of zirconium salt, 2-5 g / L of yttrium salt, 5-10 g / L of aluminum oxide nanoparticles, 20-50 ml of triethanolamine, and 95 g / L of water.

4. The micro-arc oxidation film layer of aluminum alloy with high resistance to plasma fluorination environment according to claim 2, characterized in that: The zirconium salt is analytically pure and is selected from one or more of potassium fluozirconate, zirconium nitrate, zirconium sulfate or zirconium chloride.

5. The micro-arc oxidation film layer of aluminum alloy with high resistance to plasma fluorination environment according to claim 2, characterized in that: The yttrium salt is an analytically pure yttrium-containing compound, and the yttrium-containing compound is one or more of yttrium acetate, yttrium nitrate, yttrium chloride or yttrium sulfate.

6. The micro-arc oxidation film layer of aluminum alloy with high resistance to plasma fluorination environment according to claim 2, characterized in that: The temperature of the micro-arc oxidation electrolyte is 15-50°C, and the specific conditions of the high voltage pulse are: pulse frequency 100-1000Hz, pulse voltage 350-600V, duty cycle 50 / 30, current density 1-4A / dm 2 , oxidation time 10 to 60 minutes; forming a micro-arc oxidation film.