Preparation method and device of high-density yttrium oxide coating

Abstract

The invention belongs to the technical field of coating preparation, and provides a high-density yttrium oxide coating preparation method and device.According to the method, a first nozzle sprays aerosol formed by small-particle-size yttrium oxide powder, and a second nozzle sprays aerosol formed by large-particle-size yttrium oxide powder; and a first nozzle and a second nozzle of the powder spraying mechanism are driven by the XYZ platform to finish aerosol deposition on the base material in the deposition chamber along a set spraying path, so that a high-density yttrium oxide coating is formed on the surface of the base material. The double-nozzle aerosol deposition technology is adopted, the bonding strength and compactness of the yttrium oxide coating are improved, and the porosity of the yttrium oxide coating is reduced.

Description

Technical Field

[0001] This invention relates to the field of coating preparation technology, specifically to a method for preparing a high-density yttrium oxide coating, and also to an apparatus for preparing a high-density yttrium oxide coating. Background Technology

[0002] Aerosol deposition is a low-vacuum solid-state deposition method. Under low-vacuum conditions, the pressure difference between the aerosol generator and the deposition chamber accelerates yttrium oxide powder aerosols to sonic or even supersonic speeds. The high-speed moving yttrium oxide powder aerosol impacts the substrate, causing strong plastic deformation to form a yttrium oxide coating. Throughout the process, the deposition chamber is in a low-vacuum state, and the particle size of the yttrium oxide powder aerosol needs to be submicron. However, as the particle size of the yttrium oxide powder aerosol decreases, the influence of the shock wave (the high-speed gas is compressed when it impacts the substrate, forming a gas wave in front of the substrate) increases, resulting in a lower impact velocity of the yttrium oxide powder aerosol on the substrate surface and poorer plastic deformation, thus leading to weaker adhesion between the formed yttrium oxide coating and the substrate.

[0003] In existing technologies, to improve the adhesion between yttrium oxide coatings and substrates, the following methods are commonly used: laser-assisted spraying, heat treatment of yttrium oxide powder, or preheating treatment of the substrate. The main purpose of these methods is to increase the energy of the yttrium oxide powder and promote its deformation to a certain extent. However, when using these conventional techniques to perform aerosol deposition on yttrium oxide powder with high hardness, the plastic deformation of the yttrium oxide powder is not significantly improved, resulting in yttrium oxide coatings with high porosity and low bonding strength. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method and apparatus for preparing a high-density yttrium oxide coating, which can solve or at least alleviate one or more of the above-mentioned problems and other problems existing in the prior art.

[0005] This invention provides a method for preparing a high-density yttrium oxide coating, comprising the following steps:

[0006] S1. At least one substrate is clamped and fixed by the clamping mechanism in the deposition chamber;

[0007] S2. Vacuum the sedimentation chamber to bring the vacuum level of the sedimentation chamber to the set value;

[0008] S3. At least one powder spraying mechanism is arranged in the deposition chamber. The number of powder spraying mechanisms corresponds to the number of substrates. Each powder spraying mechanism has a first nozzle and a second nozzle. The first nozzle and the second nozzle are arranged in the same X direction or the same Y direction with a spacing. The first nozzle and the second nozzle of the powder spraying mechanism are moved to one side of the initial deposition position of the substrate through the XYZ platform.

[0009] S4. Spray aerosol formed by small-diameter yttrium oxide powder with the first nozzle, and spray aerosol formed by large-diameter yttrium oxide powder with the second nozzle.

[0010] S5. Adjust the distance between the first nozzle and the second nozzle and the corresponding substrate using the XYZ platform to achieve the set value;

[0011] S6. After the aerosols sprayed by the first nozzle and the second nozzle have stabilized, the first nozzle and the second nozzle of the powder spraying mechanism are driven by the XYZ platform to complete the aerosol deposition along the set spraying path, so that a high-density yttrium oxide coating is formed on the surface of the corresponding substrate. During the aerosol deposition process, the first nozzle is always located in front of the second nozzle along the spraying path.

[0012] Preferably, in step S4, a certain amount of small-particle-size yttrium oxide powder is placed in the first aerosol generator. A first flow meter is installed on the hose connecting the first aerosol generator to the first pressurized gas source. The first flow meter can control the pressure inside the first aerosol generator. By controlling the pressure inside the first aerosol generator to reach a set value through the first flow meter, the aerosol formed by the small-particle-size yttrium oxide powder is sprayed through the first nozzle. A certain amount of large-particle-size yttrium oxide powder is placed in the second aerosol generator. A second flow meter is installed on the hose connecting the second aerosol generator to the second pressurized gas source. The second flow meter can control the gas pressure inside the second aerosol generator. By controlling the pressure inside the second aerosol generator to reach a set value through the second flow meter, the aerosol formed by the large-particle-size yttrium oxide powder is sprayed through the second nozzle.

[0013] Preferably, in step S4, the small-particle-size yttrium oxide powder is formed by mixing powder one and powder two in a mass ratio of (1-2):(9-8), wherein powder one is spherical yttrium oxide powder with a particle size of 0.05-0.1 μm and powder two is spherical yttrium oxide powder with a particle size of 0.3-0.5 μm; the large-particle-size yttrium oxide powder is spherical yttrium oxide powder with a particle size of 2-5 μm.

[0014] Preferably, in step S5, the distance between the first nozzle and the second nozzle and the substrate is set to 5-30 mm.

[0015] Preferably, in step S6, the distance between the first nozzle and the second nozzle is 5-10 mm, the scanning speed of the first nozzle and the second nozzle is 10-50 mm / s, and the powder feeding rate of the first nozzle and the second nozzle is 5-10 g / min.

[0016] This invention also provides an apparatus for preparing a high-density yttrium oxide coating, employing the method described above, comprising: a deposition chamber; a clamping mechanism disposed within the deposition chamber for clamping at least one substrate; an XYZ platform disposed within the deposition chamber, located below the clamping mechanism, and movable along the X, Y, and Z directions; and a powder spraying mechanism disposed on the XYZ platform, with at least one set of powder spraying mechanisms corresponding to each substrate, the powder spraying mechanism being used to spray yttrium oxide powder aerosol onto the corresponding substrate; the powder spraying mechanism includes a first nozzle and a second nozzle; the first nozzle is used to spray small-particle-size yttrium oxide powder aerosol onto the substrate to form a yttrium oxide coating; the second nozzle is used to spray large-particle-size yttrium oxide powder aerosol onto the yttrium oxide coating.

[0017] Preferably, the high-density yttrium oxide coating preparation apparatus further includes a driving mechanism; the powder spraying mechanism includes: a mounting base disposed on the XYZ platform, the mounting base having a through-hole extending along the X direction, and mounting windows communicating with the mounting hole on both sides of the mounting base; a first slider slidably disposed within the mounting hole along the X direction, the first slider being connected to the first nozzle; and a second slider slidably disposed within the mounting hole along the X direction, the second slider being connected to the second nozzle, the second slider being able to slide closer to or further away from the first slider; the driving mechanism is used to drive the first slider and the second slider to slide; the first nozzle and the second nozzle can be located directly above the mounting hole.

[0018] Preferably, the powder spraying mechanism further includes two centrally symmetrically arranged connecting components; the two connecting components are respectively located on both sides of the mounting base; each connecting component includes: a connecting tube extending along the Z direction, the upper end of the connecting tube being connected to the first nozzle or the second nozzle; a first connecting arm, one end of the first connecting arm passing through the corresponding mounting window and being connected to the first slider or the second slider; a second connecting arm inclined, the lower end of the second connecting arm being connected to the end of the first connecting arm away from the first slider or the second slider; and a third connecting arm, the length direction of the third connecting arm being arranged along the Y direction, one end of the third connecting arm being connected to the upper end of the second connecting arm, the other end of the third connecting arm being connected to the corresponding connecting tube, and the third connecting arm being telescopic; when the first slider and the second slider approach each other, the second connecting arms in the two connecting components are staggered.

[0019] Preferably, the third connecting arm includes: a connecting post, one end of which is connected to the upper end of the second connecting arm, and the other end of which has a connecting square hole extending along the center line; a limiting ring, the outer ring of which is connected to the inner wall of the connecting square hole; a limiting block, which is a cuboid structure and slides with the connecting square hole, and can abut against the limiting ring; a spring, which is disposed in the connecting square hole, and the two ends of which abut against the bottom of the connecting square hole and the limiting block respectively; and a telescopic post, one end of which passes through the limiting ring and is connected to the limiting block, and the other end of which is connected to the corresponding connecting pipe; the powder spraying mechanism also includes a transmission assembly; when the first nozzle and the second nozzle approach each other, the transmission assembly can move the telescopic post toward the bottom of the connecting square hole by means of the movement of the first slider and the second slider.

[0020] Preferably, the transmission assembly includes: a turntable, rotatably disposed above the mounting base, the turntable having two symmetrically arranged strip-shaped limiting holes, and two connecting pipes respectively located in the corresponding strip-shaped limiting holes; two sleeves, each sleeve being connected to the end of a corresponding telescopic column away from the spring, and the sleeve being fitted over the corresponding connecting pipe; two gears, each gear being rotatably fitted over the corresponding sleeve; and two transmission columns, each transmission column being connected to the lower end of the turntable, the two transmission columns being able to abut against the corresponding connecting column, and the line connecting the two transmission columns being perpendicular to the line connecting the two strip-shaped limiting holes.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] In this invention, a first nozzle is used to spray small-diameter yttrium oxide powder (particle size less than 1 μm). When the small-diameter yttrium oxide powder particles impact the substrate, they undergo plastic deformation, forming an effective deposition on the substrate surface. Subsequently, a second nozzle is used to spray large-diameter yttrium oxide powder (particle size greater than 1 μm). The large-diameter yttrium oxide powder particles impact the previously deposited small-diameter yttrium oxide powder particles. Through the mechanical interlocking effect induced by plastic deformation and the regulation of interfacial stress, the bonding strength between the substrate and the small-diameter yttrium oxide powder particles, as well as the bonding strength between the small-diameter yttrium oxide powder particles and the large-diameter yttrium oxide powder particles, is strengthened, thereby improving the density and bonding strength of the yttrium oxide coating. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0024] Figure 1 This is a perspective view of a high-density yttrium oxide coating preparation apparatus according to an embodiment of the present invention;

[0025] Figure 2 for Figure 1 A three-dimensional view of the coordination between the powder spraying mechanism and the drive mechanism;

[0026] Figure 3 for Figure 2 Top view;

[0027] Figure 4 for Figure 2 Another 3D image;

[0028] Figure 5 for Figure 2 3D view of the powder spraying mechanism (without turntable);

[0029] Figure 6 for Figure 5 A 3D view of the connecting component in the middle;

[0030] Figure 7 for Figure 6 Internal structure diagram of the third connecting arm;

[0031] Figure 8 for Figure 2 State diagram;

[0032] Figure 9 for Figure 2 Another state diagram (a has a turntable, b has no turntable);

[0033] Figure 10 for Figure 2 Another state diagram.

[0034] Figure label:

[0035] 10. Substrate;

[0036] 20. XYZ platform;

[0037] 30. Powder spraying mechanism; 31. First nozzle; 32. Second nozzle; 33. Mounting base; 331. Mounting hole; 332. Mounting window; 34. First slider; 35. Second slider; 36. Connecting assembly; 361. Connecting pipe; 362. First connecting arm; 363. Second connecting arm; 364. Third connecting arm; 365. Connecting column; 366. Connecting square hole; 367. Limiting ring; 368. Limiting block; 369. Spring; 370. Telescopic column; 38. Transmission assembly; 381. Turntable; 382. Strip-shaped limiting hole; 383. Sleeve; 384. Gear; 385. Transmission column; 386. Slide groove;

[0038] 40. Motor; 41. Drive rod;

[0039] 50. Arc-shaped support block; 51. Arc-shaped guide block. Detailed Implementation

[0040] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0041] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0042] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0043] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0044] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] Example 1

[0047] This embodiment provides a method for preparing a high-density yttrium oxide coating, including the following steps:

[0048] S1. At least one substrate is clamped and fixed by the clamping mechanism in the deposition chamber;

[0049] S2. Vacuum the sedimentation chamber to achieve a set vacuum level of 10 Pa. The sedimentation chamber is connected to an external vacuum pump via a vacuum pipeline. The vacuum pump can perform vacuuming on the sedimentation chamber. This technology is existing technology and will not be described in detail here.

[0050] S3. At least one powder spraying mechanism 30 is arranged in the deposition chamber. The number of powder spraying mechanisms 30 corresponds to the number of substrates. Each powder spraying mechanism 30 has a first nozzle 31 and a second nozzle 32. The first nozzle 31 and the second nozzle 32 are arranged along the same X direction or the same Y direction with a spacing. The first nozzle 31 and the second nozzle 32 of the powder spraying mechanism 30 are moved to one side of the initial deposition position of the substrate through the XYZ platform. The first nozzle 31 and the second nozzle 32 are arranged in parallel, and the spacing between the first nozzle 31 and the second nozzle 32 is 5-10 mm.

[0051] S4. Spray aerosol formed by small-diameter yttrium oxide powder onto the first nozzle 31, and spray aerosol formed by large-diameter yttrium oxide powder onto the second nozzle 32.

[0052] S5. Adjust the distance between the first nozzle 31 and the second nozzle 32 and the corresponding substrate through the XYZ platform to reach the set value; the distance between the first nozzle 31 and the second nozzle 32 and the substrate is set to 5-30mm;

[0053] S6. After the aerosol sprayed by the first nozzle 31 and the second nozzle 32 stabilizes, the first nozzle 31 and the second nozzle 32 of the powder spraying mechanism 30 are driven by the XYZ platform to complete the aerosol deposition along the set spraying path, so that a high-density yttrium oxide coating is formed on the surface of the corresponding substrate. During the aerosol deposition process, the first nozzle 31 is always located in front of the second nozzle 32 along the spraying path.

[0054] In step S4, a measured amount of small-particle-size yttrium oxide powder is placed in the first aerosol generator. A first flow meter is installed on the hose connecting the first aerosol generator to the first pressurized gas source. The first flow meter controls the pressure inside the first aerosol generator. By controlling the pressure inside the first aerosol generator to a set value, the aerosol formed by the small-particle-size yttrium oxide powder is sprayed through the first nozzle. A measured amount of large-particle-size yttrium oxide powder is placed in the second aerosol generator. A second flow meter is installed on the hose connecting the second aerosol generator to the second pressurized gas source. The second flow meter controls the pressure inside the second aerosol generator. By controlling the pressure inside the second aerosol generator to a set value, the aerosol formed by the large-particle-size yttrium oxide powder is sprayed through the second nozzle. The pressure inside both the first and second aerosol generators is maintained at 0.5 MPa.

[0055] In step S4, the small-particle-size yttrium oxide powder is formed by mixing powder one and powder two in a mass ratio of 1:9. Powder one is spherical yttrium oxide powder with a particle size of 0.05-0.1 μm, and powder two is spherical yttrium oxide powder with a particle size of 0.3-0.5 μm. The large-particle-size yttrium oxide powder is spherical yttrium oxide powder with a particle size of 2-5 μm.

[0056] In step S6, the scanning speed of the first nozzle 31 and the second nozzle 32 is 10-50 mm / s, and the powder feeding rate of the first nozzle 31 and the second nozzle 32 is 5-10 g / min.

[0057] In different tests and practical production, the first nozzle 31 and the second nozzle 32 can be arranged along the same X direction or the same Y direction. In this embodiment, the arrangement of the first nozzle 31 and the second nozzle 32 along the same X direction is used as an example. In step S3, the distance between the first nozzle 31 and the second nozzle 32 can be 5-10 mm. In step S4, the quantitative amount refers to the amount of large / small particle size yttrium oxide powder calculated by those skilled in the art based on the area and thickness of the deposited coating, or the amount of large / small particle size yttrium oxide powder added based on empirical values, to meet the powder feeding amount of the nozzles and the required amount of coating. In step S5, the distance between the first nozzle 31 and the second nozzle 32 and the substrate can be set to 5-30 mm. In step S6, the spraying path adopts a serpentine scanning path, that is, the first nozzle 31 and the second nozzle 32 move alternately along parallel lines on the substrate surface with the X direction as the reference (e.g., from left to right → from right to left → from left to right in the X direction, etc.). After completing each row, the first nozzle 31 and the second nozzle 32 skip one scanning interval in the vertical direction, forming a serpentine scanning trajectory, until the corresponding surface of the substrate is deposited, forming a yttrium oxide coating on the substrate. The serpentine scanning path is a common technique used by those skilled in the art and will not be described in detail here. In step S6, the scanning speed of the first nozzle 31 and the second nozzle 32 can be 5-10 mm / s, and the powder feed rate of the first nozzle 31 and the second nozzle 32 can both be 5-10 g / min.

[0058] Of course, those skilled in the art can adjust the particle size distribution and particle size range of small-diameter yttrium oxide powder and large-diameter yttrium oxide powder as needed. Since the particle size distribution and particle size range are adjusted, the distance between the first nozzle 31 and the second nozzle 32 also needs to be adjusted according to empirical values. The distance between the first nozzle 31 and the second nozzle 32 and the substrate can be set to be the same or different as needed to ensure the performance of the aerosol-deposited yttrium oxide coating. The performance here includes, but is not limited to, bonding strength and porosity.

[0059] Example 2

[0060] The preparation process of this embodiment is the same as that of Example 1, except that the small-particle-size yttrium oxide powder is made by mixing powder one and powder two in a mass ratio of 2:8.

[0061] Example 3

[0062] The preparation process in this embodiment is the same as that in Example 1, except that the small-particle-size yttrium oxide powder is made by mixing powder one and powder two in a mass ratio of 3:7.

[0063] Comparative Example 1

[0064] The preparation process in this embodiment is the same as in Example 1, except that the small-particle-size yttrium oxide powder is composed of powder one.

[0065] Comparative Example 2

[0066] The preparation process in this embodiment is the same as in Example 1, except that the small-particle-size yttrium oxide powder is composed of powder two.

[0067] Comparative Example 3

[0068] The preparation process in this embodiment is the same as that in Example 1. The difference is that this embodiment uses a single nozzle for aerosol deposition. The particle size of the spherical yttrium oxide powder used for aerosol deposition is 0.3-0.6 mm, and the powder feeding rate is 10 g / min.

[0069] In Examples 1-3 and Comparative Examples 1-3, the following parameters are used as examples:

[0070] The distance between the first nozzle 31 and the substrate is set to 5 mm, and the distance between the second nozzle 32 and the substrate is set to 10 mm. The distance between the first nozzle 31 and the second nozzle 32 is 10 mm. The scanning speed of the first nozzle 31 and the second nozzle 32 is 10 mm / s. The powder feeding rate of the first nozzle 31 is 10 g / min, and the powder feeding rate of the second nozzle 32 is 5 g / min.

[0071] Performance testing

[0072] Testing standards:

[0073] (1) The porosity was calculated by using ImageJ software to mark the pores in the area shown in the figure.

[0074] (2) The bonding strength shall comply with the national standard GB / T 8642-2002;

[0075] (3) Hardness shall be in accordance with the national standard GB / T 4340.1-2024.

[0076] Test results: The performance test results are shown in Table 1.

[0077] Table 1

[0078] Porosity / % Bond strength / MPa Hardness / HV Example 1 <0.1 23 1035 Example 2 <0.1 25.6 1095 Example 3 <0.1 22.3 983 Comparative Example 1 0.15 18 645 Comparative Example 2 0.18 16 538 Comparative Example 3 0.13 17.2 762

[0079] Based on aerosol deposition technology, those skilled in the art know that particles with a diameter less than 1 μm undergo plastic deformation when impacting a substrate, forming effective deposition on the substrate surface; while particles with a diameter greater than 1 μm undergo very little plastic deformation when impacting a substrate, and cannot form effective deposition. The technical solution of the present invention first uses a first nozzle (31) to spray small-diameter yttrium oxide powder (particle size less than 1 μm). When the small-diameter yttrium oxide powder particles impact the substrate, they undergo plastic deformation, forming effective deposition on the substrate surface; then, a second nozzle 32 sprays large-diameter yttrium oxide powder (particle size greater than 1 μm). The large-diameter yttrium oxide powder particles impact the previously deposited small-diameter yttrium oxide powder particles. Through the mechanical interlocking effect induced by plastic deformation and the control of interfacial stress, the bonding strength between the substrate and the small-diameter yttrium oxide powder particles, as well as the bonding strength between the small-diameter yttrium oxide powder particles and the large-diameter yttrium oxide powder particles, is strengthened. Among these, plastic deformation-induced mechanical interlocking refers to the plastic deformation (such as flattening, breakage, or localized rheology) of small-diameter yttrium oxide powder particles caused by bombardment of large-diameter yttrium oxide powder particles. This results in mechanical interlocking between the small-diameter yttrium oxide powder particles and the substrate or adjacent particles (including large-diameter yttrium oxide powder particles). This process serves two purposes: firstly, it compacts the yttrium oxide coating to increase its density; secondly, it enhances the coating's inherent strength and the bonding strength between the coating and the substrate. Interfacial stress modulation refers to the residual compressive stress or dislocation multiplication effects generated during bombardment, which inhibit interfacial crack propagation and promote interatomic bonding, ultimately improving the bonding strength.

[0080] As can be seen from Table 1, by introducing the dual-nozzle aerosol deposition technology (the preparation process of Examples 1-3 above), the bonding strength and hardness of the yttrium oxide coating can be improved, and the porosity of the yttrium oxide coating can be reduced.

[0081] See Figures 1 to 10 The present invention also provides a high-density yttrium oxide coating preparation apparatus, including a deposition chamber (not shown), a clamping mechanism (not shown), an XYZ platform 20 and a powder spraying mechanism 30.

[0082] The deposition chamber is under a low vacuum. A clamping mechanism is located within the deposition chamber to hold at least one substrate 10, allowing for the simultaneous processing of one or more substrates 10. The substrate 10 can be made of alumina. An XYZ platform 20 is located within the deposition chamber, below the clamping mechanism. The XYZ platform 20 is driven by a power system, enabling it to move in the X, Y, and Z directions. A powder spraying mechanism 30 is mounted on the XYZ platform 20 and is externally connected to an aerosol generator. At least one powder spraying mechanism 30 is provided for each substrate 10, and it is used to spray yttrium oxide powder aerosol onto the corresponding substrate 10. The deposition chamber, power system, clamping mechanism, and aerosol generator all utilize existing technology and will not be described in detail here.

[0083] The powder spraying mechanism 30 includes a first nozzle 31 and a second nozzle 32. There are two aerosol generators, tentatively designated as a first aerosol generator and a second aerosol generator. The first aerosol generator contains small-particle-size yttrium oxide powder, and the second aerosol generator contains large-particle-size yttrium oxide powder. The first aerosol generator is connected to the first nozzle 31, and the second aerosol generator is connected to the second nozzle 32. The first nozzle 31 is used to spray small-particle-size yttrium oxide powder aerosol onto the substrate 10 to deposit a small-particle-size yttrium oxide coating. The second nozzle 32 is used to spray large-particle-size yttrium oxide powder aerosol onto the small-particle-size yttrium oxide coating. Specifically, the small-particle-size yttrium oxide powder aerosol can be obtained by using yttrium oxide powder with a particle size of less than 1 micrometer through a first aerosol generator, so that it undergoes plastic deformation upon impact with the substrate 10, thereby forming an effective deposition; while the large-particle-size yttrium oxide powder aerosol can be obtained by using yttrium oxide powder with a particle size of more than 1 micrometer through a second aerosol generator, so that its impact with the small-particle-size yttrium oxide coating achieves a compaction effect and strengthens the interparticle bonding strength. After the powder spraying mechanism 30 moves to the area to be sprayed on the substrate 10 on the XYZ platform 20, the first nozzle 31 of the powder spraying mechanism 30 can first spray small-particle-size yttrium oxide powder aerosol onto the substrate 10 above to form a small-particle-size yttrium oxide coating, and the second nozzle 32 then sprays large-particle-size yttrium oxide powder aerosol onto the small-particle-size yttrium oxide coating along the forward path, so that the yttrium oxide powder with a particle size of more than 1 micrometer impacts the small-particle-size yttrium oxide coating. The drive mechanism moves the XYZ platform 20 in the Z direction, allowing it to move vertically closer to or further away from the substrate 10. The drive mechanism can also move the XYZ platform in the X and Y directions in the horizontal plane, enabling the powder spraying mechanism 30 to form a yttrium oxide coating on different areas of the substrate 10. When the clamping mechanism holds multiple substrates 10, the multiple substrates 10 are arranged side-by-side, and multiple powder spraying mechanisms 30 on the XYZ platform 20 are arranged side-by-side, allowing for simultaneous yttrium oxide coating preparation on multiple substrates 10. The ability of the drive mechanism to move the XYZ platform in the X, Y, and Z directions is prior art and will not be elaborated further here.

[0084] In this embodiment, for a target area on the substrate 10, the first nozzle 31 and the second nozzle 32 of the powder spraying mechanism 30 successively spray yttrium oxide powder aerosol with a particle size of less than 1 micrometer and yttrium oxide powder aerosol with a particle size of more than 1 micrometer onto the target area. The yttrium oxide powder aerosol with a particle size of less than 1 micrometer first undergoes plastic deformation on the surface of the substrate 10 and combines with the substrate 10 to form a small-particle-size yttrium oxide coating. The yttrium oxide powder aerosol with a particle size of more than 1 micrometer is sprayed from the second nozzle 32 and impacts the small-particle-size yttrium oxide coating. After being subjected to force, the bonding force between the small-particle-size yttrium oxide coating and the substrate 10 increases, and the bonding area between the yttrium oxide powder forming the small-particle-size yttrium oxide coating and the substrate 10 increases after being deformed by impact, further improving the bonding force between the two and achieving enhanced bonding. In addition, as the yttrium oxide powder forming the yttrium oxide coating undergoes further plastic deformation, the gaps between the yttrium oxide powder particles in the yttrium oxide coating can be reduced, thereby reducing the porosity. The yttrium oxide powder with a particle size greater than 1 micrometer ejected from the second nozzle 32 can combine with the yttrium oxide powder of the small-particle-size yttrium oxide coating formed (the small-particle-size yttrium oxide powder particles and the large-particle-size yttrium oxide powder particles that form the yttrium oxide coating are combined through plastic deformation), thereby improving the density of the yttrium oxide coating and further reducing the porosity.

[0085] In one embodiment, the apparatus for preparing a high-density yttrium oxide coating further includes a drive mechanism.

[0086] The powder spraying mechanism 30 includes a mounting base 33, a first slider 34, and a second slider 35.

[0087] Mounting base 33 is disposed on XYZ platform 20. Mounting base 33 has a through mounting hole 331 extending along the X direction. Mounting windows 332 communicating with mounting hole 331 are respectively provided on both sides of mounting base 33. First slider 34 is slidably disposed in mounting hole 331 along X direction. First slider 34 is connected to first nozzle 31. Second slider 35 is slidably disposed in mounting hole 331 along X direction. Second slider 35 is connected to second nozzle 32. Second slider 35 can slide closer to or away from first slider 34. Driving mechanism is used to drive first slider 34 and second slider 35 to slide. First nozzle 31 and second nozzle 32 can be located directly above mounting hole 331. Specifically, first nozzle 31 and second nozzle 32 can be movable, but when spraying yttrium oxide powder aerosol, first nozzle 31 and second nozzle 32 need to be located directly above mounting hole 331, so that when XYZ platform 20 moves along X direction, first nozzle 31 and second nozzle 32 move along X direction to spray yttrium oxide powder aerosol onto substrate 10 in sequence.

[0088] In this embodiment, the distance between the first nozzle 31 and the second nozzle 32 in the X direction can be adjusted by driving the first slider 34 and the second slider 35 to move closer or further apart. As the mounting base 33 moves from one end of the substrate 10 to the other along the X direction, the first nozzle 31 is in front and the second nozzle 32 is behind, and both continuously spray yttrium oxide powder aerosol. The first nozzle 31 first sprays yttrium oxide powder aerosol to form a small-particle-size yttrium oxide coating on the substrate 10, and then the second nozzle 32 sprays yttrium oxide powder aerosol to impact the small-particle-size yttrium oxide coating for reinforcement. By adjusting the distance between the first nozzle 31 and the second nozzle 32, the interval between the second nozzle 32 spraying yttrium oxide powder aerosol to strengthen the small-particle-size yttrium oxide coating after the first nozzle 31 sprays yttrium oxide powder aerosol to form the small-particle-size yttrium oxide coating is adjusted. This allows for a better strengthening effect of the yttrium oxide powder aerosol sprayed by the second nozzle 32 on the yttrium oxide coating, depending on the actual production situation.

[0089] In one embodiment, the powder spraying mechanism 30 further includes two centrally symmetrically arranged connecting components 36; the two connecting components 36 are located on both sides of the mounting base 33. The first slider 34 is connected to the first nozzle 31 through the connecting components 36, and the second slider 35 is connected to the second nozzle 32 through the other connecting component 36.

[0090] The connecting assembly 36 includes a connecting tube 361, a first connecting arm 362, a second connecting arm 363, and a third connecting arm 364.

[0091] A connecting tube 361 extends along the Z-direction, with its upper end connected to either the first nozzle 31 or the second nozzle 32, and its lower end connected to the corresponding aerosol generator via a flexible hose. One end of the first connecting arm 362 passes through the corresponding mounting window 332 and connects to either the first slider 34 or the second slider 35, extending along the Y-direction. A second connecting arm 363 is inclined, with its lower end connected to the end of the first connecting arm 362 furthest from the first slider 34 or the second slider 35. A third connecting arm 364 is positioned along the Y-direction, with one end connected to the upper end of the second connecting arm 363, and its other end connected to the corresponding connecting tube 361; the third connecting arm 364 is telescopic. When the first slider 34 and the second slider 35 approach each other, the second connecting arms 363 in the two connecting assemblies 36 are staggered. The projection of the second slider 35 on the horizontal plane is located between the projections of the first slider 34 and the first nozzle 31 on the horizontal plane, and the projection of the first slider 34 on the horizontal plane is located between the projections of the second slider 35 and the second nozzle 32 on the horizontal plane.

[0092] In this embodiment, as Figure 2 and Figure 8a. At this point, the first slider 34 and the second slider 35 are in their closest position, and the distance between the first nozzle 31 on the left and the second nozzle 32 on the right is at its maximum. When the first slider 34 moves to the right and the second slider 35 moves to the left, the first nozzle 31 on the left and the second nozzle 32 on the right approach each other until they almost touch, at which point the distance between the first nozzle 31 and the second nozzle 32 is at its minimum. Figure 8 b. When the distance between the first nozzle 31 and the second nozzle 32 is at its minimum and the first slider 34 and the second slider 35 continue to move away from each other, the third connecting arm 364 retracts, thereby causing the first nozzle 31 and the second nozzle 32 to move away from each other in the Y direction and become misaligned and far apart (the corresponding two connecting pipes 361 move away from each other). Figure 9 a and Figure 9 b. Then, the third connecting arm 364 extends, and the first nozzle 31 and the second nozzle 32 are once again positioned directly above the mounting hole 331. At this time, the distance between the first nozzle 31 and the second nozzle 32 is at its minimum for the second time, and the front-to-back relationship of the first nozzle 31 and the second nozzle 32 in the X direction changes, such as... Figure 10 a. As the first slider 34 and the second slider 35 move further apart, the first nozzle 31 moves to the right and the second nozzle 32 moves to the left. At this point, the first nozzle 31 and the second nozzle 32 are at their maximum distance for the second time. Figure 10 b. When the first slider 34 and the second slider 35 approach each other, the above process is reversed once. That is, the movement of the first slider 34 and the second slider 35 away from or towards each other can cause the first nozzle 31 and the second nozzle 32 to interchange positions, thereby causing the powder spraying mechanism 30 to move along the positive X direction below the substrate 10, with the first nozzle 31 in front and the second nozzle 32 behind for yttrium oxide powder aerosol spraying. When the powder spraying mechanism 30 moves along the negative X direction below the substrate 10, the first nozzle 31 is still in front and the second nozzle 32 is behind for yttrium oxide powder aerosol spraying after the first nozzle 31 and the second nozzle 32 have interchanged positions, thus achieving high-efficiency operation. In addition, the spacing between the first nozzle 31 and the second nozzle 32 can also be controlled as needed before and after the position change.

[0093] In one embodiment, the third connecting arm 364 includes a connecting post 365, a limiting ring 367, a limiting block 368, a spring 369, and a telescopic post 370.

[0094] One end of the connecting post 365 is connected to the upper end of the second connecting arm 363, and the other end of the connecting post 365 is provided with a connecting square hole 366 extending along the center line.

[0095] The outer ring of the limiting ring 367 is connected to the inner wall of the connecting square hole 366. The limiting block 368 has a cuboid structure and slides with the connecting square hole 366, and can abut against the limiting ring 367. The spring 369 is disposed in the connecting square hole 366, and its two ends abut against the bottom of the connecting square hole 366 and the limiting block 368, respectively. One end of the telescopic column 370 passes through the limiting ring 367 and is connected to the limiting block 368, and the other end of the telescopic column 370 is connected to the corresponding connecting pipe 361. The powder spraying mechanism 30 also includes a transmission assembly 38; when the first nozzle 31 and the second nozzle 32 approach each other, the transmission assembly 38 can move the telescopic column 370 towards the bottom of the connecting square hole 366 by means of the movement of the first slider 34 and the second slider 35.

[0096] In this embodiment, the spring 369 abuts the limiting block 368 against the limiting ring 367, thereby keeping the connecting pipe 361 at the end of the telescopic column 370 in place. This ensures that the first nozzle 31 and the second nozzle 32 above the connecting pipe 361 are aligned on the same line when spraying yttrium oxide powder aerosol, and spray yttrium oxide powder aerosol onto the substrate 10 sequentially to complete the formation and strengthening of the yttrium oxide coating.

[0097] In one embodiment, the transmission assembly 38 includes a turntable 381, a sleeve 383, a gear 384, and a transmission column 385.

[0098] A turntable 381 is rotatably mounted above the mounting base 33. Two symmetrically arranged strip-shaped limiting holes 382 are formed on the turntable 381, and two connecting pipes 361 are located within the corresponding strip-shaped limiting holes 382. The two strip-shaped limiting holes 382 are centrally symmetrically arranged with the axis of the turntable 381 as the center line, and the strip-shaped limiting holes 382 penetrate the turntable 381 along the Z-direction. Two sleeves 383 are provided, each sleeve 383 connected to the end of the corresponding telescopic column 370 away from the spring 369, and the sleeve 383 is fitted over the corresponding connecting pipe 361. Two gears 384 are provided, and the gears 384 are rotatably fitted over the corresponding sleeves 383. Two rotating columns are provided, and two transmission columns 385 are connected to the lower end of the turntable 381. The two transmission columns 385 can abut against the corresponding connecting columns 365, and the line connecting the two transmission columns 385 is perpendicular to the line connecting the two strip-shaped limiting holes 382. The two connecting components 36 are centrally symmetrical about the axis of the turntable 381.

[0099] In this embodiment, as Figure 5When the first slider 34 drives the corresponding connecting pipe 361 and the first nozzle 31 to move to the right, in the connecting assembly 36 connected to the first slider 34, the connecting post 365 moves to the right and first abuts against the transmission post 385 below the turntable 381. At this time, the first nozzle 31 has not yet moved to the rightmost end of the left strip-shaped limiting hole 382 (there is still a certain distance). Thus, the connecting post 365 drives the turntable 381 to rotate through the transmission post 385. At the same time, the two gears 384 mesh. When the turntable 381 rotates at an angle under the drive of the connecting column 365, the two connecting pipes 361 move away from each other in the Y direction and move closer to each other in the X direction, thus causing the two connecting pipes 361 to gradually misalign. At this time, the transmission column 385 disengages from the connecting column 365 due to the rotation of the turntable 381. The left connecting column 365 moves continuously to the right, and the right connecting column 365 moves continuously to the left. Under the action of the spring 369, the two gears 384 always remain meshed. Since the two gears 384 are misaligned with the connecting pipes 361, the two gears 384 rotate around the axis of the turntable 381 as they move along the X direction with the connecting column 365 while in mesh. This realizes the rotational interchange of the connecting pipe 361 and the first nozzle 31 and the second nozzle 32 on it, and drives the turntable 381 to rotate 180 degrees. The line connecting the two gears 384 is temporarily positioned at the midpoint in the Y direction. After the two gears 384 pass this midpoint, they simultaneously move closer together in the Y direction under the action of the spring 369. This design ensures that the minimum distance between the first nozzle 31 and the second nozzle 32 is only the axial distance between the two gears 384, meaning the adjustable distance between the first nozzle 31 and the second nozzle 32 is small. Furthermore, the first nozzle 31 and the second nozzle 32 can be directly and quickly interchanged in the X direction.

[0100] In one embodiment, both the first slider 34 and the second slider 35 have a drive hole that extends through the X direction.

[0101] The drive mechanism includes a motor 40 and a drive rod 41.

[0102] Motor 40 is mounted on XYZ platform 20. One end of drive rod 41 is connected to the output end of motor 40, and the other end of drive rod 41 passes through the drive hole of first slider 34 and the drive hole of second slider 35. Drive rod 41 is threadedly connected to the drive hole of first slider 34; drive rod 41 is also threadedly connected to the drive hole of second slider 35; the thread direction of the threaded connection between drive rod 41 and the drive hole of first slider 34 is opposite to the thread direction of the threaded connection between drive rod 41 and the drive hole of second slider 35.

[0103] In this embodiment, the motor 40 drives the drive rod 41 to rotate, thereby causing the first slider 34 and the second slider 35 in the powder spraying mechanism 30 to move away from or towards each other. The drive rod 41 can be connected to the first slider 34 and the second slider 35 in multiple powder spraying mechanisms 30 simultaneously, thereby driving multiple powder spraying mechanisms 30.

[0104] In one embodiment, a circumferential groove 386 is provided on the outer wall of the turntable 381; two symmetrically arranged arc-shaped support blocks 50 are connected to the upper end of the mounting base 33; the two arc-shaped support blocks 50 are respectively located on both sides of the turntable 381; an arc-shaped guide block 51 is connected to the side of the arc-shaped support block 50 facing the turntable 381; the arc-shaped guide block 51 slides in cooperation with the groove 386.

[0105] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for preparing a high-density yttrium oxide coating, characterized in that, Includes the following steps: S1. At least one substrate is clamped and fixed by the clamping mechanism in the deposition chamber; S2. Vacuum the sedimentation chamber to bring the vacuum level of the sedimentation chamber to the set value; S3. At least one powder spraying mechanism (30) is arranged in the deposition chamber. The number of powder spraying mechanisms (30) corresponds to the number of substrates. The powder spraying mechanism (30) has a first nozzle (31) and a second nozzle (32). The first nozzle (31) and the second nozzle (32) are arranged in the same X direction or the same Y direction with a spacing. The first nozzle (31) and the second nozzle (32) of the powder spraying mechanism (30) are moved to one side of the initial deposition position of the corresponding substrate through the XYZ platform. S4. Spray aerosol formed by small-diameter yttrium oxide powder with the first nozzle (31) and spray aerosol formed by large-diameter yttrium oxide powder with the second nozzle (32). S5. Adjust the distance between the first nozzle (31) and the second nozzle (32) and the corresponding substrate through the XYZ platform to reach the set value; S6. After the aerosol sprayed by the first nozzle (31) and the second nozzle (32) stabilizes, the first nozzle (31) and the second nozzle (32) of the powder spraying mechanism (30) are driven by the XYZ platform to complete the aerosol deposition along the set spraying path, so that a high-density yttrium oxide coating is formed on the surface of the corresponding substrate. During the aerosol deposition process, the first nozzle (31) is always located in front of the second nozzle (32) along the spraying path.

2. The method for preparing a high-density yttrium oxide coating as described in claim 1, characterized in that: In step S4, a measured amount of small-particle-size yttrium oxide powder is placed in the first aerosol generator. A first flow meter is installed on the hose connecting the first aerosol generator to the first pressurized gas source. The first flow meter can control the pressure inside the first aerosol generator. By controlling the pressure inside the first aerosol generator to a set value through the first flow meter, the aerosol formed by the small-particle-size yttrium oxide powder is sprayed through the first nozzle. A measured amount of large-particle-size yttrium oxide powder is placed in the second aerosol generator. A second flow meter is installed on the hose connecting the second aerosol generator to the second pressurized gas source. The second flow meter can control the gas pressure inside the second aerosol generator. By controlling the pressure inside the second aerosol generator to a set value through the second flow meter, the aerosol formed by the large-particle-size yttrium oxide powder is sprayed through the second nozzle.

3. The method for preparing a high-density yttrium oxide coating as described in claim 1, characterized in that: In step S4, the small-particle-size yttrium oxide powder is formed by mixing powder one and powder two in a mass ratio of (1-2):(9-8). Powder one is spherical yttrium oxide powder with a particle size of 0.05-0.1 μm, and powder two is spherical yttrium oxide powder with a particle size of 0.3-0.5 μm. The large-particle-size yttrium oxide powder is spherical yttrium oxide powder with a particle size of 2-5 μm.

4. The method for preparing a high-density yttrium oxide coating as described in claim 1, characterized in that: In step S5, the distance between the first nozzle (31) and the second nozzle (32) and the substrate is set to 5-30 mm.

5. The method for preparing a high-density yttrium oxide coating as described in claim 1, characterized in that: In step S6, the distance between the first nozzle (31) and the second nozzle (32) is 5-10 mm, the scanning speed of the first nozzle (31) and the second nozzle (32) is 10-50 mm / s, and the powder feeding rate of the first nozzle (31) and the second nozzle (32) is 5-10 g / min.

6. A high-density yttrium oxide coating preparation apparatus, employing the method described in any one of claims 1-5, characterized in that, include: Sedimentation chamber; A clamping mechanism is disposed in the deposition chamber and is used to clamp at least one substrate (10); An XYZ platform (20) is disposed within the deposition chamber, located below the clamping mechanism, and capable of moving along the X, Y, and Z directions; and A powder spraying mechanism (30) is provided on the XYZ platform (20). At least one set of powder spraying mechanisms (30) is provided for each substrate (10). The powder spraying mechanism (30) is used to spray yttrium oxide powder aerosol onto the corresponding substrate (10). The powder spraying mechanism (30) includes a first nozzle (31) and a second nozzle (32); the first nozzle (31) is used to spray small-particle-size yttrium oxide powder aerosol onto the substrate (10) to form a yttrium oxide coating; the second nozzle (32) is used to spray large-particle-size yttrium oxide powder aerosol onto the yttrium oxide coating.

7. The apparatus for preparing a high-density yttrium oxide coating as described in claim 6, characterized in that, It also includes the drive mechanism; The powder spraying mechanism (30) further includes: Mounting base (33), the mounting base (33) is disposed on the XYZ platform (20), the mounting base (33) has a mounting hole (331) extending through the X direction, and mounting windows (332) communicating with the mounting hole (331) are respectively provided on both sides of the mounting base (33); A first slider (34) is slidably disposed within the mounting hole (331) along the X direction, and the first slider (34) is connected to the first nozzle (31); and The second slider (35) is slidably disposed in the mounting hole (331) along the X direction. The second slider (35) is connected to the second nozzle (32). The second slider (35) can slide closer to or further away from the first slider (34). The driving mechanism is used to drive the first slider (34) and the second slider (35) to slide; the first nozzle (31) and the second nozzle (32) can be located directly above the mounting hole (331).

8. The apparatus for preparing a high-density yttrium oxide coating as described in claim 7, characterized in that, The powder spraying mechanism (30) also includes two centrally symmetrically arranged connecting components (36); the two connecting components (36) are respectively located on both sides of the mounting base (33); The connection component (36) includes: A connecting tube (361) extends along the Z direction, and the upper end of the connecting tube (361) is connected to the first nozzle (31) or the second nozzle (32). A first connecting arm (362) has one end passing through the corresponding mounting window (332) and connected to the first slider (34) or the second slider (35); A second connecting arm (363) is inclined, and its lower end is connected to the end of the first connecting arm (362) away from the first slider (34) or the second slider (35); and The third connecting arm (364) is arranged along the Y direction in the length direction. One end of the third connecting arm (364) is connected to the upper end of the second connecting arm (363), and the other end of the third connecting arm (364) is connected to the corresponding connecting tube (361). The third connecting arm (364) is telescopic. When the first slider (34) and the second slider (35) approach each other, the second connecting arms (363) in the two connecting components (36) are staggered.

9. The apparatus for preparing a high-density yttrium oxide coating as described in claim 8, characterized in that, The third connecting arm (364) includes: A connecting post (365) is provided, one end of which is connected to the upper end of the second connecting arm (363), and the other end of the connecting post (365) is provided with a connecting square hole (366) extending along the center line. A limiting ring (367) is provided, the outer ring of which is connected to the inner wall of the connecting square hole (366); The limiting block (368) is in the form of a cuboid structure. The limiting block (368) slides with the connecting square hole (366) and can abut against the limiting ring (367). A spring (369) is disposed within the connecting square hole (366), and both ends of the spring (369) abut against the bottom of the connecting square hole (366) and the limiting block (368), respectively; and Telescopic column (370), one end of which passes through the limiting ring (367) and is connected to the limiting block (368), and the other end of which is connected to the corresponding connecting pipe (361); The powder spraying mechanism (30) also includes a transmission assembly (38); when the first nozzle (31) and the second nozzle (32) approach each other, the transmission assembly (38) can move the telescopic column (370) toward the bottom of the connecting square hole (366) by means of the movement of the first slider (34) and the second slider (35).

10. The apparatus for preparing a high-density yttrium oxide coating as described in claim 9, characterized in that, The transmission assembly (38) includes: Turntable (381), the turntable (381) is rotatably disposed above the mounting base (33), the turntable (381) has two symmetrically arranged strip-shaped limiting holes (382) and the two connecting pipes (361) are respectively located in the corresponding strip-shaped limiting holes (382); Sleeve (383), two sleeves (383) are provided, the sleeve (383) is connected to the end of the corresponding telescopic column (370) away from the spring (369), and the sleeve (383) is sleeved on the outside of the corresponding connecting pipe (361); Gears (384), two gears (384) are provided, and the gears (384) are rotatably sleeved on the corresponding sleeves (383); and The transmission column (385) has two rotating columns. The two transmission columns (385) are connected to the lower end of the turntable (381). The two transmission columns (385) can abut against the corresponding connecting column (365). The line connecting the two transmission columns (385) is perpendicular to the line connecting the two strip-shaped limiting holes (382).

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