Cermet composite material with complete core ring structure, preparation method and application

Abstract

The application provides a cermet composite material with a complete core ring structure, a preparation method and application. The preparation method comprises the following steps: forming a ceramic phase pre-solid solution powder, which has a single phase structure and does not contain oxides; ball-milling and mixing the ceramic phase pre-solid solution powder, a second refractory metal carbide ceramic powder and a metal adhesive phase powder; the second refractory metal is different from the first refractory metal; pressing into a blank, and sequentially performing vacuum sintering, partial pressure sintering and cooling to obtain the cermet composite material. The application promotes the complete solid solution of refractory elements into the ceramic phase to form a single phase structure solid solution, and then a cermet composite material with high densification is prepared through the combined process of vacuum sintering and partial pressure sintering; the method utilizes the modification of the ceramic phase and the synergistic combination of the sintering process to generate a complete core ring structure, effectively improves the interface bonding strength and reduces the loss of mechanical properties of the material caused by the uneven microstructure.

Description

Technical Field

[0001] This invention belongs to the field of metal-ceramic composite materials technology, specifically relating to a metal-ceramic composite material with a complete core-ring structure, its preparation method, and its application. Background Technology

[0002] Metal-ceramic composites have been widely used, for example in oil drilling stabilizers and radial bearings, to improve wear resistance and extend the service life of drill tool components. In metal-ceramic composites, the ceramic phase particles mainly provide strength and hardness, while the binder phase mainly provides plasticity and deformability.

[0003] In recent years, TiC(N)-based cermet materials, as lightweight and cost-effective alternatives to WC-Co cemented carbides, have attracted widespread attention from researchers. Compared with WC-based cemented carbides, TiC(N) ceramic particles have poor wettability with the binder phase (Co or Ni), and the bonding strength between TiC(N) ceramic particles and the binder phase is not high. TiC(N)-based cermets prepared directly from TiC(N) and Co or Ni have lower toughness and strength, and their bending strength is only about 70% of that of the corresponding WC-Co cemented carbides, which greatly limits the development and application expansion of TiC(N)-based cermets in the field of machining.

[0004] Synergistically enhancing the strength and toughness of cermets has long been a research goal. Improving the wetting properties between ceramic phase particles and the binder phase (Co or Ni) is one of the important ways to improve the mechanical and service properties of cermet materials. Typically, second-order carbides such as Mo2C, WC, and TaC are added during the preparation of cermets. Because second-order carbides have lower thermodynamic stability than TiC(N), they preferentially dissolve during liquid-phase sintering, subsequently forming a ring-shaped (Ti, W, Mo…)C(N) solid solution around the undissolved ceramic particles during cooling. The formation of this core-ring structure can effectively improve wettability, increase density, and reduce porosity, thereby enhancing material properties.

[0005] The morphology and composition of the core-ring structure of cermet mainly depend on the dissolution and re-precipitation process during sintering. However, the full control of the dissolution and re-precipitation process is difficult to achieve by optimizing the sintering process alone. Cermets sintered by existing preparation techniques often have problems such as incomplete core-ring structure and non-uniform core-ring interface structure, that is, there is a phenomenon that some cores are in direct contact with the metal binder phase, which reduces the performance of cermet composite materials and cannot fully realize the benefits of the core-ring structure in improving wettability. Summary of the Invention

[0006] The main objective of this invention is to provide a metal-ceramic composite material with a complete core-ring structure, its preparation method, and its application, so as to overcome the shortcomings of the prior art.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing a metal-ceramic composite material with a complete core-ring structure, comprising:

[0009] The multi-component ceramic phase material is ball-milled and mixed, then heat-treated at a first temperature, followed by crystallization at a second temperature to form a pre-solution ceramic phase powder (Ti). 1-x M x C(N); wherein, the second temperature is higher than the first temperature, and the ceramic phase pre-solidified powder (Ti) 1-x M x C(N) has a single-phase structure and does not contain oxides, M represents the first refractory metal element, and (N) indicates that it may or may not contain nitrogen.

[0010] The ceramic phase pre-solidified powder (Ti) 1-x M x C(N), and second refractory metal carbide ceramic powder and metal binder phase powder are ball-milled and mixed to obtain a mixed powder; wherein, the second refractory metal in the second refractory metal carbide ceramic powder is different from the first refractory metal;

[0011] The mixed powder is pressed into a blank, and then subjected to vacuum sintering, partial pressure sintering and cooling to obtain a metal-ceramic composite material with a complete core-ring structure.

[0012] Secondly, the present invention provides a metal-ceramic composite material prepared by the above preparation method, which includes a ceramic phase and a binder phase, wherein the ceramic phase includes a core phase and a ring phase, and the ring phase completely encapsulates the core phase;

[0013] The core phase is made of (Ti) 1-x M x )C(N), where M represents the first refractory metal; the cyclic phase is (Ti 1-x M x A solid solution formed by C(N) and the carbide of the second refractory metal.

[0014] Thirdly, the present invention also provides the application of the above-mentioned metal-ceramic composite material in the fields of machining and oil drilling.

[0015] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0016] The preparation method provided by this invention involves heat treatment and crystallization of a mixture of materials to promote the complete dissolution of refractory elements into the ceramic phase, forming a solid solution with a single-phase structure. Then, metal-ceramic powder is prepared using powder metallurgy. Finally, a highly densified metal-ceramic composite material is prepared through a liquid-phase sintering process combining vacuum sintering and partial pressure sintering. This method utilizes the synergistic combination of ceramic phase modification and sintering processes to control the core-ring structure of the ceramic phase in the metal-ceramic composite material, generating a complete core-ring structure. This effectively improves the interfacial bonding strength between the ceramic phase and the binder phase, reducing the loss of mechanical properties of the metal-ceramic composite material due to microstructural inhomogeneity.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to enable those skilled in the art to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described below in conjunction with detailed drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of the design and preparation process of a metal-ceramic material with a complete core-ring structure, provided in a typical embodiment of the present invention.

[0020] Figure 2 This is an X-ray diffraction pattern of a ceramic phase pre-solidified powder provided in a typical embodiment of the present invention;

[0021] Figure 3 This is a backscattered scanning electron microscope image of a metal-ceramic with a complete core-ring structure provided in a typical embodiment of the present invention;

[0022] Figure 4 This is a diagram showing the microstructure and morphology of a metal-ceramic composite material provided in a typical comparative case of the present invention.

[0023] Figure 5 This is a diagram showing the microstructure and morphology of a metal-ceramic composite material provided in a typical comparative case of the present invention.

[0024] Figure 6 This is a typical comparative case of the present invention, showing the microstructure and morphology of a metal-ceramic composite material. Detailed Implementation

[0025] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate the technical solution, its implementation process, and its principles.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0027] This invention first provides a method for preparing a metal-ceramic composite material with a complete core-ring structure, which includes the following steps:

[0028] S1. The multi-component ceramic phase material is ball-milled and mixed, then heat-treated at a first temperature, followed by crystallization at a second temperature to form a pre-solution ceramic phase powder (Ti). 1-x M x C(N); wherein, the second temperature is higher than the first temperature, and the ceramic phase pre-solidified powder (Ti) 1-x M x C(N) has a single-phase structure and does not contain oxides, M represents the first refractory metal element, and (N) indicates that it may or may not contain N.

[0029] S2, Presolubilize the ceramic phase powder (Ti) 1-x M x The mixture is obtained by ball milling and mixing C(N), second refractory metal carbide ceramic powder and metal binder phase powder; wherein the second refractory metal in the second refractory metal carbide ceramic powder is different from the first refractory metal.

[0030] In the two steps S1-S2 above, ceramic phase pre-solution powder (Ti) is used. 1-x M x The main reason why combining C(N) with carbide powders of different refractory elements can achieve a complete core-ring structure is that, on the one hand, the ceramic phase pre-solidified powder (Ti) 1-x M x C(N) can thermodynamically promote the dissolution and exudation process of the ceramic phase. Simultaneously, when different refractory metal atoms dissolve into the ceramic phase, the difference in atomic radius often causes lattice distortion, providing sufficient nucleation sites, reducing nucleation work, and making nucleation on the ceramic surface easier. On the other hand, pre-solution powders of the ceramic phase (Ti) 1-x M x C(N) can reduce the difference in interplanar spacing between the core phase and the newly formed ring phase, reduce the lattice mismatch rate, and is conducive to the stable existence of the ring phase.

[0031] S3. The mixed powder is pressed into a blank, and then subjected to vacuum sintering, partial pressure sintering and cooling to obtain a metal-ceramic composite material with a complete core-ring structure.

[0032] In step S3, the mixed powder is pressed and then subjected to liquid phase sintering, which combines vacuum sintering and partial pressure sintering, to complete the densification of the sample. This mainly allows the second-phase ceramic to dissolve in the liquid binder phase, which facilitates the precipitation of a uniform core-ring structure on the surface of the ceramic phase during the cooling stage.

[0033] Based on the same goal of achieving a complete core-ring structure, some existing technologies have proposed methods for preparing complete core-ring structures. For example, Chinese invention patent CN110396632A, "A Ti(C,N)-based cermet with a homogeneous ring core structure and its preparation method," utilizes two-step ball milling and long-term solid-phase nitrogen partial pressure sintering to give Ti(C,N)-based cermets a complete inner and outer ring phase structure. However, during nitrogen partial pressure sintering, due to the material's inherent thickness, a gradient is generated due to nitrogen diffusion. At the same time, the long-term high-temperature sintering of cermets leads to abnormal growth of the ceramic phase, resulting in deterioration of mechanical properties, making it unsuitable for the preparation of high-performance materials.

[0034] The preparation method provided by this invention obviously does not employ the technique of long-term solid-phase nitrogen partial pressure sintering, thus avoiding the problems existing in the prior art. It belongs to a completely new technical route for forming a complete core-ring structure.

[0035] There are also some existing technologies, such as the Chinese invention patent CN116752022A entitled "A (Ti,M)C-based cermet with a composite binder phase and its preparation method", which proposes a cermet composed of a (Ti,M)C solid solution hard phase and a nickel and high-entropy alloy composite binder phase. The microstructure of the (Ti,M)C-based cermet, from the inside out, consists of a hard core phase, a ring phase, a nickel binder phase, a transition layer, and a high-entropy alloy binder phase. However, in this prior art, although the refractory metal M is introduced, the ceramic phase powder is not strictly defined as a fully pre-solidified powder with a single-phase structure. Furthermore, the binder phase uses a high-entropy metal plus carbon powder method, which is not a strict carbide ceramic. This results in the fact that only a coreless or weakly cored ring structure can be generated by (Ti,M)C + Ni + high-entropy alloy, because the ring phase generated by the refractory element M only has a slight difference in elemental content from the core phase, which cannot meet the necessary conditions for the generation of a complete core-ring structure in this invention.

[0036] Furthermore, while the existing technology adds a high-entropy refractory metal to the binder phase region and the carbide ceramic powder added in this invention has a similar tendency to form cyclic phases, the state and content of the C element are significantly different. This results in a difference in the driving force for the formation of cyclic phase structures: in this invention, the carbide provides a second refractory metal element different from the ceramic phase and also provides a C source that is conducive to the formation of (Ti,M')C cyclic phases (M' represents the second refractory metal); while in the existing technology, the addition of the refractory metal to the binder phase only provides the refractory element M. Due to the lack of C element, the cyclic phases formed will inevitably have a tendency and may lead to uneven cyclic phase formation.

[0037] Furthermore, in the prior art, high-entropy alloys often exhibit sluggish diffusion effects and cocktail effects, which means that the M element diffuses outward more slowly, and theoretically, the amount of ring phase formed is less, further exacerbating the tendency of the ring phase to be inhomogeneous, which is completely contrary to the purpose of this invention to form a uniform ring phase.

[0038] Regarding the specific components and their contents, in some embodiments, the multi-component ceramic phase material includes:

[0039] Combination 1: comprising TiO2, oxide powder of the first refractory metal, and elemental carbon; or, Combination 2: comprising TiC, carbide powder of the first refractory metal, and TiN (optionally present or absent); or, a mixture of Combination 1 and Combination 2.

[0040] In some implementations, x ranges from 0.03 to 0.5, and the ceramic phase pre-solidified powder (Ti) 1-x M x The particle size of C(N) is less than 2 μm.

[0041] It should be noted that the specific proportions of the multi-component ceramic phase materials are not specifically limited in this invention; the feeding ratio is based on the pre-solidified ceramic phase powder (Ti). 1-x M x The elemental ratio of C(N) can be adjusted; in addition, for ceramic phase pre-solidified powders (Ti) 1-x M x As far as C(N) is concerned, it can be (Ti) 1-x M x C can also be (Ti) 1-x M x Whether or not nitrogen is included in CN is optional, depending on the specific requirements. The means of adding nitrogen include, but are not limited to, using a nitrogen-containing atmosphere, such as nitrogen gas, during heat treatment.

[0042] See Figure 1As shown, as a typical example of the above technical solution, the specific process steps of the preparation method provided by the present invention may include: uniformly mixing TiO2, oxide powder of a first refractory metal, and elemental carbon and carrying out a high-temperature carbothermic reaction (optionally in a nitrogen atmosphere). In this step, part of the carbon element reacts with oxygen element, and the other part generates refractory metal carbides. Alternatively, commercial TiC (optionally including TiN) and carbide powder of the first refractory metal are ball-milled and uniformly mixed, followed by heat treatment and sintering. In this step, TiC, (TiN), and carbide powder of the first refractory metal undergo mechanical alloying, generating greater stress, which facilitates subsequent powder processing. Subsequently, further reaction and crystallization treatment is carried out at high temperature to form a ceramic phase pre-solidified powder (TiO2) with a single-phase structure. 1-x M x The C(N) step, under high-temperature conditions, can enhance the interdiffusion between refractory elements, promoting the stable formation of a single-phase structure. The formation of single-phase pre-solidified ceramic powder means that the ceramic phase powder is no longer obtained by simple mechanical mixing, but rather by mixing at the atomic / molecular level, forming a completely new homogeneous phase.

[0043] The above-mentioned pre-solution powder of ceramic phase (Ti) was obtained 1-x M x After C(N), X-ray diffraction testing can usually be performed to ensure the formation of a single-phase structure. It should be noted that this step is not mandatory.

[0044] Then, according to the designed ratio, the ceramic phase pre-solidified powder (Ti) was added. 1-x M x C(N), metal binder phase powder, second refractory metal carbide ceramic powder, and commonly used powder metallurgy forming agents and other additives (such as paraffin wax, zinc stearate, etc., added at 3%-5% by weight of the material) are ball-milled and granulated to obtain a dry powder (anhydrous alcohol can be completely evaporated by vacuum drying at a temperature of 75-90 ℃, and then sieved after drying), which is then pressed, molded, and sintered to obtain a high-performance metal-ceramic composite material with a complete core-ring structure.

[0045] Regarding the specific processing temperature, in some implementations, the first temperature is 1400-1600 ℃, and the second temperature is above 1800 ℃, specifically 1800-2200 ℃.

[0046] Furthermore, regarding the selection of refractory metal elements and metal binder phase elements, in some embodiments, the first refractory metal and the second refractory metal are both independently and non-overlappingly selected from any one or a combination of two or more of W, Mo, Ta, Nb, V, and Zr.

[0047] In some embodiments, the material of the metal binder powder includes any one or more combinations of Ni, Co, Al, and Mo, and is not limited thereto.

[0048] For the final sintering process, in some embodiments, the temperature of the vacuum sintering and partial pressure sintering is 1400-1500 ℃, the time of the vacuum sintering is 1-2.5 h, the time of the partial pressure sintering is 0.5-2 h, and the total time of the vacuum sintering and partial pressure sintering is controlled to be less than 3 h.

[0049] Of course, before liquid phase sintering (vacuum sintering + partial pressure sintering), there is usually a debinding sintering step. The debinding sintering temperature is usually 250-300 ℃, the sintering time is 1-3 h, and sintering is carried out in an argon atmosphere. The purpose is to remove organic components such as forming agents. This is not an important step in this invention and will not be described in detail here. The cooling after sintering can be negative pressure strong cooling, and the cooling atmosphere is argon.

[0050] More specifically, in some embodiments, the atmosphere for partial pressure sintering is an inert gas with a pressure of 40-70 MPa.

[0051] In addition, regarding other preparation details, in some embodiments, the ball milling mixing method is wet high-energy ball milling, the ball milling speed is 250-400 rpm, the ball milling time is 20-30 h, the ball-to-material ratio is 8:1-15:1, the ball milling media includes anhydrous ethanol, and the ball milling media is removed by drying after ball milling mixing.

[0052] In some embodiments, the pressure at which the mixed powder is pressed into a blank is 120-250 MPa, and the holding time is 5-20 s.

[0053] In some embodiments, the mixed powder contains a ceramic phase pre-solution powder (Ti). 1-x M x The mass fraction of C(N) is 60-80%, the mass fraction of the second refractory metal carbide ceramic powder is 10-20%, and the mass fraction of the metal binder phase powder is 10-20%.

[0054] Embodiments of the present invention also provide a metal-ceramic composite material prepared by the preparation method provided in any of the above embodiments, comprising a ceramic phase and a binder phase, wherein the ceramic phase comprises a core phase and a ring phase, and the ring phase completely encapsulates the core phase; the core phase is made of (Ti) 1-x M x )C(N), where M represents the first refractory metal; the cyclic phase is (Ti 1-x M xA solid solution formed by C(N) and the carbide of the second refractory metal.

[0055] Furthermore, embodiments of the present invention also provide applications of metal-ceramic composite materials in machining and oil drilling.

[0056] The technical solution of the present invention will be further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only for illustrating the present invention and do not limit the scope of the present invention.

[0057] Example 1

[0058] This embodiment illustrates the preparation and characterization process of a metal-ceramic composite material, as detailed below:

[0059] 0.94 mol TiO2, 0.06 mol MoO3, and 3 mol C were mixed evenly in a ball mill. The mixture was then subjected to a carbothermic reaction at 1500 °C, and the temperature was further increased to 1800 °C to improve the crystallinity of the ceramic phase. Nitrogen gas was then introduced at the high temperature to form (TiO2). 0.94 Mo 0.06 (C,N) pre-solidified powder was further used to verify the structure of the metal-ceramic composite material using X-ray diffraction, and the results are as follows: Figure 2 As shown, the characteristic peaks of the ceramic phase are shifted to the left compared to those of Ti(C,N). This indicates that Mo atoms are dissolved in Ti(C,N), and the solid solution effect is very good, with no other characteristic peaks present.

[0060] Then, according to the following weight proportions: 65 parts of (Ti) 0.94 Mo 0.06 )(C,N), 9 parts TaC, 10 parts WC, 8 parts Co, and 8 parts Ni. A total of 100 parts were mixed and carried out in the following steps.

[0061] Paraffin, (Ti) will be added in a certain proportion 0.94 Mo 0.06Powders of C, N, WC, TaC, Co, and Ni were placed in a cemented carbide ball mill jar and anhydrous ethanol was added until the powder was completely wetted. The ball mill jar was then placed in a planetary ball mill with a ball-to-powder ratio of 10:1, a rotation speed of 350 rpm, and a milling time of 24 h. The milled slurry was then dried in a vacuum drying oven at 75 ℃ and sieved to obtain a dry mixed powder. The powder was then pressed into shape at a pressure of 150 MPa for 10 s. The pressed compact was then placed in an atmosphere sintering furnace for debinding and sintering at a vacuum debinding temperature of 500 ℃ and an argon atmosphere for 2 h. Vacuum sintering was then performed at a maximum sintering temperature of 1450 ℃ for 2 h, followed by partial pressure sintering at the same temperature with an argon atmosphere and a partial pressure of 60 MPa for 1 h. The sample was then cooled using negative pressure cooling until it reached room temperature.

[0062] Figure 3 The image is a backscattered scanning image of the metal-ceramic composite material prepared in Example 1. It can be observed that the ceramic phase forms a complete ring structure, without any exposed core phase or undissolved ceramic particles, and there is no phenomenon of the core phase directly contacting the binder phase.

[0063] The mechanical properties of the metal-ceramic composite material obtained in this embodiment were tested, and its hardness was 1542 HV. 30 The fracture toughness is 12.4 MPa·m 1 / 2 .

[0064] Example 2

[0065] This embodiment illustrates the preparation process of a metal-ceramic composite material, as shown below:

[0066] 0.38 mol TiC, 0.5 mol TiN, 0.12 mol WC, and 3.5 mol C were mixed evenly in a ball mill. The resulting powder was then subjected to sintering heat treatment at 1550 °C, with the temperature further increased to 2000 °C to enhance the crystallinity of the ceramic phase and form (TiN) under high-temperature conditions. 0.88 W 0.12 (C,N) presolidified powder.

[0067] According to the following mass distribution ratio: 73 parts of (Ti) 0.88 W 0.12 )(C,N), 4 parts TaC, 7 parts Mo2C, 8 parts Co, 8 parts Ni. Total 100 parts. Proceed to the next step.

[0068] The preparation steps of the metal ceramic are as follows: paraffin wax and (Ti) are mixed in a certain proportion. 0.88, W 0.12Powders of C, N, WC, TaC, Co, and Ni were placed in a cemented carbide ball mill jar, and anhydrous ethanol was added until the powder was completely wetted. The ball mill jar was then placed in a planetary ball mill with a ball-to-powder ratio of 15:1, a rotation speed of 350 rpm, and a milling time of 30 h. The milled slurry was then dried in a vacuum drying oven at 75 ℃ and sieved to obtain a dry mixed powder. The powder was then pressed into shape at a pressure of 120 MPa for 10 s. The pressed compact was then placed in an atmosphere sintering furnace for debinding and sintering. The vacuum debinding temperature was 500 ℃, the debinding atmosphere was argon, and the holding time was 2 h. The maximum sintering temperature was 1450 ℃, and the vacuum sintering time was 2 h. Subsequently, partial pressure sintering was performed at a pressure of 50 MPa in an argon atmosphere for 1 h. Cooling was performed using negative pressure forced cooling.

[0069] Example 3

[0070] This embodiment illustrates the preparation process of a metal-ceramic composite material, as shown below:

[0071] 0.5 mol TiO2, 0.5 mol ZrO2, and 3 mol C were mixed evenly in a ball mill. The mixture was then subjected to a carbothermic reaction at 1500 °C, with the temperature further increased to 1850 °C to enhance the crystallinity of the ceramic phase and form (TiO2) under high temperature conditions. 0.5 ,Zr 0.5 C presolidified powder.

[0072] According to the following mass distribution ratio: 70 parts of (Ti) 0.5 ,Zr 0.5 )C, 10 parts Mo2C, 16 parts Ni, 4 parts Al. A total of 100 parts are used for subsequent steps.

[0073] The preparation steps of the metal ceramic are as follows: paraffin wax and (Ti) are mixed in a certain proportion. 0.5 ,Zr 0.5 C, MoC, Ni, and Al powders were placed in a cemented carbide ball mill jar, and anhydrous ethanol was added until the powder was completely wetted. The ball mill jar was then placed in a planetary ball mill with a ball-to-powder ratio of 8:1, a rotation speed of 350 rpm, and a milling time of 20 h. The milled slurry was then dried in a vacuum drying oven at 75 ℃ and sieved to obtain a dry mixed powder. The powder was then pressed into shape at a pressure of 160 MPa for 10 s. The pressed compact was then placed in an atmosphere sintering furnace for debinding and sintering. The vacuum debinding temperature was 500 ℃, the debinding atmosphere was argon, and the holding time was 2 h. The maximum sintering temperature was 1400 ℃, and the vacuum sintering time was 2.5 h. Subsequently, partial pressure sintering was performed at a pressure of 70 MPa in an argon atmosphere for 0.5 h. Cooling was achieved using negative pressure forced cooling.

[0074] Both Examples 2 and 3 above yielded metal-ceramic composite materials with complete ring-phase structures, and their mechanical properties were significantly improved. Further details will not be elaborated here.

[0075] Comparative Example 1

[0076] The difference between this comparative example and Example 1 is as follows:

[0077] Using existing commercial Ti(C,N) cermets, without using pre-solidified ceramic phase powder as the original ceramic phase powder, and otherwise identical to Example 1, no complete core-ring structure was formed. Characterization results are as follows: Figure 4 As shown.

[0078] The mechanical properties of the metal-ceramic composite material obtained in this embodiment were tested, and its hardness was 1489 HV30 and its fracture toughness was 10.8 MPa·m. 1 / 2 .

[0079] Comparative Example 2

[0080] This comparative example is largely the same as Example 1, except that the crystallization process above 1800°C is omitted, while the rest of the preparation process remains the same.

[0081] The microstructure characterization results of this embodiment are similar to those of Comparative Example 1, revealing a large number of non-uniform ring phases and exposed core phases. The mechanical properties of the metal-ceramic composite material obtained in this comparative example were tested, showing a hardness of 1348 HV30 and a fracture toughness of 7.8 MPa·m. 1 / 2 .

[0082] Comparative Example 3

[0083] The difference between this comparative example and Example 1 is that partial pressure sintering was not used at the liquid phase sintering temperature; only vacuum sintering was employed (the vacuum sintering time was extended to be equal to the total time of vacuum sintering + partial pressure sintering in Example 1). Everything else is the same as in Example 1. It did not generate a complete core-ring structure, and the result is as follows: Figure 5 As shown.

[0084] The mechanical properties of the metal-ceramic composite material obtained in this comparative example were tested, and its hardness was 1498 HV30 and its fracture toughness was 9.6 MPa·m. 1 / 2 .

[0085] Comparative Example 4

[0086] The difference between this comparative example and Example 1 is that MC carbide powder, which is the same as the first refractory metal element M in the pre-solidified ceramic phase, is used to replace the second refractory metal carbide ceramic powder. All other aspects are the same as in Example 1. It does not generate a complete core-ring structure, and the result is as follows: Figure 6 As shown.

[0087] The mechanical properties of the metal-ceramic composite material obtained in this comparative example were tested, and its hardness was 1520 HV30 and its fracture toughness was 10.39 MPa·m. 1 / 2 .

[0088] Based on the above embodiments and comparative examples, it can be clearly understood that the preparation method provided by the embodiments of the present invention involves heat treatment and crystallization of the mixed materials to promote the complete dissolution of refractory elements into the ceramic phase, forming a solid solution with a single-phase structure. Then, metal-ceramic powder is prepared by powder metallurgy, and a highly densified metal-ceramic composite material is prepared by a liquid-phase sintering process combining vacuum sintering and partial pressure sintering. This method utilizes the synergistic combination of ceramic phase modification and sintering process to achieve the control of the core-ring structure of the ceramic phase in the metal-ceramic composite material, generating a complete core-ring structure, effectively improving the interfacial bonding strength between the ceramic phase and the binder phase, and reducing the loss of mechanical properties of the metal-ceramic composite material caused by microstructure inhomogeneity.

[0089] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a metal-ceramic composite material with a complete core-ring structure, characterized in that, include: The multi-component ceramic phase material is ball-milled and mixed, then heat-treated at a first temperature, followed by crystallization at a second temperature to form a pre-solution ceramic phase powder (Ti). 1-x M x C(N); where x ranges from 0.03 to 0.5, the first temperature is 1400-1600 ℃, the second temperature is 1800-2200 ℃, and the ceramic phase pre-solidified powder (Ti 1-x M x C(N) has a single-phase structure and does not contain oxides, M represents the first refractory metal element, and (N) indicates that it may or may not contain nitrogen. The ceramic phase pre-solidified powder (Ti) 1-x M x The mixture is obtained by ball milling and mixing C(N) with a second refractory metal carbide ceramic powder and a metal binder phase powder; wherein the second refractory metal in the second refractory metal carbide ceramic powder and the first refractory metal are both independently and non-overlappingly selected from any one or more combinations of W, Mo, Ta, Nb, V, and Zr; and the ceramic phase pre-solidified powder (Ti) in the mixed powder contains a ceramic phase pre-solidified powder. 1-x M x The mass fraction of C(N) is 60-80%, the mass fraction of the second refractory metal carbide ceramic powder is 10-20%, and the mass fraction of the metal binder phase powder is 10-20%. The mixed powder is pressed into a green body, and then subjected to vacuum sintering, partial pressure sintering and cooling in sequence to obtain a metal-ceramic composite material with a complete core-ring structure. The temperature of vacuum sintering and partial pressure sintering is 1400-1500 ℃, the time of vacuum sintering is 1-2.5 h, the time of partial pressure sintering is 0.5-2 h, and the total time of vacuum sintering and partial pressure sintering is controlled to be less than 3 h.

2. The preparation method according to claim 1, characterized in that, The multi-component ceramic phase material includes: Combination 1: includes TiO2, oxide powder of the first refractory metal, and elemental carbon; Alternatively, combination two: includes TiC, carbide powder of the first refractory metal, and TiN, which may or may not be present; Or, a mixture of combination one and combination two.

3. The preparation method according to claim 1, characterized in that, The material of the metal binder powder includes any one or a combination of two or more of Ni, Co, Al, and Mo.

4. The preparation method according to claim 1, characterized in that, The atmosphere for partial pressure sintering is an inert gas with a pressure of 40-70 MPa.

5. The preparation method according to claim 1, characterized in that, The ball milling method is wet high-energy ball milling, with a ball milling speed of 250-400 rpm, a ball milling time of 20-30 h, a ball-to-material ratio of 8:1-15:1, and the ball milling medium includes anhydrous ethanol. After ball milling and mixing, the ball milling medium is removed by drying. The mixed powder is pressed into a blank at a pressure of 120-250 MPa.

6. The metal-ceramic composite material prepared by the preparation method according to any one of claims 1-5, characterized in that, It includes a ceramic phase and a binder phase, wherein the ceramic phase comprises a core phase and a ring phase, and the ring phase completely encapsulates the core phase; The core phase is made of (Ti) 1-x M x )C(N), where M represents the first refractory metal; the cyclic phase is (Ti 1-x M x A solid solution formed by C(N) and the carbide of the second refractory metal.

7. The application of the metal-ceramic composite material according to claim 6 in the fields of machining and oil drilling.

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