Ultrafast laser-induced micro-nano particle jet 3D printing method for hierarchical porous ceramic

Abstract

The invention discloses an ultrafast laser-induced micro-nano particle injection 3D printing method for hierarchical porous ceramic. The method comprises the steps that S1, three-dimensional model design and model slicing treatment of a multi-stage dot matrix ceramic structure are conducted; s2, performing ultrafast laser-induced fine spraying to form a single-layer structure with a precise deposition pattern; s3, layer-by-layer deposition is carried out, a multi-stage dot matrix ceramic deposition green body is formed, and external field regulation and control are carried out in the deposition process; s4, Joule flash sintering of the multi-stage dot matrix ceramic is conducted, and auxiliary heat control and auxiliary magnetic field external force control are conducted in the sintering process; and S5, preparing and forming the precise multi-stage dot matrix ceramic. Precise high-performance ceramic forming preparation of the electromagnetic / thermal functional ceramic structure is achieved, and the method has important significance on a head hot end assembly of a high-speed aircraft.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of precision structure 3D printing, and particularly relates to a method for superfast laser-induced micro-nanoparticle material jetting 3D printing of multi-level porous ceramics. BACKGROUND

[0002] Flash Joule Heating is a kind of environment-friendly, energy-saving, rapid and high-performance ceramic structure preparation method, which uses high-voltage electric field to generate current Joule heat on ceramic blanks, realizes rapid sintering of ceramic blanks, and can reach thousands of degrees Celsius in a very short time. During the flash sintering process, the material blank generates Joule heat under the action of direct current / alternating current electric field (typically at 20-60 V / cm), so that the local temperature instantaneously rises to the sintering threshold (zirconia can be densified at 850℃, which is about 400℃ lower than traditional sintering). When the current density reaches the critical value (such as Al2O3 requires current density ≥ 50 mA / mm 2 ), the material resistivity drops sharply, forming the Joule effect of flash sintering. In addition, the Joule heat flash sintering process also has a non-thermal effect driven by an electric field, that is, the applied high-strength electric field can reduce the ion migration activation energy and accelerate diffusion. For example, the oxygen vacancy migration rate of Y2O3 stabilized ZrO2 is increased by 10 3 times in flash sintering, resulting in rapid recombination of grain boundaries, thereby obtaining the sintering mechanism effect of pure electric field action. The problem of Joule heat flash sintering process is that it is difficult for non-oxide particles, and there is a lack of necessary methods and measures for the synergistic coupling of electric field, magnetic field and heat flow field for flash sintering of material structure.

[0003] The head of a high-speed aircraft is a kind of thermal end component with multi-material, precise function and complex high-temperature distribution, which is also the core area of intelligent thermal management of the head. Heat-resistant and heat-insulating ceramic materials, copper metal, diamond, graphene and other high-thermal-conductivity materials are often used for heat distribution regulation and control. Thermal conduction and thermal insulation are often integrated according to actual needs, resulting in the design of complex structures such as multi-level porous ceramics and micro-nano super surfaces.

[0004] 3D printing can be combined with joule flash sintering to achieve better material structure and function integration, especially for fine structure parts, the micro-nano particle deposition of ultrafast laser induced jetting can realize the realization of multi-level and multi-scale structure from micro-macro. The problem faced by the preparation of multi-level and multi-scale structure is that the low-dimensional raw material itself has weak structure and high stress, so that the microstructure of the blank itself has unstable characteristics. When using ultrafast laser to induce the deposition of micro-nano particles to the substrate, it is expected to overcome the weak structure and high stress constraints in the process of ceramic blank preparation. The precision and strength of the micro-nano structure of the fine ceramic structure blank are inherited and maintained in the subsequent sintering, which is the second difficulty faced by the existing technology, and the combination of joule flash sintering method can better break through the uncontrollable problem of sintering process.

[0005] The statements herein merely provide background technology related to the present application, and do not necessarily constitute prior art. SUMMARY

[0006] The purpose of the present application is to provide a multi-level porous ceramic ultrafast laser induced micro-nano particle material jetting 3D printing method, which overcomes the defects of the prior art and is applied to the design and implementation of complex structure integration of multi-material, precise function, high temperature distribution complex thermal end component fine structure multi-level porous ceramic and micro-nano super surface of high-speed aircraft head, and can also be applied to the precision manufacturing of electric functional structure and super surface optical structure.

[0007] In order to achieve the above purpose, the present application provides a multi-level porous ceramic ultrafast laser induced micro-nano particle material jetting 3D printing method, comprising: S1, three-dimensional model design and model slicing processing of multi-level dot array ceramic structure; S2, ultrafast laser induced fine jetting, forming a single layer structure with precise deposition pattern; S3, layer-by-layer deposition, forming a multi-level dot array ceramic deposition blank, accompanied by external field regulation during the deposition process; S4, joule flash sintering of multi-level dot array ceramic, auxiliary heat control and auxiliary magnetic field external force control during sintering process; S5, preparation and forming of precise multi-level dot array ceramic.

[0008] Optionally, the step S1 is specifically: designing a three-dimensional digital model of multi-level dot array ceramic structure, slicing and layering the model to obtain a model of multi-level dot array ceramic structure composed of a plurality of single layer structures, and planning and optimizing the scanning path of each layer according to the process mechanism of ultrafast laser induced fine jetting, and defining the precise deposition pattern of each layer.

[0009] Optionally, in step S2, ultrafast laser-induced fine jet 3D printing device is used for ultrafast laser-induced fine jet, and the 3D printing device is provided with an ultrafast laser scanning galvanometer, an optical induction medium plate and a deposition substrate from top to bottom; The upper surface of the optical induction medium plate is an ultrafast laser incidence surface, and an anti-reflection film is arranged on the ultrafast laser incidence surface; the lower surface of the optical induction medium plate is an ultrafast laser emission surface, and an anti-reflection film and an adhesion layer are arranged on the ultrafast laser emission surface, and micro-nano ceramic particles are uniformly adhered on the adhesion layer; The ultrafast laser is incident on the upper surface of the optical induction medium plate through the ultrafast laser scanning galvanometer, and propagates inside the optical induction medium plate, and the energy is concentrated on the lower surface, and acts on the micro-nano ceramic particles adhered to the lower surface, and the micro-nano ceramic particles are jetted out from the lower surface of the optical induction medium plate under the driving of the ultrafast laser and are deposited on the deposition substrate.

[0010] Optionally, the 3D printing device further comprises an ultrafast laser generator for generating ultrafast laser, an adjustment platform of the optical induction medium plate for adjusting the position of the optical induction medium plate, and a deposition substrate control and positioning platform for moving and controlling the deposition substrate to realize the control of the deposition position and angle.

[0011] Optionally, the optical induction medium plate is one of an alumina single crystal plate, a zirconia single crystal plate and a quartz single crystal plate. The micro-nano ceramic particles are ceramic precursors composed of elemental metals of the target ceramic and polymer monomers of the target ceramic, or are ceramic particles of a finer degree of the target ceramic. The ultrafast laser is a picosecond ultrafast pulsed laser beam or a femtosecond ultrafast pulsed laser beam.

[0012] Optionally, the step S2 comprises the following steps: S2.1, performing printing preparation work, including selecting matched fine jet environment conditions according to the properties of the transported micro-nano ceramic particles; S2.2, performing ultrafast laser-induced fine jet to obtain a single-layer structure with a precise deposition pattern.

[0013] Optionally, the step S3 is specifically: The step S2.2 of ultrafast laser-induced fine jet is repeatedly performed until the layer-by-layer deposition is completed, and a compact structure of the multi-level dot array ceramic deposition blank is obtained through external field regulation; The external field regulation is a follow-up treatment process, including static pressure treatment and ultrasonic vibration.

[0014] Optionally, the step S4 is specifically: A joule flash burning device is used to perform joule flash burning on the multi-level dot array ceramic deposition blank. The joule flash firing device comprises a sealed cavity, a sealed cavity control system for controlling the sealed cavity, an external field heat and force control system, a gas charging and discharging system, and a flash firing control system; and the multi-stage dot array ceramic deposition blank is subjected to joule flash firing inside the sealed cavity; The external field heat and force control system comprises a three-phase power driver; the gas charging and discharging system comprises a gas charging channel and a gas discharging channel; and the flash firing control system comprises a flash firing power controller; The sealed cavity is a hexahedron, comprising two opposite surfaces as conductive contact surfaces, on which conductive interfaces connected to the flash firing power controller are arranged; the other four surfaces of the sealed cavity are insulating surfaces, one pair of the four insulating surfaces is connected to the gas charging channel and the gas discharging channel respectively; and the other pair of the four insulating surfaces is connected to the three-phase power driver, for applying an external heat field and an external magnetic field, and for assisting heat control and external magnetic field force control during the firing process of the multi-stage dot array ceramic deposition blank.

[0015] Optionally, discharge needle structures are further arranged on the two conductive contact surfaces of the sealed cavity, for penetrating into the multi-stage dot array ceramic and applying a high-voltage electric field to generate a current joule heat effect; The gas flow added to the inside of the sealed cavity through the gas charging channel is an oxidizing component of the target ceramic; The joule flash firing comprises a flash firing incubation stage, a flash firing occurrence stage, and a flash firing holding stage.

[0016] Optionally, the step S5 comprises: after the flash firing holding stage of the joule flash firing, performing an auxiliary external field treatment to remove stress and anneal, so as to strengthen and toughen.

[0017] The application provides a kind of multi-stage hole ceramic's ultrafast laser induced micro-nano particle material jet 3D printing method, mainly using ultrafast laser induced material transport and precision deposition to substrate surface, form fine multi-stage dot array ceramic structure.The application focuses on solving the 3D printing precision of fine structure additive manufacturing without dispersing agent, reducing sintering shrinkage and realizing nanoscale densification problem, proposes a flash firing system with atmosphere environment for fine structure 3D printing;In particular, a transparent medium plate is used, which is "target material" granulated and adhered to the exit surface of the transparent medium, so as to fully utilize the effect of photo-induced plasma pulse of ultrafast laser action, and to high specific impulse jet to the deposition substrate, under the action of ultrafast laser precise control, realize the densification and high-precision printing of solid materials.The application uses the plasma fluid driven micro-nano particle material directional emission and deposition to the substrate by ultrafast laser action material, forms high-precision micro-assembly of multi-stage dot array ceramic structure, and combines joule flash firing process to make ceramic blank extremely temperature rise to extremely high temperature, so as to realize the precise high-performance ceramic preparation of electromagnetic / thermal functional ceramic structure, which has important significance for high-speed aircraft head end components. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 This is a flowchart of the ultrafast laser-induced micro / nano particle jet 3D printing method of the present invention; Figure 2 This is a schematic diagram of the ultrafast laser-induced micro / nano particle jetting 3D printing device of the present invention; Figure 3 This is a schematic diagram of a single-layer structure with a precise deposition pattern deposited according to the present invention; Figure 4 This is a schematic diagram of the multi-level lattice ceramic deposited in this invention; Figure 5 This is a schematic diagram of the Joule flash firing device for multi-level lattice ceramics according to the present invention; Figure 6 This is a schematic diagram of the precision multi-level lattice ceramic prepared according to the present invention. Detailed Implementation

[0019] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the ultrafast laser-induced micro / nano particle jetting 3D printing method for multi-level porous ceramics proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clarify the illustration of the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0020] This invention provides an ultrafast laser-induced jetting 3D printing method for multi-level porous ceramics, such as... Figure 1 As shown, the method includes the following steps: S1. Design and slice the 3D model of the multi-level lattice ceramic structure to generate multi-level lattice ceramic layer data for controlling 3D printing.

[0021] Specifically, a three-dimensional digital model of a multi-level lattice ceramic structure is designed. The model is sliced ​​and layered to obtain a model of a multi-level lattice ceramic structure composed of multiple single-layer structures. In combination with the process mechanism of ultrafast laser-induced fine jetting, the scanning path of each layer is planned and optimized, and the precision deposition pattern of each layer is defined. The pattern setting adapted to the ultrafast laser-induced fine jetting process is completed, laying the foundation for layer-by-layer deposition.

[0022] In addition, the interface bonding quality between layers is fully considered, and the layer lamination process parameters are optimized, including but not limited to layer thickness, layer internal path block division strategy, splicing lap quantity, layer internal path jump strategy, to ensure the integrity of the three-dimensional structure.

[0023] S2, ultrafast laser induced fine spraying, forming a single layer structure with precise deposition pattern.

[0024] The ultrafast laser induced fine spraying uses a transparent optical induction medium as the interface; a galvanometer is used as the scanning device of the incident ultrafast laser beam to perform dot scanning on the incident surface of the optical induction medium; a substrate is used as the shaped base body. As shown in Figure 2 The 3D printing device is provided from top to bottom with an ultrafast laser scanning galvanometer 11, an optical induction medium plate 12, and a deposition substrate 13, which correspond to the scanning device, the optical induction medium, and the substrate respectively.

[0025] The ultrafast laser is incident on the upper surface of the optical induction medium plate 12 via the ultrafast laser scanning galvanometer 11, so the upper surface of the optical induction medium plate 12 is the ultrafast laser incident surface, and an antireflection film is arranged on the ultrafast laser incident surface; the lower surface of the optical induction medium plate 12 is the ultrafast laser exit surface, and an antireflection film and an adhesion layer are arranged on the ultrafast laser exit surface, and a printing material is uniformly adhered to the adhesion layer, and in this embodiment, the printing material is micro-nano ceramic particles. The ultrafast laser propagates inside the optical induction medium plate 12, and the energy is concentrated on the lower surface, thereby acting on the micro-nano ceramic particles adhered to the surface, and the micro-nano ceramic particles are ejected from the lower surface of the optical induction medium plate 12 under the drive of the ultrafast laser, forming a directional particle beam and depositing onto the deposition substrate 13. The two antireflection films are used to reduce the reflection of the ultrafast laser and increase the transmittance of the ultrafast laser, so as to ensure that the energy of the ultrafast laser enters the optical induction medium and finally acts on the printing material to the maximum extent.

[0026] The optical induction medium plate 12 includes but is not limited to an alumina single crystal plate, a zirconia single crystal plate, and a quartz single crystal plate.

[0027] The adhesion layer adheres the printing material, which includes but is not limited to a ceramic precursor composed of constituent metal elements of the target ceramic and polymer monomers of the target ceramic, and can also contain ceramic particles of a finer degree of the target ceramic. The printing material is ejected from the optical induction medium plate 12 to the deposition substrate 13 by the ultrafast laser induction, to form a ceramic body layer by layer, and is sintered into a functional structure ceramic body through a subsequent sintering process.

[0028] The ultrafast laser includes a picosecond, femtosecond ultrafast pulsed laser beam, for example but not limited to 1064 nm, with a pulse energy of 20 μJ, which can ionize the printing material and form a plasma plume recoil flow, so that the printing material particles attached to the adhesion layer are subjected to a recoil force and transported to the direction and position determined by the control program.

[0029] The step S2 specifically includes the following steps: S2.1, before performing the jet deposition, printing preparation work is performed, including but not limited to: loading the adhesion layer with micro-nano ceramic particles to the exit surface of the ultrafast laser; adjusting the positions of the ultrafast laser scanning galvanometer 11, the optical induction medium plate 12, and the deposition substrate 13; selecting matching laser-induced fine jet environment conditions according to the properties of the transported micro-nano ceramic particles, including but not limited to reaction atmosphere or vacuum, ambient atmosphere pressure, temperature, or applied auxiliary electric field, magnetic field, etc.

[0030] The transported micro-nano ceramic particles include precursors of the target ceramic, such as but not limited to constituent metal elements, polymer monomers, etc. of the target ceramic, and can also include finer degree ceramic particles of the target ceramic itself.

[0031] S2.2, performing ultrafast laser-induced fine jetting to obtain a single-layer structure with a precise deposition pattern, as shown in Figure 3 .

[0032] During the printing process, if the printing material on the adhesion layer is completely induced to jet, the adhesion layer and the printing material are automatically replaced.

[0033] S3, layer-by-layer deposition to form a multi-level dot array ceramic deposition blank, as shown in Figure 4 .

[0034] The multi-level dot array ceramic deposition blank is a cyclic iteration of the single-layer precise deposition pattern formed by the ultrafast laser-induced fine jetting of step S2.2. The ultrafast laser-induced fine jetting of step S2.2 is repeatedly performed until the layer-by-layer deposition is completed, and the compact structure of the multi-level dot array ceramic deposition blank is obtained through certain external field regulation. This structure has the characteristics of maintaining the strength and precision of the structure body before and during the next step.

[0035] The external field regulation is accompanied by processing processes such as gas isostatic pressing treatment and ultrasonic vibration compaction to obtain the required body strength and precision.

[0036] S4, Joule flash sintering of the multi-level dot array ceramic.

[0037] Specifically, as shown in Figure 5As shown, the multi-stage dot matrix ceramic deposition blank is subjected to joule flash in the sealed cavity 21. The sealed cavity 21 is a hexahedron, including two opposite conductive contact surfaces, on which conductive interfaces 24 (commonly graphite) are arranged and connected to a flash power controller 23; the other four surfaces of the sealed cavity 21 are insulating surfaces, one pair of the four insulating surfaces is connected to an inflation channel 25 arranged to inflate the interior of the sealed cavity 21 and an exhaust channel 26 for exhaust; the other pair of the four insulating surfaces is connected to a three-phase power driver 22 for applying an external heating field and an external magnetic field, for auxiliary thermal control and auxiliary magnetic field external force control in the multi-stage dot matrix ceramic deposition blank firing process.

[0038] The two conductive contact surfaces also have a discharge needle structure for penetrating into the interior of the multi-stage dot matrix ceramic structure and applying an electric field with an intensity of not less than 40 V / cm. The joule heat effect of high electric field discharge at both ends of the sintered product is used to obtain the effects of internal thermal runaway, sudden drop in specific resistance, and strong flash. The joule flash is mainly divided into a flash incubation stage, a flash occurrence stage, and a flash holding stage.

[0039] The gas flow added to the interior of the sealed cavity 21 is an oxidizing component of the target ceramic, for example, if the target ceramic is an oxide ceramic, ozone containing oxygen is introduced; if the target ceramic is a nitride ceramic, ammonia is introduced; without limitation, and so on. Both inflation and exhaust are controlled by a sealed one-way valve 27, when a strong oxidizing agent atmosphere is introduced, the conductive electrode should use an oxidation-resistant electrode material as the conductive interface 24, which is in contact with the sintered material and directly high-strength discharges to quickly sinter, the oxidation-resistant electrode material includes but is not limited to a diamond / graphite and ceramic composite electrode.

[0040] S5, preparation and shaping of the precise multi-stage dot matrix ceramic.

[0041] The preparation and shaping of the precise multi-stage dot matrix ceramic includes corresponding auxiliary external field treatment after the holding stage of the flash, stress relief and annealing, and the purpose of strength preservation and toughness increase. The prepared precise multi-stage dot matrix ceramic is as shown in Figure 6 .

[0042] The application also provides a multi-stage hole ceramic ultrafast laser-induced micro-nano particle material jet 3D printing device, as shown in Figure 2As shown, the 3D printing device comprises: an ultrafast laser generator (not shown in the figure) for ultrafast laser generation; an ultrafast laser scanning galvanometer 11 for guiding the incident direction of the ultrafast laser beam; an optical induction medium plate 12 and its adjusting platform, the bottom of the optical induction medium plate 12 is provided with an adhesive layer for providing feed, and the printing material (such as micro-nano ceramic particles in the embodiment) is temporarily and stably adhered on the adhesive layer, and the adjusting platform is used for adjusting the position of the optical induction medium plate 12 and feed control, and automatically replacing the printing material when the printing material on the adhesive layer is all induced to be ejected; a deposition substrate 13 as a shaped base; a deposition substrate control and positioning platform (not shown in the figure) for moving and controlling the deposition substrate 13, realizing control of the deposition position and angle.

[0043] The process of realizing the feed control and printing material replacement by the adjusting platform is as follows: the printing material also contains an adhesive medium and is placed in a specific container (not shown in the figure), and the adhesive medium includes but is not limited to an aqueous organic slurry, which is used for wetting the printing material and has the characteristics of drop-by-drop transfer and adhesion; when the adjusting platform performs feed control, the optical induction medium plate 12 is delivered above the container and wet and adheres a new layer of the printing material surface, and is transferred to the position of the ultrafast laser-induced printing shaping to complete printing, so as to realize automatic material replacement printing in cycles.

[0044] The application also provides a multi-stage dot matrix ceramic joule flash burning device. Figure 5 As shown, the joule flash burning device is composed of a sealed cavity 21, a sealed cavity control system for controlling the sealed cavity 21, an external field heat and external field force control system, a charging and discharging system, a flash burning control system and the like.

[0045] The external field heat and external field force control system comprises a three-phase power driver 22. The charging and discharging system comprises a charging channel 25 and a discharging channel 26, and a one-way valve 27 is arranged on each of the charging channel 25 and the discharging channel 26. The flash burning control system comprises a flash burning power controller 23. The sealed cavity 21 is a hexahedron, and one pair of opposite surfaces thereof are conductive contact surfaces, on which a conductive interface 24 is arranged and connected with the flash burning power controller 23; the other four surfaces of the sealed cavity 21 are insulating surfaces, and one pair of the four insulating surfaces are connected with the charging channel 25 and the discharging channel 26 respectively; the other pair of the four insulating surfaces are connected with the three-phase power driver 22, and are used for applying an external heat field and an external magnetic field.

[0046] In summary, the present application provides a kind of multi-level hole ceramic ultrafast laser-induced micro-nanoparticle material jet 3D printing method, mainly using ultrafast laser-induced driving material transport and precision deposition to substrate surface, form fine multi-level dot array ceramic structure, then integrated on improved joule heat system, so as to the multi-level hole ceramic ultrafast laser-induced micro-nanoparticle material jet 3D printing play good improvement effect.The present application focuses on solving the 3D printing precision of fine structure additive manufacturing without dispersing agent, reducing sintering shrinkage and realizing nanoscale densification problem, a fine structure 3D printing facing atmosphere environment flash system is proposed;Especially using transparent medium plate, its "target material" is granulated and adhered to the exit surface of transparent medium, so as to make full use of the effect of photo-induced plasma pulse of ultrafast laser action, and high specific impulse jet to deposition substrate, under the action of ultrafast laser precise control, realize the densification and high-precision printing of solid material.The present application uses the plasma fluid driven micro-nanoparticle material of ultrafast laser acting material to direct emission and deposition to substrate, form high-precision micro-fine assembly of multi-level dot array ceramic structure, and combine with joule flash process to make ceramic blank in extreme time to extremely high temperature, so as to realize the precise high-performance ceramic preparation of electromagnetic / thermal functional ceramic structure, which has important significance for high-speed aircraft head end component.

[0047] It should be noted that in this paper, the term "include", "contain" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or equipment.In the absence of more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or equipment including the element.

[0048] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "height", "thickness", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application.In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0049] In the description of the application, unless otherwise clearly specified and limited, the terms "mounting", "connection", "linking", "fixing" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through intermediate medium, can be internal communication of two elements or interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0050] In the present application, unless otherwise clearly specified and limited, "on" or "under" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "above" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. "Under", "below" and "below" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0051] Although the content of the present application has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present application. After reading the above content, various modifications and alternatives of the present application will be obvious to those skilled in the art. Therefore, the protection scope of the present application should be defined by the appended claims.

Claims

1. A method for ultrafast laser-induced micro- and nanoscale particle jet 3D printing of a hierarchically porous ceramic, characterized in that The application relates to a method for preparing a precision multistage dot matrix ceramic, and belongs to the technical field of ceramic 3D printing. The method comprises the following steps: S1, three-dimensional model design and model slicing processing of a multistage dot matrix ceramic structure; S2, ultrafast laser-induced fine spraying to form a single-layer structure with a precision deposition pattern; S3, layer-by-layer deposition to form a multistage dot matrix ceramic deposition blank, and external field regulation during the deposition process; S4, joule flash burning of the multistage dot matrix ceramic, and auxiliary thermal control and auxiliary magnetic field external force control during the burning process; 2. The ultrafast laser-induced micro-nano particulate feed jet 3D printing method of multi-level porous ceramic according to claim 1, characterized in that, S5, preparation and forming of the precision multistage dot matrix ceramic.

3. The ultrafast laser-induced micro-nano particulate feed jet 3D printing method of multi-level porous ceramic according to claim 1, characterized in that, The step S1 is specifically as follows: a three-dimensional digital model of a multistage dot matrix ceramic structure is designed, the model is subjected to slicing and layering processing, a model of the multistage dot matrix ceramic structure composed of a plurality of single-layer structures is obtained, and the scanning path of each layer is planned and optimized in combination with the process mechanism of ultrafast laser-induced fine spraying, and a precision deposition pattern of each layer is defined. In the step S2, ultrafast laser-induced fine spraying is performed by using an ultrafast laser-induced micro-nano particle spraying 3D printing device, the 3D printing device is provided with an ultrafast laser scanning galvanometer (11), an optical induction medium plate (12) and a deposition substrate (13) from top to bottom; The upper surface of the optical induction medium plate (12) is an ultrafast laser incidence surface, and an antireflection film is arranged on the ultrafast laser incidence surface; the lower surface of the optical induction medium plate (12) is an ultrafast laser emission surface, and an antireflection film and an adhesion layer are arranged on the ultrafast laser emission surface, and micro-nano ceramic particles are uniformly adhered to the adhesion layer; 4. The ultrafast laser-induced micro-nano particulate feedstock jetting 3D printing method of multi-level porous ceramic according to claim 3, characterized in that, The ultrafast laser is incident on the upper surface of the optical induction medium plate (12) through the ultrafast laser scanning galvanometer (11), propagates in the optical induction medium plate (12), and the energy is concentrated on the lower surface, acts on the micro-nano ceramic particles adhered to the lower surface, and the micro-nano ceramic particles are sprayed out of the lower surface of the optical induction medium plate (12) under the driving of the ultrafast laser and are deposited on the deposition substrate (13).

5. The ultrafast laser-induced micro-nano particulate feedstock jetting 3D printing method of multi-level porous ceramic according to claim 3, characterized in that, The 3D printing device further comprises an ultrafast laser generator for generating the ultrafast laser, an adjusting platform of the optical induction medium plate (12) for adjusting the position of the optical induction medium plate (12), and a deposition substrate control and positioning platform for moving and controlling the deposition substrate (13) and realizing the control of the deposition position and angle. The optical induction medium plate (12) is one of an alumina single crystal plate, a zirconia single crystal plate and a quartz single crystal plate; The micro-nano ceramic particles are ceramic precursors composed of constituent metal elements of a target ceramic and polymer monomers of the target ceramic, or are ceramic particles of a target ceramic with a finer degree; 6. The ultrafast laser-induced micro-nano particulate feed jet 3D printing method of multi-level porous ceramic according to claim 5, wherein, The ultrafast laser is a picosecond ultrafast pulsed laser beam or a femtosecond ultrafast pulsed laser beam. The step S2 comprises the following steps: S2.1, performing printing preparation work, including selecting matched laser-induced fine spraying environmental conditions according to the properties of the micro-nano ceramic particles to be transported; 7. The ultrafast laser-induced micro-nano particulate feed jet 3D printing method of multi-level porous ceramic according to claim 6, wherein, S2.2, performing ultrafast laser-induced fine spraying to obtain a single-layer structure with a precision deposition pattern. The step S3 is specifically as follows: The step S2.2 of the ultrafast laser-induced fine spraying is repeatedly performed until the layer-by-layer deposition is completed, and a compact structure of the multistage dot matrix ceramic deposition blank is obtained through external field regulation; The external field regulation is a processing process, including static pressure treatment and ultrasonic vibration.

8. The ultrafast laser-induced micro-nano particulate feed jet 3D printing method of multi-level porous ceramic according to claim 1, wherein, The step S4 is specifically: The multi-stage dot array ceramic deposition body is subjected to the joule flash firing by using a joule flash firing device; The joule flash firing device comprises a sealed cavity (21), a sealed cavity control system for controlling the sealed cavity (21), an external field heat and external field force control system, a gas charging and discharging system, and a flash firing control system; the multi-stage dot array ceramic deposition body is subjected to the joule flash firing in the sealed cavity (21); The external field heat and external field force control system comprises a three-phase power driver (22); the gas charging and discharging system comprises a gas charging channel (25) and a gas discharging channel (26); and the flash firing control system comprises a flash firing power controller (23); The sealed cavity (21) is a hexahedron, comprising two opposite conductive contact surfaces, on which conductive interfaces (24) connected to the flash firing power controller (23) are arranged; the other four surfaces of the sealed cavity are insulating surfaces, one pair of the four insulating surfaces is connected to the gas charging channel (25) and the gas discharging channel (26) respectively; and the other pair of the four insulating surfaces is connected to the three-phase power driver (22), for applying an external heat field and an external magnetic field, and for assisting the heat control and the external magnetic field force control during the firing process of the multi-stage dot array ceramic deposition body.

9. The ultrafast laser-induced micro-nano particulate feed jet 3D printing method of multi-level porous ceramic according to claim 8, characterized in that, The two conductive contact surfaces of the sealed cavity (21) are further provided with discharge needle structures, for penetrating into the multi-stage dot array ceramic and applying a high-voltage electric field to generate a current joule heat effect; The gas flow added to the sealed cavity (21) through the gas charging channel (25) is an oxidizing component of the target ceramic; The joule flash firing comprises a flash firing incubation stage, a flash firing occurrence stage, and a flash firing holding stage.

10. The ultrafast laser-induced micro-nano particulate feed jet 3D printing method of multi-level porous ceramic according to claim 9, wherein, The step S5 comprises: after the flash firing holding stage of the joule flash firing, an auxiliary external field treatment is performed for stress relief and annealing to strengthen and toughen.

Images