Ceramic material layer-by-layer ink-jet printing processing method and equipment

Abstract

The invention relates to a layer-by-layer ink-jet printing processing method and device for a ceramic material, and the method comprises the following steps: printing a first layer of ceramic green body, and heating the first layer of ceramic green body to preliminarily shape the first layer of ceramic green body; scanning the upper surface appearance of the heated ceramic green body, and comparing the upper surface appearance with an ideal model; performing correction and microstructure engraving on the upper surface of the ceramic blank according to a comparison result, so that the hydrophilicity and roughness of the ceramic blank are close to those of an ideal model; the steps are repeated, and the ceramic component green body is printed from bottom to top in sequence until the finished ceramic component green body is obtained; removing the water-soluble supporting material on the surface of the ceramic green body; and sintering the ceramic green body to obtain a finished ceramic component. According to the method, the ink-jet printing additive manufacturing technology and the laser processing subtractive manufacturing technology are combined, the accumulated height error in the additive manufacturing process can be corrected, the surface microstructure of the deposition face can be modified, and the manufacturing precision and quality of the ceramic part are improved.

Description

Technical Field

[0001] The present application relates to the technical field of ceramic additive manufacturing, and in particular to a method and equipment for layer-by-layer inkjet printing of ceramic materials. Background Art

[0002] The customized production of high-precision, multi-material complex ceramic components is widely needed in fields such as aerospace, mechanical manufacturing, and biomedicine. Additive manufacturing technology is an effective way to customize the production of complex ceramic components. Among them, ceramic inkjet printing is widely used in the production of ceramic components because of its high molding accuracy and the ability to produce multi-material components.

[0003] Currently, ceramic inkjet printing additive manufacturing has the following drawbacks: 1. The amount and uniformity of inkjet during the printing process cannot be accurately controlled. As the number of layers of inkjet printing additive manufacturing increases, the error in the amount of inkjet will accumulate and increase, increasing the dimensional error in the height direction. In addition, due to the uneven amount of inkjet at each position, the error in the shape of the upper surface will increase after accumulation.

[0004] 2. The surface microstructure obtained by the deposition of ceramic ink in inkjet additive manufacturing is difficult to control, which will have an adverse effect on the strength and density of ceramic components manufactured by inkjet additive manufacturing. Summary of the invention

[0005] Based on this, it is necessary to provide a method and equipment for layer-by-layer inkjet printing of ceramic materials to overcome the defects mentioned in the above background technology.

[0006] A method for processing ceramic materials by inkjet printing layer by layer, comprising the following steps: Step 1: Print the first layer of ceramic green body, and heat the layer of ceramic green body to make it initially shaped; Step 2: Scan the upper surface morphology of the heated ceramic green body and compare it with the ideal model; Step 3: According to the comparison results, the upper surface of the ceramic embryo is modified and microstructured to make its hydrophilicity and roughness close to the ideal model; Step 4: Repeat step 1 to step 3, and print the ceramic component embryos from bottom to top, until a completed ceramic component embryo is obtained; Step 5: removing the water-soluble support material on the surface of the ceramic green body; Step 6: Sinter the ceramic green body to obtain a finished ceramic component.

[0007] As a preferred method for the layer-by-layer inkjet printing processing of ceramic materials in the present invention, the step three specifically includes: Move the ceramic embryo to the laser processing position, and use the comparison results in step 2 to control the galvanometer and external optical path to modify and microstructure the upper surface of the ceramic embryo. The amendments specifically include: Compare the actual height data of the top surface of the current printing layer with the theoretical height data. When the actual height is less than the theoretical value, record the difference between the two and compensate by increasing the number of printing layers. When the actual height is greater than the theoretical value, ablate the top of the green body with preset laser processing parameters to remove the excess protruding part of the top of the green body. The microstructure engraving comprises: If the structural strength of the ceramic component needs to be improved, an infrared picosecond laser is used to scan parallel lines perpendicular to the extension direction of the ridges and grooves on the upper surface of the green embryo, so that a scale-like structure appears on the upper surface of the ceramic green embryo; If you need to reduce the surface roughness of the ceramic component, use an infrared picosecond laser to repeatedly scan the raised areas until the raised areas are completely removed.

[0008] As a preferred embodiment of the layer-by-layer inkjet printing processing method for ceramic materials in the present invention, in the scale-like structure, a single scale-like protrusion is about 50 μm long, about 40 μm wide, and about 20 μm high.

[0009] As a preferred method for the layer-by-layer inkjet printing processing of ceramic materials in the present invention, the step five specifically includes: The ceramic green body was immersed in pure water for 1 hour to remove the water-soluble support material, and then allowed to stand in the air for 3 hours to dry naturally.

[0010] A device for the layer-by-layer inkjet printing processing method of the ceramic material comprises a mounting frame, the lower part of the mounting frame is provided with a two-dimensional motion platform along its axial direction, the upper part of the mounting frame is provided with a printing module, a heating lamp module, a detection module and a laser module in sequence along its axial direction, and also comprises a host computer for controlling the two-dimensional motion platform, the printing module, the heating lamp module, the detection module and the laser module.

[0011] As a preferred embodiment of the device of the present invention, a workbench is provided on the top of the two-dimensional motion platform, which includes a bracket, the bracket is fixedly connected to the two-dimensional motion platform, and a heat insulation layer and a manufacturing substrate are provided on the top of the bracket.

[0012] As a preferred embodiment of the device described in the present invention, the printing module includes a moving Y-axis mounting frame, which is fixedly connected to the mounting frame, and a moving Y-axis hanging basket slidably connected to the moving Y-axis mounting frame is provided below the moving Y-axis hanging basket, and an inkjet printing nozzle is provided on the moving Y-axis hanging basket.

[0013] As a preferred embodiment of the device of the present invention, the heating lamp module comprises a heating lamp mounting frame, which is fixedly connected to the mounting frame, and a heating lamp is arranged on the heating lamp mounting frame.

[0014] As a preferred embodiment of the device described in the present invention, the detection module includes a detection head mounting frame, which is fixedly connected to the mounting frame. A laser triangulation detection head is provided on the detection head mounting frame, which is connected to a host computer via an external signal processing module.

[0015] As a preferred embodiment of the device described in the present invention, the laser module includes a galvanometer mounting frame, which is fixedly connected to the mounting frame. The galvanometer mounting frame is provided with a galvanometer. The light inlet of the galvanometer is connected to the external optical path, and is connected to the host computer through an external processing module.

[0016] Beneficial effects of the present invention: The present invention combines inkjet printing additive manufacturing technology with laser processing subtractive manufacturing technology, which can correct the cumulative height error in the additive manufacturing process and modify the surface microstructure of the deposition surface, thereby improving the manufacturing accuracy and quality of ceramic parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is one of the structural diagrams of the device in the embodiment of the present application; Figure 2 This is the second structural diagram of the device in the embodiment of the present application; Figure 3 One of the structural schematic diagrams of the printing module in the embodiment of the present application; Figure 4 The second structural diagram of the printing module in the embodiment of the present application; Figure 5 This is a schematic diagram of the structure of the printing module in the embodiment of the present application when it is working; Figure 6 This is a schematic diagram of the structure of the heating lamp module in the embodiment of the present application; Figure 7 This is a schematic diagram of the structure of the detection module in the embodiment of the present application when it is working; Figure 8 This is a schematic diagram of the structure of the laser module in the embodiment of the present application when it is working; Description of reference numerals: 1. Mounting frame; 2. 2D motion platform; 21. Motion X-axis; 22. Motion X-axis slider; 23. Motion Z-axis; 24. Motion Z-axis slider 3. Printing module; 31. Motion Y-axis mounting frame; 32. Motion Y-axis hanging basket; 33. Inkjet printing nozzle; 34. Motion Y-axis motor; 35. Guide rod; 36. Lead screw; 4. Heating lamp module; 41. Heating lamp mounting bracket; 42. Heating lamp; 5. Detection module; 51. Detection head mounting frame; 52. Laser triangulation detection head; 6. Laser module; 61. Galvanometer mounting frame; 62. Galvanometer; 7. Workbench; 71. Bracket; 72. Heat insulation layer; 73. Manufacturing substrate; 8. Ceramic component green body. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0020] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0022] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0024] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0025] Example The present embodiment provides a method for layer-by-layer inkjet printing processing of ceramic materials, and also provides a device for implementing the above-mentioned method for layer-by-layer inkjet printing processing of ceramic materials, so as to overcome the defects of existing ceramic inkjet printing additive manufacturing such as large cumulative error, poor strength and density.

[0026] like Figure 1 and Figure 2 As shown, the device includes a mounting frame 1, a two-dimensional motion platform 2 is provided at the lower part of one side of the mounting frame 1, a printing module 3, a heating lamp module 4, a detection module 5 and a laser module 6 are provided in sequence on the upper part of the mounting frame along its axial direction, and a workbench 7 which can slide along its axial direction is provided on the two-dimensional motion platform 2.

[0027] The workbench 7 includes a bracket 71, which is connected to the two-dimensional motion platform 2 through the bracket 71. The top of the bracket 71 is provided with an insulation layer 72 and a manufacturing substrate 73 from bottom to top. Holes are processed in the manufacturing substrate 73 for installing a heating rod and a thermocouple, which can heat and control the temperature of the manufacturing substrate 73.

[0028] The two-dimensional motion platform 2 includes a motion X-axis 21, one end of which is fixedly connected to the mounting frame 1, and the other end of which is provided with a motion X-axis slider 22 slidably connected thereto. The end of the motion X-axis slider 22 away from the motion X-axis 21 is provided with a motion Z-axis 23 fixed thereto, and the motion Z-axis 23 is connected to the bracket 71 together with the motion Z-axis slider 24 slidably connected thereto. Driven by the two-dimensional motion platform 2, the workbench 7 can slide along the X-axis and Z-axis directions of the mounting frame 1.

[0029] like Figure 3 and Figure 4 As shown, the printing module 3 includes a moving Y-axis mounting frame 31 and a moving Y-axis hanging basket 32, which are fixed on the mounting frame 1. The moving Y-axis mounting frame 31 is provided with a moving Y-axis motor 34, and a lead screw 36 is provided at its output end. The lead screw 36 can rotate under the drive of the moving Y-axis motor 34, and guide rods 35 are provided on both sides of the lead screw 36; the moving Y-axis hanging basket 32 ​​is slidably connected with the guide rod 35 through a sliding bearing, and is also screwed and connected with the lead screw 36. The moving Y-axis hanging basket 32 ​​can move horizontally along the guide rod 35 under the rotation of the lead screw 36. The moving Y-axis hanging basket 32 ​​is provided with an inkjet printing nozzle 33, and the ink inlet and ink outlet of the inkjet printing nozzle 33 are connected to the external ink path, one of the inkjet printing nozzles 33 sprays ceramic ink, and the other inkjet printing nozzle 33 sprays water-soluble support material ink, and the control line of the inkjet printing nozzle 33 is connected to the host computer through an external control board.

[0030] The heating lamp module 4 includes a heating lamp mounting frame 41 , which is fixed to the mounting frame 1 . A heating lamp 42 is disposed on the heating lamp mounting frame 41 .

[0031] The detection module 5 comprises a detection head mounting frame 51 , which is fixedly connected to the mounting frame 1 . A laser triangulation detection head 52 is arranged on the detection head mounting frame 51 , which is connected to a host computer via an external signal processing module.

[0032] The laser module 6 includes a galvanometer mounting frame 61, which is fixed to the mounting frame 1. A galvanometer 62 is provided on the galvanometer mounting frame 61. The light inlet hole 62 of the galvanometer is connected to the external optical path, and is connected to the host computer through an external processing module.

[0033] The ceramic material layer-by-layer inkjet printing processing method comprises the following steps: S1: The manufacturing substrate 73 is heated to 170° C., the external ink circuit supplies ink to the inkjet printing nozzle 33, and the laser triangulation detection head 52 and the galvanometer 62 are powered on for self-test.

[0034] S2: Move the Y-axis hanging basket 32 ​​through the two-dimensional motion platform 2 and the printing module 3 to move the workbench 7 and the inkjet printing nozzle 33 to the position as shown in FIG. Figure 5 At the printing starting position shown, the moving X-axis 21 drives the workbench 7 to move horizontally at a uniform speed, and the inkjet printing nozzle 33 selectively sprays ink when the workbench 7 moves to an appropriate position until the workbench 7 moves to the printing ending position.

[0035] S3: The two-dimensional motion platform 2 moves the workbench 7 to Figure 6 At the heating starting position shown, the heating lamp 42 is turned on, and the moving X-axis 21 drives the workbench 7 to move horizontally at a uniform speed until the workbench 7 moves to the heating ending position, and the heating lamp 42 is turned off.

[0036] S4: The two-dimensional motion platform 2 moves the workbench 7 to Figure 7 At the detection starting position shown, the laser triangulation detection head 52 is started, and the moving X-axis 21 drives the workbench 7 to move at a uniform speed. At the same time, the laser triangulation detection head 52 scans the upper surface morphology of the ceramic component green body 8 and models it in the host computer, until the workbench 7 moves to the detection end position, and the laser triangulation detection head 52 stops scanning.

[0037] S5: The two-dimensional motion platform 2 moves the workbench 7 to Figure 8 At the laser processing position shown, the host computer controls the galvanometer 62 and the external optical path to correct and microstructure the upper surface of the ceramic component green body 8 according to the comparison result between the upper surface morphology of the ceramic component green body 8 measured in S4 and the ideal model. In the actual processing process, the common results of the upper surface morphology test of the ceramic component green body 8 in S4 are: periodic ridges and gullies extending parallel to the direction of the motion axis X appear on the upper surface of the green body, with a peak-to-valley height difference of 20μm and a peak-to-peak distance of 50μm. At this time, the laser processing parameters are planned according to the process requirements.

[0038] The amendments specifically include: The actual height data of the top surface of the current printing layer is compared with the theoretical height data. When the actual height is less than the theoretical value, the difference between the two is recorded and compensated by increasing the number of printing layers. When the actual height is greater than the theoretical value, the preset laser processing parameters are used to ablate the top of the green body to remove the excess protrusion on the top of the green body.

[0039] The structural carving comprises: If you need to improve the structural strength of the printed part, use an infrared picosecond laser (wavelength 1035nm, frequency 1800kHz) with 40% power to scan parallel lines perpendicular to the extension direction of the ridges and grooves (i.e. parallel to the Y direction of the motion axis) at a speed of 1200mm / s and a spacing of 40μm. Repeat the scan along the same path for a total of 2 times. A scaly structure will appear on the upper surface of the ceramic green body. A single scaly protrusion is 50μm long, 40μm wide, and 20μm high, which can increase the hydrophilicity of the upper surface of the green body and facilitate the deposition of ceramic particles in the subsequent ink to improve the structural strength.

[0040] If the surface roughness of the printed part needs to be reduced, an infrared picosecond laser (wavelength 1035nm, frequency 1800kHz) is used to scan the raised position at a speed of 1200mm / s at 40% power. 10μm of green material is removed in a single scan, and the scan is repeated until the raised position is completely removed.

[0041] To reduce the surface roughness of the printed part, S6: Repeat S2, S3, S4 and S5, inkjet print the ceramic component green body 8 layer by layer from bottom to top and perform correction and microstructure carving until a complete ceramic component green body 8 is obtained.

[0042] S7: Soak the ceramic component green body 8 obtained in S6 in pure water (conductivity < 20 μS / cm) for 1 hour to remove the water-soluble supporting material, and then leave it to stand in the air for 3 hours to dry naturally.

[0043] S8: Place the ceramic component green body 8 after the support is removed obtained in S7 into a programmable high-temperature sintering furnace for sintering, heating from 25°C to 250°C at a heating rate of 4°C / min, and keeping at 250°C for 2 hours; heat to 350°C at the same heating rate and keep for 3 hours; heat to 450°C at the same heating rate and keep for 3 hours; then heat to 800°C at a heating rate of 3°C / min for pre-sintering, and keep for 3.6 hours; finally heat to 1450°C at a rate of 3°C / min for sintering, keep warm for 9 hours, and then cool to room temperature at a rate of 3°C / min to obtain a finished ceramic component.

[0044] In this embodiment, for a ceramic component green body 8 with a volume less than 0.5 cm³ or a maximum cross-sectional thickness less than 2 mm, the holding time at each stage in the sintering process can be shortened by 30%, thereby improving operating efficiency while ensuring quality; for larger or thicker-walled parts, the heating rate should be appropriately reduced and the holding time should be extended to ensure component quality.

[0045] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0046] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for processing ceramic materials by inkjet printing layer by layer, characterized in that: The steps include: Step 1: Print the first layer of ceramic green body, and heat the layer of ceramic green body to make it initially shaped; Step 2: Scan the upper surface morphology of the heated ceramic green body and compare it with the ideal model; Step 3: According to the comparison results, the upper surface of the ceramic embryo is modified and microstructured to make its hydrophilicity and roughness close to the ideal model; Step 4: Repeat step 1 to step 3, and print the ceramic component embryos from bottom to top, until a completed ceramic component embryo is obtained; Step 5: removing the water-soluble support material on the surface of the ceramic green body; Step 6: Sinter the ceramic green body to obtain a finished ceramic component.

2. The method for layer-by-layer inkjet printing of ceramic materials according to claim 1, characterized in that: The step three specifically includes: The ceramic embryo is moved to a laser processing position, and the comparison result in step 2 is used to control the galvanometer and the external optical path to modify and microstructure the upper surface of the ceramic embryo; The amendments specifically include: Compare the actual height data of the top surface of the current printing layer with the theoretical height data. When the actual height is less than the theoretical value, record the difference between the two and compensate by increasing the number of printing layers. When the actual height is greater than the theoretical value, ablate the top of the green body with preset laser processing parameters to remove the excess protruding part of the top of the green body. The microstructure engraving comprises: If the structural strength of the ceramic component needs to be improved, an infrared picosecond laser is used to scan parallel lines perpendicular to the extension direction of the ridges and grooves on the upper surface of the green embryo, so that a scale-like structure appears on the upper surface of the ceramic green embryo; If you need to reduce the surface roughness of the ceramic component, use an infrared picosecond laser to repeatedly scan the raised areas until the raised areas are completely removed.

3. The method for layer-by-layer inkjet printing of ceramic materials according to claim 2, characterized in that: In the squamous structure, a single squamous protrusion is about 50 μm long, about 40 μm wide, and about 20 μm high.

4. The method for layer-by-layer inkjet printing of ceramic materials according to claim 2, characterized in that: The step five specifically includes: The ceramic green body was immersed in pure water for 1 hour to remove the water-soluble support material, and then allowed to stand in the air for 3 hours to dry naturally.

5. A device for implementing the layer-by-layer inkjet printing method of ceramic materials according to claim 1, characterized in that: It includes a mounting frame, a two-dimensional motion platform is provided at the lower part of the mounting frame along its axial direction, a printing module, a heating lamp module, a detection module and a laser module are provided at the upper part of the mounting frame in sequence along its axial direction, and also includes a host computer for controlling the two-dimensional motion platform, the printing module, the heating lamp module, the detection module and the laser module.

6. The device according to claim 5, characterized in that: A workbench is provided on the top of the two-dimensional motion platform, which includes a bracket, the bracket is fixedly connected to the two-dimensional motion platform, and a heat insulation layer and a manufacturing substrate are provided on the top of the bracket.

7. The device according to claim 5, characterized in that: The printing module comprises a moving Y-axis mounting frame which is fixedly connected to the mounting frame. A moving Y-axis hanging basket which is slidably connected to the moving Y-axis mounting frame is arranged below the moving Y-axis hanging basket, and an inkjet printing nozzle is arranged on the moving Y-axis hanging basket.

8. The device according to claim 5, characterized in that: The heating lamp module comprises a heating lamp mounting frame which is fixedly connected to the mounting frame, and a heating lamp is arranged on the heating lamp mounting frame.

9. The device according to claim 5, characterized in that: The detection module comprises a detection head mounting frame, which is fixedly connected to the mounting frame. A laser triangulation detection head is arranged on the detection head mounting frame, which is connected to a host computer via an external signal processing module.

10. The device according to claim 5, characterized in that: The laser module comprises a galvanometer mounting frame, which is fixedly connected to the mounting frame. The galvanometer mounting frame is provided with a galvanometer. The light inlet of the galvanometer is communicated with the external optical path, and the galvanometer is connected to the host computer through the external processing module.

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