Method of binder jet printing, three-dimensional printed component and binder jet printing device

Abstract

The application relates to the field of additive manufacturing technology, in particular to a binder jetting printing method, a three-dimensional printing component and a binder jetting printing device. The method performs first corona treatment on a powder bed after powder laying to activate the powder surface and improve the wetting performance; performs second corona treatment on a printing layer after binder jetting to promote binder cross-linking and solidification and strengthen interface bonding; through the synergistic effect of the two times of corona treatment, the green strength and interlayer bonding strength are improved while the printing precision advantage of the single-component binder is maintained. The application also provides a device for implementing the method and a use method. The application has simple process and is suitable for additive manufacturing of various materials.

Description

Technical Field

[0001] This application belongs to the field of additive manufacturing technology and relates to a method for adhesive jet printing, a three-dimensional printed component, and an adhesive jet printing apparatus. Background Technology

[0002] Binder jetting (BJ) is a typical powder bed additive manufacturing technology. Its basic principle is to selectively spray liquid binder onto the surface of a powder bed through a nozzle along a predetermined path, causing the powder particles to bond in localized areas. Three-dimensional structures are then built layer by layer through powder layering and binder jetting. This technology eliminates the need for high-temperature melting of materials and offers advantages such as wide applicability to various materials, high forming efficiency, and the ability to manufacture complex structures. It has attracted widespread attention in the additive manufacturing of ceramics, metals, and polymers.

[0003] However, several technical challenges remain when using binder jetting technology to fabricate shaped components. First, the low surface energy of powders leads to poor interfacial compatibility with common binders, resulting in insufficient wetting and penetration of the binder on the powder bed surface. This can easily lead to uneven binder diffusion or localized insufficient penetration, thus affecting printing accuracy and interlayer bonding quality. Second, in existing binder jetting technologies, single-component binder systems, due to their simple formulation and good jetting stability, typically achieve high printing resolution, giving them an advantage in precision component manufacturing. However, the curing mechanism of single-component binders is relatively simple, limiting their ability to bond powder particles. This often results in low green strength of the printed preform, making it prone to breakage or deformation during subsequent powder cleaning, handling, and debinding sintering processes. Furthermore, traditional single-component binder curing processes usually require an external heat source for binder curing, which not only increases equipment energy consumption but also prolongs the printing cycle.

[0004] To address the aforementioned issues of poor interfacial compatibility between powder and binder, and insufficient green strength, researchers have attempted to pre-treat or in-situ process powders using methods such as laser treatment, plasma treatment, and electrostatic spraying. Laser treatment utilizes a high-energy laser beam to locally heat the powder surface, which can improve surface activity, but carries the risk of thermal damage, particularly affecting heat-sensitive materials. Conventional plasma treatment (such as radio frequency plasma and microwave plasma) can introduce active groups onto the powder surface, but it typically requires a vacuum chamber, resulting in complex equipment, long processing cycles, and difficulty in online integration with layer-by-layer printing processes. Electrostatic spraying uses a high-voltage electrostatic field to adsorb charged coating particles onto the workpiece surface, but it requires the sprayed material to have a certain degree of conductivity, limiting its application in non-conductive powders such as ceramics and polymers. Therefore, how to introduce a surface modification technology suitable for layer-by-layer powder bed processing while maintaining the high printing accuracy advantages of single-component binders, and effectively couple it with the binder spraying process, has become a key technical problem urgently needing to be solved in this field. Summary of the Invention

[0005] The purpose of this application is to address the problems of poor powder wettability, insufficient green strength, and reliance on external heat sources for curing in the prior art, and to propose a method for adhesive jet printing, a three-dimensional printed component, and an adhesive jet printing device.

[0006] The first objective of this application is achieved through the following technical solution: A method for adhesive jet printing, the method comprising the following steps: (1) Powder material is laid on the forming platform to form a powder layer, and the powder layer is compacted to form a powder bed; (2) The surface of the powder bed is subjected to a first corona treatment; wherein the temperature of the powder bed surface after the first corona treatment is lower than the melting point of the powder material; (3) Based on the printing path corresponding to the slice data of the preset three-dimensional model, the adhesive solution is selectively sprayed onto the surface of the powder bed after the first corona treatment to form a pre-printed layer; (4) The pre-printed layer is subjected to a second corona treatment to cause the adhesive in the adhesive solution to undergo a cross-linking and curing reaction to form a single-layer printed layer; wherein, after the second corona treatment, the curing temperature of the adhesive is lower than its thermal curing temperature; (5) Repeat steps (1~4) to build the three-dimensional green body layer by layer.

[0007] This application employs a two-stage corona treatment. The first corona treatment activates the powder bed surface and performs chemical modification. A high-voltage electric field ionizes the air, generating electrons, ions, and free radicals. These high-energy particles bombard the powder surface, breaking the surface molecular chains and introducing polar functional groups such as hydroxyl (-OH), carboxyl (-COOH), and carbonyl (-C=O). This increases the powder's surface energy and improves its wettability to the binder solution, allowing the binder solution to spread evenly and penetrate deeply. Furthermore, this process does not rely on high temperatures, avoiding thermal damage to heat-sensitive powders. The second corona treatment initiates chemical cross-linking of the binder. Active species in the plasma trigger cross-linking polymerization reactions in the unsaturated bonds or active functional groups of the binder molecules, forming a three-dimensional network structure. This plasma-induced chemical initiation achieves rapid curing of the binder; it can be completed at low temperatures without the need for a curing agent or external heat source, while simultaneously enhancing the interfacial bonding between the powder material and the binder. The two corona treatments create a synergistic effect of "activation + curing", which significantly improves the interlayer bonding strength and overall structural stability of the printed green body while maintaining high printing accuracy.

[0008] The two corona treatments were applied at different stages of the same printed layer, both targeting the same powder bed. Due to the excellent thermal conductivity of the powder bed (especially metal powder), heat dissipated rapidly within a short time, quickly homogenizing the local temperature rise. The time interval between the first and second corona treatments was extremely short (typically only a few seconds to tens of seconds), and the second treatment was performed before the powder bed had had time to dissipate heat, resulting in a cumulative heat effect. Furthermore, during the second corona treatment, the cross-linking and curing reaction of the binder released some reaction heat, further increasing the complexity of the thermal effect. However, although the interval between the two corona treatments was extremely short, the powder bed dissipated heat very quickly, and the actual measured temperature rise of the powder bed was not significantly higher than that of a single corona treatment due to the cumulative heat and reaction heat; the overall temperature rise difference was not significant.

[0009] Preferably, in step (1), the thickness of the powder layer is 10~150μm.

[0010] Preferably, in step (1), the powder material includes at least one of metal powder, ceramic powder or polymer powder.

[0011] More preferably, the metal powder includes at least one of pure metal powder, stainless steel powder, titanium alloy powder, aluminum alloy powder, nickel-based alloy powder, cobalt-chromium alloy powder, mold steel powder, copper alloy powder, or high-entropy alloy powder. The ceramic powder includes oxide ceramic powder and non-oxide ceramic powder; The oxide ceramic powder includes at least one of alumina powder and zirconium oxide powder; The non-oxide ceramic powder includes at least one of silicon carbide powder, silicon nitride powder, and aluminum nitride powder. The polymer powder includes at least one of nylon powder, thermoplastic polyurethane elastomer powder, polyetheretherketone powder, polylactic acid powder, polyamide powder, acrylonitrile-butadiene-styrene copolymer powder, and polypropylene powder.

[0012] Preferably, in step (1), the average particle size D of the powder material is... 50 The value is 10~50μm.

[0013] Preferably, in step (2), the power of the first corona treatment is 1~1000W and the treatment time is 0.1~60s.

[0014] Further preferably, the power of the first corona treatment is 10~100W, and the treatment time is 0.5~5s.

[0015] Preferably, in step (2), the temperature of the powder bed surface after the first corona treatment is 30~80℃.

[0016] Preferably, in step (2), the first corona treatment is performed in an atmospheric pressure air environment.

[0017] Preferably, in step (3), the viscosity of the adhesive solution is 1~50 mPa·s.

[0018] Further preferred, in step (3), the viscosity of the adhesive solution is 1~25 mPa·s.

[0019] Preferably, in step (3), the solid content of the adhesive solution is 10~50wt%.

[0020] Preferably, in step (3), the adhesive solution includes an adhesive and a solvent.

[0021] More preferably, the thermosetting temperature of the adhesive is 120~250℃.

[0022] More preferably, the adhesive comprises a single-component adhesive or a compounded single-component adhesive.

[0023] More preferably, the single-component adhesive is an organic adhesive or an inorganic adhesive; The organic binder includes at least one of polyvinyl alcohol, polyethylene glycol, or acrylic resin; The inorganic binder includes at least one of silicate binders or phosphate binders.

[0024] More preferably, the compounded single-component adhesive includes at least two of polyvinyl alcohol, polyethylene glycol, acrylic resin, silicate adhesive, or phosphate adhesive.

[0025] More preferably, the solvent includes at least one selected from water, ethanol, isopropanol, ethylene glycol, acetone, dimethyl sulfoxide, dimethylformamide, ethylene glycol monomethyl ether, or ethylene glycol butyl ether.

[0026] Preferably, in step (3), the adhesive solution is sprayed into the target area, and the mass of the adhesive in the adhesive solution in the target area is 0.1 to 15 wt% of the mass of the powder bed.

[0027] More preferably, when the powder material is metal powder, the mass of the binder in the binder solution in the target region is 0.5~5 wt% of the mass of the powder bed; When the powder material is ceramic powder, the mass of the binder in the binder solution in the target region is 1-8 wt% of the mass of the powder bed. When the powder material is a polymer powder, the mass of the binder in the binder solution in the target region is 2 to 10 wt% of the mass of the powder bed.

[0028] Preferably, in step (4), the power of the second corona treatment is 10~1000W and the treatment time is 1~120s.

[0029] Further preferably, the power of the second corona treatment is 20~200W, and the treatment time is 1~10s.

[0030] Further preferably, the power of the second corona treatment is greater than the power of the first corona treatment.

[0031] Preferably, in step (4), the second corona treatment is performed in an atmospheric pressure air environment.

[0032] Preferably, in step (4), the curing temperature in the crosslinking curing reaction is 30~80℃.

[0033] Further preferred, in step (4), the curing temperature in the crosslinking curing reaction is 40~60℃.

[0034] Preferably, in step (4), the thickness of the single-layer printing layer is 10~150μm.

[0035] Preferably, in steps (2) and (4), the first corona treatment and the second corona treatment are performed using a corona treatment device, which includes a linear corona electrode array arranged along the width of the powder bed.

[0036] Further preferably, the linear corona electrode array includes multiple needle-shaped electrodes or wire-shaped electrodes, which are connected to a power source for corona discharge.

[0037] Preferably, the adhesive jet printing method further includes a preparation stage, which includes: setting the single printing layer thickness, forming a printing path from the slice data generated by slicing the 3D model and importing it into the control unit, and loading powder material and adhesive solution.

[0038] Preferably, the adhesive jet printing method further includes a post-processing stage, which includes: removing the three-dimensional green body that has been built layer by layer, performing degreasing and sintering treatment, or performing thermal melting treatment, to obtain a dense three-dimensional printed component.

[0039] Preferably, steps (1-5) of the adhesive jet printing method are performed using an adhesive jet printing device.

[0040] The second objective of this application is achieved through the following technical solution: A three-dimensional printed component, wherein the three-dimensional printed component is a three-dimensional green blank obtained by the adhesive jet printing method.

[0041] Preferably, the dimensional accuracy of the 3D printed component is ≤ ±50μm.

[0042] Further preferably, the dimensional accuracy of the 3D printed component is ≤ ±10μm.

[0043] The third objective of this application is achieved through the following technical solution: A three-dimensional printed component is obtained by post-processing the three-dimensional green body.

[0044] Preferably, the post-treatment includes at least one of degreasing treatment, sintering treatment, and hot melting treatment.

[0045] Further preferably, when the powder material is metal powder, the post-processing includes degreasing and sintering.

[0046] More preferably, the degreasing treatment is performed at a temperature of 100~600℃ for a holding time of 1~12h; the sintering treatment is performed at a temperature of 1000~1800℃ for a holding time of 1~24h.

[0047] Further preferably, when the powder material is ceramic powder, the post-processing includes degreasing and sintering.

[0048] More preferably, the degreasing treatment is performed at a temperature of 100~600℃ for a holding time of 1~12h; the sintering treatment is performed at a temperature of 1000~1800℃ for a holding time of 1~24h.

[0049] Further preferably, when the powder material is a polymer powder, the post-processing includes a thermal melting process.

[0050] More preferably, the temperature of the hot melt treatment is higher than the melting point of the polymer powder, and the difference between the two is 5~50℃, and the heat preservation time of the hot melt treatment is 1~12h.

[0051] Preferably, the post-processing further includes at least one of powder removal, washing, drying, or annealing.

[0052] Preferably, the dimensional accuracy of the 3D printed component is ≤ ±50μm.

[0053] Further preferably, the dimensional accuracy of the 3D printed component is ≤ ±10μm.

[0054] The fourth objective of this application is achieved through the following technical solution: An adhesive jet printing apparatus, comprising: A forming cylinder includes a forming platform and a piston that drives the forming platform to rise and fall; The powder spreading mechanism includes a powder supply cylinder, a powder spreading arm, and rollers, wherein the powder spreading arm is connected to the powder supply cylinder; A corona treatment device includes a linear corona electrode array and a power supply connected to the linear corona electrode array; Piezoelectric nozzle, A motion mechanism, which is disposed above the forming platform, is used to drive the powder spreading arm, the roller, the piezoelectric nozzle and the linear corona electrode array to move respectively; The control unit is electrically connected to the motion mechanism, the piezoelectric nozzle, the power supply, and the piston, respectively, and is used to control the timing of each mechanism to execute the adhesive jet printing method.

[0055] Preferably, the motion mechanism includes a first motion guide rail and a second motion guide rail; the first motion guide rail and the second motion guide rail are arranged in parallel above the forming platform; the two ends of the powder spreading arm and the roller are respectively connected to the first motion guide rail and the second motion guide rail, and can move along the first motion guide rail and the second motion guide rail.

[0056] More preferably, the powder spreading arm and the roller are fixedly connected to the first motion guide rail and the second motion guide rail respectively, and there is a height difference between the powder spreading arm and the roller and they are staggered. The powder spreading arm is located in front and the roller is located behind, so that under the drive of the first motion guide rail and the second motion guide rail, the powder spreading arm first spreads the powder layer, and then the roller compacts the spread powder layer.

[0057] In a further preferred embodiment, the powder spreading arm and the roller are detachably connected to the first motion guide rail and the second motion guide rail, respectively. The powder spreading arm moves before the roller. After the powder spreading arm completes the powder layer spreading, the roller compacts the powder layer.

[0058] Preferably, the motion mechanism further includes a fixed guide rail, a third motion guide rail, and a fourth motion guide rail; the fixed guide rail is disposed above the forming platform; the third motion guide rail and the fourth motion guide rail are both perpendicularly disposed on the fixed guide rail, and are parallel to each other, and can both move along the fixed guide rail.

[0059] Preferably, the linear corona electrode array is disposed on the fourth motion guide rail.

[0060] Further preferably, the piezoelectric nozzle is disposed on the third motion guide rail.

[0061] Preferably, the linear corona electrode array includes at least one set of electrodes, which are needle-shaped electrodes and / or wire-shaped electrodes.

[0062] More preferably, the distance between the electrode and the powder bed surface is 1~10 mm.

[0063] More preferably, the distance between the electrode and the powder bed surface is 3~8 mm.

[0064] Preferably, the linear corona electrode array is arranged along the width direction of the powder bed and moves along the length direction of the powder bed; Alternatively, the linear corona electrode array is arranged along the length of the powder bed and moves along the width of the powder bed.

[0065] Preferably, the corona treatment device and the piezoelectric nozzle are mounted on the same motion mechanism and move synchronously along the width or length of the powder bed.

[0066] Preferably, the corona treatment device further includes an electrode support and an insulating component, wherein the electrode support is used to fix the linear corona electrode array and the insulating component is used to achieve electrical insulation.

[0067] Preferably, the control unit is configured to store slice data generated from 3D model slices, set the single printing layer thickness, and generate timing control commands for the motion mechanism, the piezoelectric nozzle, the power supply, and the piston based on the slice data.

[0068] The fifth objective of this application is achieved through the following technical solution: A method of using the adhesive jet printing apparatus includes the following steps: S1. Set the thickness of a single printing layer, form a printing path from the slice data generated by 3D model slicing and import it into the control unit, load powder material into the powder supply cylinder of the powder spreading mechanism, and load binder solution into the piezoelectric nozzle; S2. The control unit controls the movement of the powder spreading arm and rollers of the powder spreading mechanism: the powder spreading arm spreads the powder in the powder supply cylinder onto the forming platform, and the rollers then compact it to form a powder bed; S3. In an atmospheric pressure air environment, the control unit starts the corona treatment device, and uses the power supply to make the linear corona electrode array generate corona discharge. At the same time, it controls the motion mechanism to move the linear corona electrode array to perform the first corona treatment on the powder bed surface. S4. The control unit controls the piezoelectric nozzle to selectively spray the binder solution onto the powder bed surface after the first corona treatment according to the printing path corresponding to the slice data, forming a pre-printed layer. S5. The control unit restarts the corona treatment device and controls the motion mechanism to move the linear corona electrode array to perform a second corona treatment on the pre-printed layer, causing the adhesive to undergo a cross-linking and curing reaction to form a single-layer printed layer. S6. The control unit controls the piston of the forming cylinder to drive the forming platform down by one single printing layer thickness, and repeats the above steps S2 to S5 to build a three-dimensional green blank layer by layer.

[0069] Preferably, the thickness of the powder bed is the same as the thickness of the single-print layer.

[0070] Compared with the prior art, this application has the following beneficial effects: 1. This application employs a first corona treatment to activate the powder bed surface using plasma. A high-voltage electric field ionizes the air, generating electrons, ions, free radicals, and other active species. These high-energy particles bombard the powder surface, breaking down surface molecular chains and introducing polar functional groups such as hydroxyl, carboxyl, and carbonyl groups. This effectively increases the powder surface energy and improves the interfacial compatibility between the powder and the binder. After treatment, the powder surface contact angle decreases, and the wetting performance is significantly improved, which is beneficial for the uniform spreading and penetration of the binder in the powder bed.

[0071] 2. This application utilizes a second corona treatment following selective adhesive spraying to efficiently activate the activity of single-component adhesive molecules, initiating a rapid cross-linking polymerization reaction to form a three-dimensional network structure, thus achieving rapid curing of the adhesive. This curing mechanism is primarily chemical cross-linking rather than thermal curing, allowing curing to be completed at lower temperatures without relying on an external heat source, significantly shortening interlayer waiting time and improving printing efficiency.

[0072] 3. The synergistic effect of the two-step corona treatment in this application enables the effective coupling between powder surface activation and binder curing, significantly improving relative density and three-point bending strength.

[0073] 4. Under the condition of using a single-component binder system, this application enhances the bonding effect through corona treatment, which not only maintains the advantages of stable spraying and high printing accuracy of single-component binders, but also overcomes the inherent defects of insufficient green strength, thus achieving a balance between accuracy and strength.

[0074] 5. This application does not require a complex multi-component adhesive system or additional curing agent, nor does it rely on an external heat source for curing, and the process is simple.

[0075] 6. The adhesive jet printing apparatus of this application can be adapted to the adhesive jet printing method and is suitable for additive manufacturing of various materials such as metals, ceramics, and polymers, with high versatility. Attached Figure Description

[0076] Figure 1 This is a process flow diagram of the adhesive jet printing method of this application; Figure 2 This is a schematic diagram of the adhesive jet printing apparatus of this application; Figure 3 These are physical images of the silicon carbide three-dimensional green blank (a) and the silicon carbide three-dimensional printed component (b) of Embodiment 1 of this application; Figure 4 This is a schematic diagram comparing the surface roughness of a silicon carbide three-dimensional green blank (a) and a silicon carbide three-dimensional printed component (b) in Embodiment 1 of this application; Figure 5 The images show a comparison of the microstructures of the three-dimensional printed component (a) of Embodiment 1 and the three-dimensional printed component (b) of Comparative Example 1.

[0077] Among them, 1. forming cylinder, 21. forming platform, 22. piston, 3. powder spreading arm, 4. roller, 51. first motion guide rail, 52. second motion guide rail, 6. piezoelectric nozzle, 61. third motion guide rail, 7. linear corona electrode array, 71. fourth motion guide rail, 8. fixed guide rail. Detailed Implementation

[0078] The technical solutions of this application will be further described and illustrated below through specific embodiments. It should be understood that the specific embodiments described herein are only for the purpose of helping to understand this application and are not intended to limit the specific scope of this application.

[0079] Unless otherwise specified, the raw materials used in the embodiments of this application are all commonly used in the art, and the methods used in the embodiments are all conventional methods in the art.

[0080] In this paper, the process flow diagram of the adhesive jet printing method of this application is shown in [reference needed]. Figure 1 ; The adhesive jet printing method includes a preparation stage, a layer-by-layer cyclic printing stage, and a post-processing stage. The preparation stage includes: setting the thickness of a single printing layer, forming a printing path from the slice data generated by slicing the 3D model and importing it into the control unit, and loading powder material and binder solution.

[0081] The layer-by-layer cyclic printing stage includes: (1) laying powder material on the forming platform and forming a powder layer, compacting the powder layer to form a powder bed; (2) The powder bed surface is subjected to a first corona treatment in an atmospheric pressure air environment; wherein the temperature of the powder bed surface after the first corona treatment is lower than the melting point of the powder material; (3) Based on the printing path corresponding to the slice data of the preset three-dimensional model, the adhesive solution is selectively sprayed onto the surface of the powder bed after the first corona treatment to form a pre-printed layer; (4) In an ambient air environment, the pre-printed layer is subjected to a second corona treatment to cause the adhesive to undergo a cross-linking and curing reaction, forming a single-layer printed layer; wherein, after the second corona treatment, the curing temperature of the adhesive is lower than its thermal curing temperature; (5) Repeat steps (1~4) to build the three-dimensional green body layer by layer.

[0082] The post-processing stage includes: removing the three-dimensional green body that has been constructed layer by layer, performing degreasing and sintering treatments, or performing hot melting treatments, to obtain a dense three-dimensional printed component.

[0083] In this paper, if the first corona treatment is replaced with plasma treatment (e.g., in a vacuum chamber, under an argon atmosphere, with a radio frequency power of 100W and a treatment time of 5 minutes), the conventional plasma treatment must be carried out in a vacuum chamber. The airflow generated during the process will disperse the compacted powder bed, damaging the smoothness of the powder layer and leading to uneven subsequent binder spraying, thus preventing normal printing. In contrast, the first corona treatment used in this application is performed at atmospheric pressure, without airflow interference, ensuring the smoothness of the powder bed.

[0084] In this paper, if the first corona treatment is replaced with 350W ultraviolet irradiation, although it is carried out at atmospheric pressure, the activation effect is still limited after 5 minutes of treatment, with the contact angle only decreasing from 110° to 95°, which cannot meet the rapid processing requirements of the layer-by-layer printing process. However, the first corona treatment used in this application can achieve a significant activation effect in a very short time.

[0085] In this paper, if the first corona treatment is replaced with ozone treatment at 25 vol%, even if the treatment time is extended to 10 minutes, the activation effect is still not obvious (the contact angle only decreases from 110° to 105°), and the long treatment time also fails to meet the rapid processing requirements of the layer-by-layer printing process. The first corona treatment used in this application has the advantages of both high efficiency and speed.

[0086] In this document, a schematic diagram of the adhesive jet printing apparatus used in this application is shown below. Figure 2 As shown, it includes: A forming cylinder 1, which includes a forming platform 21 and a piston 22, wherein the piston 22 is connected to the forming platform 21 and drives the forming platform 21 to rise and fall; The powder spreading mechanism includes a powder supply cylinder, a powder spreading arm 3, a roller 4, a first motion guide rail 51, and a second motion guide rail 52. The powder spreading arm 3 is connected to the powder supply cylinder. The first motion guide rail 51 and the second motion guide rail 52 are arranged parallel to each other above the forming platform 21. The two ends of the powder spreading arm 3 and the roller 4 are respectively connected to the first motion guide rail 51 and the second motion guide rail 52. The first motion guide rail 51 and the second motion guide rail 52 drive the powder spreading arm 3 to move above the forming platform 21 to spread the powder layer, and the first motion guide rail 51 and the second motion guide rail 52 drive the roller 4 to move on the surface of the forming platform 21 to compact the powder layer. The powder spreading arm 3 moves before the roller 4. Fixed guide rail 8 is disposed above the forming platform 21; The third motion guide rail 61 is disposed on the fixed guide rail 8 and can move along the fixed guide rail 8; The piezoelectric nozzle 6 is mounted on the third motion guide rail 61, and the third motion guide rail 61 drives the piezoelectric nozzle 6 to move. The fourth motion guide rail 71 is disposed on the fixed guide rail 8 and moves along the fixed guide rail 8. The fourth motion guide rail 71 is disposed parallel to the third motion guide rail 61 and is perpendicular to the fixed guide rail 8. A linear corona electrode array 7 is mounted on the fourth motion guide rail 71, and the fourth motion guide rail 71 drives the linear corona electrode array 7 to move. The power supply is electrically connected to the linear corona electrode array 7. The control unit is electrically connected to the first motion guide rail 51, the second motion guide rail 52, the third motion guide rail 61, the fourth motion guide rail 71, the piezoelectric nozzle 6, the power supply, and the piston 22, respectively, and controls the timing of each mechanism to execute the adhesive jet printing method.

[0087] In this document, the method of using the adhesive jet printing apparatus employed in this application includes: S1. Set the thickness of a single printing layer, import the slice data generated by the 3D model slicing into the control unit, load powder material into the powder supply cylinder, and load binder solution into the piezoelectric nozzle 6. S2. The control unit controls the first motion guide rail 51 and the second motion guide rail 52 to drive the powder spreading arm 3 and the roller 4 to move: the powder spreading arm 3 first spreads the powder material in the powder supply cylinder onto the forming platform 21, and then the roller 4 compacts it to form a powder bed. S3. In an ambient air environment, the control unit starts the power supply to make the linear corona electrode array 7 generate corona discharge, and at the same time controls the fourth motion guide rail 71 to move along the fixed guide rail 8, so as to drive the linear corona electrode array 7 to perform the first corona treatment on the powder bed surface to improve the powder surface energy and wettability. S4. The control unit controls the third motion guide rail 61 to move along the fixed guide rail 8, driving the piezoelectric nozzle 6 to selectively spray the adhesive solution onto the powder bed surface after the first corona treatment according to the printing path corresponding to the slice data, forming a pre-printed layer. S5. The control unit restarts the power supply to make the linear corona electrode array 7 generate corona discharge, and at the same time controls the fourth motion guide rail 71 to move along the fixed guide rail 8 to perform a second corona treatment on the pre-printed layer, so that the adhesive undergoes a cross-linking and curing reaction to form a single-layer printed layer. S6. The control unit controls the piston 22 to drive the forming platform 21 down by one single printing layer thickness, and repeats the above steps S2 to S5 to build a three-dimensional green blank layer by layer.

[0088] In this article, the raw materials include: Silicon carbide powder, β-phase silicon carbide powder, purity ≥99%, purchased from Guangzhou Metal Metallurgy (Group) Co., Ltd. 316L stainless steel powder: D 50 =25 μm, purchased from Jiangsu Weilai New Material Technology Co., Ltd.; Polyamide 12 (PA12) powder: melting point ~180℃, D 50 =40μm, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; Polyvinyl alcohol (PVA) solution: An aqueous solution prepared from PVA powder, which was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Polyethylene glycol (PEG) solution: An aqueous solution of PEG powder, which was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0089] The testing methods described in this article include: Powder particle size testing: The test was conducted using a laser particle size analyzer; Surface contact angle test: The test was conducted using an optical contact angle meter and the test liquid was deionized water; Surface roughness test: The test is performed using a profilometer or white light interferometer, and the result is expressed as Ra (arithmetic mean deviation). Three-point bending strength test: The three-point bending method was adopted and tested according to GB / T 4740. The sample size was 40mm×8mm×4mm, the span was 30mm, and the loading rate was 0.5mm / min. Density test of sintered body: Archimedes' displacement method was used for testing; Microstructure: Observed using a scanning electron microscope (SEM).

[0090] Example 1

[0091] The adhesive jet printing method in this embodiment includes the following steps: (S0) Preparation stage: Set the single printing layer thickness to 60μm, form the printing path from the slicing data generated by the 3D model slicing and import it into the control unit, load silicon carbide powder into the powder supply cylinder of the powder spreading mechanism, and load a single-component polyvinyl alcohol solution (solid content of 20%) into the piezoelectric nozzle. The silicon carbide powder used has a particle size D50 = 35μm.

[0092] (S1) Powder spreading and compaction: In the forming cylinder, silicon carbide powder is evenly spread on the surface of the forming platform by the powder spreading arm, and the powder layer thickness is 60μm. After the powder spreading is completed, the powder layer is compacted and leveled by rollers with a compaction pressure of 0.6MPa to make the surface flat and the thickness uniform, forming a powder bed.

[0093] (S2) First corona treatment: The powder bed surface is subjected to a first corona treatment using a corona treatment device to activate the silicon carbide powder surface with plasma. The corona treatment power is set to 60W, the treatment time is 2s, and the distance between the electrode tip of the linear corona electrode array and the powder bed surface is 5mm.

[0094] (S3) Adhesive Spraying: Based on the printing path corresponding to the pre-set 3D model slicing data, a single-component polyvinyl alcohol solution is selectively sprayed in microdroplet form onto the powder bed surface after the first corona treatment using a piezoelectric nozzle. The spraying saturation is set to 100%, and the spraying amount per unit area is 25 mL / m². 2 The adhesive, after being sprayed, penetrates into the gaps between the powder particles, initially bonding them to form a pre-printed layer.

[0095] (S4) Second corona treatment: The printing area of ​​the pre-printed layer is subjected to a second corona treatment. The power is set to 150W and the treatment time is 5s. A cross-linking curing reaction occurs, and the printed layer is formed after curing.

[0096] (S5) Layer-by-layer printing: The forming platform descends by one layer thickness (60μm), and then repeats steps (S1) to (S4) to print layer by layer until the construction of the target structure blank is completed, and a three-dimensional silicon carbide blank with an accuracy of ±18μm is obtained.

[0097] (S6) Post-processing stage: The obtained silicon carbide 3D green blank is subjected to powder cleaning treatment, degreasing treatment at 400℃ for 3h, and then sintering treatment at 1650℃ for 2h to obtain silicon carbide 3D printed components. Its accuracy is ±42μm.

[0098] In this embodiment, the physical images of the silicon carbide 3D green preform and the silicon carbide 3D printed component are as follows: Figure 3 (a) and Figure 3 As shown in (b), both surfaces have clear contours, neat edges, and good interlayer bonding. The surface roughness Ra of both is as follows: Figure 4 As shown, the thicknesses are 2.01 μm and 1.23 μm, respectively, indicating that the surface of the silicon carbide 3D printed component is smoother. Figure 5 (a) is a SEM image of the silicon carbide 3D printed component, which is basically free of pores, proving that densification has been achieved.

[0099] Performance tests were conducted, and the relative density of the silicon carbide 3D printed component reached 94.1%, with a three-point bending strength of 318 MPa. Specific performance details are shown in Table 1.

[0100] Example 2

[0101] The adhesive jet printing method in this embodiment includes the following steps: (S0) Preparation stage: Set the single printing layer thickness to 50μm, form the printing path from the slice data generated by 3D model slicing and import it into the control unit, load 316L stainless steel metal powder into the powder supply cylinder of the powder spreading mechanism, and load a single-component polyvinyl alcohol solution (solid content of 25%) into the piezoelectric nozzle. The particle size of the 316L stainless steel powder used is D50=25μm.

[0102] (S1) Powder spreading and compaction: In the forming cylinder, 316L stainless steel powder is evenly spread on the surface of the forming platform by the powder spreading arm, and the powder layer thickness is 50μm. After the powder spreading is completed, the powder layer is compacted and leveled by rollers with a compaction pressure of 0.5MPa to make the surface flat and the thickness uniform, forming a powder bed.

[0103] (S2) First corona treatment: The powder bed surface is subjected to a first corona treatment using a corona treatment device to activate the 316L stainless steel powder surface with plasma. The corona treatment power is set to 30W, the treatment time is 2s, and the distance between the electrode tip of the linear corona electrode array and the powder bed surface is 5mm.

[0104] (S3) Adhesive Spraying: Based on the pre-set printing path corresponding to the slicing data of the 3D model, a single-component polyvinyl alcohol solution is selectively sprayed in microdroplet form onto the powder bed surface after the first corona treatment using a piezoelectric nozzle. The nozzle's single droplet volume is 40 pL, the spray saturation is set to 120%, and the spray rate per unit area is 0.7 g / cm³. 2 The adhesive, after being sprayed, penetrates into the gaps between powder particles, initially bonding and forming a pre-printed layer.

[0105] (S4) Second corona treatment: The printing area of ​​the pre-printed layer is subjected to a second corona treatment. The power is set to 100W and the treatment time is 5s. A cross-linking curing reaction occurs, and the printed layer is formed after curing.

[0106] (S5) Layer-by-layer printing: The forming platform descends by one layer thickness (50μm), and then repeats steps (S1) to (S4) to print layer by layer until the construction of the target structure blank is completed, and a 316L stainless steel three-dimensional green blank is obtained.

[0107] (S6) Post-processing stage: The obtained 316L stainless steel 3D green blank is subjected to powder cleaning treatment, degreasing treatment at 500℃ for 2 hours, and then sintering treatment at 1300℃ for 3 hours to obtain 316L stainless steel 3D printed components. Its surface contour is clear, the edges are neat, and the interlayer bonding is good.

[0108] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0109] Example 3

[0110] The adhesive jet printing method in this embodiment includes the following steps: (S0) Preparation stage: Set the thickness of a single printing layer to 100μm, form the printing path from the slice data generated by the 3D model slice and import it into the control unit, load polyamide 12 (PA12) polymer powder into the powder supply cylinder of the powder spreading mechanism, and load a single-component polyvinyl alcohol solution (solid content of 12%) into the piezoelectric nozzle.

[0111] (S1) Powder spreading and compaction: In the forming cylinder, PA12 powder is evenly spread on the surface of the forming platform by the powder spreading arm, and the powder layer thickness is 100μm. After the powder spreading is completed, the powder layer is compacted and leveled by rollers with a compaction pressure of 0.3MPa to make the surface flat and the thickness uniform, forming a powder bed.

[0112] (S2) First corona treatment: The powder bed surface is subjected to a first corona treatment using a corona treatment device to activate the PA12 powder surface with plasma. The corona treatment power is set to 90W, the treatment time is 3s, and the distance between the electrode tip of the linear corona electrode array and the powder bed surface is 5mm.

[0113] The measured temperature of the powder surface during the processing was 55℃, which is far below the melting point of PA12 (180℃), so there is no risk of thermal damage.

[0114] (S3) Adhesive Spraying: Based on the pre-set printing path corresponding to the slice data of the 3D model, a single-component polyvinyl alcohol solution is selectively sprayed in the form of microdroplets onto the powder bed surface after the first corona treatment using a piezoelectric nozzle. The single droplet volume is 25 pL, the spray saturation is set to 80%, and the spray amount per unit area is 0.6 g / cm². After spraying, the adhesive penetrates into the gaps between powder particles, initially bonding to form a pre-printed layer.

[0115] (S4) Second corona treatment: The printing area of ​​the pre-printed layer is subjected to a second corona treatment. The power is set to 200W and the treatment time is 8s. A cross-linking curing reaction occurs, and the printed layer is formed after curing.

[0116] During the second corona treatment, the measured temperature of the powder surface was 75℃, which is far below the melting point of PA12, ensuring that the polymer powder does not melt and deform.

[0117] (S5) Layer-by-layer printing: The forming platform descends by one layer thickness (100μm), and then repeats steps (S1) to (S4) to print layer by layer until the construction of the target structure blank is completed, and the PA12 three-dimensional green blank is obtained.

[0118] After printing, the powder was removed, and the edges of the PA12 3D green body remained intact without any obvious damage.

[0119] (S6) Post-processing stage: The PA12 three-dimensional preform is placed in an oven for hot melting treatment, heated to 190°C at 5°C / min and kept at the temperature for 2 hours to ensure full melting and bonding; then it is naturally cooled to room temperature to obtain the PA12 three-dimensional printed component.

[0120] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0121] Example 4

[0122] The adhesive jet printing method in this embodiment includes the following steps: (S0) Preparation stage: Set the single printing layer thickness to 25μm, form the printing path from the slice data generated by 3D model slicing and import it into the control unit, load fine-particle-size silicon carbide powder into the powder supply cylinder of the powder spreading mechanism, and load a single-component polyvinyl alcohol solution (solid content of 20%) into the piezoelectric nozzle. The silicon carbide powder used has a particle size D50 = 10μm.

[0123] (S1) Powder spreading and compaction: In the forming cylinder, silicon carbide powder is evenly spread on the surface of the forming platform by the powder spreading arm, and the powder layer thickness is 25μm. After the powder spreading is completed, the powder layer is compacted and leveled by rollers with a compaction pressure of 0.6MPa to make the surface flat and the thickness uniform, forming a powder bed.

[0124] (S2) First corona treatment: The powder bed surface is subjected to the first corona treatment using a corona treatment device. The power is set to 60W, the treatment time is 1.5s, and the distance between the electrode and the powder bed is 5mm.

[0125] (S3) Adhesive Spraying: Based on the pre-set printing path corresponding to the slicing data of the 3D model, a single-component polyvinyl alcohol solution is selectively sprayed in microdroplet form onto the powder bed surface after the first corona treatment using a piezoelectric nozzle. The nozzle droplet volume is 20 pL, the spray saturation is set to 100%, and the spray rate per unit area is 0.5 g / cm². 2 The adhesive, after being sprayed, penetrates into the gaps between the powder particles, initially bonding them to form a pre-printed layer.

[0126] (S4) Second corona treatment: Perform a second corona treatment on the printing area of ​​the pre-printed layer. The power is set to 150W and the treatment time is 4s to promote the cross-linking and curing of the adhesive and form the printing layer.

[0127] (S5) Layer-by-layer printing: The forming platform descends by one layer thickness (25μm), and then repeats steps (S1) to (S4) to print layer by layer until the construction of the target structure blank is completed, and a three-dimensional green blank of silicon carbide is obtained.

[0128] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0129] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0130] Example 5

[0131] The adhesive jet printing method in this embodiment includes the following steps: (S0) Preparation stage: Set the single printing layer thickness to 80μm, form the printing path from the slice data generated by 3D model slicing and import it into the control unit, load fine-particle-size silicon carbide powder into the powder supply cylinder of the powder spreading mechanism, and load a single-component polyvinyl alcohol solution (solid content of 20%) into the piezoelectric nozzle. The silicon carbide powder used has a particle size D50 = 50μm.

[0132] (S1) Powder spreading and compaction: In the forming cylinder, silicon carbide powder is evenly spread on the surface of the forming platform by the powder spreading arm, and the powder layer thickness is 80μm. After the powder spreading is completed, the powder layer is compacted and leveled by rollers with a compaction pressure of 0.5MPa to make the surface flat and the thickness uniform, forming a powder bed.

[0133] (S2) First corona treatment: The powder bed surface is subjected to the first corona treatment using a corona treatment device. The power is set to 60W, the treatment time is 2.5s, and the distance between the electrode and the powder bed is 5mm.

[0134] (S3) Adhesive Spraying: Based on the pre-set printing path corresponding to the slicing data of the 3D model, a single-component polyvinyl alcohol solution is selectively sprayed in microdroplet form onto the powder bed surface after the first corona treatment using a piezoelectric nozzle. The single droplet volume is 40 pL, the spray saturation is set to 100%, and the spray rate per unit area is 1.2 g / cm³. 2 The adhesive, after being sprayed, penetrates into the gaps between the powder particles, initially bonding them to form a pre-printed layer.

[0135] (S4) Second corona treatment: The printing area of ​​the pre-printed layer is subjected to a second corona treatment with a power of 150W and a treatment time of 6s to promote cross-linking and curing of the adhesive and form the printing layer.

[0136] (S5) Layer-by-layer printing: The forming platform descends by one layer thickness (80μm), and then repeats steps (S1) to (S4) to print layer by layer until the construction of the target structure blank is completed, and a three-dimensional silicon carbide green blank is obtained.

[0137] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0138] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0139] Example 6

[0140] The adhesive jet printing method in this embodiment includes the following steps: (S0) Preparation stage: Set the single printing layer thickness to 10μm, form the printing path from the slice data generated by 3D model slicing and import it into the control unit, load fine-particle-size silicon carbide powder into the powder supply cylinder of the powder spreading mechanism, and load a single-component polyvinyl alcohol solution (solid content of 20%) into the piezoelectric nozzle. The silicon carbide powder used has a particle size D50 = 10μm.

[0141] (S1) Powder spreading and compaction: In the forming cylinder, silicon carbide powder is evenly spread on the surface of the forming platform by the powder spreading arm, and the powder layer thickness is 10μm. After the powder spreading is completed, the powder layer is compacted and leveled by rollers with a compaction pressure of 0.6MPa to make the surface flat and the thickness uniform, forming a powder bed.

[0142] (S2) First corona treatment: The powder bed surface is subjected to the first corona treatment using a corona treatment device. The power is set to 40W, the treatment time is 1s, and the distance between the electrode and the powder bed is 3mm.

[0143] (S3) Adhesive Spraying: Based on the pre-set printing path corresponding to the slicing data of the 3D model, a single-component polyvinyl alcohol solution is selectively sprayed in microdroplet form onto the powder bed surface after the first corona treatment using a piezoelectric nozzle. The single droplet volume is 10 pL, the spray saturation is set to 100%, and the spray rate per unit area is 0.15 g / cm². 2 The adhesive, after being sprayed, penetrates into the gaps between the powder particles, initially bonding them to form a pre-printed layer.

[0144] (S4) Second corona treatment: Perform a second corona treatment on the printing area of ​​the pre-printed layer. The power is set to 100W and the treatment time is 3s to promote the cross-linking and curing of the adhesive and form the printing layer.

[0145] (S5) Layer-by-layer printing: The forming platform descends by one layer thickness (10μm), and then repeats steps (S1) to (S4) to print layer by layer until the construction of the target structure blank is completed, and a three-dimensional silicon carbide green blank is obtained.

[0146] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0147] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0148] Example 7

[0149] The adhesive jet printing method in this embodiment includes the following steps: (S0) Preparation stage: Set the single printing layer thickness to 150μm, form the printing path from the slicing data generated by the 3D model slicing and import it into the control unit, load fine-particle-size silicon carbide powder into the powder supply cylinder of the powder spreading mechanism, and load a single-component polyvinyl alcohol solution (solid content of 20%) into the piezoelectric nozzle. The silicon carbide powder used has a particle size D50 = 50μm.

[0150] (S1) Powder spreading and compaction: In the forming cylinder, silicon carbide powder is evenly spread on the surface of the forming platform by the powder spreading arm, and the powder layer thickness is 150μm. After the powder spreading is completed, the powder layer is compacted and leveled by rollers with a compaction pressure of 0.5MPa to make the surface flat and the thickness uniform, forming a powder bed.

[0151] (S2) First corona treatment: The powder bed surface is subjected to the first corona treatment using a corona treatment device. The power is set to 80W, the treatment time is 4s, and the distance between the electrode and the powder bed is 8mm.

[0152] (S3) Adhesive Spraying: Based on the pre-set printing path corresponding to the slicing data of the 3D model, a single-component polyvinyl alcohol solution is selectively sprayed in microdroplet form onto the powder bed surface after the first corona treatment using a piezoelectric nozzle. The nozzle droplet volume is 50 pL, the spray saturation is set to 100%, and the spray rate per unit area is 1.8 g / cm². 2 The adhesive, after being sprayed, penetrates into the gaps between the powder particles, initially bonding them to form a pre-printed layer.

[0153] (S4) Second corona treatment: Perform a second corona treatment on the printing area of ​​the pre-printed layer. The power is set to 200W and the treatment time is 8s to promote the cross-linking and curing of the adhesive and ensure that the adhesive inside the thick layer is fully cured to form the printing layer.

[0154] (S5) Layer-by-layer printing: The forming platform descends by one layer thickness (150μm), and then steps (S1) to (S4) are repeated to print layer by layer until the target structure blank is completed, resulting in a three-dimensional silicon carbide green blank. The number of layers is significantly reduced during thick-layer printing, thus improving printing efficiency.

[0155] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0156] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0157] Example 8

[0158] The adhesive jet printing method in this embodiment includes the following steps: (S0) Preparation Stage: The single-print layer thickness is set to 60μm. The slicing data generated from the 3D model is used to form the printing path and imported into the control unit. Fine-grained silicon carbide powder is loaded into the powder supply cylinder of the powder spreading mechanism, and a compounded single-component binder is loaded into the piezoelectric nozzle. This binder is composed of polyvinyl alcohol (PVA, molecular weight 60000) and polyethylene glycol (PEG, molecular weight 2000) in a mass ratio of 4:1, with a total solid content of 20%, deionized water as the solvent, and a viscosity of 10 mPa·s (25℃). The silicon carbide powder used has a particle size D50 = 35μm.

[0159] (S1) Powder spreading and compaction: In the forming cylinder, silicon carbide powder is evenly spread on the surface of the forming platform by the powder spreading arm, and the powder layer thickness is 60μm. After the powder spreading is completed, the powder layer is compacted and leveled by rollers with a compaction pressure of 0.6MPa to make the surface flat and the thickness uniform, forming a powder bed.

[0160] (S2) First corona treatment: The powder bed surface is subjected to the first corona treatment using a corona treatment device. The power is set to 60W, the treatment time is 2s, and the distance between the electrode and the powder bed is 5mm.

[0161] (S3) Adhesive Spraying: Based on the pre-set printing path corresponding to the slicing data of the 3D model, the compound adhesive is selectively sprayed in microdroplet form onto the powder bed surface after the first corona treatment using a piezoelectric nozzle. The single droplet volume is 30 pL, the spray saturation is set to 100%, and the spray rate per unit area is 0.8 g / cm³. 2 .

[0162] (S4) Second corona treatment: The printing area of ​​the pre-printed layer is subjected to a second corona treatment. The power is set to 150W and the treatment time is 4s. A cross-linking and curing reaction occurs to form the printing layer.

[0163] (S5) Layer-by-layer printing: The forming platform descends by one layer thickness (60μm), and then steps (S1) to (S4) are repeated to print layer by layer until the target structure blank is completed, resulting in a three-dimensional silicon carbide green blank. The edges of the green blank are clear and complete.

[0164] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0165] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0166] Comparative Example 1 The adhesive jet printing method in this comparative example includes the following steps: (S0) Preparation stage: Proceed according to step (S0) of Example 1.

[0167] (S1) Spreading powder and compacting: Perform according to step (S1) of Example 1.

[0168] (S2) Spraying adhesive: Performed according to step (S3) of Example 1.

[0169] (S3) Heat curing (interlayer): Use a 180 W light source lamp for initial interlayer curing.

[0170] (S4) Layer-by-layer printing: Follow the steps (S5) of Example 1 to obtain a three-dimensional green blank.

[0171] (S5) Post-curing: The three-dimensional green body obtained in step (S4) is kept at 180° for 2 hours for post-curing.

[0172] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0173] The edge contours of the 3D green blank in this comparative example are unclear, and the local dimensional accuracy is reduced, with an accuracy of ±83μm. The SEM image of the post-processed silicon carbide 3D printed component is shown below. Figure 5 (b) There are obvious pores.

[0174] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0175] Comparative Example 2 The adhesive jet printing method in this comparative example includes the following steps: (S0) Preparation stage: Proceed according to step (S0) of Example 1.

[0176] (S1) Spreading powder and compacting: Perform according to step (S1) of Example 1.

[0177] (S2) Spraying adhesive: Performed according to step (S3) of Example 1.

[0178] (S3) Second corona treatment: Performed according to step (S4) of Example 1.

[0179] (S4) Print layer by layer: Follow the steps (S5) of Example 1.

[0180] (S5) Post-processing stage: Performed according to step (S6) of Example 1.

[0181] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0182] Comparative Example 3 The adhesive jet printing method in this comparative example includes the following steps: (S0) Preparation stage: Proceed according to step (S0) of Example 1.

[0183] (S1) Spreading powder and compacting: Perform according to step (S1) of Example 1.

[0184] (S2) First corona treatment: Performed according to step (S2) of Example 1.

[0185] (S3) Spraying adhesive: Perform according to step (S3) of Example 1.

[0186] (S4) Heat curing: Proceed according to step (S3) of Comparative Example 1.

[0187] (S5) Print layer by layer: Follow the steps (S5) of Example 1.

[0188] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0189] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0190] Comparative Example 4 The adhesive jet printing method in this comparative example includes the following steps: (S0) Preparation stage: Proceed according to step (S0) of Example 1.

[0191] (S1) Spreading powder and compacting: Perform according to step (S1) of Example 1.

[0192] (S2) Spraying adhesive: Performed according to step (S3) of Example 1.

[0193] (S3) Heat curing (interlayer): Proceed according to step (S3) of Comparative Example 1.

[0194] (S4) Print layer by layer: Follow the steps (S5) of Example 1.

[0195] (S5) Corona treatment: The entire green body is subjected to corona treatment with a power of 150W and a time of 120s. The distance between the electrode tip of the linear corona electrode array and the powder bed surface is 5mm.

[0196] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0197] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0198] Comparative Example 5 The adhesive jet printing method in this comparative example includes the following steps: (S0) Preparation stage: Proceed according to step (S0) of Example 1.

[0199] (S1) Spreading powder and compacting: Perform according to step (S1) of Example 1.

[0200] (S2) First corona treatment: Performed according to step (S2) of Example 1.

[0201] (S3) Spraying adhesive: Perform according to step (S3) of Example 1.

[0202] (S4) Second corona treatment: Performed according to step (S4) of Example 1, except that the power is set to 60W, the treatment time is 2s, and the distance between the electrode tip of the linear corona electrode array and the powder bed surface is 5mm.

[0203] (S5) Print layer by layer: Follow the steps (S5) of Example 1.

[0204] (S6) Post-processing stage: Performed according to step (S6) of Example 1.

[0205] Performance tests were conducted, and the specific performance data is shown in Table 1.

[0206] Table 1. Performance data of 3D green blanks and 3D printed components in the examples and comparative examples.

[0207] As shown in Table 1, this application achieves a synergistic effect between powder surface activation and binder curing by performing corona treatment after powder spreading and after binder spraying, significantly improving the interlayer bonding strength and overall structural stability of the printed preform. In Example 8, due to the compounded single-component formulation, the binder surface tension is lower, resulting in better compatibility between the powder surface and the binder after the first corona treatment. Compared to Example 1, the relative density of Comparative Example 1 decreased by 8.8 percentage points, and the flexural strength decreased by 51.4%. The results of Comparative Example 2 (second corona treatment only) and Comparative Example 3 (first corona treatment only) are significantly worse than those of Example 1, demonstrating that the two corona treatments perform different functions of powder activation and binder curing, respectively, and neither is dispensable. The results of Comparative Example 5 (same corona parameters for both treatments) indicate that the second corona treatment requires a higher power than the first to effectively promote binder crosslinking and curing. The results of Comparative Example 4 (overall treatment after printing) indicate that the overall corona treatment after printing cannot achieve the effects of layer-by-layer activation and in-situ curing.

[0208] In summary, this application achieves synergistic enhancement of powder surface activation and rapid binder curing in binder jet printing through a two-step corona treatment: the first corona treatment introduces polar functional groups on the powder surface, improving wettability and interfacial compatibility; the second corona treatment induces rapid chemical cross-linking of the single-component binder, enabling low-temperature curing without an external heat source and significantly shortening interlayer waiting time. This method maintains stable single-component binder jetting and high printing accuracy while overcoming the deficiency of insufficient green strength, effectively improving relative density and three-point flexural strength. Furthermore, the process is simple, requiring no complex multi-component systems or additional curing agents, and is applicable to additive manufacturing of various materials such as metals, ceramics, and polymers, demonstrating high versatility.

[0209] All aspects, embodiments, and features of this application are to be considered illustrative in all respects and do not limit the application; the scope of this application is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of this application as claimed.

[0210] In the preparation method of this application, the order of the steps is not limited to the listed order. For those skilled in the art, variations in the order of the steps without inventive effort are also within the scope of protection of this application. Furthermore, two or more steps or actions can be performed simultaneously.

[0211] Finally, it should be noted that the specific embodiments described herein are merely illustrative examples and are not intended to limit the implementation of this application. Those skilled in the art to which this application pertains can make various modifications or additions to the described specific embodiments or use similar methods to replace them; it is neither necessary nor possible to provide exhaustive examples of all implementations here. However, obvious variations or modifications derived from the essential spirit of this application still fall within the protection scope of this application, and interpreting them as any additional limitation would contradict the spirit of this application.

Claims

1. A method for adhesive jet printing, characterized in that, The method includes the following steps: (1) Powder material is laid on the forming platform to form a powder layer, and the powder layer is compacted to form a powder bed; (2) The surface of the powder bed is subjected to a first corona treatment; wherein the temperature of the powder bed surface after the first corona treatment is lower than the melting point of the powder material; (3) Based on the printing path corresponding to the slice data of the preset three-dimensional model, the adhesive solution is selectively sprayed onto the surface of the powder bed after the first corona treatment to form a pre-printed layer; (4) The pre-printed layer is subjected to a second corona treatment to cause the adhesive in the adhesive solution to undergo a cross-linking and curing reaction to form a single-layer printed layer; wherein, after the second corona treatment, the curing temperature of the adhesive is lower than its thermal curing temperature; (5) Repeat steps (1~4) to build the three-dimensional green body layer by layer.

2. The adhesive jet printing method according to claim 1, characterized in that, In step (1), the powder material includes at least one of metal powder, ceramic powder, or polymer powder; the average particle size D of the powder material 50 The value is 10~50μm.

3. The adhesive jet printing method according to claim 1, characterized in that, In step (2), the power of the first corona treatment is 1~1000W and the treatment time is 0.1~60s; the temperature of the powder bed surface after the first corona treatment is 30~80℃.

4. The adhesive jet printing method according to claim 1, characterized in that, In step (3), the viscosity of the adhesive solution is 1~50 mPa·s; the solid content of the adhesive solution is 10~50 wt%; the adhesive solution includes an adhesive and a solvent; the adhesive includes a single-component adhesive or a compounded single-component adhesive.

5. The adhesive jet printing method according to claim 1, characterized in that, In step (3), the adhesive solution is sprayed into the target area, and the mass of the adhesive in the adhesive solution in the target area is 0.1 to 15 wt% of the mass of the powder bed.

6. The adhesive jet printing method according to claim 1, characterized in that, In step (4), the power of the second corona treatment is 10~1000W and the treatment time is 1~120s; the curing temperature in the crosslinking curing reaction is 30~80℃.

7. The adhesive jet printing method according to claim 1, characterized in that, In step (2), the first corona treatment is performed in an atmospheric pressure air environment; In step (4), the second corona treatment is performed in an atmospheric pressure air environment.

8. A three-dimensional printed component, characterized in that, The three-dimensional printed component is a three-dimensional green body obtained by the adhesive jet printing method as described in any one of claims 1 to 7.

9. A three-dimensional printed component, characterized in that, The three-dimensional printed component is obtained by post-processing a three-dimensional green body obtained by the adhesive jet printing method as described in any one of claims 1 to 7; the post-processing includes at least one of degreasing treatment, sintering treatment, and hot melting treatment.

10. The three-dimensional printed component according to claim 9, characterized in that, When the powder material is metal powder, the post-processing includes degreasing and sintering. When the powder material is ceramic powder, the post-processing includes degreasing and sintering. When the powder material is a polymer powder, the post-processing includes a thermal melting process.

11. An adhesive jet printing apparatus, characterized in that, It includes: The forming cylinder (1) includes a forming platform (21) and a piston (22) that drives the forming platform (21) to rise and fall. The powder spreading mechanism includes a powder supply cylinder, a powder spreading arm (3) and a roller (4), wherein the powder spreading arm (3) is connected to the powder supply cylinder; A corona treatment device includes a linear corona electrode array (7) and a power supply connected to the linear corona electrode array (7); Piezoelectric nozzle (6); The motion mechanism is located above the forming platform (21) and is used to drive the powder spreading arm (3), the roller (4), the piezoelectric nozzle (6) and the linear corona electrode array (7) to move. The control unit is electrically connected to the motion mechanism, the piezoelectric nozzle (6), the power supply and the piston (22) respectively, and is used to control the timing of each mechanism to perform the adhesive jet printing method as described in any one of claims 1 to 7.

12. The adhesive jet printing apparatus according to claim 11, characterized in that, It includes: The motion mechanism includes a first motion guide rail (51) and a second motion guide rail (52); the first motion guide rail (51) and the second motion guide rail (52) are arranged parallel above the forming platform (21); the two ends of the powder spreading arm (3) and the roller (4) are respectively connected to the first motion guide rail (51) and the second motion guide rail (52), and can move along the first motion guide rail (51) and the second motion guide rail (52); The motion mechanism further includes a fixed guide rail (8), a third motion guide rail (61), and a fourth motion guide rail (71); the fixed guide rail (8) is disposed above the forming platform (21); the third motion guide rail (61) and the fourth motion guide rail (71) are both vertically disposed on the fixed guide rail (8), and are parallel to each other, and can both move along the fixed guide rail (8); the linear corona electrode array (7) is disposed on the fourth motion guide rail (71); the piezoelectric nozzle (6) is disposed on the third motion guide rail (61).

13. A method of using the adhesive jet printing apparatus as described in any one of claims 11-12, characterized in that, Includes the following steps: S1. Set the thickness of the single-layer printing layer, import the slice data generated by the three-dimensional model slicing into the control unit, load powder material into the powder supply cylinder of the powder spreading mechanism, and load binder solution into the piezoelectric nozzle (6); S2. The control unit controls the first motion guide rail (51) and the second motion guide rail (52) to drive the powder spreading arm (3) and the roller (4) to move: the powder spreading arm (3) spreads the powder onto the forming platform (21), and then the roller (4) compacts it to form a powder bed, the thickness of which is the thickness of the single-layer printing layer; S3. In a normal pressure air environment, the control unit controls the fourth motion guide rail (71) to move along the fixed guide rail (8) and starts the power supply to make the linear corona electrode array (7) generate corona discharge to perform the first corona treatment on the powder bed surface. The thickness of the powder bed is the thickness of the single-layer printing layer. S4. The control unit controls the third motion guide rail (61) to move along the fixed guide rail (8) and controls the piezoelectric nozzle (6) to selectively spray the adhesive solution onto the powder bed surface after the first corona treatment according to the printing path corresponding to the slice data, forming a pre-printed layer. S5. The control unit controls the fourth motion guide rail (71) to move again and starts the linear corona electrode array (7) to perform a second corona treatment on the pre-printed layer, so that the adhesive undergoes a cross-linking and curing reaction to form a single-layer printing layer. S6. The control unit controls the piston (22) to drive the forming platform (21) down by one single-layer printing layer thickness, and repeats the above steps S2 to S5 to build a three-dimensional green blank layer by layer.

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