Selective laser sintering porous conductive ceramic 3D printing consumable and preparation method

Abstract

The present invention relates to the technical field of porous conductive ceramics. Disclosed are a selective laser sintering porous conductive ceramic 3D printing consumable and a preparation method. The selective laser sintering porous conductive ceramic 3D printing consumable comprises the following components in percentage by weight: 30-60 wt% of modified silicon carbide powder, 10-40 wt% of conductive phase powder, 10-30 wt% of a polymer binder, and 0.1-5 wt% of a lipid. The selective laser sintering porous conductive ceramic 3D printing consumable is obtained by means of a direct mixing ball milling method or a xylene solution mixed washing method. A porous conductive ceramic green body is printed by means of a laser 3D printer, and is subjected to thermal debinding and sintering to obtain a ceramic sintered part.

Description

A selective laser sintering porous conductive ceramic 3D printing consumables and preparation method

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 28, 2023, with application number 202311096666.7 and application name “A Selective Laser Sintering of Porous Conductive Ceramic 3D Printing Consumables and Preparation Method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the technical field of porous conductive ceramics, and in particular to a selective laser sintering porous conductive ceramic 3D printing consumable and a preparation method thereof. Background Art

[0003] Existing HNB circumferential heating tubes are divided into insulating ceramic tubes and metal tubes. Insulating ceramic tubes are non-conductive and require coating or lamination on the outer surface to form a heating element. However, the outer surface coating easily falls off after use and is not resistant to oxidation, resulting in increasing resistance. In addition, ceramic tubes are heated from the outer wall, absorbing some heat while dissipating the remaining heat outside the tube. Energy utilization is not concentrated, resulting in a slow heating rate and low smoke production. Metal tubes are easily oxidized at high temperatures and are not corrosion-resistant, resulting in a metallic taste in the smoke, which affects the taste.

[0004] The porous ceramics of the prior art need to be sintered with the addition of pore-forming agents. On the one hand, they have poor strength and are prone to powdering after a long period of sintering. The powdering not only affects the taste of the atomized liquid but also easily causes safety hazards. On the other hand, the molding process of porous ceramics is complicated, and the pore size and porosity cannot be precisely controlled. Even if a pore-forming agent is used, it is difficult to precisely control the size. At the same time, there are dead holes and blind holes in local locations, which affect the delivery of the atomized liquid, resulting in insufficient liquid supply and affecting the dry-burning life of the heating element. In addition, the existing porous ceramic atomization core requires a mold to be made, and ceramic models of complex shapes are difficult to make, that is, it is difficult to make porous ceramic atomization cores of complex shapes. Existing porous ceramic heating elements are mostly metal heating wires or thick film heating slurries. Due to the large difference in thermal expansion coefficients between the heating element and the porous ceramic, the heating element is bonded to the substrate with solder paste or high-temperature glue. Stress is easily generated during the atomization process, causing the heating element to demold or the thick film heating element to break, and the porous ceramic and the heating element to fall off and separate, affecting the product's service life and experience.

[0005] Summary of the Invention

[0006] In a first aspect, the present invention provides a selective laser sintering porous conductive ceramic 3D printing consumable, comprising the following components in mass percentage: 30-60wt% modified silicon carbide powder, 10-40wt% conductive phase powder, 10-30wt% polymer binder, and 0.1-5wt% lipid.

[0007] In a second aspect, the present invention provides a method for preparing a selective laser sintering porous conductive ceramic 3D printing consumables, comprising the following steps: adding a conductive phase powder, a polymer binder, and a lipid to a modified silicon carbide powder in proportion by mass, and obtaining a selective laser sintering porous conductive ceramic 3D printing consumables by mechanical mixing, ball milling, or coating.

[0008] In a third aspect, the present invention provides a method for preparing selective laser sintering porous conductive ceramic 3D printing consumables, comprising the following steps: adding modified silicon carbide powder and conductive phase powder to a p-xylene solution in a mass ratio, mixing, and then heating to 110±5°C, then adding a polymer binder and a lipid, stirring and mixing at a constant temperature of 110±5°C, cooling naturally, washing with anhydrous ethanol and deionized water in turn, and then vacuum drying to obtain selective laser sintering porous conductive ceramic 3D printing consumables.

[0009] In a fourth aspect, the present invention further provides a ceramic method comprising the following steps:

[0010] (1) using a laser 3D printer to print the selective laser sintering porous conductive ceramic 3D printing consumables to obtain a porous conductive ceramic green body;

[0011] (2) The porous conductive ceramic green body is subjected to a thermal degreasing process and then sintered to obtain a ceramic sintered part. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] FIG1 is a structural diagram of a porous rectangular conductive ceramic provided in Example 2 of the present invention.

[0014] FIG2 is a front view of a porous rectangular conductive ceramic provided in Example 2 of the present invention.

[0015] FIG3 is a side view of the porous rectangular conductive ceramic provided in Example 2 of the present invention.

[0016] FIG4 is a top view of the porous rectangular conductive ceramic provided in Example 2 of the present invention.

[0017] Explanation of the symbols in the figure: 1-porous conductive ceramic; 2-separation groove; 3-longitudinal through hole; 4-transverse through hole. DETAILED DESCRIPTION

[0018] The present invention is further described below by means of specific examples. It should be understood that the examples are only used to explain the present invention and are not intended to limit the technical solutions of the present invention.

[0019] In order to solve the above technical problems, the purpose of the present invention is achieved through the following technical solutions.

[0020] Provided is a selective laser sintering porous conductive ceramic 3D printing consumable, comprising the following components in mass percentage: 30-60wt% of modified silicon carbide powder, 10-40wt% of conductive phase powder, 10-30wt% of polymer binder, and 0.1-5wt% of lipid.

[0021] The modified silicon carbide powder is prepared by the following steps: preparing a silane coupling agent KH570 ethanol solution, wherein the mass ratio of the silane coupling agent KH570 to ethanol is (3-5):1; adding silicon carbide powder after ultrasonic mixing; and stirring and mixing to obtain solution A; adjusting the pH of solution A to 2-6 with acetic acid solution and continuing to stir and mix to obtain solution B; adjusting the pH of solution B to 9-12 with ammonia water; and performing heat drying and grinding to obtain modified silicon carbide powder.

[0022] In some embodiments, the modified silicon carbide powder is prepared by the following steps:

[0023] (1) preparing a silane coupling agent KH570 ethanol solution, wherein the mass ratio of the silane coupling agent KH570 to ethanol is 4:1, ultrasonicating for 15-20 minutes, adding silicon carbide powder, and stirring for 1 hour to obtain solution A;

[0024] (2) adjusting the pH of solution A to 2-6 with acetic acid solution and continuing stirring for 4-5 hours to obtain solution B;

[0025] (3) Adjust the pH of solution B to 9-12 with aqueous ammonia, heat in a water bath until dried to obtain a modified silicon carbide block, and grind and sieve to obtain a modified silicon carbide powder.

[0026] In some embodiments, the silicon carbide powder is spherical, has a purity of not less than 99%, and a particle size of 50-800 μm. The mass fraction of the silane coupling agent KH570 in the modified silicon carbide powder is 2-12 wt%.

[0027] The conductive phase powder is selected from at least one of titanium nitride, zirconium nitride, titanium carbonitride, titanium carbide, zirconium carbide, thallium carbide, hafnium carbide, titanium boride, zirconium boride, thallium boride, hafnium boride, molybdenum silicide, and tungsten carbide. In some embodiments, the conductive phase powder has a particle size of no greater than 500 μm and a purity of no less than 99%.

[0028] The lipid is selected from at least one of dioctyl phthalate, stearic acid, chlorinated paraffin, and polydimethylsiloxane.

[0029] The polymer binder is selected from at least one of polypropylene, polyamide, polyvinyl alcohol and epoxy resin.

[0030] The preparation method of the selective laser sintering porous conductive ceramic 3D printing consumables can adopt one of the direct mixing ball milling method and the xylene solution mixed water washing method.

[0031] Specifically, the direct mixing and ball milling method involves adding a conductive phase powder, a polymer binder, and a lipid to modified silicon carbide powder in a proportional mass ratio, followed by mechanical mixing and ball milling or coating to produce a selective laser sintered porous conductive ceramic 3D printing consumable. This mechanical mixing and ball milling or coating allows the polymer to evenly coat the silicon carbide powder, allowing it to fully wet and bond to the silicon carbide powder surface under the action of the laser, improving the likelihood of forming.

[0032] In some embodiments, the direct mixing ball milling method comprises the following steps:

[0033] (1) According to the above mass ratio, the polymer binder, modified silicon carbide powder, conductive phase powder and lipid are loaded into a ball mill with a ball-to-material ratio of (3-4):1, the rotation speed is 400-600 r / min, and the ball milling is carried out for 3-5 hours to obtain silicon carbide composite powder;

[0034] (2) The silicon carbide composite powder is dried, ground and sieved to obtain selective laser sintering porous conductive ceramic 3D printing consumables.

[0035] Specifically, the xylene solution mixed water washing method includes the following steps: adding modified silicon carbide powder and conductive phase powder to p-xylene solution according to mass proportion, mixing and heating to 110±5°C, then adding polymer binder and lipid and stirring and mixing at a constant temperature of 110±5°C, cooling naturally and washing with anhydrous ethanol and deionized water in turn, and then vacuum drying to obtain selective laser sintering porous conductive ceramic 3D printing consumables.

[0036] In some embodiments, the xylene solution mixed water washing method comprises the following steps:

[0037] (1) Add modified silicon carbide powder and conductive phase powder to the p-xylene solution according to the mass ratio, stir at room temperature for 2-2.5 hours, and then heat to 110°C;

[0038] (2) After adding the polymer binder and lipid, continue stirring at a constant temperature for 1-1.5 hours, cool naturally, wash with anhydrous ethanol and deionized water in turn, dry under vacuum conditions, grind and sieve to obtain selective laser sintering porous conductive ceramic 3D printing consumables.

[0039] The present invention also provides a ceramic method, comprising the following steps:

[0040] (1) using a laser 3D printer to print the selective laser sintering porous conductive ceramic 3D printing consumables to obtain a porous conductive ceramic green body;

[0041] (2) The porous conductive ceramic green body is subjected to a thermal degreasing process and then sintered to obtain a ceramic sintered part.

[0042] Referring to Figures 2-4, in some embodiments, the structural member of the porous conductive ceramic green body can be a cylinder, a cuboid, or a cube. The diameter of the cylinder is 2-10 mm and the thickness is 0.1-8 mm. The length of the cuboid is 2-10 mm, the width is 2-10 mm, and the thickness is 0.1-8 mm. The length of the cube is 2-10 mm and the thickness is 0.1-8 mm. Furthermore, the porous conductive ceramic green body is longitudinally (from top to bottom) distributed with a plurality of longitudinal through holes 3, with an aperture of 10-500 μm and a hole spacing of 20-1000 μm. The hole shape can be circular, square, prismatic, star-shaped, and heart-shaped.

[0043] In some embodiments, a plurality of transverse through holes 4 are provided in the middle and lower portion of the porous conductive ceramic green body in the thickness direction. The diameter of the transverse through holes 4 is 10-500 μm, and the hole spacing is 20-1000 μm.

[0044] A separation groove 2 is provided at the bottom of the porous conductive ceramic green body, which divides the middle and lower parts of the porous conductive ceramic green body into two parts in the thickness direction. The depth of the separation groove 2 is 0.07-5.00 mm or (0.25-0.5) times the thickness of the porous conductive ceramic green body.

[0045] Furthermore, the thermal degreasing process is divided into 6 stages: the first stage is heating from room temperature to 200°C, with a heating rate of 1-3°C / min, and keeping warm for 1-1.5 hours; the second stage is heating from 200°C to 350°C, with a heating rate of 1-3°C / min, and keeping warm for 1-1.5 hours; the third stage is heating from 350°C to 450°C, with a heating rate of 0.5-1.5°C / min, and keeping warm for 1-1.5 hours; the fourth stage is heating from 450°C to 500°C, with a heating rate of 0.3-1°C / min, and keeping warm for 4-4.5 hours; the fifth stage is heating from 500°C to 1000°C, with a heating rate of 1-3°C / min, and keeping warm for 5-5.5 hours; and the sixth stage is cooling from 1000°C to room temperature.

[0046] Preferably, the thermal degreasing process is divided into 6 stages: the first stage is heating from room temperature to 200°C, with a heating rate of 2°C / min, and keeping warm for 1-1.5h; the second stage is heating from 200°C to 350°C, with a heating rate of 2°C / min, and keeping warm for 1-1.5h; the third stage is heating from 350°C to 450°C, with a heating rate of 1°C / min, and keeping warm for 1-1.5h; the fourth stage is heating from 450°C to 500°C, with a heating rate of 0.5°C / min, and keeping warm for 4-4.5h; the fifth stage is heating from 500°C to 1000°C, with a heating rate of 2°C / min, and keeping warm for 5-5.5h; the sixth stage is cooling from 1000°C to room temperature.

[0047] In some embodiments, the thermal debinding process is carried out in a muffle furnace and can be divided into 6 stages: the first stage is heating from room temperature to 200°C at a heating rate of 2°C / min and keeping warm for 1 hour; the second stage is heating from 200°C to 350°C at a heating rate of 2°C / min and keeping warm for 1 hour; the third stage is heating from 350°C to 450°C at a heating rate of 1°C / min and keeping warm for 1 hour; the fourth stage is heating from 450°C to 500°C at a heating rate of 0.5°C / min and keeping warm for 4 hours; the fifth stage is heating from 500°C to 1000°C at a heating rate of 2°C / min and keeping warm for 5 hours; the sixth stage is cooling from 1000°C to room temperature.

[0048] Furthermore, the sintering is divided into three stages. The first stage is heating from room temperature to 500°C at a heating rate of 2-5°C / min and keeping warm for 2-2.5 hours; the second stage is heating from 500°C to 1900°C at a heating rate of 5-15°C / min and keeping warm for 4-4.5 hours; the third stage is natural cooling from 1900°C.

[0049] In some embodiments, sintering is divided into three stages: the first stage is heating from room temperature to 500°C at a heating rate of 3°C / min and keeping warm for 2-2.5 hours; the second stage is heating from 500°C to 1900°C at a heating rate of 10°C / min and keeping warm for 4-4.5 hours; the third stage is natural cooling from 1900°C.

[0050] In some embodiments, sintering is carried out in a vacuum pressureless sintering furnace and can be divided into three stages: the first stage is heating from room temperature to 500°C at a heating rate of 3°C / min and keeping warm for 2 hours; the second stage is heating from 500°C to 1900°C at a heating rate of 10°C / min and keeping warm for 4 hours; the third stage is natural cooling from 1900°C.

[0051] Furthermore, the laser 3D printer includes a laser, which can be one of a YAG laser, a continuous CO2 laser, and a fiber laser; the wavelength of the YAG laser is 1.06 μm, the wavelength of the continuous CO2 laser is 10.60 μm, and the wavelength of the fiber laser is 1064 μm.

[0052] Specifically, the laser power of the fiber laser is 175-215W, the scanning speed is 350-550mm / s, and the laser energy density is 0.010-0.021J / mm 2 .

[0053] The present invention provides a selective laser sintering porous conductive ceramic 3D printing consumable and a preparation method. The selective laser sintering porous conductive ceramic 3D printing consumable comprises 30-60wt% of modified silicon carbide powder, 10-40wt% of conductive phase powder, 10-30wt% of polymer binder, and 0.1-5wt% of lipid. The selective laser sintering porous conductive ceramic 3D printing consumable is obtained by a direct mixing ball milling method or a xylene solution mixed water washing method. The porous conductive ceramic green body is printed using a laser 3D printer. The porous conductive ceramic green body has various structures. After thermal degreasing and sintering, a ceramic sintered part is obtained. The selective laser sintering porous conductive ceramic 3D printing consumables and preparation method of the present invention have a simple preparation process and low cost; the porous conductive ceramic green body is printed by a laser 3D printer with high printing precision, and the pore size and porosity of the porous conductive ceramic green body can be accurately controlled without the use of a pore-forming agent. Ceramic models with complex shapes can be produced without a mold, and multiple ceramic models can be printed simultaneously, meeting the conditions for mass production; the technical problems of hot melting and oil conduction and storage of porous conductive ceramic atomization cores can be solved without the need for the porous conductive ceramic body to be made into thin sheets.

[0054] Example 1

[0055] The preparation method of the selective laser sintering silicon carbide conductive ceramic 3D printing consumables of this embodiment is as follows:

[0056] (1) Preparation of modified silicon carbide.

[0057] ① Prepare a silane coupling agent KH570 ethanol solution with a mass ratio of silane coupling agent KH570 to ethanol of 4:1. After ultrasonication for 15 minutes, add spherical silicon carbide powder with a particle size of 60 nm and stir for 1 hour to obtain solution A.

[0058] ② Adjust the pH of solution A to 5 with acetic acid solution and continue stirring for 4 hours to obtain solution B;

[0059] ③ Adjust the pH of solution B to 10 with ammonia water, heat in a water bath until dried to obtain a modified silicon carbide block, and grind and sieve to obtain a modified silicon carbide powder.

[0060] The mass fraction of the silane coupling agent KH570 in the modified silicon carbide powder obtained in this embodiment is 8 wt %.

[0061] (2) Component selection.

[0062] According to mass percentage, the modified silicon carbide powder is 40wt%, the conductive phase powder is 40wt%, the polymer binder is 18wt%, and the lipid is 2wt%.

[0063] The conductive phase powder is selected from titanium nitride and titanium carbide, the mass ratio of titanium nitride to titanium carbide is 1:2, and the particle sizes are 40nm and 60nm respectively; the polymer binder is selected from polypropylene PP; and the lipid is selected from stearic acid.

[0064] (3) Preparation of selective laser sintering porous conductive ceramic 3D printing consumables by direct mixing ball milling method.

[0065] ① According to the mass ratio in step (2), the polymer binder, modified silicon carbide powder, conductive phase powder and lipid are loaded into a ball mill with a ball-to-material ratio of 3:1, a rotation speed of 500 r / min, and ball milling for 5 h to obtain silicon carbide composite powder;

[0066] ② The silicon carbide composite powder is dried, ground and sieved to obtain selective laser sintering porous conductive ceramic 3D printing consumables.

[0067] (4) Ceramicization.

[0068] ① Using a laser 3D printer to print 3D printing consumables for selective laser sintering of porous conductive ceramics 1 to obtain a porous conductive ceramic green body.

[0069] The laser is a fiber laser with a wavelength of 1064 nm, a laser power of 210 W, a scanning speed of 550 mm / s, and a laser energy density of 0.015 J / mm 2 .

[0070] The printed porous cylindrical conductive ceramic green body has a diameter of 8 mm, a thickness of 0.2 mm, and a pore size of 80 μm.

[0071] ② The porous cylindrical conductive ceramic green body is subjected to a thermal degreasing process and then sintered to obtain a ceramic sintered part.

[0072] The porous cylindrical conductive ceramic green body is directly placed in the debinding sintering tray, and then the placed debinding tray is directly placed in the debinding sintering furnace. The thermal debinding is carried out in a muffle furnace and can be divided into 6 stages: the first stage is heated from room temperature to 200℃, with a heating rate of 2℃ / min, and kept warm for 1h; the second stage is heated from 200℃ to 350℃, with a heating rate of 2℃ / min, and kept warm for 1h; the third stage is heated from 350℃ to 450℃, with a heating rate of 1℃ / min, and kept warm for 1h; the fourth stage is heated from 450℃ to 500℃, with a heating rate of 0.5℃ / min, and kept warm for 4h; the fifth stage is heated from 500℃ to 1000℃, with a heating rate of 2℃ / min, and kept warm for 5h; the sixth stage is cooled from 1000℃ to room temperature.

[0073] After thermal debinding, it is placed in a vacuum pressureless sintering furnace for sintering, which can be divided into three stages: the first stage is heating from room temperature to 500°C at a heating rate of 3°C / min and keeping warm for 2 hours; the second stage is heating from 500°C to 1900°C at a heating rate of 10°C / min and keeping warm for 4 hours; the third stage is natural cooling from 1900°C.

[0074] Finally, porous cylindrical conductive ceramics are obtained.

[0075] Example 2

[0076] The preparation method of the selective laser sintering silicon carbide conductive ceramic 3D printing consumables of this embodiment is as follows:

[0077] (1) Preparation of modified silicon carbide.

[0078] ① Prepare a silane coupling agent KH570 ethanol solution with a mass ratio of silane coupling agent KH570 to ethanol of 4:1. After ultrasonic treatment for 15 minutes, add spherical silicon carbide powder with a particle size of 80 nm and stir for 1 hour to obtain solution A.

[0079] ② Adjust the pH of solution A to 6 with acetic acid solution and continue stirring for 4 hours to obtain solution B;

[0080] ③ Adjust the pH of solution B to 9 with ammonia water, heat in a water bath until dried to obtain a modified silicon carbide block, and grind and sieve to obtain a modified silicon carbide powder.

[0081] The mass fraction of the silane coupling agent KH570 in the modified silicon carbide powder obtained in this embodiment is 9 wt %.

[0082] (2) Component selection.

[0083] According to mass percentage, the modified silicon carbide powder is 50wt%, the conductive phase powder is 23wt%, the polymer binder is 24wt%, and the lipid is 3wt%.

[0084] The conductive phase powder is selected from titanium boride and titanium carbide, the mass ratio of titanium boride and titanium carbide is 1:1, and the particle sizes are 60nm and 60nm respectively; the polymer binder is selected from epoxy resin; and the lipid is selected from stearic acid.

[0085] (3) Preparation of 3D printing consumables for selective laser sintering of porous conductive ceramics 1 by mixed water washing method using xylene solution.

[0086] Modified silicon carbide powder and conductive phase powder were added to the p-xylene solution in proportion by mass, stirred at room temperature for 2 h, and then heated to 110°C.

[0087] After adding the polymer binder and lipid, stirring was continued at a constant temperature for 1 hour. After natural cooling, the mixture was washed with anhydrous ethanol and deionized water in sequence, dried under vacuum conditions, and then ground and sieved to obtain 3D printing consumables of selective laser sintering porous conductive ceramic 1.

[0088] (4) Ceramicization.

[0089] ① Using a laser 3D printer to print 3D printing consumables for selective laser sintering of porous conductive ceramics 1 to obtain a porous conductive ceramic green body.

[0090] The laser selected is a fiber laser with a wavelength of 1064nm, a laser power of 200W, a scanning speed of 500mm / s, and a laser energy density of 0.021J / mm 2 .

[0091] The printed porous rectangular conductive ceramic green body is 8 mm long, 2.5 mm wide, 0.1 mm thick, and has a pore size of 80 μm.

[0092] ② The porous rectangular conductive ceramic green body is subjected to a thermal degreasing process and then sintered to obtain a ceramic sintered part.

[0093] The porous rectangular conductive ceramic green body is directly placed on the debinding sintering tray, and then the placed debinding tray is directly placed in the debinding sintering furnace. The thermal debinding is carried out in a muffle furnace and can be divided into 6 stages: the first stage is heated from room temperature to 200℃, with a heating rate of 2℃ / min, and kept warm for 1h; the second stage is heated from 200℃ to 350℃, with a heating rate of 2℃ / min, and kept warm for 1h; the third stage is heated from 350℃ to 450℃, with a heating rate of 1℃ / min, and kept warm for 1h; the fourth stage is heated from 450℃ to 500℃, with a heating rate of 0.5℃ / min, and kept warm for 4h; the fifth stage is heated from 500℃ to 1000℃, with a heating rate of 2℃ / min, and kept warm for 5h; the sixth stage is cooled from 1000℃ to room temperature.

[0094] After thermal debinding, it is placed in a vacuum pressureless sintering furnace for sintering, which can be divided into three stages: the first stage is heating from room temperature to 500°C at a heating rate of 3°C / min and keeping warm for 2 hours; the second stage is heating from 500°C to 1900°C at a heating rate of 10°C / min and keeping warm for 4 hours; the third stage is natural cooling from 1900°C.

[0095] Finally, a porous rectangular conductive ceramic as shown in FIG1 is obtained.

[0096] Example 3

[0097] The preparation method of the selective laser sintering silicon carbide conductive ceramic 3D printing consumables of this embodiment is as follows:

[0098] (1) Preparation of modified silicon carbide.

[0099] ① Prepare a silane coupling agent KH570 ethanol solution with a mass ratio of silane coupling agent KH570 to ethanol of 4:1. After ultrasonication for 15 minutes, add spherical silicon carbide powder with a particle size of 60 nm and stir for 1 hour to obtain solution A.

[0100] ② Adjust the pH of solution A to 6 with acetic acid solution and continue stirring for 4 hours to obtain solution B;

[0101] ③ Adjust the pH of solution B to 10 with ammonia water, heat in a water bath until dried to obtain a modified silicon carbide block, and grind and sieve to obtain a modified silicon carbide powder.

[0102] The mass fraction of the silane coupling agent KH570 in the modified silicon carbide powder obtained in this embodiment is 10 wt %.

[0103] (2) Component selection.

[0104] According to mass percentage, the modified silicon carbide powder is 40wt%, the conductive phase powder is 29wt%, the polymer binder is 27wt%, and the lipid is 4wt%.

[0105] The conductive phase powder is selected from titanium nitride, titanium carbide and titanium boride, the mass ratio of titanium nitride, titanium carbide and titanium boride is 1:1:1, and the particle sizes are 40nm, 60nm and 60nm respectively; the polymer binder is selected from polypropylene PP; and the lipid is selected from stearic acid.

[0106] (3) 3D printing consumables of selective laser sintering porous conductive ceramics 1 were prepared by direct mixing ball milling method.

[0107] ① According to the mass ratio in step (2), the polymer binder, modified silicon carbide powder, conductive phase powder and lipid are loaded into a ball mill with a ball-to-material ratio of 3:1, a rotation speed of 500 r / min, and ball milling for 5 h to obtain silicon carbide composite powder;

[0108] ② The silicon carbide composite powder is dried, ground and sieved to obtain the 3D printing consumables of selective laser sintering porous conductive ceramic 1.

[0109] (4) Ceramicization.

[0110] ① Using a laser 3D printer to print 3D printing consumables for selective laser sintering of porous conductive ceramics 1 to obtain a porous conductive ceramic green body.

[0111] The laser selected is a fiber laser with a wavelength of 1064nm, a laser power of 180W, a scanning speed of 500mm / s, and a laser energy density of 0.021J / mm 2 .

[0112] The printed porous rectangular conductive ceramic green body is 8 mm long, 2.5 mm wide, 0.2 mm thick, and has a pore size of 100 μm.

[0113] ② The porous rectangular conductive ceramic green body is subjected to a thermal degreasing process and then sintered to obtain a ceramic sintered part.

[0114] The porous rectangular conductive ceramic green body is directly placed on the debinding sintering tray, and then the placed debinding tray is directly placed in the debinding sintering furnace. The thermal debinding is carried out in a muffle furnace and can be divided into 6 stages: the first stage is heated from room temperature to 200℃, with a heating rate of 2℃ / min, and kept warm for 1h; the second stage is heated from 200℃ to 350℃, with a heating rate of 2℃ / min, and kept warm for 1h; the third stage is heated from 350℃ to 450℃, with a heating rate of 1℃ / min, and kept warm for 1h; the fourth stage is heated from 450℃ to 500℃, with a heating rate of 0.5℃ / min, and kept warm for 4h; the fifth stage is heated from 500℃ to 1000℃, with a heating rate of 2℃ / min, and kept warm for 5h; the sixth stage is cooled from 1000℃ to room temperature.

[0115] After thermal debinding, it is placed in a vacuum pressureless sintering furnace for sintering, which can be divided into three stages: the first stage is heating from room temperature to 500°C at a heating rate of 3°C / min and keeping warm for 2 hours; the second stage is heating from 500°C to 1900°C at a heating rate of 10°C / min and keeping warm for 4 hours; the third stage is natural cooling from 1900°C.

[0116] Finally, porous rectangular conductive ceramics are obtained.

[0117] Example 4

[0118] The preparation method of the selective laser sintering silicon carbide conductive ceramic 3D printing consumables of this embodiment is as follows:

[0119] (1) Preparation of modified silicon carbide.

[0120] ① Prepare a silane coupling agent KH570 ethanol solution with a mass ratio of silane coupling agent KH570 to ethanol of 4:1. After ultrasonication for 15 minutes, add spherical silicon carbide powder with a particle size of 60 nm and stir for 1 hour to obtain solution A.

[0121] ② Adjust the pH of solution A to 5 with acetic acid solution and continue stirring for 4 hours to obtain solution B;

[0122] ③ Adjust the pH of solution B to 10 with ammonia water, heat in a water bath until dried to obtain a modified silicon carbide block, and grind and sieve to obtain a modified silicon carbide powder.

[0123] The mass fraction of the silane coupling agent KH570 in the modified silicon carbide powder obtained in this embodiment is 6 wt %.

[0124] (2) Component selection.

[0125] According to mass percentage, the modified silicon carbide powder is 50wt%, the conductive phase powder is 16wt%, the polymer binder is 30wt%, and the lipid is 4wt%.

[0126] The conductive phase powder is selected from titanium nitride and titanium carbide, the mass ratio of titanium nitride and titanium carbide is 1:1, and the particle sizes are 60nm and 60nm respectively; the polymer binder is selected from polyamide PA12; and the lipid is selected from dioctyl phthalate.

[0127] (3) Preparation of 3D printing consumables for selective laser sintering of porous conductive ceramics 1 by mixed water washing method using xylene solution.

[0128] Add modified silicon carbide powder and conductive phase powder to the p-xylene solution according to the mass ratio, stir at room temperature for 2 hours and then heat to 110°C;

[0129] After adding the polymer binder and lipid, stirring was continued at a constant temperature for 1 hour. After natural cooling, the mixture was washed with anhydrous ethanol and deionized water in sequence, dried under vacuum conditions, and then ground and sieved to obtain 3D printing consumables of selective laser sintering porous conductive ceramic 1.

[0130] (4) Ceramicization.

[0131] ① Using a laser 3D printer to print 3D printing consumables for selective laser sintering of porous conductive ceramics 1 to obtain a porous conductive ceramic green body.

[0132] The laser selected is a fiber laser with a wavelength of 1064nm, a laser power of 180W, a scanning speed of 500mm / s, and a laser energy density of 0.017J / mm 2 .

[0133] The printed porous rectangular conductive ceramic green body is 8 mm long, 2.5 mm wide, 0.1 mm thick, and has a pore size of 80 μm.

[0134] ② The porous rectangular conductive ceramic green body is subjected to a thermal degreasing process and then sintered to obtain a ceramic sintered part.

[0135] The porous rectangular conductive ceramic green body is directly placed on the debinding sintering tray, and then the placed debinding tray is directly placed in the debinding sintering furnace. The thermal debinding is carried out in a muffle furnace and can be divided into 6 stages: the first stage is heated from room temperature to 200℃, with a heating rate of 2℃ / min, and kept warm for 1h; the second stage is heated from 200℃ to 350℃, with a heating rate of 2℃ / min, and kept warm for 1h; the third stage is heated from 350℃ to 450℃, with a heating rate of 1℃ / min, and kept warm for 1h; the fourth stage is heated from 450℃ to 500℃, with a heating rate of 0.5℃ / min, and kept warm for 4h; the fifth stage is heated from 500℃ to 1000℃, with a heating rate of 2℃ / min, and kept warm for 5h; the sixth stage is cooled from 1000℃ to room temperature.

[0136] After thermal debinding, it is placed in a vacuum pressureless sintering furnace for sintering, which can be divided into three stages: the first stage is heating from room temperature to 500°C at a heating rate of 3°C / min and keeping warm for 2 hours; the second stage is heating from 500°C to 1900°C at a heating rate of 10°C / min and keeping warm for 4 hours; the third stage is natural cooling from 1900°C.

[0137] Finally, porous rectangular conductive ceramics are obtained.

[0138] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A selective laser sintering porous conductive ceramic 3D printing consumables, characterized in that: The invention comprises the following components in percentage by weight: 30-60wt% of modified silicon carbide powder, 10-40wt% of conductive phase powder, 10-30wt% of polymer binder and 0.1-5wt% of lipid.

2. The selective laser sintering porous conductive ceramic 3D printing consumable according to claim 1, characterized in that: The modified silicon carbide powder is prepared by the following steps: preparing a silane coupling agent KH570 ethanol solution, wherein the mass ratio of the silane coupling agent KH570 to ethanol is (3-5):1, adding silicon carbide powder after ultrasonic mixing, stirring and mixing to obtain solution A; adjusting the pH of solution A to 2-6 with acetic acid solution, and continuing to stir and mix to obtain solution B; adjusting the pH of solution B to 9-12 with ammonia water, and drying by heat, and grinding to obtain modified silicon carbide powder.

3. The selective laser sintering porous conductive ceramic 3D printing consumables according to claim 1 or 2, characterized in that: The conductive phase powder is selected from at least one of titanium nitride, zirconium nitride, titanium carbonitride, titanium carbide, zirconium carbide, thallium carbide, hafnium carbide, titanium boride, zirconium boride, thallium boride, hafnium boride, molybdenum silicide, and tungsten carbide.

4. The selective laser sintering porous conductive ceramic 3D printing consumable according to any one of claims 1 to 3, characterized in that: The lipid material is selected from at least one of dioctyl phthalate, stearic acid, chlorinated paraffin and polydimethylsiloxane.

5. The selective laser sintering porous conductive ceramic 3D printing consumable according to any one of claims 1 to 4, characterized in that: The polymer binder is selected from at least one of polypropylene, polyamide, polyvinyl alcohol and epoxy resin.

6. The selective laser sintering porous conductive ceramic 3D printing consumable according to any one of claims 1 to 5, characterized in that: The conductive phase powder is selected from titanium nitride and titanium carbide, the mass ratio of the titanium nitride to the titanium carbide is 1:2, and the particle sizes are 40 nm and 60 nm respectively.

7. A method for preparing a selective laser sintering porous conductive ceramic 3D printing consumable according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: adding the conductive phase powder, the polymer binder and the lipid into the modified silicon carbide powder in proportion by mass, and obtaining the selective laser sintering porous conductive ceramic 3D printing consumables through mechanical mixing, ball milling or coating.

8. A method for preparing a selective laser sintering porous conductive ceramic 3D printing consumable according to any one of claims 1 to 6, characterized in that: The following steps are involved: According to the mass ratio, the modified silicon carbide powder and the conductive phase powder are added to the p-xylene solution, the mixture is heated to 110±5°C, the polymer binder and the lipid are added, and the mixture is stirred and mixed at a constant temperature of 110±5°C. After natural cooling, the mixture is washed with anhydrous ethanol and deionized water in turn, and then vacuum dried to obtain the selective laser sintering porous conductive ceramic 3D printing consumables.

9. A ceramic method, characterized in that: The following steps are involved: Printing the selective laser sintering porous conductive ceramic 3D printing consumables as claimed in any one of claims 1 to 6 using a laser 3D printer to obtain a porous conductive ceramic green body; The porous conductive ceramic green body is subjected to thermal degreasing process and then sintered to obtain a ceramic sintered part.

10. The ceramicization method according to claim 9, characterized in that: The thermal debinding process is divided into 6 stages: the first stage is heating from room temperature to 200°C, with a heating rate of 1-3°C / min, and keeping warm for 1-1.5h; the second stage is heating from 200°C to 350°C, with a heating rate of 1-3°C / min, and keeping warm for 1-1.5h; the third stage is heating from 350°C to 450°C, with a heating rate of 0.5-1.5°C / min, and keeping warm for 1-1.5h; the fourth stage is heating from 450°C to 500°C, with a heating rate of 0.3-1°C / min, and keeping warm for 4-4.5h; the fifth stage is heating from 500°C to 1000°C, with a heating rate of 1-3°C / min, and keeping warm for 5-5.5h; the sixth stage is cooling from 1000°C to room temperature.

11. The ceramicization method according to claim 9 or 10, characterized in that: The sintering is divided into three stages. The first stage is heating from room temperature to 500°C at a heating rate of 2-5°C / min and keeping warm for 2-2.5h; the second stage is heating from 500°C to 1900°C at a heating rate of 5-15°C / min and keeping warm for 4-4.5h; the third stage is natural cooling from 1900°C.

12. The ceramicizing method according to any one of claims 9 to 11, characterized in that: The porous conductive ceramic green body is longitudinally distributed with a plurality of through holes, the hole diameter is 10-500 μm, and the hole spacing is 20-1000 μm.

13. The ceramicizing method according to any one of claims 9 to 12, characterized in that: The porous conductive ceramic green body is provided with a plurality of transverse through holes in the middle and lower part in the thickness direction. The diameter of the transverse through holes is 10-500 μm, and the hole spacing is 20-1000 μm.

14. The ceramicizing method according to any one of claims 9 to 13, characterized in that: A separation groove is provided at the bottom of the porous conductive ceramic green body, which separates the middle and lower parts of the porous conductive ceramic green body into two parts in the thickness direction. The depth of the separation groove is 0.07-5.00 mm or (0.25-0.5) times the thickness of the porous conductive ceramic green body.

15. The ceramicizing method according to any one of claims 9 to 14, characterized in that: The laser is a fiber laser with a wavelength of 1064 nm, a laser power of 210 W, a scanning speed of 550 mm / s, and a laser energy density of 0.015 J / mm 2 .

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