High toughness cermet particles and method of making same

Abstract

The present application belongs to the technical field of cermet, and particularly relates to a high-toughness cermet particle and a preparation method thereof, the particle being composed of a composite hard phase of ceramic micropowder, surface-modified ceramic powder and rare earth element carbonitride, dispersed in a metal matrix composed of multiple metal elements, and introducing a synergistic control component to optimize the interface bonding and the uniformity of the structure. The particle adopts a step-by-step heat treatment and isopressing 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 stability, and is suitable for the application field of wear-resistant and crack-resistant under extreme working conditions, and has compact structure and mechanical stability.

Description

Technical Field

[0001] This invention belongs to the technical field of metal ceramics, specifically relating to a high-toughness metal ceramic particle and its preparation method. Background Technology

[0002] Cermet is a type of composite material composed of two phases: metal and ceramic. It combines the toughness of metals with the high hardness, high melting point, and wear resistance of ceramics, and is widely used in cutting tools, wear-resistant parts, aerospace, and high-temperature structures. However, traditional cermet particles often suffer from insufficient toughness and easy fracture due to weak interfacial bonding or uneven phase distribution, which limits their reliability in high-impact and high-strength applications.

[0003] In existing technologies, methods to improve the toughness of cermets mainly include refining grain size, introducing a second phase for reinforcement, and improving the sintering process. For example, obtaining ultrafine powder through high-energy ball milling, improving density through hot isostatic pressing or discharge plasma sintering, and introducing nanostructures or functionally graded material structures have all improved mechanical properties to some extent. However, these methods are often complex in preparation and costly, and lack systematic control over the composite mechanism and structural design of the material itself, resulting in limited improvement in toughness and insufficient stability.

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

[0005] To address the above problems, the present invention aims to provide a high-toughness metal-ceramic particle, which is composed of a hard phase, a metal matrix phase, and synergistic regulatory components.

[0006] The hard phase is composed of the following three types of particles:

[0007] (1) The ceramic micro powder is at least two of silicon carbide, silicon nitride, silicon oxide, titanium carbide, titanium nitride, aluminum oxide, and zirconium carbide;

[0008] (2) Modified ceramic powder 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.

[0009] (3) Rare earth element carbides and nitrides are hafnium carbide and tantalum nitride, and any two of (1), (2) and (3) are not nitrides at the same time;

[0010] The metallic matrix phase is composed of at least three metallic elements selected from iron, nickel, cobalt, chromium, titanium, and aluminum, with each single element accounting for 10% to 40% of the total mass.

[0011] The synergistic regulatory components include at least two of graphene oxide, boron trioxide, and glyceryl monostearate. In the composite structure, some of the synergistic regulatory components form particulate precipitates with the rare earth components, while the other part exists in a solid solution state in the metal matrix phase.

[0012] In a preferred embodiment, the total content of the hard phase is 25-50 wt% based on a total mass of 100%, the total mass percentage of the synergistic regulating components does not exceed 5 wt%, and the remaining portion is the total content of the metal matrix phase.

[0013] In a preferred embodiment, based on the total mass of the hard phase being 100%, the ceramic micro powder accounts for 40-60 wt% of the hard phase, the rare earth element carbides and nitrides together account for 5-20 wt%, and the remaining portion is the modified ceramic powder.

[0014] The average particle size of the ceramic micro powder 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 carbonitrides is 0.1–0.8 μm.

[0015] In a preferred embodiment, among any three components of the metal matrix phase (iron, nickel, cobalt, chromium, titanium, and aluminum), the mass ratio of nickel to cobalt is 1 to 2:1, and the metal matrix phase is distributed in a continuous phase structure between the ceramic particles to form an interlocking composite configuration.

[0016] In a preferred embodiment, the mass ratio of graphene oxide to boron trioxide in the synergistic regulatory component is (1-3):1, and the component is uniformly distributed in the form of submicron particles between the grain boundaries of the metal matrix phase and the interface of the ceramic particles in the microstructure.

[0017] The present invention also provides a method for preparing the aforementioned high-toughness metal-ceramic particles, comprising the following steps:

[0018] S1. Raw material weighing: Weigh ceramic micro powder, modified ceramic powder, rare earth element carbides and nitrides, and metal matrix powder to 100% of the total amount by mass percentage, and add 1-4% of the synergistic regulating component. The resulting mixture is the original composite powder.

[0019] S2. Pretreatment of ceramic particles: Ceramic micro powder, modified ceramic powder, and rare earth element carbides and nitrides are ball-milled in a vacuum environment for 2 to 4 hours, and then heated to 1000 to 1100°C at a rate of 5°C / min. After holding at this temperature for 15 to 30 minutes, the temperature is further maintained 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.

[0020] S3. Composite mixing treatment: The ceramic particles obtained in step S2 are put into a ceramic-lined ball mill jar together with the metal matrix powder and the synergistic regulating components. Ethanol solution is added as a dispersion medium and ball milling is carried out for 8 to 12 hours. The ball-to-material ratio is 5:1 to 6:1. The ball milling medium is zirconia balls with a particle size of 0.5 to 1.5 mm. The ball milling temperature does not exceed 40°C.

[0021] S4. Drying and molding: After ball milling, the slurry is mixed with water and then filtered by pressure. The resulting filter cake is dried at 60℃ and -0.08 to -0.1 MPa for 3 hours to obtain dried powder. The dried powder is placed in a cold isostatic pressing device, and a pressure of 20 to 30 MPa is applied for a holding time of not less than 3 minutes to form a dense molded body.

[0022] S5. Sintering treatment: The molded body is placed in a high-purity argon atmosphere for sintering treatment. The sintering temperature is 1250-1350℃ and the holding time is 90-120 minutes. Before sintering, three vacuum-argon gas cycles are performed to make the oxygen content less than 0.5 vol%. The body is cooled at a cooling rate of 3-5℃ / min.

[0023] In a preferred embodiment, 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 ​​1-4%; the ball milling dispersion medium is anhydrous ethanol, and the solid-liquid ratio is 1:2-1:3.

[0024] In a preferred embodiment, the milling media are zirconia balls with a diameter of 0.5 to 1.5 mm, the milling jar is lined with zirconia ceramic, the milling process is carried out under nitrogen protection, and the total milling time is not less than 8 hours.

[0025] In a preferred embodiment, the filter cake after pressure filtration 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.

[0026] In a preferred embodiment, the purity of argon gas before sintering is not less than 99.999%, the sintering heating rate is 10℃ / min, and the argon atmosphere is maintained during the cooling process after sintering until the sample temperature drops below room temperature.

[0027] Beneficial effects

[0028] This invention constructs a composite hard phase composed of ceramic micropowder, surface-modified ceramic powder, and rare earth element carbides and nitrides, forming a multiphase synergistic structure in a metal matrix, effectively improving the comprehensive performance of the material and having the following beneficial effects:

[0029] 1. Improve fracture toughness and structural stability: The modified ceramic powder in the hard phase, through the coating of transition metal carbonitride layer, forms a stable interfacial reaction zone with rare earth element carbonitride during high-temperature treatment, which enhances the interfacial bonding between ceramic particles and between ceramic particles and the metal matrix, and significantly improves the anti-debonding ability and crack propagation resistance of ceramic particles under load conditions.

[0030] 2. Enhanced uniformity and microstructure density: The composite of multi-component ceramic micropowder and rare earth carbonitrides guides the grain refinement mechanism. The resulting submicron-sized precipitates are uniformly distributed during sintering, which helps to control the particle size and porosity of the microstructure, and improves the overall density and mechanical uniformity.

[0031] 3. Enhanced thermal stability and resistance to thermal shock: The introduction of various high-melting-point transition metal elements (such as titanium, chromium, nickel, etc.) into the metal matrix forms a continuous network structure, and the synergistic regulation of components such as graphene oxide and boron trioxide forms a thermal buffer distribution in the grain boundary region, effectively alleviating thermal expansion mismatch and improving the structural stability of the material under high-temperature cycling environment.

[0032] 4. Improved sintering adaptability and process controllability: Through oxygen content control and step-by-step heat treatment technology, the reaction process between the coating layer and rare earth in the modified ceramic powder is carried out stably under specific redox conditions. Combined with cold isostatic pressing and inert atmosphere sintering process, the final particle structure is consistent and the processing shrinkage rate is stable, which has good engineering adaptability.

[0033] 5. Achieving a multi-scale synergistic enhancement mechanism: The multiphase particle system constructed in this invention exhibits grain boundary strengthening and fine-grain blocking effects at the microscale, and forms a structural framework with hard phases embedded in continuous metallic phases at the macroscale, achieving a balance between toughness and strength under multiple working conditions such as fracture, wear and impact. Attached Figure Description

[0034] Figure 1 The image shows a four-point SEM image of Embodiment 1 of the present invention. In the image, A, B, C, and D represent four imaging points on the same sample.

[0035] Figure 2 This is a schematic diagram showing the results of the comparative experiment of the present invention (bending strength).

[0036] Figure 3This is a schematic diagram of the results of the comparative experiment of the present invention (fracture toughness).

[0037] Figure 4 This is a schematic diagram of the results of the comparative experiment of the present invention (HV0.5 hardness).

[0038] Figure 5 This is a schematic diagram showing the results of the comparative experiment of the present invention (thermal shock stability).

[0039] Figure 6 This is a schematic diagram of the results of the comparative experiment of the present invention (1000℃ durability strength). Detailed Implementation

[0040] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0041] Example 1 (T1)

[0042] This embodiment provides a preparation method for high-toughness cermet particles, the structure of which consists of a hard phase, a metal matrix phase, and synergistic control components. The components are designed and prepared according to the following proportions and parameters:

[0043] Based on a total mass of 100%, the mass percentages of the three-phase components are as follows:

[0044] Hard phase: 40 wt%; Metal matrix phase: 57 wt%; Synergistic control components: 3 wt%.

[0045] The specific composition of the hard phase is as follows:

[0046] Ceramic micro powder: accounting for 55% of the total hard phase, it is composed of silicon carbide (SiC) and alumina (Al2O3) mixed in a mass ratio of 2:1, with an average particle size of 0.8 μm;

[0047] Modified ceramic powder: accounting for 25% of the total hard phase, wherein the modified ceramic powder is silicon carbide particles coated with a titanium nitride carbide (TiCN) layer, wherein the coating thickness is controlled at 80 nm, and the average particle size of the modified powder is 1.0 μm;

[0048] Rare earth element carbides and nitrides account for 20% of the total hard phase, of which hafnium carbide (HfC) and tantalum nitride (TaN) have a mass ratio of 1:1 and an average particle size of 0.5 μm.

[0049] The specific composition of the metal matrix phase is as follows: iron (Fe): accounting for 43.9% of the metal matrix; nickel (Ni): accounting for 35.1% of the metal matrix; cobalt (Co): accounting for 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 mixing and ball milling.

[0050] The composition of the synergistic control component is as follows: graphene oxide (GO); boron trioxide (B2O3); the mass ratio of the two is 2:1. The resulting powder is uniformly distributed during the mixing and ball milling process, and subsequently dispersed in the matrix grain boundaries and ceramic-metal phase interfaces in a submicron particle state during the sintering process.

[0051] Preparation steps:

[0052] Weigh out the various raw materials according to the above proportions, and first dry mix the ceramic micro powder, modified ceramic powder, and rare earth carbonitrides evenly.

[0053] The hard phase powder was ball-milled in a vacuum environment for 2 hours, and then held at 1050℃ for 20 minutes. A trace amount of oxygen was gradually introduced to control the atmosphere, and the oxygen content was maintained at 2.5 wt%. The heat treatment was continued for 40 minutes.

[0054] The heat-treated ceramic part, metal matrix powder, and synergistic regulating components were put into a ball mill jar and wet-milled for 10 hours under nitrogen protection. The ball-to-material ratio was 5.5:1, and ethanol was used as the dispersion medium.

[0055] The ball-milled slurry was mixed with water and then filtered by pressure. The resulting filter cake was dried at 60℃ and -0.09 MPa for 3 hours to obtain a dry composite powder.

[0056] The dry powder was formed by cold isostatic pressing under a pressure of 25 MPa and held under pressure for 5 minutes.

[0057] The molded body was placed in a high-purity argon atmosphere, heated to 1300℃, and held at that temperature for 90 minutes to complete sintering. During the process, three vacuum-argon-filling cycles were performed to ensure that the oxygen content was below 0.5 vol%. The cooling rate was 4℃ / min.

[0058] Example 2 (T2)

[0059] This embodiment provides a high-toughness metal-ceramic particle with the following composition: 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 regulating component accounting for 3 wt% of the total mass.

[0060] The hard phase consists of the following three types of particles (based on a total mass of 100%):

[0061] Ceramic micro powder: 50 wt%, composed of silicon nitride (Si3N4) and zirconium carbide (ZrC) in a mass ratio of 1:1, with an average particle size of 1.5 μm;

[0062] Modified ceramic powder: 35 wt%, wherein the modified ceramic powder is titanium nitride (TiN) particles coated with niobium carbide (NbCN), the coating thickness is about 100 nm, and the overall average particle size is about 1.2 μm;

[0063] Rare earth element carbides and nitrides: 15 wt%, of which hafnium carbide (HfC) and tantalum nitride (TaN) have a mass ratio of 3:2 and an average particle size of about 0.4 μm.

[0064] The metallic matrix phase is composed of the following elements (based on 100% of the total mass of the metallic matrix phase): iron (Fe): 38 wt%; chromium (Cr): 34 wt%; titanium (Ti): 28 wt%. The metallic matrix phase forms a continuous distribution structure and a dense coating interface with the hard particles.

[0065] The synergistic regulating component (3 wt% of the total mass) includes: boron dioxide (B2O3): 2 wt%; glyceryl monostearate (GMS): 1 wt%. The mass ratio of the two components is 2:1, and the particle size is controlled below 500 nm. During ball milling, they can be uniformly dispersed in the grain boundaries and particle contact areas.

[0066] The particle system was prepared using the same process as in Example 1, including vacuum heat treatment to control oxygen content, ball milling and compounding, pressure filtration and drying, isostatic pressing and inert atmosphere sintering, etc. The sintering temperature was set at 1280℃ and the holding time was 100 minutes.

[0067] Example 3 (T3)

[0068] The high-toughness metal-ceramic particles provided in this embodiment are composed of: 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 regulatory component accounting for 3 wt% of the total mass.

[0069] The hard phase consists of the following three types of particles (based on a total mass of 100%):

[0070] Ceramic micro powder: 60 wt%, composed of silicon oxide (SiO2) and titanium carbide (TiC) in a mass ratio of 3:2, with an average particle size of 1.0 μm;

[0071] Modified ceramic powder: 30 wt%, which is silicon carbide (SiC) powder coated with zirconium carbide (ZrCN), with a coating thickness of about 80 nm and an overall average particle size controlled at 0.8 μm;

[0072] Rare earth element carbides and nitrides: 10 wt%, made by mixing hafnium carbide (HfC) and tantalum nitride (TaN) in a mass ratio of 2:1, with an average particle size of 0.3 μm.

[0073] The metallic matrix phase is composed of the following three metallic elements (based on the total mass of the metallic matrix phase as 100%): aluminum (Al): 40 wt%; cobalt (Co): 35 wt%; and iron (Fe): 25 wt%. Among them, aluminum imparts good thermal conductivity and toughness to the matrix, while cobalt and iron together form the structural framework. The three elements are embedded in the gaps between ceramic particles in a continuous phase coating structure.

[0074] The synergistic regulatory components include: graphene oxide (GO): 2 wt%; glyceryl monostearate (GMS): 1 wt%; the mass ratio of the two is 2:1. During ball milling, a submicron-scale composite dispersion structure is formed and distributed in the grain boundaries of the metal matrix and the transition zone between ceramic particles.

[0075] Preparation process description:

[0076] The hard phase component was first dry-mixed and then ball-milled under vacuum for 2 hours, and then heated to 1100℃ under gradient heating and held for 20 minutes.

[0077] An atmosphere with a controlled oxygen content of 2.2 wt% was introduced, and the temperature was maintained for another 40 minutes to induce an in-situ interfacial reaction between the coating layer and the rare earth particles.

[0078] Then, it was wet ball-milled together with the metal matrix powder and synergistic regulating components for 10 hours, with a ball-to-material ratio of 6:1 and ethanol as the dispersion medium.

[0079] The ball-milled slurry was dewatered by pressure filtration, and the filter cake was dried at 60℃ and -0.1 MPa for 3 hours. The resulting powder was then cold isostatically pressed at 30 MPa.

[0080] The molded body was sintered at 1300℃ in a high-purity argon atmosphere and held for 100 minutes. During the cooling process, the argon atmosphere was maintained and the cooling rate was controlled at 4℃ / min.

[0081] Comparative Example 1 (C1)

[0082] This comparative example prepared a cermet particle with a structure consisting of a hard phase, a metal matrix phase, and a synergistic regulating component. The mass percentages of each component are as follows: hard phase: 55 wt%; metal matrix phase: 42 wt%; synergistic regulating component: 3 wt%.

[0083] The hard phase consists of the following three parts (based on a total mass of 100%):

[0084] Ceramic micro powder: 30 wt%, composed of silicon carbide (SiC) and silicon oxide (SiO2) in a mass ratio of 1:1, with an average particle size of approximately 2.2 μm;

[0085] Modified ceramic powder: 50 wt%, composed of titanium nitride (TiN) coated with titanium carbide (TiCN), with an average particle size of 1.8 μm;

[0086] Rare earth element carbides and nitrides: 20 wt%, made by mixing hafnium carbide (HfC) and tantalum nitride (TaN) in a mass ratio of 1:1, with an average particle size of 0.2 μm.

[0087] The metal matrix phase comprises the following three metal elements (based on 100% of the total mass of the metal matrix phase): Nickel (Ni): 25 wt%; Cobalt (Co): 10 wt%; Chromium (Cr): 7 wt%. The synergistic regulatory component consists of graphene oxide (GO) and boron trioxide (B2O3) in a mass ratio of 3:1.

[0088] The preparation method is briefly described below:

[0089] After mixing, the raw materials were ball-milled under vacuum for 2 hours and kept at 1100℃ for 20 minutes, with the oxygen content in the atmosphere controlled at about 2.5 wt%. Subsequently, they were wet-ball-milled together with metal matrix powder and synergistic regulating components for 10 hours, with a ball-to-material ratio of 6:1 and ethanol as the dispersant.

[0090] The resulting mixed slurry was filtered and dried, and then cold isostatically pressed at 30 MPa. The molded body was sintered at 1280℃ in a high-purity argon atmosphere for 90 minutes with a cooling rate of 4℃ / min.

[0091] Comparative Example 2 (C2)

[0092] The comparative example of cermet particles consists of a hard phase, a metallic matrix phase, and synergistic control components. The composition and parameters are as follows:

[0093] Total content of hard phase: 55 wt%, of which: ceramic micro powder (silicon carbide + alumina): 30 wt% of hard phase; modified ceramic powder (titanium carbide, zirconium-coated): 65 wt% of hard phase; rare earth carbonitride (hafnium carbide): 5 wt% of hard phase.

[0094] Total content of the metal matrix phase: 40 wt%, of which: nickel: 15 wt%; iron: 10 wt%; cobalt: 15 wt%.

[0095] Total content of synergistic regulatory components: 5 wt%, including: graphene oxide: 3.5 wt%; boron trioxide: 1.5 wt%.

[0096] Particle size parameters: The average particle size of ceramic micro powder is 2.2 μm; the average particle size of modified ceramic powder is 1.7 μm; and the average particle size of rare earth carbonitrides is 0.9 μm.

[0097] Other structural features: The mass ratio of graphene oxide to boron trioxide in the synergistic regulatory components is 7:3; the mass ratio of nickel to cobalt is 1:1.

[0098] The comparative material was formed by vacuum hot pressing sintering and then cooled after being held at 1400℃ and 30 MPa for 60 minutes.

[0099] Comparative Example 3 (C3)

[0100] This comparative example uses a common traditional metal-ceramic particle preparation route, whose structure consists of a hard phase and a metal binder phase, without introducing modified ceramic powder, rare earth carbonitrides, or synergistic control components.

[0101] The particle consists of the following two parts:

[0102] Hard phase: 80 wt%, tungsten carbide (WC), with an average particle size of 1.5 μm;

[0103] Metallic binder phase: 20 wt%, pure cobalt (Co).

[0104] After the raw material is dry ball-milled for 4 hours, it is sintered at 1380℃ for 90 minutes in a hydrogen atmosphere. The cooling process is natural and without the maintenance of a protective gas.

[0105] The obtained particles are typical WC-Co materials. The hard phase is distributed in a blocky manner in its structure, the metal phase is thinly wrapped, there are obvious signs of fracture at the bonding interface, and the microstructure lacks fine-grained precipitates and composite ceramic interface structure.

[0106] Comparative Example 4 (C4)

[0107] This comparative example uses a common conventional metal-ceramic particle structure. The material consists of a hard ceramic phase and a metal-bonded phase, and does not contain modified ceramic particles, rare earth carbonitrides, or interface control components.

[0108] The particle composition is as follows:

[0109] Hard phase: TiC, accounting for 70 wt% of the total mass, with an average particle size of 2.0 μm;

[0110] Metal matrix phase: Ni, accounting for 30 wt% of the total mass.

[0111] The raw materials were dry ball-milled for 3 hours, pressed into shape, and sintered at 1350℃ for 60 minutes under a hydrogen protective atmosphere, with a natural cooling rate.

[0112] Comparative experiment

[0113] S1. Sample Preparation

[0114] High-toughness metal-ceramic particles were prepared according to the set parameters and processes of each group, and the resulting samples were pressed into standard test columnar blocks with a diameter of 10 mm and a height of 15 mm.

[0115] S2. Microstructure Analysis

[0116] The morphology of the sintered microstructure was observed using scanning electron microscopy (SEM).

[0117] S3. Mechanical performance testing

[0118] Bending strength test: determined according to the national standard "Test method for bending strength of fine ceramics (GB / T 6569-2006 / ISO14704:2000)" using the three-point bending method;

[0119] Fracture toughness test: The SEVNB method (single-sided notched beam with slit) was used for determination;

[0120] Hardness test: Measured using a Vickers hardness tester (HV10).

[0121] S4. Thermal Performance Evaluation

[0122] Thermal shock stability test: Starting at 1100℃, the sample is rapidly immersed in cold water, and the number of cycles required to cause the sample to break is determined.

[0123] High-temperature creep strength: After being subjected to a load of 60 MPa at 1000℃ for 1 hour, the sample was observed to be damaged.

[0124] The comparative experimental results are shown in Table 1:

[0125] Table 1 Comparison of experimental results data

[0126]

[0127] Analysis of experimental results:

[0128] 1. Figure 1 This is a SEM image of the sample prepared according to Embodiment 1 of the present invention, wherein, Figure 1 In the image, A, B, C, and D represent four sampling points on the same sample; for example... Figure 1 As shown, after sintering, the hard phases of different particle sizes in the sample of Embodiment 1 of the present invention come into contact with and intercalate with each other, and are wrapped by the metal matrix, achieving coating at different scales and having a stable bonding effect. Furthermore, the coating at the four points is similar, indicating that the sample has good uniformity at the microscopic level.

[0129] 2. For example Figure 2 As shown, the flexural strength analysis (MPa) of experimental groups T1, T2, and T3 were 920±18, 875±20, and 838±22 MPa, respectively, all significantly higher than those of the control groups C1–C4 (710±25 to 642±26 MPa). Group T1 showed the largest increase, approximately 43.3% higher than group C4. This result indicates that the process of this invention significantly enhances the overall load-bearing capacity of the material.

[0130] 3. For example Figure 3 As shown, fracture toughness analysis ( The fracture toughness of group T1 was 12.8 ± 0.4 MPa·√m, while that of T2 and T3 were 11.9 ± 0.3 and 11.2 ± 0.4 MPa·√m, respectively. This was significantly better than the control group C1–C4, which ranged from 9.3±0.5 to 7.8±0.6. The T1 group showed an improvement of over 60% compared to the C4 group, indicating that this material performs better in terms of crack propagation resistance and possesses excellent structural crack resistance stability.

[0131] 4. For example Figure 4 As shown, hardness analysis (HV 0.5): the hardnesses of groups T1, T2, and T3 were 1760±22, 1715±25, and 1650±20 HV, respectively, all higher than the control group C1–C4 (1520±35 to 1435±38 HV). The largest increase was observed in group T1, which was 18.1% higher than group C4. Higher hardness means enhanced wear resistance, enabling it to withstand more demanding working conditions.

[0132] 5. For example Figure 5 As shown, the thermal shock stability analysis (times) shows that group T1 achieved a stability of 38±2 times in the thermal shock test, while T2 and T3 achieved 35±2 and 33±3 times, respectively, demonstrating a significant advantage compared to groups C1–C4 (21±3 to 17±3 times). Group T1 showed a 123.5% improvement over group C4, indicating a significant enhancement in the material's crack resistance under conditions of rapid heating and cooling at high temperatures.

[0133] 6. For example Figure 6 As shown, high-temperature creep strength analysis ( The endurance strength of group T1 was 109±5 hours, T2 and T3 were 98±4 hours and 87±6 hours respectively, while the control group C1–C4 showed significantly insufficient performance, with only 58±7 to 39±5 hours. Group T1 improved by about 179% compared with group C4, indicating its excellent mechanical retention ability under high temperature and long-term service conditions.

[0134] Conclusion: Experimental groups T1, T2, and T3 significantly outperformed traditional formulations C1–C4 in all performance indicators, especially in terms of flexural strength, fracture toughness, and thermal shock stability. This indicates that the materials prepared by the process of this invention have significant advantages in mechanical strength, crack resistance, heat resistance, and high-temperature service life, and have good prospects for industrial application.

[0135] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-toughness metal-ceramic particle, characterized in that, It consists of a hard phase, a metallic matrix phase, and synergistic regulatory components; Based on a total mass of 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 remaining portion is the total content of the metal matrix phase; Based on the total mass of the hard phase as 100%, ceramic micro powder accounts for 40-60 wt% of the hard phase, rare earth element carbides and nitrides account for 5-20 wt% in total, and the remaining part is modified ceramic powder. The average particle size of the ceramic micro powder 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 carbonitrides is 0.1–0.8 μm. The mass ratio of graphene oxide to boron trioxide in the synergistic regulatory component is (1-3):1, and the component is uniformly distributed in the form of submicron particles between the grain boundaries of the metal matrix phase and the interface of the ceramic particles in the microstructure. The hard phase is composed of the following three types of particles: (1) The ceramic micro powder is at least two of silicon carbide, silicon nitride, silicon oxide, titanium carbide, titanium nitride, aluminum oxide, and zirconium carbide; (2) Modified ceramic powder 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 are hafnium carbide and tantalum nitride, and any two of (1), (2) and (3) are not nitrides at the same time; The metallic matrix phase is composed of at least three metallic elements selected from iron, nickel, cobalt, chromium, titanium, and aluminum, with each single element accounting for 10-40% of the mass percentage of the metallic matrix phase. The synergistic regulatory components include at least two of graphene oxide, boron trioxide, and glyceryl monostearate, and in the composite structure, part of the synergistic regulatory components and rare earth components form particulate precipitates, while the other part exists in a solid solution state in the metal matrix phase. The preparation method of the high-toughness metal-ceramic particles includes the following steps: S1. Raw material weighing: Weigh ceramic micro powder, modified ceramic powder, rare earth element carbides and nitrides, and metal matrix powder to 100% of the total amount by mass percentage, and add 1-4% of the synergistic regulating component. The resulting mixture is the original composite powder. S2. Pretreatment of ceramic particles: Ceramic micro powder, modified ceramic powder, and rare earth element carbides and nitrides are ball-milled in a vacuum environment for 2 to 4 hours, and then heated to 1000 to 1100°C at a rate of 5°C / min. After holding at this temperature for 15 to 30 minutes, the temperature is further maintained 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 are put into a ceramic-lined ball mill jar together with the metal matrix powder and the synergistic regulating components. Ethanol solution is added as a dispersion medium and ball milling is carried out for 8 to 12 hours. The ball-to-material ratio is 5:1 to 6:

1. The ball milling medium is zirconia balls with a particle size of 0.5 to 1.5 mm. The ball milling temperature does not exceed 40°C. S4. Drying and molding: After ball milling, the slurry is mixed with water and then filtered by pressure. The resulting filter cake is dried at 60℃ 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 device, and a pressure of 20 to 30 MPa is applied for a holding time of not less than 3 minutes to form a dense molded body. S5. Sintering treatment: The dense molded body is placed in a high-purity argon atmosphere for sintering treatment. The sintering temperature is 1250-1350℃ and the holding time is 90-120 minutes. Before sintering, three vacuum-argon-filling cycles are performed to make the oxygen content less than 0.5 vol%. The body is cooled at a cooling rate of 3-5℃ / min.

2. The high-toughness metal-ceramic particles according to claim 1, characterized in that, In the metal matrix phase, any three of the components selected from iron, nickel, cobalt, chromium, titanium, and aluminum are used, with the mass ratio of nickel to cobalt being 1 to 2:

1. The metal matrix phase is distributed in a continuous phase structure between the ceramic particles, forming an interlocking composite configuration.

3. The high-toughness metal-ceramic particles according to claim 1, characterized in that, 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.

4. The high-toughness metal-ceramic particles according to claim 3, characterized in that, The milling media are zirconia balls with a diameter of 0.5 to 1.5 mm, the milling jar is lined with zirconia ceramic, the milling process is carried out under nitrogen protection, and the total milling time is not less than 8 hours.

5. The high-toughness metal-ceramic particles according to claim 4, characterized in that, The filter cake after pressure filtration 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.

6. The high-toughness metal-ceramic particles according to claim 5, characterized in that, The argon gas purity before sintering is not less than 99.999%, the sintering heating rate is 10℃ / 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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