A method for additive manufacturing of stainless steel using a cermet matrix

Abstract

The present invention belongs to the technical field of 3D printing manufacturing, and discloses a method for additive manufacturing of stainless steel using a metal-ceramic matrix, aiming to solve the possible deficiencies in hardness, wear resistance and corrosion resistance of traditional metal-ceramic matrix composite materials. After mixing and treating flake graphite with a concentrated acid solution, potassium permanganate and graphite are added, and then treated again to obtain a suspension; the cooled suspension after the reaction is mixed and reacted with an ethanol intercalation solvent and ultrasonically treated to obtain an intercalated solution; diethanolamine and the intercalated solution are put into a high-pressure reactor for treatment, and finally filtered, washed with water and dried to obtain nitrogen-doped graphene; titanium carbide, sulfonated silicon carbide and nitrogen-doped graphene are loaded into a mixer in different proportions for premixing to obtain a composite powder, which is used in the additive manufacturing process of stainless steel. The method for additive manufacturing of stainless steel using a metal-ceramic matrix according to the present invention has precise 3D finished product dimensions, improves the quality of the finished product, has a smooth surface without defects, and has improved hardness and wear resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing manufacturing, and particularly relates to a method for additive manufacturing of stainless steel using a cermet matrix. Background Art

[0002] Cermet is a composite material composed of a ceramic hard phase and a metal or alloy binder phase. Cermets are widely used in wear-resistant components such as cutting tools. Additive manufacturing technology (also known as 3D printing) is a kind of rapid prototyping technology. It is a technology that constructs objects by layer-by-layer stacking based on a digital model file, using powdered metals or plastics and other bondable materials, and is increasingly widely used in fields such as cutting tools, automobiles, aerospace, and medical.

[0003] In the traditional field of cutting tool and fixture manufacturing, the additive manufacturing of cermet matrices may face higher forming complexity. Especially for complex-structured parts, more complex processes and additional processing steps may be required to complete, which increases the manufacturing cost and cycle. Additionally, the cermet matrix may have poor thermal conductivity, resulting in poor heat transfer within the material, affecting the thermal stability and service life of the material. At the same time, poor thermal conductivity may also lead to difficulties in temperature control during the processing, further affecting the quality and performance of the product. Moreover, due to problems such as high forming complexity and poor thermal conductivity, the processing cycle of the unimproved technology may be relatively long. This not only increases the production cost but may also limit the production efficiency, failing to meet the market's demand for rapid response and high-efficiency production. The cermet matrix composite material prepared by the original technology may have deficiencies in hardness, wear resistance, and corrosion resistance. These deficiencies in performance may cause the product to be easily damaged or fail during use, reducing the service life and reliability of the product.

[0004] To solve the existing problems, we propose a method for additive manufacturing of stainless steel using a cermet matrix. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for additive manufacturing of stainless steel using a cermet matrix to solve the problems raised in the above background art.

[0006] A method for additive manufacturing of stainless steel using a cermet matrix, the preparation steps include:

[0007] S1: Mix flake graphite and concentrated acid solution at a mass ratio of 1:(110 - 140), stir at 40 - 60°C, then add potassium permanganate and graphite at a mass ratio of (5 - 8):1, react at 50 - 80°C for 6 - 7 hours, then raise the temperature to 70 - 100°C and react for 30 - 60 min to obtain a suspension; Mix the cooled suspension and ethanol intercalation solvent at a volume ratio of 22:(1 - 1.5), react and perform ultrasonic treatment to obtain an intercalation solution; Put diethanolamine and the intercalation solution at a volume ratio of (1 - 5):100 into a high-pressure reactor, treat at 190 - 220°C for 8 - 12 h, and finally perform suction filtration, water washing and drying to obtain nitrogen-doped graphene;

[0008] S2: Load titanium carbide, sulfonated silicon carbide and nitrogen-doped graphene into a mixer in different proportions for premixing to obtain a composite powder;

[0009] S3: Put the composite powder into a stainless-steel jacket, evacuate the stainless-steel jacket, and then put the jacket into a hot isostatic press for hot isostatic pressing to make an ingot;

[0010] S4: Put the ingot into a vacuum heat treatment furnace, perform hot extrusion treatment on the ingot at 800 - 870°C for 250 - 300 min to prepare an extrusion wire;

[0011] S5: Draw the extrusion wire into a finished cermet wire on a hot drawing device;

[0012] S6: Load the cermet wire prepared in S5 onto a plastic 3D printer, and print a cermet green body according to the three-dimensional modeling program in the computer;

[0013] S7: Place stainless-steel powder on the surface of the cermet matrix, use a 3D printer to lay it 35 - 50 layers repeatedly, and after printing, obtain a green body with stainless-steel additive;

[0014] S8: Put the green body with additive into a sintering furnace filled with inert protective gas, sinter at a sintering temperature of 700 - 800°C for 380 - 460 min, and then cool to room temperature in the furnace and take it out;

[0015] S9: Modify the surface of the finished product with a high-current pulsed electron beam, with an accelerating voltage of 20 - 25 kV, a pulse width of 2.5 - 3.5 μs, a pulse number of 5 - 25 times, and a target distance of 6 - 10 cm to obtain the finished product;

[0016] The sulfonated silicon carbide in S2 includes the following groups:

[0017] 。

[0018] Preferably, in S2, the weight ratio of titanium carbide, sulfonated silicon carbide, and nitrogen-doped graphene is (5-10):(2-6):(0.1-0.5).

[0019] Preferably, in S3, the hot isostatic pressing parameters are a holding pressure of 90-150 MPa, a temperature of 850-870 °C, and a holding time of 2-3 h.

[0020] Preferably, the hot extrusion process parameters in S4 are an extrusion cylinder temperature of 400-410 °C, an extrusion cylinder holding time of 2-4 h, an extrusion pressure of 200-250 MPa, and an extrusion speed of 4-8 mm / s.

[0021] Preferably, the hot drawing process parameters in S5 are a current of 85-100 A and a wire drawing machine frequency of 3-5 hz.

[0022] Preferably, the raw materials of the sulfonated silicon carbide include silicon carbide and 4,4'-dichlorodiphenyl sulfone.

[0023] Preferably, the preparation steps of the sulfonated silicon carbide include:

[0024] T1: Introduce ammonia gas into the device containing silicon carbide and react at a temperature of 1000-1300 °C for 1-20 h to obtain aminated silicon carbide;

[0025] T2: Dissolve 4,4'-dichlorodiphenyl sulfone in a solvent to obtain a solution, then add a catalyst and aminated silicon carbide to the solution, react at a temperature of 80-150 °C for 2-24 h, and filter and dry to obtain sulfonated silicon carbide.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] The present invention adopts a method of additive manufacturing stainless steel with a cermet matrix, and the prepared 3D finished product has precise dimensions, improves the quality of the finished product, has a smooth surface without defects, and the hardness and wear resistance are improved. Specific Embodiments

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] The present invention provides several technical solutions.

[0030] Example 1:

[0031] Preparation of sulfonated silicon carbide:

[0032] T1: Ammonia gas is introduced into the device containing silicon carbide and processed at 1000 °C for 1 h to obtain silicon carbide amide through reaction.

[0033] T2: 20 parts of 4,4'-dichlorodiphenyl sulfone are dissolved in dichlorobenzene to obtain a solution. Then, 0.2 part of cuprous chloride and silicon carbide amide are added into the solution, and the mixture is processed at 80 °C for 2 h. After suction filtration and drying, silicon carbide sulfonated with groups is obtained.

[0034] Preparation of cermet matrix additive manufacturing stainless steel:

[0035] S1: Flake graphite and concentrated sulfuric acid solution are mixed at a mass ratio of 1:110 and stirred at 40 °C. After stirring evenly, potassium permanganate and graphite are added at a mass ratio of 5:1, and the mixture reacts at 50 °C for 6 h and then is heated to 70 °C for 30 min to obtain a suspension; the cooled suspension after reaction and an intercalation solvent of ethanol with a concentration of 70% are mixed and reacted at a volume ratio of 22:1 and ultrasonically treated to obtain an intercalation solution; diethanolamine and the intercalation solution are put into a high-pressure reactor and processed at 190 °C for 8 h. Finally, nitrogen-doped graphene is obtained after suction filtration, washing with water and drying.

[0036] S2: Titanium carbide, silicon carbide sulfonated, and nitrogen-doped graphene with a weight ratio of 5:2:0.1 are loaded into a mixer for premixing to obtain a composite powder.

[0037] S3: The composite powder is put into a stainless steel sheath, and the stainless steel sheath is evacuated. Subsequently, the sheath is placed in a hot isostatic press for hot isostatic pressing to form an ingot. The parameters for isostatic pressing are a holding pressure of 90 MPa, a temperature of 850 °C, and a holding time of 2 h.

[0038] S4: The ingot is put into a vacuum heat treatment furnace, and hot extrusion treatment is carried out at an ingot temperature of 800 °C and a holding time of 250 min. The temperature of the extrusion cylinder is 400 °C, the holding time of the extrusion cylinder is 2 h, the extrusion pressure is 200 MPa, and the extrusion speed is 4 mm / s to prepare an extruded wire.

[0039] S5: The extruded wire is drawn into a finished cermet wire on a hot drawing device, and the drawing process parameters are a current of 85 A and a frequency of the wire drawing machine of 3 hz.

[0040] S6: The cermet wire prepared in S5 is loaded onto a plastic 3D printer, and according to the three-dimensional modeling program in the computer, a cermet green body is printed.

[0041] S7: Place the stainless steel powder on the surface of the cermet matrix, and use a 3D printer to lay it repeatedly for 35 layers. After the printing is completed, a green body with stainless steel additive is obtained.

[0042] S8: Put the green body with additive into a sintering furnace filled with inert protective gas, keep it at 700 °C for 380 min, and after sintering, cool it in the furnace to room temperature and take it out.

[0043] S9: Modify the surface of the finished product with a high-current pulsed electron beam. The acceleration voltage is 20 kV, the pulse width is 2.5 μs, the number of pulses is 5 times, and the target distance is 6 cm to obtain the finished product.

[0044] Example 2:

[0045] Preparation of sulfonated silicon carbide:

[0046] T1: Pass ammonia gas into the equipment containing silicon carbide and treat it at 1300 °C for 20 h to react and obtain amino silicon carbide.

[0047] T2: Dissolve 30 parts of 4,4'-dichlorodiphenyl sulfone in dimethylformamide to obtain a solution, and then put 1 part of aluminum chloride and amino silicon carbide into the solution. Treat it at 150 °C for 24 h, filter it by suction and dry it to obtain sulfonated silicon carbide with groups.

[0048] Preparation of cermet matrix additive manufacturing stainless steel:

[0049] S1: Mix flake graphite and concentrated nitric acid solution according to a mass ratio of 1:140, stir at 60 °C, and after stirring evenly, add potassium permanganate and graphite according to a mass ratio of 8:1. React at 80 °C for 7 h, and then raise the temperature to 100 °C and react for 60 min to obtain a suspension; Mix the cooled suspension after the reaction and the intercalation solvent of 95% ethanol in a volume ratio of 22:1.5 for reaction and perform ultrasonic treatment to obtain an intercalation solution; Put diethanolamine and the intercalation solution into a high-pressure reaction kettle, treat it at 220 °C for 12 h, and finally filter it by suction, wash it with water and dry it to obtain nitrogen-doped graphene.

[0050] S2: Load titanium carbide, sulfonated silicon carbide and nitrogen-doped graphene with a weight ratio of 10:6:0.5 into a mixer for premixing to obtain a composite powder;

[0051] S3: Put the composite powder into a stainless steel sheath, and perform a vacuum treatment on the stainless steel sheath. Then put the sheath in a hot isostatic press for hot isostatic pressing to make an ingot. The parameters of the isostatic pressing treatment are a holding pressure of 150 MPa, a temperature of 870 °C, and a holding time of 3 h.

[0052] S4: Place the ingot into a vacuum heat treatment furnace, and conduct hot extrusion treatment at an ingot temperature of 870 °C for 300 min. The temperature of the extrusion cylinder is 410 °C, the holding time of the extrusion cylinder is 4 h, the extrusion pressure is 250 MPa, and the extrusion speed is 8 mm / s to prepare the extruded wire.

[0053] S5: Draw the extruded wire into a finished cermet wire on a hot drawing device. The drawing process parameters are a current of 100 A and a wire drawing machine frequency of 5 hz.

[0054] S6: Load the cermet wire prepared in S5 onto a plastic 3D printer, and print out the cermet green body according to the three-dimensional modeling program in the computer.

[0055] S7: Place the stainless steel powder on the surface of the cermet matrix, use a 3D printer to lay it repeatedly for 50 layers, and after the printing is completed, obtain the green body after stainless steel additive manufacturing.

[0056] S8: Place the green body after additive manufacturing into a sintering furnace filled with inert protective gas, hold it at 800 °C for 460 min, and after sintering, cool it in the furnace to room temperature and take it out.

[0057] S9: Modify the surface of the finished product with a high-current pulsed electron beam. The acceleration voltage is 25 kV, the pulse width is 3.5 μs, the number of pulses is 25 times, and the target distance is 10 cm to obtain the finished product.

[0058] Example 3:

[0059] Preparation of sulfonated silicon carbide:

[0060] T1: Pass ammonia gas into the equipment containing silicon carbide, and treat it at 1200 °C for 10 h to react to obtain amino silicon carbide.

[0061] T2: Dissolve 25 parts of 4,4'-dichlorodiphenyl sulfone in xylene to obtain a solution, and then add 0.5 part of copper chloride and amino silicon carbide into the solution, treat it at 100 °C for 15 h, and after filtration and drying, obtain sulfonated silicon carbide with groups.

[0062] Preparation of stainless steel by additive manufacturing of cermet matrix:

[0063] S1: Mix flake graphite and concentrated sulfuric acid solution at a mass ratio of 1:120, stir at a temperature of 50 °C. After stirring evenly, add potassium permanganate and graphite at a mass ratio of 7:1, react at 70 °C for 6.5 hours, then raise the temperature to 90 °C and react for 50 min to obtain a suspension; Mix the cooled suspension after the reaction and an ethanol intercalation solvent with a concentration of 90% at a volume ratio of 22:1.2 for reaction and perform ultrasonic treatment to obtain an intercalation solution; Put diethanolamine and the intercalation solution into a high-pressure reactor, process at a temperature of 200 °C for 10 h, and finally perform suction filtration, washing with water and drying to obtain nitrogen-doped graphene.

[0064] S2: Load titanium carbide, sulfonated silicon carbide and nitrogen-doped graphene with a weight ratio of 6:3:0.3 into a mixer for premixing to obtain a composite powder.

[0065] S3: Put the composite powder into a stainless steel jacket, perform vacuum treatment on the stainless steel jacket, and then put the jacket into a hot isostatic press for hot isostatic pressing to make an ingot blank. The static pressure treatment parameters are a holding pressure of 120 MPa, a temperature of 860 °C, and a holding time of 2.5 h.

[0066] S4: Put the ingot blank into a vacuum heat treatment furnace, perform hot extrusion treatment at an ingot temperature of 830 °C and a holding time of 260 min, the extrusion barrel temperature is 405 °C, the extrusion barrel holding time is 3 h, the extrusion pressure is 230 MPa, and the extrusion speed is 6 mm / s to prepare an extrusion wire.

[0067] S5: Draw the extrusion wire into a finished cermet wire on a hot drawing device. The drawing process parameters are a current of 90 A and a drawing machine frequency of 4 hz.

[0068] S6: Load the cermet wire prepared in S5 onto a plastic 3D printer and print a cermet green body according to the three-dimensional modeling program in the computer.

[0069] S7: Place stainless steel powder on the surface of the cermet matrix, use a 3D printer to lay it repeatedly for 40 layers, and after the printing is completed, obtain a green body after stainless steel additive manufacturing.

[0070] S8: Put the green body after additive manufacturing into a sintering furnace filled with inert protective gas, hold at 750 °C for 400 min, and after sintering, cool the furnace to room temperature and take it out.

[0071] S9: Modify the surface of the finished product with a high-current pulsed electron beam. The acceleration voltage is 22 kV, the pulse width is 3 μs, the number of pulses is 15 times, and the target distance is 8 cm to obtain the finished product.

[0072] Comparative Example 1:

[0073] Preparation of sulfonated silicon carbide:

[0074] T1: Ammonia gas is introduced into a device containing silicon carbide and processed at 1200 °C for 10 h to obtain silicon carbide amide through reaction.

[0075] T2: 25 parts of 4,4'-dichlorodiphenyl sulfone are dissolved in xylene to obtain a solution. Then, 0.5 part of copper chloride and silicon carbide amide are added to the solution, and the mixture is processed at 100 °C for 15 h. After suction filtration and drying, sulfonated silicon carbide with the group is obtained.

[0076] Preparation of a cermet matrix for additive manufacturing of stainless steel:

[0077] S1: Flake graphite and concentrated sulfuric acid solution are mixed at a mass ratio of 1:120 and stirred at 50 °C. After stirring evenly, potassium permanganate and graphite are added at a mass ratio of 7:1, and the reaction is carried out at 70 °C for 6.5 h. Then, the temperature is raised to 90 °C and the reaction is carried out for 50 min to obtain a suspension; the cooled suspension after the reaction and an intercalation solvent of ethanol with a concentration of 90% are mixed and reacted at a volume ratio of 22:1.2, and ultrasonic treatment is carried out to obtain an intercalation solution; diethanolamine and the intercalation solution are put into a high-pressure reaction kettle and processed at 200 °C for 10 h. Finally, suction filtration, washing with water and drying are carried out to obtain nitrogen-doped graphene.

[0078] S2: Titanium carbide, sulfonated silicon carbide and nitrogen-doped graphene with a weight ratio of 6:3:0.3 are loaded into a mixer for premixing to obtain a composite powder.

[0079] S3: The composite powder is put into a stainless steel sheath, and the stainless steel sheath is evacuated. Subsequently, the sheath is placed in a hot isostatic press for hot isostatic pressing to form an ingot blank. The parameters of the isostatic pressing treatment are a holding pressure of 120 MPa, a temperature of 860 °C, and a holding time of 2.5 h.

[0080] S4: The ingot blank is put into a vacuum heat treatment furnace, and hot extrusion treatment is carried out at an ingot temperature of 830 °C and a holding time of 260 min. The temperature of the extrusion cylinder is 405 °C, the holding time of the extrusion cylinder is 3 h, the extrusion pressure is 230 MPa, and the extrusion speed is 6 mm / s to prepare an extruded wire.

[0081] S5: The extruded wire is drawn into a finished cermet wire on a hot drawing device. The drawing process parameters are a current of 90 A and a frequency of the wire drawing machine of 4 Hz.

[0082] S6: The cermet wire prepared in S5 is loaded onto a plastic 3D printer, and according to the three-dimensional modeling program in the computer, a cermet green body is printed.

[0083] S7: Place the stainless steel powder on the surface of the cermet matrix, and use a 3D printer to lay it repeatedly for 40 layers. After the printing is completed, a green body with stainless steel additive is obtained.

[0084] S8: Put the green body with additive into a sintering furnace filled with inert protective gas, keep it at 750 °C for 400 min, cool it to room temperature in the furnace after sintering, and then take it out to obtain the finished product.

[0085] Comparative Example 2:

[0086] Preparation of cermet matrix with stainless steel additive manufacturing:

[0087] S1: Mix the flake graphite and concentrated sulfuric acid solution according to a mass ratio of 1:120, stir at a temperature of 50 °C. After stirring evenly, add potassium permanganate and graphite according to a mass ratio of 7:1, react at a temperature of 70 °C for 6.5 hours, and then raise the temperature to 90 °C and react for 50 min to obtain a suspension; Mix the cooled suspension after the reaction and an intercalation solvent of ethanol with a concentration of 90% in a volume ratio of 22:1.2 for reaction, and perform ultrasonic treatment to obtain an intercalation solution; Put diethanolamine and the intercalation solution into a high-pressure reaction kettle, treat at a temperature of 200 °C for 10 h, and finally perform suction filtration, washing and drying to obtain nitrogen-doped graphene.

[0088] S2: Load titanium carbide, silicon carbide and nitrogen-doped graphene with a weight ratio of 6:3:0.3 into a mixer for premixing to obtain a composite powder.

[0089] S3: Put the composite powder into a stainless steel sheath, evacuate the stainless steel sheath, and then put the sheath into a hot isostatic press for hot isostatic pressing to make an ingot blank. The static pressure treatment parameters are a holding pressure of 120 MPa, a temperature of 860 °C, and a holding time of 2.5 h.

[0090] S4: Put the ingot blank into a vacuum heat treatment furnace, perform hot extrusion treatment at an ingot blank temperature of 830 °C and a holding time of 260 min, the extrusion barrel temperature is 405 °C, the extrusion barrel holding time is 3 h, the extrusion pressure is 230 MPa, and the extrusion speed is 6 mm / s to prepare an extrusion wire.

[0091] S5: Draw the extrusion wire into a finished cermet wire on a hot drawing device. The drawing process parameters are a current of 90 A and a drawing machine frequency of 4 hz.

[0092] S6: Load the cermet wire prepared in S5 onto a plastic 3D printer and print a cermet green body according to the three-dimensional modeling program in the computer.

[0093] S7: Place the stainless steel powder on the surface of the cermet matrix, and use a 3D printer to lay it repeatedly for 40 layers. After the printing is completed, a green body with stainless steel additive is obtained.

[0094] S8: Put the green body with additive into a sintering furnace filled with inert protective gas, keep it at 750 °C for 400 min, and after sintering, cool it to room temperature in the furnace and take it out.

[0095] S9: Modify the surface of the finished product with a high-current pulsed electron beam, with an accelerating voltage of 22 kV, a pulse width of 3 μs, a pulse number of 15 times, and a target distance of 8 cm to obtain the finished product.

[0096] Comparative Example 3:

[0097] Preparation of sulfonated silicon carbide:

[0098] T1: Pass ammonia gas into the equipment containing silicon carbide, and treat it at 1200 °C for 10 h to react to obtain amino silicon carbide.

[0099] T2: Dissolve 25 parts of 2,5-dichlorodiphenyl sulfone in xylene to obtain a solution, then add 0.5 part of copper chloride and amino silicon carbide into the solution, treat it at 100 °C for 15 h, and after suction filtration and drying, obtain sulfonated silicon carbide.

[0100] Preparation of cermet matrix additive manufacturing stainless steel:

[0101] S1: Mix flake graphite and concentrated sulfuric acid solution according to a mass ratio of 1:120, stir at 50 °C, after stirring evenly, add potassium permanganate and graphite according to a mass ratio of 7:1, react at 70 °C for 6.5 h, and then raise the temperature to 90 °C and react for 50 min to obtain a suspension; mix the cooled suspension after the reaction and an intercalation solvent of ethanol with a concentration of 90% according to a volume ratio of 22:1.2 and react, and perform ultrasonic treatment to obtain an intercalation solution; put diethanolamine and the intercalation solution into a high-pressure reaction kettle, treat it at 200 °C for 10 h, and finally perform suction filtration, water washing and drying to obtain nitrogen-doped graphene.

[0102] S2: Load titanium carbide, sulfonated silicon carbide and nitrogen-doped graphene with a weight ratio of 6:3:0.3 into a mixer for premixing to obtain a composite powder.

[0103] Put the composite powder into a stainless steel sheath, and perform vacuum treatment on the stainless steel sheath. Then put the sheath into a hot isostatic press for hot isostatic pressing treatment to make an ingot blank, where the static pressure treatment parameters are a holding pressure of 120 MPa, a temperature of 860 °C, and a holding time of 2.5 h.

[0104] S4: Place the ingot into a vacuum heat treatment furnace, and conduct hot extrusion treatment at an ingot temperature of 830 °C for 260 min. The temperature of the extrusion cylinder is 405 °C, the holding time of the extrusion cylinder is 3 h, the extrusion pressure is 230 MPa, and the extrusion speed is 6 mm / s to prepare extrusion wire.

[0105] S5: Draw the extrusion wire into finished wire on a hot drawing device. The drawing process parameters are a current of 90 A and a wire drawing machine frequency of 4 Hz.

[0106] S6: Load the cermet wire prepared in S5 onto a plastic 3D printer, and print out a cermet green body according to the three-dimensional modeling program in the computer.

[0107] S7: Place the stainless steel powder on the surface of the cermet matrix, use a 3D printer to lay it repeatedly for 40 layers, and after the printing is completed, obtain a green body with stainless steel additive.

[0108] S8: Put the green body with additive into a sintering furnace filled with inert protective gas, hold it at 750 °C for 400 min, and after sintering, cool it to room temperature in the furnace and take it out.

[0109] S9: Modify the surface of the finished product with a high-current pulsed electron beam. The acceleration voltage is 22 kV, the pulse width is 3 μs, the number of pulses is 15 times, and the target distance is 8 cm to obtain the finished product.

[0110] Comparative Example 4:

[0111] Preparation of sulfonated silicon carbide:

[0112] T1: Pass ammonia gas into the equipment containing silicon carbide, and treat it at 1200 °C for 10 h to react to obtain amino silicon carbide.

[0113] T2: Dissolve 25 parts of 4,4'-dichlorodiphenyl sulfone in xylene to obtain a solution, and then add 0.5 part of copper chloride and amino silicon carbide into the solution. Treat it at a temperature of 100 °C for 15 h, and after suction filtration and drying, obtain Sulfonated silicon carbide with groups.

[0114] Preparation of stainless steel by additive manufacturing of cermet matrix:

[0115] S1: Load titanium carbide, sulfonated silicon carbide and graphene with a weight ratio of 6:3:0.3 into a mixer for premixing to obtain composite powder.

[0116] S2: Put the composite powder into a stainless steel sheath, and conduct vacuum treatment on the stainless steel sheath. Then place the sheath in a hot isostatic press for hot isostatic pressing treatment to make an ingot. The static pressure treatment parameters are a holding pressure of 120 MPa, a temperature of 860 °C, and a holding time of 2.5 h.

[0117] S3: Place the ingot into a vacuum heat treatment furnace, and conduct hot extrusion treatment at an ingot temperature of 830 °C for 260 min. The temperature of the extrusion cylinder is 405 °C, the holding time of the extrusion cylinder is 3 h, the extrusion pressure is 230 MPa, and the extrusion speed is 6 mm / s to prepare the extruded wire.

[0118] S4: Draw the extruded wire into a finished cermet wire on a hot drawing device. The drawing process parameters are a current of 90 A and a wire drawing machine frequency of 4 Hz.

[0119] S5: Load the cermet wire prepared in S5 onto a plastic 3D printer, and print out the cermet green body according to the three-dimensional modeling program in the computer.

[0120] S6: Place the stainless steel powder on the surface of the cermet matrix, and use a 3D printer to lay it repeatedly for 40 layers. After the printing is completed, a green body with stainless steel additive is obtained.

[0121] S7: Put the green body with additive into a sintering furnace filled with inert protective gas, hold it at 750 °C for 400 min, and after sintering, cool it in the furnace to room temperature and take it out.

[0122] S8: Modify the surface of the finished product with a high-current pulsed electron beam. The acceleration voltage is 22 kV, the pulse width is 3 μs, the number of pulses is 15 times, and the target distance is 8 cm to obtain the finished product.

[0123] Observe the surface state of the finished products prepared in Examples 1-3 and Comparative Examples 1-4, and detect the hardness and wear resistance of the finished products;

[0124] Detect the tensile strength, elongation and Young's modulus of the extruded wire during the preparation of the finished product.

[0125] Table 1 Test Results

[0126]

[0127] It can be seen from the comparison between Examples 1-3 and Comparative Example 1 that the size of the finished product prepared in Comparative Example 1 is qualified, but there is 1 crack on the surface, and the hardness and wear resistance are significantly reduced.

[0128] It can be seen from the comparison between Examples 1-3 and Comparative Example 2 that the size of the finished product prepared in Comparative Example 2 is unqualified, there are 2 internal contractions and 2 burrs. The hardness changes little, but the wear resistance is significantly reduced. The tensile strength of the extruded wire in Comparative Example 2 changes little, but the elongation is about 50% lower than that in Examples 1-3, and the difference in Young's modulus is small.

[0129] From the comparison between Examples 1 - 3 and Comparative Example 3, it can be seen that the finished product prepared in Comparative Example 3 has qualified dimensions, but there is 1 air hole, the surface state is poor, the hardness and wear resistance change little, the tensile strength of the extrusion wire in Comparative Example 3 decreases by about 30%, the elongation rate is about 50% lower, and the Young's modulus changes little.

[0130] From the comparison between Examples 1 - 3 and Comparative Example 4, it can be seen that the finished product prepared in Comparative Example 4 has unqualified dimensions, there are 2 internal contractions, and there are 3 air holes, the surface state is poor, the hardness and wear resistance change little, the tensile strength of the extrusion wire in Comparative Example 4 decreases by about 30%, the elongation rate is about 25% lower, and the Young's modulus changes little.

[0131] Although the embodiments of the present invention have been shown and described (see the detailed description above), for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for additively manufacturing stainless steel using a metal ceramic matrix, characterized in that: The preparation steps include: S1: Mix flake graphite with concentrated acid solution in a mass ratio of 1:(110-140), stir at a temperature of 40-60°C, then add potassium permanganate and graphite in a mass ratio of (5-8):1, react at a temperature of 50-80°C for 6-7 hours, then heat to 70-100°C and react for 30-60 minutes to obtain a suspension; mix the cooled suspension with an ethanol intercalation solvent in a volume ratio of 22:(1-1.5) and ultrasonically treat to obtain an intercalation solution; put diethanolamine in a volume ratio of (1-5):100 and the intercalation solution into a high-pressure reactor, treat at a temperature of 190-220°C for 8-12 hours, and finally filter, wash with water and dry to obtain nitrogen-doped graphene; S2: titanium carbide, sulfone-based silicon carbide and nitrogen-doped graphene are charged into a mixer in different proportions for premixing to obtain composite powder; S3: The composite powder is placed in a stainless steel bag, and the stainless steel bag is vacuumed, and then the bag is placed in a hot isostatic press for hot isostatic pressing to form an ingot; S4: placing the ingot into a vacuum heat treatment furnace, and performing hot extrusion treatment on the ingot at 800-870° C. for 250-300 minutes to prepare an extruded wire; S5: drawing the extruded wire into a finished metal ceramic wire on a hot drawing device; S6: loading the metal ceramic wire prepared in S5 onto a plastic 3D printer, and printing out a metal ceramic green body according to a three-dimensional modeling program in a computer; S7: Stainless steel powder is placed on the surface of the metal ceramic substrate, and 35 to 50 layers are repeatedly laid using a 3D printer. After the printing is completed, a green embryo with stainless steel additives is obtained; S8: placing the green body after material addition into a sintering furnace with an inert protective gas, sintering at a temperature of 700-800°C and a holding time of 380-460 min, and then cooling the furnace to room temperature and taking it out after sintering; S9: Modify the surface of the finished product with a high-current pulsed electron beam, with an acceleration voltage of 20-25 kV, a pulse width of 2.5-3.5 μs, a pulse number of 5-25 times, and a target distance of 6-10 cm to obtain the finished product; The sulfonated silicon carbide in S2 includes the group: 。 2. The method for additively manufacturing stainless steel using a metal ceramic matrix according to claim 1, characterized in that: The weight ratio of titanium carbide, sulfone-containing silicon carbide and nitrogen-doped graphene in S2 is (5-10): (2-6): (0.1-0.5).

3. The method for additively manufacturing stainless steel using a metal ceramic matrix according to claim 1, characterized in that: The hot isostatic pressing treatment parameters in S3 are: a holding pressure of 90 to 150 MPa, a temperature of 850 to 870° C., and a holding time of 2 to 3 h.

4. The method for additively manufacturing stainless steel using a metal ceramic matrix according to claim 1, characterized in that: The hot extrusion process parameters in S4 are: extrusion barrel temperature of 400-410°C, extrusion barrel insulation time of 2-4 h, extrusion pressure of 200-250 MPa, and extrusion speed of 4-8 mm / s.

5. The method for additively manufacturing stainless steel using a metal ceramic matrix according to claim 1, characterized in that: The process parameters of the hot drawing described in S5 are a current of 85 to 100 A and a wire drawing machine frequency of 3 to 5 Hz.

6. The method for additively manufacturing stainless steel using a metal ceramic matrix according to claim 1, characterized in that: The raw materials of the sulfonated silicon carbide include silicon carbide and 4,4'-dichlorodiphenyl sulfone.

7. The method for additively manufacturing stainless steel using a metal ceramic matrix according to claim 6, characterized in that: The preparation steps of the sulfonated silicon carbide include: T1: introducing ammonia into a device containing silicon carbide, reacting at a temperature of 1000-1300°C for 1-20 hours to obtain amino silicon carbide; T2: Dissolve 4,4'-dichlorodiphenyl sulfone with a solvent to obtain a solution, then add the catalyst and amino silicon carbide into the solution, react at a temperature of 80-150°C for 2-24 hours, and filter and dry to obtain sulfonated silicon carbide.

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