Oxidation device for preparing composite ceramic coating on surface of aluminum alloy pot and preparation method

Abstract

The invention relates to an oxidation device for preparing a composite ceramic coating on the surface of an aluminum alloy pot and a preparation method, the oxidation device comprises a frame, a micro-arc oxidation zone, an electrolyte tank and a liquid pump, an anode of the micro-arc oxidation zone is arranged on the frame, a pot body is arranged on the anode, a cathode is arranged above the pot body in an up-and-down moving mode, the cathode comprises a cathode plate, and the electrolyte tank is arranged on the liquid pump. A cylinder for driving the cathode plate to move up and down is arranged on the frame, a cathode liquid outlet pipe is arranged above the cathode plate, a plurality of liquid penetrating holes are formed in the bottom and the side surface of the cathode plate, the funnel is arranged on the frame and is positioned below the anode, a diversion trench is arranged below the funnel, the other end of the diversion trench extends into the electrolyte tank, a liquid inlet pipe is arranged on one side of the electrolyte tank, and a liquid outlet pipe is arranged on the other side of the electrolyte tank. The liquid inlet pipe is connected with a cathode liquid outlet pipe through a liquid pump, a hose and a liquid outlet pipe; the preparation method is scientific and reasonable, the oxidation device is simple in structure and convenient to operate, and the wear resistance and corrosion resistance of the composite coating are greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of surface treatment and relates to an oxidizing device for preparing a ceramic coating composite on the surface of an aluminum alloy pot and a preparation method. BACKGROUND

[0002] The non-stick pot is favored by consumers at home and abroad because of its beautiful and novel appearance, non-stick, non-stick, easy cleaning and easy washing during cooking, and has become the darling of the current cookware industry and is known as the "sunrise industry". Non-stick pots have entered thousands of households in Europe and other developed countries since the 1960s, and the popularization rate is quite high. At present, the main principle of the non-stick pot sold on the market is to spray a layer of non-stick coating on the surface of the aluminum alloy pot body, which is mainly made of polytetrafluoroethylene (PTFE). In recent years, with the continuous deepening of scientific research, people have had various concerns and worries about whether the long-term use of non-stick pots containing polytetrafluoroethylene coating is harmful to the human body. Some researchers have shown that non-stick pots made of Teflon coating with polytetrafluoroethylene as the main component have potential toxicity and slight toxicity, and long-term use of these products may cause cancer.

[0003] Therefore, research institutions at home and abroad are accelerating the development of new green and healthy non-stick pot products. Ceramic-coated non-stick pots have been sought after by consumers since they were introduced to the market. They not only overcome the shortcomings of traditional iron pots, such as easy sticking and difficult cleaning, but also are more wear-resistant and safe than PTFE-coated non-stick pots, and thus have become a powerful assistant for foodies to cook delicious food. However, the ceramic coating is brittle, which leads to cracks and peeling of the ceramic coating on the non-stick pot during use, and the use of non-stick pots is accompanied by complex environments such as acid, alkali and salt, which seriously affects the service life. SUMMARY

[0004] The first technical problem to be solved by the application is to provide an oxidation device for preparing a ceramic coating composite on the surface of an aluminum alloy pot.

[0005] The second technical problem to be solved by the application is to provide a preparation method of a ceramic coating composite on the surface of an aluminum alloy pot.

[0006] The technical scheme adopted by the present application to solve the first technical problem is: an oxidizing device for preparing a composite ceramic coating on the surface of an aluminum alloy pot, characterized in that the oxidizing device comprises a frame, a micro-arc oxidation zone, an electrolyte tank and a liquid pump, the micro-arc oxidation zone comprises a funnel, an anode, a pot body and a cathode, the anode is arranged on the frame, the pot body is arranged on the anode, the outer edge of the anode is provided with an anode wire interface connected with a positive pole of a micro-arc oxidation power supply, the cathode is movably arranged above the pot body, the cathode comprises a cathode plate, a gas cylinder for driving the cathode plate to move up and down is arranged on the frame, a cathode liquid outlet pipe is arranged above the cathode plate, the cathode liquid outlet pipe is provided with a cathode wire interface connected with a negative pole of the micro-arc oxidation power supply, a plurality of liquid-permeable holes are arranged on the bottom and the side of the cathode plate, when the cathode plate is placed in the pot body, the vertical distance between each point on the inner wall of the pot body and the outer surface of the cathode plate is equal, the funnel is arranged on the frame below the anode, a flow guide groove is arranged below the funnel, the other end of the flow guide groove extends into the electrolyte tank, a liquid inlet pipe is arranged on one side of the electrolyte tank, and the liquid inlet pipe is connected with the cathode liquid outlet pipe through the liquid pump, a hose and a liquid outlet pipe.

[0007] As an improvement, the frame is welded by two long straight rods, two short straight rods and a plurality of cross rods, the two short straight rods are arranged on the front side of the long straight rods, the upper end, the middle and lower part and the bottom of the two short straight rods are connected with the corresponding long straight rods through the first cross rods respectively, the middle and lower part and the bottom of the two short straight rods are connected through the second cross rods respectively, the upper end, the middle and the bottom of the two long straight rods are connected through the third cross rods respectively, the short straight rods and the long straight rods are fixed to form a rectangular frame, the top of the two long straight rods is respectively welded with a top rod, the top rod is above the first cross rod and parallel to the first cross rod, and the length of the top rod is shorter than that of the first cross rod.

[0008] Further, the uppermost two first cross rods are respectively provided with insulating pads, the anode is arranged on the insulating pads, the anode is a circular cake structure provided with an anode groove on the upper end face, the pot body is arranged on the anode groove, and the outer surface profile structure of the pot body is the same as the curved surface profile structure of the anode groove.

[0009] Further, the structure of the cathode plate is the same as the inner wall profile structure of the pot body, and the vertical distance between each point on the inner wall of the pot body and the outer surface of the cathode plate is equal during work, and the vertical distance is 10-20 mm; the cathode liquid outlet pipe is vertically arranged above the center of the cathode plate, and the upper edge of the cathode plate is provided with a connecting rod connected with the cathode liquid outlet pipe.

[0010] Further, the cathode liquid outlet pipe is assembled by a straight pipe and an elbow, the elbow is connected to the upper end of the straight pipe, the other end of the elbow is connected with the liquid outlet pipe, the connecting rods are three and are uniformly arranged along the upper edge circumference of the cathode plate, the upper end of the connecting rod is connected with the elbow, and the cathode wire interface is arranged on one side of the elbow; the funnel is arranged below the two first horizontal rods at the uppermost end, and the flow guide groove is arranged on the two first horizontal rods in the middle and is located directly below the funnel mouth, and the low end of the flow guide groove extends into the electrolyte tank.

[0011] Further, the gas cylinder is two, which are symmetrically installed on the outer sides of the two top rods respectively, a T-shaped support is arranged on the top rod, the left and right ends of the T-shaped support are connected with the cylinder rods of the gas cylinder, and the lower end of the T-shaped support is connected and fixed with the cathode liquid outlet pipe.

[0012] Finally, the liquid pump is a corrosion-resistant liquid pump, the anode is made of aluminum alloy or titanium alloy, the frame, the cathode plate, the connecting rod and the cathode liquid outlet pipe are made of stainless steel, and the insulating pad is made of insulating rubber or temperature-resistant resin plate; the hose is telescopic and forms 1-1.5 times the height of the pot body 12; the outer diameter of the anode is 0.6-0.8 times the outer diameter of the pot body, the upper end diameter of the funnel is 1.3-1.7 times the outer diameter of the pot body, the flow guide groove forms an angle of 5-15° with the horizontal plane, and the upper end surface of the anode needs to be leveled before the oxidation device works.

[0013] The technical scheme adopted by the present application to solve the second technical problem is: a preparation method of an aluminum alloy pot surface composite ceramic coating, characterized by comprising the following steps:

[0014] 1) Preparing a preset base layer before micro-arc oxidation: including micro-arc oxidation and rinsing, wherein the micro-arc oxidation is prepared by using the above oxidation device, and the micro-arc oxidation process is:

[0015] Electrolyte: sodium silicate, sodium hydroxide and deionized water = (10-30) : (2-5) : (100-200), mass ratio;

[0016] Oxidation mode: single pulse, constant current oxidation;

[0017] Electric parameters: current 19-21A, frequency 6000-7000Hz, duty cycle 28-32%;

[0018] Oxidation time: 18-22s.

[0019] The rinsing process is: deionized water rinsing at room temperature for 40-50s, and then natural drying;

[0020] 2) Laser alloying process to prepare alloyed coating: the alloying powder mixture system is uniformly sprayed on the inner wall of the pot by high-pressure spray gun, and then obtained by vacuum drying treatment, the vacuum drying temperature is 120-180℃, and the drying time is 20-40min;

[0021] The alloying powder mixture system is prepared by uniformly mixing and stirring a certain mass ratio of nanoparticle mixture and dispersant. The mass ratio of components of the nanoparticle mixture is Ag: Nb: SiC: Fe: Al = 1: (1-3): (10-30): (1-5): (30-50), and the dispersant is n-propanol, ethyl acetate or a mixture of the two. The volume ratio of the nanoparticle mixture to the dispersant is 1: (2-5).

[0022] 3) Composite ceramic coating prepared by micro-arc oxidation post-treatment: prepared by using the above oxidation device, and the micro-arc oxidation process is as follows:

[0023] Electrolyte: sodium silicate, sodium hydroxide, nano-SiC particles and deionized water = (10-30): (2-5): (1-3): (100-200), mass ratio;

[0024] Oxidation mode: double pulse, constant current, medium frequency oxidation,

[0025] Electric parameters: positive current 14-16A, frequency 1000-3000Hz, duty cycle 28-32%, negative current 4-6A, frequency 800-1200Hz, duty cycle 28-32%;

[0026] Oxidation time: 280-320s.

[0027] Further, the specific process of the oxidation treatment of step 1) is as follows: the pot to be treated is placed in the recess of the anode, the cylinder is controlled to descend, the cathode is controlled to descend into the interior of the pot, and the vertical distance between the cathode plate and the inner wall of the pot is controlled to be the same. Then the liquid pump is started, the electrolyte flows from the electrolyte tank through the liquid inlet pipe, the liquid pump, the hose, the liquid outlet pipe, the cathode liquid outlet pipe into the interior of the pot, and then overflows from the edge of the pot into the funnel directly below, and then flows into the flow guide groove through the funnel mouth, and finally flows into the electrolyte tank along the slope of the flow guide groove. After the electrolyte circulation starts, the micro-arc oxidation power supply is started to start the oxidation treatment.

[0028] Finally, the laser treatment process of step 2) is as follows:

[0029] Laser power: 4-6kW;

[0030] Laser spot: 1.9-2.1mm;

[0031] Laser overlap rate: 38-42%.

[0032] Laser scanning speed: 8-10 m / min

[0033] The thickness of the pre-prepared base layer is 3-8 mu m, the thickness of the prepared alloying coating is 15-20 mu m, and the thickness of the prepared composite ceramic coating is 25-35 mu m.

[0034] Compared with the prior art, the advantages of the present application are that:

[0035] 1. Micro-arc oxidation is used as a pretreatment process of laser alloying treatment, which can effectively reduce the roughness of the pot body surface and the inclusion of the pot body surface, provide a flat and clean base layer for alloying pre-treatment, effectively reduce the generation of defects such as cavities and cracks in the alloying process, and improve the service life of the coating.

[0036] 2. The Ag, Nb, SiC, Fe, Al alloying powder system can generate Ag-Nb and Nb-Al phases during the alloying process, which can improve the adhesion of the alloying coating to the substrate and improve the antibacterial performance of the pot.

[0037] 3. Micro-arc oxidation is used as a post-treatment process of alloying treatment, which can form a strong Al2O3-based network oxide ceramic coating on the crack defects and weak areas of the alloying coating, and can include SiC powder in the composite ceramic coating, reducing the risk of SiC particles falling off due to friction during use, and improving the overall wear resistance of the coating.

[0038] 4. The anode with a groove structure and the liftable cathode can make the clamping and fixing of the workpiece convenient and fast, and improve the oxidation efficiency; the design of the cathode plate attached to the inner wall of the pot can make the vertical distance between each point on the oxidation surface of the inner wall of the pot and the cathode equal, and improve the uniformity of the oxidation film on the inner wall of the pot.

[0039] 5. The micro-arc oxidation reaction site is arranged inside the pot body, so that the oxidation state of the pot body changes from traditional overall immersion oxidation to local oxidation of the inner wall, the oxidation area is greatly reduced, thereby reducing the requirement of the power supply for the oxidation of the pot body, and greatly reducing the power consumption.

[0040] The preparation method of the present application is scientific and reasonable, the oxidation device structure is simple, the operation is convenient, the surface flatness of the substrate is effectively improved through micro-arc oxidation pretreatment, the adhesion of the laser alloying coating is improved, the network structure coating prepared by micro-arc oxidation post-treatment can effectively repair the defects and weak areas of the alloying coating, the SiC particles are fixed in the composite coating, and the wear resistance and corrosion resistance of the composite coating are greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1This is a schematic diagram of the oxidation device provided by the present invention;

[0042] Figure 2 yes Figure 1 Decomposition diagram of the micro-arc oxidation zone. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0044] like Figure 1 , 2 As shown, an oxidation device for preparing a composite ceramic coating on the surface of an aluminum alloy pot includes a frame 1, a micro-arc oxidation zone A, an electrolyte tank 2, and a liquid pump 4. The micro-arc oxidation zone A includes a funnel 6, an anode 7, a pot body 8, and a cathode 9. The anode 7 is mounted on the frame 1, and the pot body 8 is mounted on the anode 7. The outer edge of the anode 7 is provided with an anode wire interface 70 connected to the positive terminal of the micro-arc oxidation power supply. The cathode 9 is movably mounted above the pot body 8 and includes a cathode plate 91. The frame 1 is provided with a cylinder 5 for driving the cathode plate 91 to move up and down. A cathode outlet pipe 9 is provided above the cathode plate 91. 2. The cathode outlet pipe 92 is provided with a cathode wire interface 90 connected to the negative electrode of the micro-arc oxidation power supply. The bottom and side of the cathode plate 91 are provided with multiple liquid permeation holes 911. When the cathode plate 91 is placed in the pot body 8, the vertical distance between each point on the inner wall of the pot body 8 and the outer surface of the cathode plate 91 is equal. The funnel 6 is set on the frame 1 below the anode 7. The funnel 6 is provided with a guide groove 3 below it. The other end of the guide groove 3 extends into the electrolyte tank 2. The side of the electrolyte tank 2 is provided with an inlet pipe 10. The inlet pipe 10 is connected to the cathode outlet pipe 92 through a liquid pump 4, a hose 30, and an outlet pipe 20.

[0045] The specific structure is as follows: Frame 1 is welded together from two long straight rods 11, two short straight rods 12 and several crossbars 13, 14 and 15. The two short straight rods 12 are set in front of the long straight rods 11. The upper end, lower middle and bottom of the two short straight rods 12 are respectively connected to the corresponding long straight rods 11 through the first crossbar 13. The lower middle and bottom of the two short straight rods 12 are respectively connected through the second crossbar 14. The upper end, middle and bottom of the two long straight rods 11 are respectively connected through the third crossbar 15. The short straight rods 12 and the long straight rods 11 are fixed together to form a rectangular frame. The top of the two long straight rods 11 is respectively welded with a top rod 16. The top rod 16 is located above the first crossbar 13 and parallel to the first crossbar 13. The length of the top rod 16 is shorter than that of the first crossbar 13. The uppermost two of the first horizontal bars 13 are respectively provided with insulating pads 40. The anode 7 is set on the insulating pad 40. The anode 7 is a disc structure with an anode groove 71 on the upper end face. The pot body 8 is set on the anode groove 71. The outer surface contour structure of the pot body 8 is the same as the curved surface contour structure of the anode groove 71. The structure of the cathode plate 91 is similar to the inner wall contour structure of the pot body 8. During operation, the vertical distance between each point on the inner wall of the pot body 8 and the outer surface of the cathode plate 91 is equal, and the vertical distance is 10-20mm. The cathode outlet pipe 92 is vertically set at the center above the cathode plate 91. The upper edge of the cathode plate 91 is provided with a connecting rod 93 connected to the cathode outlet pipe 91. The cathode outlet pipe 92 is assembled from a straight pipe and an elbow 920. The elbow 920 is connected to the upper end of the straight pipe, and the other end of the elbow 920 is connected to the outlet pipe 20. There are three connecting rods 93 evenly spaced along the upper edge of the cathode plate 91. The upper end of the connecting rod 93 is connected to the elbow 920. The cathode wire interface 90 is located on one side of the elbow 920. The funnel 6 is located below the two uppermost first horizontal bars 13. The guide channel 3 is inclined on the two middle first horizontal bars 13 and located directly below the funnel opening. The angle between the guide channel 3 and the liquid level is 5-15°. The lower end of the guide channel 3 extends into the electrolyte tank 2.

[0046] There are two cylinders 5, one on the left and one on the right, which are symmetrically installed on the outside of the two push rods 16. A T-shaped bracket 50 is provided on the push rod 16. The left and right ends of the T-shaped bracket 50 are connected to the cylinder rod of the cylinder 5, and the lower end of the T-shaped bracket 5 is connected and fixed to the cathode outlet pipe 92.

[0047] In this embodiment, the liquid pump 3 is a corrosion-resistant liquid pump, the anode 7 is made of aluminum alloy or titanium alloy, the frame 1, cathode plate 91, connecting rod 93, and cathode outlet pipe 92 are made of stainless steel, and the insulating pad 40 is made of insulating rubber or heat-resistant resin board; the flexible hose 30 can be extended to form a height of 1-1.5 times that of the pot body 8; the outer diameter of the anode 7 is 0.6-0.8 times the outer diameter of the pot body 8, and the upper diameter of the funnel 6 is 1.3-1.7 times the outer diameter of the pot body 8. Before the oxidation device is put into operation, the upper surface of the anode 7 needs to be leveled.

[0048] The working principle and operating procedure of the oxidation device are as follows:

[0049] In use, assemble the oxidation device according to the above structure, place the pot body 8 to be treated into the groove 71 of the anode 7, control the cylinder 5 to descend, so that the cathode 9 descends into the interior of the pot body 8, control the stroke of the cylinder 5 to make the vertical distance between the cathode plate 91 and the inner wall of the pot body 8 the same; then turn on the liquid pump 4, and the electrolyte enters the interior of the pot body 8 from the electrolyte tank 2 through the inlet pipe 10, the liquid pump 4, the hose 30, the outlet pipe 30, and the cathode outlet pipe 92 in sequence, and then overflows from the edge of the pot body 8 into the funnel 6 directly below, and then collects through the funnel opening and flows into the guide channel 3, and finally flows into the electrolyte tank 2 along the slope of the guide channel 3; after the electrolyte circulation begins, turn on the micro-arc oxidation power supply to start the oxidation treatment.

[0050] A method for preparing a composite ceramic coating on the surface of an aluminum alloy pot includes the following steps:

[0051] 1) Preparation of the pre-prepared substrate layer by micro-arc oxidation pretreatment: This includes micro-arc oxidation and rinsing. The micro-arc oxidation is performed using the aforementioned oxidation device. The micro-arc oxidation process is as follows:

[0052] Electrolyte: Sodium silicate, sodium hydroxide and deionized water = (10-30):(2-5):(100-200), mass ratio;

[0053] Oxidation modes: Single-pulse, constant-current oxidation;

[0054] Electrical parameters: Current 10A, frequency 6500Hz, duty cycle 30%;

[0055] Oxidation time: 20s.

[0056] The rinsing process is as follows: rinse with room temperature deionized water for 45 seconds, then air dry naturally;

[0057] The thickness of the pre-prepared substrate layer in step 1) is 3-8 μm;

[0058] 2) Laser alloying treatment to prepare alloy coating: The alloy powder mixture system is uniformly sprayed onto the inner wall of the pot by a high-pressure spray gun, and then vacuum dried. The vacuum drying temperature is 150℃ and the drying time is 30min.

[0059] The alloyed powder mixing system is prepared by mixing and stirring a certain mass ratio of nanoparticle mixture with a dispersant. The mass ratio of the nanoparticle mixture is Ag:Nb:SiC:Fe:Al=1:(1-3):(10-30):(1-5):(30-50). The dispersant is n-propanol, ethyl acetate or a mixture of both. The volume ratio of the nanoparticle mixture to the dispersant is 1:(2-5).

[0060] The laser processing technology is as follows:

[0061] Laser power: 5kW;

[0062] Laser spot size: 2mm;

[0063] Laser overlap rate: 40%;

[0064] Laser scanning speed: 9m / min.

[0065] The thickness of the alloyed coating prepared in step 2) is 15-20 μm;

[0066] 3) Preparation of composite ceramic coatings after micro-arc oxidation post-treatment: The above-mentioned oxidation device is used for preparation. The micro-arc oxidation process is as follows:

[0067] Electrolyte: Sodium silicate, sodium hydroxide, nano-SiC particles and deionized water = (10-30):(2-5):(1-3):(100-200), mass ratio;

[0068] Oxidation modes: dual-pulse, constant current, medium-frequency oxidation.

[0069] Electrical parameters: positive current 15A, frequency 2000Hz, duty cycle 30%; negative current 5A, frequency 1000Hz, duty cycle 30%.

[0070] Oxidation time: 300s.

[0071] The thickness of the composite ceramic coating prepared in step 3) is 25-35 μm.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An oxidation apparatus for preparing a composite ceramic coating on the surface of an aluminum alloy pot, characterized in that: The oxidation device includes a frame, a micro-arc oxidation zone, an electrolyte tank, and a liquid pump. The micro-arc oxidation zone includes a funnel, an anode, a pot, and a cathode. The anode is mounted on the frame, and the pot is mounted on the anode. The outer edge of the anode has an anode wire interface connected to the positive terminal of the micro-arc oxidation power supply. The cathode is movably mounted above the pot and includes a cathode plate. A cylinder on the frame drives the cathode plate to move up and down. A cathode outlet pipe is located above the cathode plate, and a cathode wire interface on the cathode outlet pipe is connected to the negative terminal of the micro-arc oxidation power supply. Multiple liquid permeation holes are arranged on the bottom and sides of the cathode plate. When the cathode plate is placed inside the pot, the vertical distance between each point on the inner wall of the pot and the outer surface of the cathode plate is equal. The funnel is mounted on the frame below the anode. A guide channel is located below the funnel, and the other end of the guide channel extends into the electrolyte tank. An inlet pipe is located on one side of the electrolyte tank, and the inlet pipe is connected to the cathode outlet pipe through a liquid pump, a hose, and an outlet pipe.

2. The oxidation apparatus according to claim 1, characterized in that: The frame is welded together from two long straight rods, two short straight rods, and several crossbars. The two short straight rods are located in front of the long straight rods. The upper, lower middle, and bottom of the two short straight rods are connected to the corresponding long straight rods via first crossbars. The lower middle and bottom of the two short straight rods are connected via second crossbars. The upper, middle, and bottom of the two long straight rods are connected via third crossbars. The short straight rods and long straight rods are fixed together to form a rectangular frame. The top of each of the two long straight rods is welded with a top rod. The top rod is located above the first crossbar and parallel to the first crossbar. The length of the top rod is shorter than that of the first crossbar.

3. The oxidation apparatus according to claim 2, characterized in that: The uppermost two first crossbars are respectively provided with insulating pads at their upper ends. The anode is set on the insulating pad and is a disc structure with an anode groove on its upper end. The pot body is set on the anode groove and the outer surface contour structure of the pot body is the same as the curved surface contour structure of the anode groove.

4. The oxidation apparatus according to claim 3, characterized in that: The structure of the cathode plate is the same as the outline of the inner wall of the pot. During operation, the vertical distance between each point on the inner wall of the pot and the outer surface of the cathode plate is equal, and the vertical distance is 10-20mm. The cathode outlet pipe is vertically set at the center above the cathode plate, and the upper edge of the cathode plate is provided with a connecting rod to connect with the cathode outlet pipe.

5. The oxidation apparatus according to claim 4, characterized in that: The cathode outlet pipe is assembled from a straight pipe and an elbow. The elbow is connected to the upper end of the straight pipe, and the other end of the elbow is connected to the outlet pipe. There are three connecting rods evenly spaced along the upper edge of the cathode plate. The upper end of the connecting rod is connected to the elbow. The cathode wire interface is located on one side of the elbow. The funnel is located below the two uppermost first horizontal bars. The guide channel is inclinedly located on the two middle first horizontal bars, directly below the opening of the funnel. The lower end of the guide channel extends into the electrolyte tank.

6. The oxidation apparatus according to claim 5, characterized in that: The cylinder consists of two cylinders, left and right, which are symmetrically installed on the outside of the two push rods. A T-shaped bracket is provided on the push rod. The left and right ends of the T-shaped bracket are connected to the cylinder rod of the cylinder, and the lower end of the T-shaped bracket is connected and fixed to the cathode outlet pipe.

7. The oxidation apparatus according to claim 6, characterized in that: The liquid pump is a corrosion-resistant liquid pump, the anode is made of aluminum alloy or titanium alloy, the frame, cathode plate, connecting rod, and cathode outlet pipe are made of stainless steel, and the insulating pad is made of insulating rubber or heat-resistant resin board; the flexible hose can be extended to form a height of 1-1.5 times the pot body 12; the outer diameter of the anode is 0.6-0.8 times the outer diameter of the pot body, the upper diameter of the funnel is 1.3-1.7 times the outer diameter of the pot body, the guide groove is at an angle of 5-15° with the horizontal plane, and the upper surface of the anode needs to be leveled before the oxidation device is put into operation.

8. A method for preparing a composite ceramic coating on the surface of an aluminum alloy pot, characterized in that: Includes the following steps: 1) Preparation of a pre-prepared substrate layer by micro-arc oxidation pretreatment: including micro-arc oxidation and rinsing, wherein the micro-arc oxidation is performed using the oxidation device described in claim 7, and the micro-arc oxidation process is as follows: Electrolyte: Sodium silicate, sodium hydroxide and deionized water = (10-30):(2-5):(100-200), mass ratio; Oxidation modes: Single-pulse, constant-current oxidation; Electrical parameters: current 19-21A, frequency 6000-7000Hz, duty cycle 28-32%; Oxidation time: 18–22 s. The rinsing process is as follows: rinse with room temperature deionized water for 40-50 seconds, then air dry naturally; 2) Laser alloying treatment to prepare alloy coating: The alloy powder mixture is uniformly sprayed onto the inner wall of the pot by a high-pressure spray gun, and then vacuum dried. The vacuum drying temperature is 120-180℃ and the drying time is 20-40 min. The alloyed powder mixing system is prepared by mixing and stirring a certain mass ratio of nanoparticle mixture with a dispersant. The mass ratio of the nanoparticle mixture is Ag:Nb:SiC:Fe:Al=1:(1-3):(10-30):(1-5):(30-50). The dispersant is n-propanol, ethyl acetate or a mixture of both. The volume ratio of the nanoparticle mixture to the dispersant is 1:(2-5). 3) Preparation of composite ceramic coating by micro-arc oxidation post-treatment: The composite ceramic coating is prepared using the oxidation device described in claim 7. The micro-arc oxidation process is as follows: Electrolyte: Sodium silicate, sodium hydroxide, nano-SiC particles and deionized water = (10-30):(2-5):(1-3):(100-200), mass ratio; Oxidation modes: dual-pulse, constant current, medium-frequency oxidation; electrical parameters: positive current 14-16A, frequency 1000-3000Hz, duty cycle 28-32%; negative current 4-6A, frequency 800-1200Hz, duty cycle 28-32%. Oxidation time: 280-320s.

9. The preparation method according to claim 8, characterized in that: The specific process of oxidation treatment in step 1) is as follows: the pot to be treated is placed in the groove of the anode, the cylinder is controlled to descend, so that the cathode descends into the interior of the pot, the stroke of the cylinder is controlled so that the vertical distance between the cathode plate and the inner wall of the pot is the same; then the liquid pump is turned on, and the electrolyte enters the interior of the pot from the electrolyte tank through the inlet pipe, liquid pump, hose, outlet pipe and cathode outlet pipe in sequence, and then overflows from the edge of the pot into the funnel directly below, and then collects through the funnel opening into the guide channel, and finally flows into the electrolyte tank along the slope of the guide channel; After the electrolyte circulation begins, the micro-arc oxidation power supply is turned on to start the oxidation process.

10. The preparation method according to claim 8, characterized in that: The laser processing technology in step 2) is as follows: Laser power: 4-6kW; Laser spot size: 1.9–2.1 mm; Laser overlap rate: 38-42%; Laser scanning speed: 8–10 m / min; The thickness of the pre-prepared substrate layer in step 1) is 3-8 μm, the thickness of the alloyed coating in step 2) is 15-20 μm, and the thickness of the composite ceramic coating in step 3) is 25-35 μm.

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