High-toughness metal ceramic particle and preparation method thereof

Abstract

The invention belongs to the technical field of metal ceramic, and particularly relates to a high-toughness metal ceramic particle and a preparation method thereof.The particle is characterized in that ceramic micro powder, surface modified ceramic powder and rare earth element carbonitride form a composite hard phase, and the composite hard phase is dispersed in a metal matrix composed of multiple metal elements; and synergistic regulation and control components are introduced to optimize interface bonding and tissue uniformity. Particles are subjected to a step-by-step heat treatment and isostatic pressing forming process, and a stable structure is formed by controlling the oxygen content and the sintering atmosphere. The obtained material has high bending strength, high fracture toughness and good thermal shock resistance, is suitable for the application field of wear resistance and crack resistance under extreme working conditions, and has tissue compactness and mechanical stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal ceramics, and in particular relates to high-toughness metal ceramic particles and a preparation method thereof. Background Art

[0002] Cermets are a type of composite material composed of two phases: metal and ceramic. They combine the toughness of metal with the high hardness, high melting point, and wear resistance of ceramics. They are widely used in cutting tools, wear-resistant components, aerospace, and high-temperature structures. However, traditional cermet particles often suffer from defects such as insufficient toughness and easy fracture due to weak interfacial bonding or uneven phase distribution, limiting their reliability in high-impact and high-strength applications.

[0003] Prior art approaches to improving the toughness of metal ceramics primarily include refining the grain size, introducing secondary phase reinforcement, and improving the sintering process. For example, obtaining ultrafine powders through high-energy ball milling, increasing density through hot isostatic pressing or spark plasma sintering, and introducing nanostructures or functionally graded material structures have all improved mechanical properties to some extent. However, these methods often involve complex preparation processes and high costs, and lack systematic control over the composite mechanism and structural design of the material itself, resulting in limited toughness improvements and insufficient stability.

[0004] Therefore, how to design a metal-ceramic granular material with uniform organizational structure, high interface bonding strength and excellent toughness, and propose a preparation method with simple process and controllable cost, has become an urgent problem to be solved in the current technological development in this field. Summary of the Invention

[0005] In view of the above problems, the present invention aims to provide: a high-toughness metal ceramic particle composed of a hard phase, a metal matrix phase and a synergistic control component; The hard phase is composed of the following three types of particles: (1) Ceramic micropowder, which is at least two of silicon carbide, silicon nitride, silicon oxide, titanium carbide, titanium nitride, aluminum oxide, and zirconium carbide; (2) Modified ceramic powder, which is a ceramic particle coated with a layer of carbonitride of a transition metal element on its surface, wherein the transition metal element includes at least one of niobium, titanium or zirconium, and the carbonitride is at least one of silicon carbide nitride, titanium carbide nitride, zirconium carbide nitride and niobium carbide nitride; (3) Rare earth element carbides and nitrides, namely hafnium carbide and tantalum nitride, and any two of (1), (2) and (3) are not nitrides at the same time; The metal matrix phase is composed of at least three metal elements of iron, nickel, cobalt, chromium, titanium and aluminum, and the mass percentage of a single element is 10 to 40%; The synergistic regulating components include at least two of graphene oxide, boron trioxide, and glyceryl monostearate, and in the composite structure, part of the synergistic regulating components forms particle precipitates with the rare earth component, and the other part exists in the metal matrix phase in a solid solution state.

[0006] In a preferred technical solution, based on the total mass as 100%, the total content of the hard phase is 25-50 wt%, the total mass percentage of the synergistic regulating components does not exceed 5 wt%, and the remainder is the total content of the metal matrix phase.

[0007] In a preferred technical solution, based on the mass of the total hard phase being 100%, the ceramic powder accounts for 40-60 wt% of the hard phase, the rare earth element carbides and nitrides account for a total of 5-20 wt%, and the remainder is the modified ceramic powder; The average particle size of the ceramic micropowder is 0.3-2.0 μm, the average particle size of the modified ceramic powder is 0.2-1.5 μm, and the average particle size of the rare earth carbonitride is 0.1-0.8 μm.

[0008] In a preferred technical solution, among the three optional components of iron, nickel, cobalt, chromium, titanium and aluminum in the metal matrix phase, the mass ratio of nickel to cobalt is 1 to 2:1, and the metal matrix phase is distributed between the ceramic particles in a continuous phase structure to form an interlocking composite configuration.

[0009] In a preferred technical solution, the mass ratio of graphene oxide to boron trioxide in the synergistic regulating component is (1-3):1, and the component is uniformly distributed in the form of submicron particles in the microstructure between the grain boundaries of the metal matrix phase and the ceramic particle coating interface.

[0010] The present invention also provides a method for preparing the high-toughness metal ceramic particles, comprising the following steps: S1. Weighing raw materials: Weigh ceramic micropowder, modified ceramic powder, rare earth element carbide and nitride, and metal matrix powder according to mass percentage to 100% of the total amount, and add 1-4% of the synergistic regulating component. The resulting mixture is the original composite powder; S2. Ceramic particle pretreatment: ball milling the ceramic powder, modified ceramic powder, and rare earth element carbides and nitrides under vacuum for 2 to 4 hours, heating the mixture to 1000 to 1100°C at a rate of 5°C / min, holding the mixture for 15 to 30 minutes, and then holding the mixture for 30 to 60 minutes in an atmosphere with an oxygen content controlled at 2 to 3 wt% to obtain composite ceramic particles after in-situ reaction. S3, composite mixing treatment: the ceramic particles obtained in step S2, the metal matrix powder, and the synergistic control component are placed together in a ceramic-lined ball mill, ethanol solution is added as a dispersion medium, and ball milling is performed for 8 to 12 hours, with a ball-to-material ratio of 5:1 to 6:1, the ball milling medium is zirconia balls with a particle size of 0.5 to 1.5 mm, and the ball milling temperature does not exceed 40° C.; S4. Drying and molding: The ball-milled slurry is stirred with water and then filtered. The resulting filter cake is dried at 60°C and -0.08 to -0.1 MPa for 3 hours to obtain a dry powder. The dry powder is placed in a cold isostatic press at a pressure of 20 to 30 MPa for a holding time of not less than 3 minutes to form a dense molded body. S5. Sintering treatment: Place the molded body in a high-purity argon atmosphere for sintering treatment at a sintering temperature of 1250-1350°C and a holding time of 90-120 minutes. Before sintering, three vacuuming-argon filling cycles are performed to reduce the oxygen content to less than 0.5 vol%, and the temperature is lowered at a cooling rate of 3-5°C / min.

[0011] In a preferred technical solution, the synergistic regulating component includes at least two of graphene oxide, boron trioxide, and glyceryl monostearate, and the mass ratio of the synergistic regulating component to the metal matrix is ​​1 to 4%; the ball milling dispersion medium is anhydrous ethanol, and the solid-liquid ratio is 1:2 to 1:3.

[0012] In a preferred technical solution, the ball milling medium is zirconia balls with a diameter of 0.5 to 1.5 mm, the ball milling jar is lined with zirconia ceramic, the ball milling process is carried out under nitrogen protection, and the total ball milling time is not less than 8 hours.

[0013] In a preferred technical solution, the filter cake after filtration is dried at a constant temperature of 60°C under -0.08 to -0.1 MPa for 3 hours. After drying, it is directly used for isostatic pressing without secondary crushing.

[0014] In a preferred technical solution, the purity of argon before sintering is not less than 99.999%, the sintering heating rate is 10°C / min, and the argon atmosphere is maintained during the cooling process after sintering until the sample temperature drops below room temperature.

[0015] Beneficial effects The present invention constructs a composite hard phase composed of ceramic micropowder, surface-modified ceramic powder, and rare earth element carbides and nitrides to form a multiphase synergistic structure in the metal matrix, effectively improving the overall performance of the material and having the following beneficial effects: 1. Improve fracture toughness and structural stability: The modified ceramic powder in the hard phase is coated with a transition metal carbonitride layer, forming a stable interface reaction zone with the rare earth element carbonitride during high-temperature treatment, thereby enhancing the interface bonding between the ceramic particles and between the ceramic particles and the metal matrix, and significantly improving the ceramic particles' anti-debonding ability and crack propagation resistance under load conditions.

[0016] 2. Enhanced organizational uniformity and microscopic density: The composite of multi-component ceramic micropowders and rare earth carbonitrides guides the grain refinement mechanism. The resulting submicron-sized particle precipitates are evenly distributed during the sintering process, which helps control the microstructure particle size and void structure, and improves overall density and mechanical uniformity.

[0017] 3. Enhance thermal stability and resistance to thermal shock: A variety of high-melting-point transition metal elements (such as titanium, chromium, nickel, etc.) are introduced into the metal matrix to form a continuous network structure, and components such as graphene oxide and boron trioxide are synergistically regulated to form a thermal buffer distribution in the grain boundary area, effectively alleviating thermal expansion mismatch and improving the structural stability of the material in high-temperature cycling environment.

[0018] 4. Improve sintering adaptability and process controllability: Through oxygen content control and step-by-step heat treatment technology, the reaction process between the coating layer and the rare earth in the modified ceramic powder is stable under specific redox conditions. Combined with cold isostatic pressing and inert atmosphere sintering processes, the consistency of the final particle structure and stable processing shrinkage rate are ensured, which has good engineering adaptability.

[0019] 5. Realize a multi-scale synergistic enhancement mechanism: The multi-phase particle system constructed by the present invention exhibits grain boundary strengthening and fine-grain blocking effects at the microscale, and forms a structural framework composed of a hard phase embedded in a continuous metal phase at the macroscale, achieving a balance between toughness and strength under multiple working conditions such as fracture, wear and impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a four-point SEM photograph of Example 1 of the present invention. In the figure, A, B, C, and D respectively represent four shooting points on the same sample; Figure 2 Schematic diagram of the results of the comparative experiment of the present invention (bending strength); Figure 3 Schematic diagram of the results of the comparative experiment of the present invention (fracture toughness); Figure 4 Schematic diagram of the results of the comparative experiment of the present invention (HV0.5 hardness); Figure 5 Schematic diagram of the results of the comparative experiment of the present invention (thermal shock stability); Figure 6 Schematic diagram of the results of the comparative experiment of the present invention (1000°C endurance strength). DETAILED DESCRIPTION

[0021] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0022] Example 1 (T1) This embodiment provides a method for preparing high-toughness metal ceramic particles, whose structure consists of a hard phase, a metal matrix phase, and a coordinated control component. Each component is designed and prepared according to the following ratios and parameters: Based on 100% of the total mass, the mass percentages of the three-phase components are as follows: Hard phase: 40 wt%; metal matrix phase: 57 wt%; synergistic regulating component: 3 wt%.

[0023] Among them, the specific composition of the hard phase is as follows: Ceramic micropowder: accounts for 55% of the total hard phase, composed of silicon carbide (SiC) and aluminum oxide (Al2O3) mixed in a mass ratio of 2:1, with an average particle size of 0.8 μm; Modified ceramic powder: accounting for 25% of the total hard phase, the modified ceramic powder is silicon carbide particles coated with a titanium carbide nitride (TiCN) layer, wherein the coating layer thickness is controlled to be 80 nm, and the average particle size of the modified powder is 1.0 μm; Rare earth element carbides and nitrides: accounting for 20% of the total hard phase, of which the mass ratio of hafnium carbide (HfC) to tantalum nitride (TaN) is 1:1, and the average particle size is 0.5 μm.

[0024] The specific composition of the metal matrix phase is as follows: iron (Fe): 43.9% of the metal matrix; nickel (Ni): 35.1% of the metal matrix; cobalt (Co): 21.0% of the metal matrix; the mass ratio of nickel to cobalt is approximately 5:3, and the metal matrix forms a continuous phase network structure after mixed ball milling.

[0025] The composition of the synergistic regulatory components is as follows: graphene oxide (GO); boron trioxide (B2O3); the mass ratio of the two is 2:1. The obtained powder is evenly distributed during the mixed ball milling process, and then dispersed in the matrix grain boundaries and ceramic-metal interfaces in the form of submicron particles during the sintering process.

[0026] Preparation steps: Weigh various raw materials according to the above proportions, among which ceramic micropowder, modified ceramic powder and rare earth carbonitride are first dry-mixed and uniformly treated; The hard phase powder was ball-milled under vacuum for 2 hours, then heated to 1050°C for 20 minutes, and then heat treated for 40 minutes while gradually introducing a small amount of oxygen to control the atmosphere, maintaining the oxygen content at 2.5 wt%. The heat-treated ceramic part, metal matrix powder and synergistic control components were placed in a ball mill and wet-milled for 10 hours under a nitrogen atmosphere with a ball-to-material ratio of 5.5:1 and ethanol as the dispersion medium. The ball-milled slurry was stirred with water and then filter-pressed. The resulting filter cake was dried at 60°C and -0.09 MPa for 3 hours to obtain a dry composite powder. The dry powder was molded by cold isostatic pressing at a pressure of 25 MPa and the pressure was maintained for 5 minutes; The molded body was placed in a high-purity argon atmosphere, heated to 1300°C, and kept at this temperature for 90 minutes to complete sintering. During the process, three vacuum-and-argon filling cycles were performed to ensure that the oxygen content was less than 0.5 vol%. The cooling rate was 4°C / min.

[0027] Example 2 (T2) This embodiment provides a high-toughness metal ceramic particle, which comprises: a hard phase accounting for 45 wt% of the total mass, a metal matrix phase accounting for 52 wt% of the total mass, and a synergistic control component accounting for 3 wt% of the total mass.

[0028] The hard phase is composed of the following three types of particles (based on the total mass of the hard phase being 100%): Ceramic powder: 50 wt%, composed of silicon nitride (Si3N4) and zirconium carbide (ZrC), with a mass ratio of 1:1 and an average particle size of 1.5 μm; Modified ceramic powder: 35 wt%, the modified ceramic powder is titanium nitride (TiN) particles coated with niobium carbide nitrogen (NbCN), the coating thickness is about 100 nm, and the overall average particle size is about 1.2 μm; Rare earth element carbides and nitrides: 15 wt%, with a mass ratio of hafnium carbide (HfC) to tantalum nitride (TaN) of 3:2, and an average particle size of approximately 0.4 μm.

[0029] The metal matrix phase is composed of the following elements (based on the total mass of the metal matrix phase as 100%): iron (Fe): 38 wt%; chromium (Cr): 34 wt%; and titanium (Ti): 28 wt%. The metal matrix phase forms a continuously distributed structure and forms a dense coating interface with the hard particles.

[0030] The synergistic control components (accounting for 3 wt% of the total mass) include: diboron oxide (B2O3): 2 wt%; glycerol monostearate (GMS): 1 wt%. The mass ratio of these two components is 2:1. The particle size of each component is controlled below 500 nm, and they can be evenly dispersed at the grain boundaries and particle contact areas during ball milling.

[0031] The particle system was prepared using the same process as Example 1, including vacuum heat treatment to control oxygen content, ball milling, filter pressing and drying, isostatic pressing and inert atmosphere sintering. The sintering temperature was set at 1280°C and the holding time was 100 minutes.

[0032] Example 3 (T3) This embodiment provides a high-toughness metal ceramic particle, which comprises: a hard phase accounting for 30 wt% of the total mass, a metal matrix phase accounting for 67 wt% of the total mass, and a synergistic control component accounting for 3 wt% of the total mass.

[0033] The hard phase is composed of the following three types of particles (based on the total mass of the hard phase being 100%): Ceramic micropowder: 60 wt%, composed of silicon oxide (SiO2) and titanium carbide (TiC), with a mass ratio of 3:2 and an average particle size of 1.0 μm; Modified ceramic powder: 30 wt%, silicon carbide (SiC) powder coated with zirconium carbide nitrogen (ZrCN), with a coating thickness of approximately 80 nm and an overall average particle size controlled at 0.8 μm; Rare earth element carbides and nitrides: 10 wt%, a mixture of hafnium carbide (HfC) and tantalum nitride (TaN) with a mass ratio of 2:1, and an average particle size of 0.3 μm.

[0034] The metal matrix phase is composed of the following three metal elements (based on the total mass of the metal matrix phase as 100%): aluminum (Al): 40 wt%; cobalt (Co): 35 wt%; and iron (Fe): 25 wt%. Aluminum imparts good thermal conductivity and toughness to the matrix, while cobalt and iron form a structural framework. These three elements form a continuous encapsulating structure embedded within the interstices between ceramic particles.

[0035] The synergistic regulating components include: graphene oxide (GO): 2 wt%; glycerol monostearate (GMS): 1 wt%; the mass ratio of the two is 2:1, and a submicron-level composite dispersion structure is formed during the ball milling process and is distributed in the metal matrix grain boundaries and the ceramic intergranular transition zone.

[0036] Preparation process description: The hard phase components were dry-mixed and then ball-milled under vacuum for 2 h, and then heated to 1100 °C in a gradient temperature ramp and kept at this temperature for 20 min. An atmosphere with a controlled oxygen content of 2.2 wt% was introduced and the temperature was maintained for 40 minutes to induce an in-situ interfacial reaction between the coating layer and the rare earth particles. Then, the metal matrix powder and the synergistic regulating components were wet ball milled for 10 hours with a ball-to-material ratio of 6:1 and ethanol as the dispersion medium. The ball-milled mixed slurry was dehydrated by filter pressing, and the filter cake was dried at 60°C and -0.1 MPa for 3 h. The obtained powder was molded by cold isostatic pressing at 30 MPa. The molded body was sintered at 1300°C in a high-purity argon atmosphere and kept at this temperature for 100 minutes. The argon atmosphere was maintained during the cooling process, and the cooling rate was controlled at 4°C / min.

[0037] Comparative Example 1 (C1) This comparative example prepared a cermet particle structure consisting of a hard phase, a metal matrix phase, and a control component. The weight percentages of the components are as follows: hard phase: 55 wt%; metal matrix phase: 42 wt%; and the co-control component: 3 wt%.

[0038] The hard phase is composed of the following three parts (the total mass of the hard phase is 100%): Ceramic powder: 30 wt%, composed of silicon carbide (SiC) and silicon oxide (SiO2), with a mass ratio of 1:1 and an average particle size of approximately 2.2 μm; Modified ceramic powder: 50 wt%, composed of titanium nitride (TiN) coated with titanium carbonitride (TiCN), with an average particle size of 1.8 μm; Rare earth element carbides and nitrides: 20 wt%, a mixture of hafnium carbide (HfC) and tantalum nitride (TaN) with a mass ratio of 1:1 and an average particle size of 0.2 μm.

[0039] The metal matrix phase includes the following three metal elements (based on the total mass of the metal matrix phase as 100%): nickel (Ni): 25 wt%; cobalt (Co): 10 wt%; and chromium (Cr): 7 wt%. The synergistic regulating component is composed of graphene oxide (GO) and boron trioxide (BO) in a mass ratio of 3:1.

[0040] The preparation method is briefly described as follows: After mixing, the raw materials were ball-milled under vacuum for 2 hours and kept at 1100°C for 20 minutes. The oxygen content in the atmosphere was controlled to about 2.5 wt%. They were then wet-ball-milled with the metal matrix powder and the synergistic regulating components for 10 hours. The ball-to-material ratio was 6:1, and the dispersant was ethanol.

[0041] The obtained mixed slurry was filtered and dried, and then cold isostatically pressed at a pressure of 30 MPa; the formed body was sintered at 1280°C in a high-purity argon atmosphere, kept warm for 90 minutes, and cooled at a rate of 4°C / min.

[0042] Comparative Example 2 (C2) The metal ceramic particles of this comparative example are composed of a hard phase, a metal matrix phase and a coordinated control component, and the components and parameters are as follows: Total hard phase content: 55 wt%, including: ceramic powder (silicon carbide + aluminum oxide): 30 wt% of the hard phase; modified ceramic powder (titanium carbide, coated zirconium): 65 wt% of the hard phase; rare earth element carbonitride (hafnium carbide): 5 wt% of the hard phase.

[0043] The total content of the metal matrix phase is 40 wt%, including: nickel: 15 wt%; iron: 10 wt%; cobalt: 15 wt%.

[0044] The total content of synergistically regulated components is 5 wt%, including: graphene oxide: 3.5 wt%; boron trioxide: 1.5 wt%.

[0045] Particle size parameters: the average particle size of ceramic micropowder is 2.2 μm; the average particle size of modified ceramic powder is 1.7 μm; the average particle size of rare earth carbonitride is 0.9 μm.

[0046] Other structural features: The mass ratio of graphene oxide to boron trioxide in the synergistic regulatory component is 7:3; the mass ratio of nickel to cobalt is 1:1.

[0047] The comparative example material was formed by a vacuum hot pressing sintering process, kept at 1400° C. and 30 MPa for 60 minutes, and then cooled.

[0048] Comparative Example 3 (C3) This comparative example adopts a common traditional metal ceramic particle preparation route, whose structure consists of a hard phase and a metal binder phase, and does not introduce modified ceramic powder, rare earth carbonitride or synergistic regulating component.

[0049] The particles are composed of the following two parts: Hard phase: 80 wt%, tungsten carbide (WC), with an average particle size of 1.5 μm; Metal binder phase: 20 wt%, pure cobalt (Co).

[0050] The raw materials were dry-milled for 4 hours and then sintered at 1380°C for 90 minutes in a hydrogen atmosphere. The cooling process was natural without protective gas.

[0051] The prepared particles are typical WC-Co materials, in which the hard phase is distributed in blocks, the metal phase is thinly wrapped, there are obvious signs of fracture at the bonding interface, and the microstructure lacks fine-grained precipitation phase and composite ceramic interface structure.

[0052] Comparative Example 4 (C4) This comparative example adopts a common traditional metal ceramic particle structure. The material is composed of a hard ceramic phase and a metal bonding phase, and does not contain modified ceramic particles, rare earth carbonitrides or interface control components.

[0053] The granule composition is as follows: Hard phase: TiC, accounting for 70 wt% of the total mass, with an average particle size of 2.0 μm; Metal matrix phase: Ni, accounting for 30 wt% of the total mass.

[0054] The raw materials were dry-milled for 3 hours and then pressed into shape. They were sintered at 1350°C for 60 minutes under a hydrogen protective atmosphere, and the cooling rate was natural cooling.

[0055] Comparative experiment S1. Sample Preparation The preparation of high-toughness metal ceramic particles was completed according to the set parameters and processes of each group, and the obtained samples were pressed into standard test cylindrical blocks with a diameter of 10 mm and a height of 15 mm.

[0056] S2. Microstructure Analysis The morphology of the sintered microstructure was observed using scanning electron microscopy (SEM).

[0057] S3. Mechanical properties test Bending strength test: According to the national standard "Test method for flexural strength of fine ceramics (GB / T 6569-2006 / ISO14704:2000)", the three-point bending method is used for determination; Fracture toughness test: measured by SEVNB method (single-edge notched beam with slit); Hardness test: measured using a Vickers hardness tester (HV10).

[0058] S4. Thermal Performance Evaluation Thermal shock stability test: Starting at 1100°C, the sample is quickly immersed in cold water and the number of cycles required for rupture occurs is measured; High temperature endurance strength: Load 60 MPa at 1000℃ for 1 hour and then observe the damage of the sample.

[0059] The comparative experimental results are shown in Table 1: Table 1 Comparative experimental results Analysis of experimental results: 1. Figure 1 This is a SEM photo of the sample prepared in Example 1 of the present invention, wherein: Figure 1 A, B, C, and D in the figure represent four sampling points on the same sample. Figure 1 As shown, after sintering, the sample of Example 1 of the present invention has hard phases of different particle sizes in contact and interlock with each other and are wrapped by the metal matrix, achieving coating of different scales with a stable bonding effect, and the coating conditions at the four points are similar, indicating that the sample has good uniformity at the microscopic level.

[0060] 2. If Figure 2 As shown in the flexural strength analysis (MPa), the flexural strengths of experimental groups T1, T2, and T3 were 920±18, 875±20, and 838±22 MPa, respectively, significantly higher than those of controls C1–C4 (710±25 to 642±26 MPa). The T1 group showed the greatest improvement, increasing by approximately 43.3% compared to the C4 group. This result demonstrates that the process of this invention significantly enhances the overall load-bearing capacity of the material.

[0061] 3. If Figure 3 As shown, fracture toughness analysis ( ): The fracture toughness of group T1 is 12.8±0.4 MPa·√m, while that of T2 and T3 are 11.9±0.3 and 11.2±0.4 respectively. , which was significantly better than the control group C1–C4 (9.3±0.5 to 7.8±0.6 The T1 group improved by more than 60% compared to the C4 group, indicating that the material performed better in terms of crack propagation resistance and had excellent structural crack resistance stability.

[0062] 4. If Figure 4 As shown in the figure, hardness analysis (HV0.5) shows that the hardness of the T1, T2, and T3 groups was 1760±22, 1715±25, and 1650±20 HV, respectively, all higher than the control groups C1–C4 (1520±35 to 1435±38 HV). The greatest improvement occurred in the T1 group, which increased by 18.1% compared to the C4 group. This higher hardness indicates enhanced wear resistance, making it suitable for more demanding working conditions.

[0063] 5. If Figure 5 As shown in the thermal shock stability analysis (times), group T1 achieved 38±2 times of stability in the thermal shock test, while T2 and T3 achieved 35±2 and 33±3 times, respectively, showing a significant advantage over groups C1–C4 (21±3 to 17±3 times). The T1 group improved by 123.5% compared to the C4 group, indicating a significant enhancement in the material's crack resistance under high-temperature, rapid cooling and heating conditions.

[0064] 6. If Figure 6 As shown, high temperature endurance strength analysis ( The T1 group showed endurance strength of 109 ± 5 hours, while T2 and T3 showed strengths of 98 ± 4 and 87 ± 6 hours, respectively. This was significantly lower in the control groups C1–C4, with strengths ranging from 58 ± 7 to 39 ± 5 hours. The T1 group showed a 179% improvement over the C4 group, demonstrating its superior mechanical retention under high-temperature, long-term service conditions.

[0065] Conclusion summary: The experimental groups T1, T2, and T3 are significantly superior to the traditional formulations C1–C4 in all performance indicators, especially in flexural strength, fracture toughness, and thermal shock stability. This shows that the materials prepared by the process of the present invention have obvious advantages in mechanical strength, crack resistance, heat resistance, and high-temperature service life, and have good industrial application prospects.

[0066] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-toughness metal ceramic particle, characterized in that: It is composed of a hard phase, a metal matrix phase and synergistic control components; The hard phase is composed of the following three types of particles: (1) Ceramic micropowder, which is at least two of silicon carbide, silicon nitride, silicon oxide, titanium carbide, titanium nitride, aluminum oxide, and zirconium carbide; (2) Modified ceramic powder, which is a ceramic particle coated with a layer of carbonitride of a transition metal element on its surface, wherein the transition metal element includes at least one of niobium, titanium or zirconium, and the carbonitride is at least one of silicon carbide nitride, titanium carbide nitride, zirconium carbide nitride and niobium carbide nitride; (3) Rare earth element carbides and nitrides, namely hafnium carbide and tantalum nitride, and any two of (1), (2) and (3) are not nitrides at the same time; The metal matrix phase is composed of at least three metal elements of iron, nickel, cobalt, chromium, titanium and aluminum, and the mass percentage of a single element is 10 to 40%; The synergistic regulating components include at least two of graphene oxide, boron trioxide, and glyceryl monostearate, and in the composite structure, part of the synergistic regulating components forms particle precipitates with the rare earth component, and the other part exists in the metal matrix phase in a solid solution state.

2. The high-toughness metal ceramic particles according to claim 1, characterized in that Based on the total mass as 100%, the total content of the hard phase is 25-50 wt%, the total mass percentage of the synergistic regulating components does not exceed 5 wt%, and the remainder is the total content of the metal matrix phase.

3. The high-toughness metal ceramic particles according to claim 1, characterized in that Taking the mass of the total hard phase as 100%, the ceramic powder accounts for 40-60 wt% of the hard phase, the rare earth element carbides and nitrides account for a total of 5-20 wt%, and the remainder is the modified ceramic powder; The average particle size of the ceramic micropowder is 0.3-2.0 μm, the average particle size of the modified ceramic powder is 0.2-1.5 μm, and the average particle size of the rare earth carbonitride is 0.1-0.8 μm.

4. The high-toughness metal ceramic particles according to claim 1, characterized in that Among the three optional components of iron, nickel, cobalt, chromium, titanium and aluminum in the metal matrix phase, the mass ratio of nickel to cobalt is 1 to 2:1, and the metal matrix phase is distributed between the ceramic particles in a continuous phase structure to form an interlocking composite configuration.

5. The high-toughness metal ceramic particles according to claim 1, characterized in that The mass ratio of graphene oxide to boron trioxide in the synergistic regulating component is (1-3):1, and the component is uniformly distributed between the grain boundaries of the metal matrix phase and the coating interface of the ceramic particles in the form of submicron particles in the microstructure.

6. A method for preparing high-toughness metal ceramic particles according to any one of claims 1 to 5, characterized in that: The steps include: S1. Weighing raw materials: Weigh ceramic micropowder, modified ceramic powder, rare earth element carbide and nitride, and metal matrix powder according to mass percentage to 100% of the total amount, and add 1-4% of the synergistic regulating component. The resulting mixture is the original composite powder; S2. Ceramic particle pretreatment: ball milling the ceramic powder, modified ceramic powder, and rare earth element carbides and nitrides under vacuum for 2 to 4 hours, heating the mixture to 1000 to 1100°C at a rate of 5°C / min, holding the mixture for 15 to 30 minutes, and then holding the mixture for 30 to 60 minutes in an atmosphere with an oxygen content controlled at 2 to 3 wt% to obtain composite ceramic particles after in-situ reaction. S3, composite mixing treatment: the ceramic particles obtained in step S2, the metal matrix powder, and the synergistic control component are placed together in a ceramic-lined ball mill, ethanol solution is added as a dispersion medium, and ball milling is performed for 8 to 12 hours, with a ball-to-material ratio of 5:1 to 6:1, the ball milling medium is zirconia balls with a particle size of 0.5 to 1.5 mm, and the ball milling temperature does not exceed 40° C.; S4. Drying and molding: The ball-milled slurry is stirred with water and then filtered. The resulting filter cake is dried at 60°C and -0.08 to -0.1 MPa for 3 hours to obtain a dry powder. The dry powder is placed in a cold isostatic pressing apparatus at a pressure of 20 to 30 MPa for a holding time of not less than 3 minutes to form a dense molded body. S5. Sintering treatment: Place the molded body in a high-purity argon atmosphere for sintering treatment at a sintering temperature of 1250-1350°C and a holding time of 90-120 minutes. Before sintering, three vacuuming-argon filling cycles are performed to reduce the oxygen content to less than 0.5 vol%, and the temperature is lowered at a cooling rate of 3-5°C / min.

7. The preparation method according to claim 6, characterized in that The synergistic regulating components include at least two of graphene oxide, boron trioxide, and glyceryl monostearate, and the mass ratio of the synergistic regulating components to the metal matrix is ​​1 to 4%; the ball milling dispersion medium is anhydrous ethanol, and the solid-liquid ratio is 1:2 to 1:

3.

8. The preparation method according to claim 7, characterized in that The ball milling medium is zirconia balls with a diameter of 0.5 to 1.5 mm, the ball milling jar is lined with zirconia ceramics, the ball milling process is carried out under nitrogen protection, and the total ball milling time is not less than 8 hours.

9. The preparation method according to claim 8, characterized in that The filter cake after the filter pressing is dried at a constant temperature of 60° C. under a pressure of -0.08 to -0.1 MPa for 3 hours. After drying, it is directly used for isostatic pressing without secondary crushing.

10. The preparation method according to claim 9, characterized in that The purity of argon before sintering is not less than 99.999%, the sintering heating rate is 10°C / min, and the argon atmosphere is maintained during the cooling process after sintering until the sample temperature drops below room temperature.

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