Method for batch preparation of fine-grain Ti (C, N)-based metal ceramic through compounding of 3D printing and reaction hot isostatic pressing sintering

Abstract

The invention discloses a method for batch preparation of fine-grain Ti (C, N)-based metal ceramic by compounding 3D printing and reactive hot isostatic pressing sintering. The preparation method comprises the following steps: firstly, mixing according to a certain ratio to obtain Ti (C, N)-based metal ceramic raw materials, then curing and forming a required metal ceramic blank through bonding jet 3D printing, and then preparing the novel Ti (C, N)-based metal ceramic by virtue of degreasing and hot isostatic pressing sintering. The novel fine grain Ti (C, N)-based metal ceramic can be rapidly prepared in batches by combining three processes of a bonding spraying 3D printing forming technology, a reaction synthesis technology and a hot isostatic pressing sintering technology; the reaction of the mixture powder is relatively slow, and the reaction process is easy to control; the mixture ratio is relatively loose, and the yield is high; the novel fine-grain Ti (C, N)-based metal ceramic prepared by sintering is wide in application range, is sprayed and enhanced by being matched with a composite coating on the surface of the metal ceramic, and is high in toughness in the fields of room temperature and high temperature.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal ceramic preparation, and specifically relates to a method for preparing fine-grained Ti (C, N)-based metal ceramics in batches by composite 3D printing and reactive hot isostatic pressing sintering. Background Art

[0002] Ti(C,N)-based cermets have a series of properties such as high strength at room temperature, high hardness, low density, good chemical corrosion resistance and high temperature thermal stability. They have gradually become a new alternative material for cemented carbide and are widely used in high-speed cutting and grinding tools for finishing and semi-finishing. Ti(C,N)-based cermets are mainly composed of Ti(C,N) hard phase and metal bonding phases such as Ni, Co, and Fe. The high hardness of Ti(C,N) gives the cermets excellent wear resistance, while the bonding phases such as Ni, Co, and Fe ensure the good toughness of the cermets. However, during continuous cutting and grinding, the temperature of the blade of Ti(C,N)-based cermets is usually above 900°C, and the bonding phase is prone to softening and creep, resulting in deterioration of performance. In addition, it will oxidize rapidly in a high temperature environment, destroying the "core-ring" structure of the cermets and affecting their service life.

[0003] At present, there are mainly the following ways to optimize the high temperature performance of Ti(C,N)-based cermets: 1. Reinforcement phases such as whiskers / rods. Fang et al. (YH Fang, XR Fang, et al, Vacuum, 2021) used ZrO 2 The high-temperature rod crystal morphology of whiskers improves the high-temperature oxidation resistance of Ti(C,N)-based cermets. 2. Preparation of fine-grained / ultrafine-grained cermets. Zhao Jie et al. (Zhao Jie, Wan Xiangliang, Ke Rui, et al. Journal of Iron and Steel Research, 2023) showed that fine grain strengthening is still effective for metals / ceramics, and the deformation mechanisms are dislocation slip and dislocation slip + stacking fault + twinning, respectively. Du Bening et al. (Du Bening, Yang Jinxia, ​​Cui Chuanyong, et al., Acta Metallurgica Sinica, 2014) found that grain refinement can improve the creep properties of materials. 3. Develop new bonding phases. Including intermetallic compounds, high entropy alloys Fe / Ni-based alloys, etc. Li et al. (ZJ Li, XQ Liu, KK Guo, et al, Materials Science and Engineering A, 2019) used FeCoCrNiAl high entropy alloy as the bonding phase and TiB 2Ti(C,N)-based cermets were prepared as reinforcement phases. Since FeCoCrNiAl high entropy alloy has excellent resistance to high temperature softening, its oxidation resistance and high temperature wear resistance are better than those of Ni / Co bonding phase. Fang et al. (YH Fang, N Chen, G PDu, et al, Journal of Alloys and Compounds, 2020) studied the relationship between Ni-Co and Al 0.3 Oxidation behavior of Ti(C,N) based cermets with CoCrFeNi high entropy alloy as binder phase in static air at 1000℃. 0.3 Fe formed by oxidation in CoCrFeNi high entropy alloy 2 O 3 and Cr 2 O 5 It has strong antioxidant ability, can improve the stability of the oxide layer, reduce the diffusion of oxygen in metal ceramics and TiO 2 The formation of whiskers / high entropy alloys / fine grains greatly improves the high-temperature oxidation resistance. The high-temperature performance of Ti(C,N)-based cermets can be improved to a certain extent through the modification of whiskers / high entropy alloys / fine grains. However, due to the influence of traditional hot pressing sintering technology, powder refinement and agglomeration, and low density after whisker interference, the preparation temperature is generally higher than 1450°C. High temperature promotes the growth of grains, and it is extremely difficult to obtain fine / ultrafine grains. In addition, the molding and sintering method based on powder metallurgy pressing or extrusion and sintering process is difficult to batch prepare Ti(C,N)-based cermets with complex structures.

[0004] Binder jet forming technology is one of the latest technologies in 3D printing. Its principle is to selectively bond the powder materials on the powder bed by depositing liquid binder from the print head. It can print parts with overhangs, complex internal features and no residual stress. Therefore, it has the advantages of high efficiency and low cost, and has broad application prospects in many industries such as medical, decoration, industry, and electronics. As a typical representative of high entropy alloys, FeCoCrNi series high entropy alloys have excellent plasticity and toughness as well as high temperature stability, and have become a research hotspot at home and abroad. Reaction hot pressing sintering technology is a material preparation process developed by combining combustion synthesis with hot pressing sintering technology, which includes three driving forces: powder surface free energy, external mechanical force, and chemical reaction energy. Therefore, sintering can be completed at a relatively low sintering temperature and a short holding time to obtain fine-grained cermets. In summary, how to use appropriate molding methods to prepare fine-grained Ti (C, N)-based cermets with FeCoCrNi series high entropy alloys as metal binder phases is of great significance. Summary of the invention

[0005] In view of the problems existing in the above-mentioned background technology, the purpose of the design of the present invention is to overcome the difficulties such as the difficulty in preparing complex-shaped structures and the insufficient high-temperature performance of Ti(C, N)-based metal ceramics, and to provide a preparation method for fine-grained Ti(C, N)-based metal ceramics with excellent high-temperature performance using FeCoCrNi-based high-entropy alloys as the metal bonding phase, which can be used for batch and rapid preparation of complex-shaped structures. By adopting the technical scheme of the present invention, fine-grained Ti(C, N)-based metal ceramics metal ceramic materials produced rapidly in batches have good high-temperature performance and can be used for the production of medical, decorative, industrial, and electronic materials with complex-shaped structures.

[0006] The present invention is specifically implemented through the following technical solutions:

[0007] A method for preparing a novel fine-grained Ti(C,N)-based cermet by composite batch preparation of binder jet 3D printing and reactive hot isostatic pressing sintering, comprising the following steps:

[0008] 1) Weighing the raw materials of Ti(C,N)-based metal ceramics and the mixed binder in the process proportion weight, placing them in a V-shaped double-screw mixer and mixing them to obtain a mixed material;

[0009] 2) loading the mixture of step 1) and an inorganic environmentally friendly binder into a binder jet 3D printer, setting printing slice parameters according to the three-dimensional models of parts with different complex shapes, and curing at room temperature or slightly heated to obtain a batch-printed Ti(C,N)-based metal ceramic material blank;

[0010] 3) placing the Ti(C,N)-based cermet material body of step 3) into a gas pressure sintering furnace, completing degreasing + reaction hot isostatic pressing sintering to obtain a rough component sample;

[0011] 4) After sintering in step 3), the rough component sample is placed in an automatic sandblasting machine for appropriate surface sandblasting, and then multi-arc ion plating is completed to finally obtain a new type of fine-grained Ti (C, N) based metal ceramic.

[0012] In the above steps, by combining the binder jet 3D printing technology, the four high entropy effects of high entropy alloys, and the reactive hot isostatic pressing sintering process, the performance of new fine-grained Ti(C,N)-based cermets can be quickly prepared in batches and optimized to obtain high-temperature performance; with the help of the binder jet 3D printing technology, loose cermet powders can be bonded through droplet spraying and powder bonding to form Ti(C,N)-based cermet green bodies, and complex-shaped structural parts can be formed using additive manufacturing processes; V-shaped double-helix mixing is used to obtain highly uniform binder jet raw materials at both macro and micro levels; at the same time, the short-term high heat release of the in-situ synthesis reaction reduces the sintering temperature of the Ti(C,N)-based cermets, thereby preparing fine-grained Ti(C,N)-based composite ceramics; in addition, the introduction of the composite coating improves the hardness of the Ti(C,N)-based cermet surface and reduces the impact of low density of 3D printing.

[0013] Furthermore, in step 1), the mass ratio of the mixed raw materials is Ti: 48-56wt%, B 4 C / BN: 14-18wt%, TiN / TiC16-20: wt%, Co / Ni / FeCoCrNiX (X=Mn, Ti, V, any one of them): 10-20wt%. Among them, the mixed material binder is composed of paraffin / polyvinyl alcohol and other main components, and the content is 10-20wt% of the premix. The V-type double-helix mixer adopts a V-type main machine, and the double helix drives the internal powder mixing, which can avoid the shortcomings of lack of shear movement inside the V-type mixer, light and heavy powders floating up and down, and realizes macroscopic and microscopic uniform mixed powders. V-type main machine speed: 200-400r / min, double helix speed: 50-100r / min, can achieve forward and reverse rotation. V-type double helix loading: 50%≤loading≤80%, after mixing, a relatively uniform bonding spray 3D printing and in-situ reaction mixture is obtained, and the coefficient of variation CV of the premix mixing uniformity is ≤5%.

[0014] Furthermore, in step 2), the main components of the binder of the binder jet 3D printer include sodium silicate (20-35wt%), modifier (4-20wt%), aluminum sulfate (0.2-1wt%), promoter (1-3wt%), deionized water (40-70wt%), water-soluble silicone oil and phenolic resin (0.5-3wt%). The modifier is a mixture of disodium hydrogen phosphate, D-sorbitol, and tetraethyl silicate, and the promoter is a mixture of naphthalenesulfonic acid and sodium hydroxide. The binder composition and content are determined according to the 3D printing mixture. The binder jetting parameters are set according to the size of the parts, including the number of layers, 3D mixture and binder thickness ratio.

[0015] Further, in step 3), degreasing + process: room temperature - 500 ° C, 2--3 ° C / min; 500 ° C - 500 ° C, heat preservation for 60-120 min; 500-800 ° C, 1-2 ° C / min; 800-800 ° C, heat preservation for 60-120 min; 800-1400 ° C, 5-10 ° C / min; 1400-1400 ° C, heat preservation for 60-120 min; 1400-500 ° C, 10 ° C / min; cooling with the furnace. Reaction hot isostatic pressing sintering process: 0-1000 ° C, 0 MPa; 1000-1400 ° C, 5-8 MPa; then depressurize.

[0016] Further, in step 4), the sintered component blank is placed in an automatic sandblasting machine, and some parameters include: 1. Gun distance: 30-50mm; 2. Inclination angle 30-60°; 3. Number of round trips: 3-6 times; 4. Sandblasting pressure: 0.5-0.8MPa. After sandblasting, multi-arc ion plating composite coating TiB 2 -FeCoCrNiX-Ti(C,N) preparation. Composite coating composition parameters such as Figure 1 In the figure, 1 represents the Ti(C,N) based metal ceramic matrix, 2 represents the TiB 2 Coating, 3 represents FeCoCrNiX coating, 4 represents Ti(C,N) coating.

[0017] Further, the specific steps of sandblasting and coating are:

[0018] A) Sandblasting pretreatment: The sandblasting medium is Al 2 O 3 Sand particles, with a particle size of 10-20 μm, are cleaned for 10-40 min by ultrasonic wave after sandblasting, washed with deionized water, and then ultrasonically cleaned in acetone solution for 8-15 min, and then blown dry for later use;

[0019] B) Coating deposition process: Place the pre-treated parts evenly on the rack, load them into the multi-arc ion plating machine, rotate the rack at a certain speed, adjust the speed according to the size of the rack, generally 10-30rpm, evacuate to 10-4Pa, turn on Ar, adjust the vacuum chamber to about 0.4Pa, turn on the heater, and heat to 200-500℃; bias the substrate to 300-600V, turn on TiB 2 Target, sputter cleaning 20-40min, arc current 80A, arc voltage 20V, deposition of TiB 2 10 min, N 2 0.3-0.5Pa, arc current 80A, arc voltage 20V, TiB deposition 2 30-60min; turn on the FeCoCrNiX target and control the N 2The flow valve is set to a working pressure of about 0.5 Pa, and FeCoCrNiX is deposited for 10-30 minutes. After the deposition is completed, close the TiB 2 The target and FeCoCrNiX target are opened, the Ti(C,N) target is opened, the arc current is 80-150A, the voltage is 20-30V, and the deposition time is maintained at 10-30min; after the coating deposition is completed, the parts are cooled to less than 100℃ in the vacuum chamber, restored to normal pressure, and taken out of the furnace.

[0020] In the above process, binder jet 3D printing can be used to batch produce parts with complex shapes and structures. At the same time, with the help of in-situ reaction hot isostatic pressing sintering process, fine-grained Ti (C, N)-based metal ceramics can be obtained by relying on rapid reaction and uniform sintering densification.

[0021] The present invention has the following beneficial effects:

[0022] 1) The preparation method of the present invention can batch prepare fine-grained Ti(C,N)-based composite metal ceramics with complex shapes and excellent high-temperature performance; X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis of the material show that the crystal phase of the material obtained by the present invention is TiB 2 Ti(C,N) based cermets with TiN and FCC structural bonding phases, fine grains (500-600nm) and uniform particle distribution;

[0023] 2) The material prepared by the method of the present invention has a hardness of 18-20GPa, a bending strength of 700-950MPa, and a fracture toughness of 9-12MPa·m 1 / 2 , at 1000℃, hardness ≥10GPa, flexural strength ≥600MPa, fracture toughness ≥7MPa·m 1 / 2 ;

[0024] 3) The method of the present invention has the possibility of batch-fast preparation of fine-grained Ti (C, N)-based metal ceramic parts with complex shapes and structures, shortening the production time of materials and realizing the possibility of manufacturing parts with complex shapes;

[0025] 4) The method of the present invention has a relatively slow reaction of the mixed material powder, and the reaction process is easier to control; the mixed material ratio is relatively loose, and the yield rate is high; the new fine-grained Ti (C, N)-based cermet produced by sintering has a wide range of applications, and is sprayed with a composite coating on the surface of the cermet to enhance its strength and toughness at room temperature and high temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the composite coating of the present invention;

[0027] Figure 2 is the XRD pattern of the Ti(C,N)-based cermet of Example 1 of the present invention;

[0028] Figure 3 The polished surface SEM image and particle size distribution diagram of the Ti(C,N)-based cermet of Example 1; (a) SEM; (b) size diagram;

[0029] Figure 4 is TiB in Example 1 2 -SEM morphology of the cross section of FeCoCrNiTi-Ti(C,N) composite coating;

[0030] Figure 5 The polished surface SEM image and particle size distribution diagram of the Ti(C,N)-based cermet of Example 2; (a) SEM; (b) size diagram;

[0031] Figure 6 The TiB of Example 2 2 -SEM morphology of the cross section of Ti(C,N) composite coating. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with specific embodiments to facilitate a better understanding of the present technical solution.

[0033] Example 1: A method for preparing Ti(C,N)-based cermets by binder jet 3D printing and reactive hot isostatic pressing sintering, comprising the following steps:

[0034] Step 1: Weigh the binder jet 3D printing materials, the ratio is Ti: 53 wt%, B 4 C: 15 wt%, TiN: 17: wt%, FeCoCrNiTi: 15 wt%. Among them, the mixed material binder is composed of paraffin and other main components, and the content is 15wt% of the premix. Then the materials are placed in a V-type double-screw mixer with a loading amount of 80% and a mixing time of 24h, and the mixing is completed. After the mixing is completed, a mixture with a coefficient of variation CV of 3% is obtained.

[0035] Step 2: Load the mixture and binder into the binder jet 3D printer, and the binder content is 30wt% of the premix. The binder ingredients are: sodium silicate: 30wt%, disodium hydrogen phosphate: 4wt%, D-sorbitol: 3wt%, tetraethyl silicate: 2wt%, aluminum sulfate: 0.5wt%, naphthalenesulfonic acid: 0.5wt%, sodium hydroxide 1.5wt%, deionized water: 56wt%, water-soluble silicone oil: 0.5wt% and phenolic resin: 2wt%. Set the mixture and binder layer thickness according to the shape and structure of the parts. The ratio of mixture to binder layer thickness is 5:1. The recycled powder should be placed in an atmosphere protection chamber and sieved through a 200-mesh sieve.

[0036] Step 3: The printed parts after powder recovery are placed in a degreasing and sintering integrated furnace for sintering. Degreasing + sintering process: room temperature -500℃, 3℃ / min; 500℃-500℃, keep warm for 60min; 500-800℃, 2℃ / min; 800-800℃, keep warm for 60min; 800-1400℃, 8℃ / min; 1400-1400℃, keep warm for 60min; 1400-500℃, 10℃ / min; cool with the furnace. Reaction hot isostatic pressing sintering process: 0-1000℃, 0MPa; 1000-1400℃, 8MPa; then depressurize.

[0037] In step 4: the sintered component blank is placed in an automatic sandblasting machine. Some parameters include: 1. Gun distance: 40mm; 2. Inclination angle 45°; 3. Number of round trips: 6 times; 4. Sandblasting pressure: 0.8MPa. After sandblasting, multi-arc ion plating composite coating is performed

[0038] TiB 2 -FeCoCrNiTi-Ti(C,N) preparation.

[0039] The specific steps of sandblasting and coating are as follows:

[0040] 1) Sandblasting pretreatment: The sandblasting medium is Al 2 O 3 Sand particles with a particle size of 13 μm were used for 20 min. After sandblasting, they were ultrasonically cleaned, washed with deionized water, and then ultrasonically cleaned in acetone solution for 10 min. After cleaning, they were blown dry for later use.

[0041] 2) Coating deposition process: Place the pre-treated parts evenly on the rack, load them into the multi-arc ion plating machine, rotate the rack at a certain speed, adjust the speed according to the size of the rack, generally 20rpm, evacuate to 10-4Pa, turn on Ar, adjust the vacuum chamber to about 0.4Pa, turn on the heater, and heat to 200-500℃; bias the substrate with 500V, turn on TiB 2 Target, sputter cleaning 30min, arc current 80A, arc voltage 20V, deposition of TiB 2 10 min, N 2 When 0.4Pa, arc current 80A, arc voltage 20V, TiB deposition 2 50min; turn on the FeCoCrNiTi target and control the N 2 The flow valve is set to a working pressure of about 0.5 Pa, and FeCoCrNiTi is deposited for 20 minutes. After the deposition is completed, close the TiB 2The target and FeCoCrNiTi target were set, the Ti(C,N) target was turned on, the arc current was 100A, the voltage was 30V, and the deposition time was maintained at 20min; after the coating deposition was completed, the parts were cooled to less than 100°C in the vacuum chamber, returned to normal pressure, and taken out of the furnace.

[0042] The mechanical properties of the metal ceramic parts were tested: room temperature hardness was 19.6GPa; bending strength was 837MPa; fracture toughness was 10.4MPa·m 1 / 2 At 1000℃, the hardness is 11.1GPa, the flexural strength is 638MPa, and the fracture toughness is 7.9MPa·m 1 / 2 The XRD of the parts prepared by bond spraying and hot isostatic pressing shows Ti(C,N), TiB 2 and FCC structural binder phase, such as Figure 2 SEM images are shown in Figure 3 As shown in the figure, the Ti(C,N) grains are small (average size is 0.6μm), the whole is uniform and dense, and there are no obvious holes. Figure 4 It shows that TiB with good coating adhesion can be obtained by using appropriate preparation process. 2 -FeCoCrNiTi-Ti(C,N) composite coating. Figure 1 In the figure, 1 represents the Ti(C,N)-based metal ceramic matrix, 2 represents TiB 2 Coating, 3 represents FeCoCrNiTi coating, 4 represents Ti(C,N) coating.

[0043] Example 2: A method for preparing Ti(C,N)-based cermets by binder jet 3D printing and reactive hot isostatic pressing sintering, comprising the following steps:

[0044] Step 1: Weigh the binder jet 3D printing materials, the ratio is Ti: 56wt%, B 4 C: 16wt%, TiN: 18:wt%, FeCoCrNiMn: 10wt%. The mixed material binder is composed of polyvinyl alcohol and other main components, and the content is 10wt% of the premix. Then the materials are placed in a V-type double-screw mixer with a loading amount of 85% and a mixing time of 12h, and the mixing is completed. After the mixing is completed, a mixed material with a coefficient of variation CV of 4.8% is obtained.

[0045] Step 2: Load the mixture and binder into the binder jet 3D printer, and the binder content is 25wt% of the premix. The binder ingredients are: sodium silicate: 25wt%, disodium hydrogen phosphate: 2wt%, D-sorbitol: 2.2wt%, tetraethyl silicate: 2.0wt%, aluminum sulfate: 0.3wt%, naphthalenesulfonic acid: 0.4wt%, sodium hydroxide 1.1wt%, deionized water: 66wt%, water-soluble silicone oil: 0.2wt% and phenolic resin: 0.8wt%. Set the mixture and binder layer thickness according to the shape and structure of the parts. The ratio of mixture to binder layer thickness is 3:1. The recycled powder should be placed in an atmosphere protection chamber and sieved through a 150-mesh sieve.

[0046] Step 3: The printed parts after powder recovery are placed in a degreasing and sintering integrated furnace for sintering. Degreasing + sintering process: room temperature -500℃, 2℃ / min; 500℃-500℃, keep warm for 90min; 500-800℃, 1.5℃ / min; 800-800℃, keep warm for 90min; 800-1400℃, 5℃ / min; 1400-1400℃, keep warm for 900min; 1400-500℃, 10℃ / min; cool with the furnace. Reaction hot isostatic pressing sintering process: 0-1000℃, 0MPa; 1000-1400℃, 5MPa; then depressurize.

[0047] In step 4: the sintered component blank is placed in an automatic sandblasting machine, and some parameters include: 1. Gun distance: 30mm; 2. Inclination angle 30°; 3. Number of round trips: 3 times; 4. Sandblasting pressure: 0.5MPa. After sandblasting, multi-arc ion plating composite coating TiB 2 -Ti(C,N) preparation.

[0048] The specific steps of sandblasting and coating are as follows:

[0049] 1) Sandblasting pretreatment: The sandblasting medium is Al 2 O 3 Sand particles with a particle size of 10 μm were used for 10 min. After sandblasting, they were ultrasonically cleaned, washed with deionized water, and then ultrasonically cleaned in an acetone solution for 8 min. After cleaning, they were blown dry for later use.

[0050] 2) Coating deposition process: Place the pre-treated parts evenly on the rack, load them into the multi-arc ion plating machine, rotate the rack at a certain speed, adjust the speed according to the size of the rack, generally 10rpm, evacuate to 10-4Pa, turn on Ar, adjust the vacuum chamber to about 0.4Pa, turn on the heater, and heat to 200-500℃; bias the substrate with 300V, turn on TiB 2 Target, sputter cleaning 20min, arc current 80A, arc voltage 20V, deposition of TiB 2 10 min, N 2When 0.3Pa, arc current 80A, arc voltage 20V, TiB deposition 2 30min; after deposition is completed, turn off TiB 2 Target, turn on the Ti (C, N) target, the arc current is 80A, the voltage is 20V, and the deposition time is maintained at 10min; after the coating deposition is completed, the parts are cooled to less than 100°C in the vacuum chamber, returned to normal pressure, and taken out of the furnace.

[0051] The mechanical properties of the metal ceramic parts were tested: room temperature hardness was 18.2GPa; bending strength was 719MPa; fracture toughness was 9.3MPa·m 1 / 2 At 1000℃, the hardness is 10.1GPa, the flexural strength is 637MPa, and the fracture toughness is 7.3MPa·m 1 / 2 The XRD of the parts prepared by bond spraying and hot isostatic pressing shows Ti(C,N), TiB 2 And FCC structural bonding phase. SEM picture Figure 5 As shown, the Ti(C,N) grains are larger than those in Example 1 (average size is 0.8 μm), with more pores, and the TiB synthesized by the reaction 2 A large amount of segregation affects the performance of metal ceramics. The SEM morphology of the composite coating is shown in Figure 6 As shown, it is shown that by using a suitable preparation process, TiB with better coating adhesion can be obtained. 2 -Ti(C,N) composite coating. In the SEM image, 1 represents the Ti(C,N)-based metal ceramic matrix, 2 represents the TiB 2 Coating, 3 represents Ti(C,N) coating.

Claims

1. A method for preparing fine-grained Ti(C,N)-based cermets by composite batch 3D printing and reactive hot isostatic pressing sintering, characterized in that: The following steps are involved: 1) Weighing the raw materials of Ti(C,N)-based metal ceramics and the mixed binder in the process proportion weight, placing them in a V-shaped double-screw mixer and mixing them to obtain a mixed material; 2) loading the mixture of step 1) and an inorganic environmentally friendly binder into a binder jet 3D printer, setting printing slice parameters according to the three-dimensional models of parts with different complex shapes, and curing at room temperature or slightly heated to obtain a batch-printed Ti(C,N)-based metal ceramic material blank; 3) placing the Ti(C,N)-based cermet material body of step 3) into a gas pressure sintering furnace, completing degreasing + reaction hot isostatic pressing sintering to obtain a rough component sample; 4) After sintering in step 3), the rough component sample is placed in an automatic sandblasting machine for appropriate surface sandblasting, and then multi-arc ion plating is completed to finally obtain a new type of fine-grained Ti (C, N) based metal ceramic.

2. The method for preparing fine-grained Ti(C,N)-based cermets by 3D printing and reactive hot isostatic pressing composite batch preparation as claimed in claim 1, characterized in that In step 1), the mass ratio of the Ti(C,N)-based metal ceramic raw materials is: Ti: 48-56wt%, B4C / BN: 14-18wt%, TiN / TiC16-20: wt%, Co / Ni / FeCoCrNiX: 10-20wt%, wherein X in Co / Ni / FeCoCrNiX=any one of Mn, Ti, V; the main component of the mixed binder is paraffin / polyvinyl alcohol, and the content of the mixed binder is 10-20wt% of the raw materials.

3. The method for preparing fine-grained Ti(C,N)-based cermets by 3D printing and reactive hot isostatic pressing composite batch preparation as claimed in claim 1, characterized in that In step 1), the V-shaped double-helix mixer adopts a V-shaped main engine, the speed of the V-shaped main engine is 200-400r / min, the speed of the double helix is ​​50-100r / min, and it can realize forward and reverse rotation.

4. The method for preparing fine-grained Ti(C,N)-based cermets by 3D printing and reactive hot isostatic pressing composite batch preparation according to claim 1, characterized in that In step 2), the inorganic environmentally friendly binder mainly includes the following components: sodium silicate: 20-35wt%, modifier: 4020wt%, aluminum sulfate: 0.201wt%, promoter: 103wt%, deionized water: 40070wt%, water-soluble silicone oil and phenolic resin: 0.503wt%; wherein the modifier is a mixture of disodium hydrogen phosphate, D-sorbitol, and tetraethyl silicate, and the promoter is a mixture of naphthalenesulfonic acid and sodium hydroxide.

5. The method for preparing fine-grained Ti(C,N)-based cermets by 3D printing and reactive hot isostatic pressing composite batch preparation according to claim 1, characterized in that In step 3), the degreasing + sintering process is specifically as follows: room temperature-500°C, 2-3°C / min; 500°C-500°C, heat preservation for 60-120min; 500-800°C, 1-2°C / min; 800-800°C, heat preservation for 60-120min; 800-1400°C, 5-10°C / min; 1400-1400°C, heat preservation for 60-120min; 1400-500°C, 10°C / min; cooling with the furnace; reaction hot isostatic pressing sintering process: 0-1000°C, 0MPa; 1000-1400°C, 5-8MPa; then depressurizing.

6. The method for preparing fine-grained Ti(C,N)-based cermets by 3D printing and reactive hot isostatic pressing composite batch preparation as claimed in claim 1, characterized in that In step 4), the gun distance of the automatic sandblasting machine is 30-50 mm; the inclination angle is 30-60°; the number of round trips is 3-6 times; and the sandblasting air pressure is 0.5-0.8 MPa.

7. The method for preparing fine-grained Ti(C,N)-based cermets by 3D printing and reactive hot isostatic pressing composite batch preparation as claimed in claim 1, characterized in that In step 4), the specific steps of sandblasting and spraying are: A) Sandblasting pretreatment: The sandblasting medium is Al2O3 sand with a particle size of 10-20μm, and the time is 10-40min. After sandblasting, ultrasonic cleaning is performed, deionized water is used for cleaning, and then ultrasonic cleaning is performed in acetone solution for 8-15min. After cleaning, the sandblasting is performed and dried for standby use; B) Coating deposition process: the pre-treated parts are evenly placed on the rack, loaded into the multi-arc ion plating machine, and the rack is rotated at a certain speed. The speed is adjusted according to the size of the rack, generally 10-30rpm, and the vacuum is evacuated to 10-4Pa. Ar is turned on and the vacuum chamber is adjusted to about 0.4Pa. The heater is turned on and the temperature is raised to 200-500℃; the substrate is biased to 300-600V, the TiB2 target is turned on, the sputtering cleaning is 20-40min, the arc current is 80A, the arc voltage is 20V, and TiB2 is deposited for 10min. When N2 is introduced, 0.3-0.5Pa, the arc current is 80A, the arc voltage is 20V, and TiB2 is deposited for 30-60min; the FeCoCrNiX target is turned on, and the working pressure is 0.4Pa-0.6Pa by controlling the N2 flow valve, and FeCoCrNiX is deposited. 1030min; after the deposition is completed, the TiB2 target and FeCoCrNiX target are turned off, and the Ti(C,N) target is turned on. The arc current is 80-150A, the voltage is 20-30V, and the deposition time is maintained at 10-30min; after the coating deposition is completed, the parts are cooled to less than 100°C in the vacuum chamber, restored to normal pressure, and taken out of the furnace.

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