A duplex Ti(C,N) based ceramic material with a bimodal microstructure and a method of making

Abstract

The application belongs to the field of ceramic cutter material, and particularly relates to a dual solid solution microstructure composite Ti(C, N) based ceramic material and a preparation method. The ceramic material prepared by the application is prepared by adding ZrC, NbC and Mo2C as reinforcing phases by using discharge plasma sintering, with Ti(C, N) as a matrix. The addition of ZrC induces the formation of a Zr element-rich (Ti, Zr, Nb)(C, N) second solid solution phase; the dispersion distribution of the (Ti, Zr, Nb)(C, N) second solid solution phase at the intracrystalline and grain boundary can effectively pin the grain boundary, inhibit the abnormal grain growth in the sintering process, realize the leap from a single solid solution to a composite ceramic, and significantly improve the bending strength, hardness and wear resistance of the Ti(C, N) based ceramic material, which exhibits irreplaceable importance in the fields of cutter material and precision machining.

Description

Technical Field

[0001] This invention belongs to the field of ceramic cutting tool materials, specifically relating to a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure and its preparation method. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Ti(C,N)-based cermets possess high hardness, good wear resistance, relatively high flexural strength, and low cost, making them a preferred choice for cutting tools. However, the presence of metallic phases in Ti(C,N)-based cermets negatively impacts their hardness and chemical stability, inevitably limiting their applications. When temperatures exceed 800–1000°C, the metallic binder phases (Ni, Co, etc.) lose their load-bearing capacity due to intensified grain boundary diffusion, leading to a decrease in the overall hardness and flexural strength of the Ti(C,N)-based cermet, thus rendering it unsuitable for ultra-high temperature applications.

[0004] Compared to Ti(C,N)-based cermets with added metallic binders, Ti(C,N)-based ceramics possess advantages such as high hardness, high-temperature resistance, and chemical stability, but also suffer from the drawbacks of pure ceramics, such as poor toughness and difficulty in processing. Furthermore, densification during the sintering process is more challenging for pure Ti(C,N)-based ceramics compared to Ti(C,N)-based cermets.

[0005] In recent years, Ti(C,N) ceramics with a single solid solution structure prepared by adding one or more refractory metal carbides (such as WC, VC, and Cr3C2) and medium- and high-entropy Ti(C,N) ceramics with a metal atom ratio of 1:1:1 or 1:1:1:1:1 have been extensively prepared and studied. Their comprehensive mechanical properties have been significantly improved through solid solution strengthening, multiple lattice distortion, and the high-entropy effect. However, single-solid-solution carbonitride ceramics or high-entropy carbonitride ceramics require high temperatures and long holding times during sintering, which easily leads to abnormal grain growth. Furthermore, single-phase systems lack effective grain refinement methods, making it impossible to simultaneously achieve densification and grain refinement, resulting in significant defects in grain size and flexural strength. According to the Hall-Petch relation, fine-grained materials have higher flexural strength and hardness; however, larger grain sizes inhibit the improvement of their flexural strength and hardness, limiting their application range to some extent.

[0006] Therefore, finding a Ti(C,N)-based ceramic material that can simultaneously achieve fine grain size, high strength, and high-temperature stability is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] To address the needs of existing technologies, the present invention aims to provide a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure and its preparation method. This invention uses Ti(C,N) as the matrix phase and ZrC, NbC, and Mo2C as reinforcing phases, employing spark plasma sintering technology at 1550℃ to prepare a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure. During cooling, ZrC induces the formation of a Zr-rich (Ti,Zr,Nb)(C,N) second solid solution phase. Its dispersed distribution within the grains and at grain boundaries effectively pins the grain boundaries, inhibiting abnormal grain growth during sintering. This achieves a leap from a single solid solution to a multiphase ceramic. Through dispersion strengthening and grain refinement mechanisms, a multiphase Ti(C,N)-based ceramic material with excellent comprehensive mechanical properties and a dual solid solution microstructure is obtained. This material demonstrates irreplaceable importance in fields such as cutting tool materials and precision machining, and its application scope is expected to expand to more fields.

[0008] Specifically, the present invention provides the following technical solution:

[0009] In a first aspect, the present invention provides a multiphase Ti(C,N)-based ceramic material having a dual solid solution microstructure, comprising, by mass percentage, the following raw materials: 70%~85% Ti(C,N) powder, 5%~20% ZrC powder, 5% NbC powder, and 5% Mo2C powder; and the multiphase Ti(C,N)-based ceramic material comprising a matrix phase (Ti,Zr,Nb,Mo)(C,N) and a dispersed second solid solution phase (Ti,Zr,Nb)(C,N).

[0010] Preferably, the multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure is composed of the following raw materials by mass percentage: 80% Ti(C,N) powder, 10% ZrC powder, 5% NbC powder, and 5% Mo2C powder.

[0011] Preferably, the average particle size of the Ti(C,N) powder is 0.5 μm, and the average particle size of the ZrC powder, NbC powder and Mo2C powder is 1~3 μm.

[0012] A second aspect of the present invention provides a method for preparing the above-mentioned multiphase Ti(C,N)-based ceramic material having a dual solid solution microstructure, comprising the following steps:

[0013] S1. Dissolve polyethylene glycol in anhydrous ethanol, heat in a water bath, and stir to obtain a polyethylene glycol-anhydrous ethanol dispersion.

[0014] S2. Add the ceramic powder obtained by mixing Ti(C,N) powder, ZrC powder, NbC powder and Mo2C powder to the dispersion prepared in step S1, and disperse by ultrasonic stirring to obtain a ceramic powder mixed solution.

[0015] S3. The mixed solution is subjected to high-energy ball milling under nitrogen protection to obtain a ball milling slurry;

[0016] S4. Vacuum dry and sieve the ball-milled slurry to obtain a mixed powder;

[0017] S5. The mixed powder is placed in a mold and subjected to discharge plasma sintering under vacuum conditions to obtain a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure.

[0018] Preferably, in step S1, the polyethylene glycol is PEG6000, and its addition amount is 1% of the total mass of the ceramic powder.

[0019] Preferably, in step S1, the water bath heating temperature is 55~65℃, and the stirring speed is 1200~1600r / min.

[0020] Preferably, in step S2, the ultrasonic time is 25-40 min and the stirring speed is 350-400 r / min.

[0021] Preferably, in step S3, the ball-to-material mass ratio of the high-energy ball mill is 10:1, the grinding balls are cemented carbide balls with diameters of 5 mm and 10 mm, the mass ratio of which is 2:5, and the rotational speed of the ball mill is 350~450 r / min.

[0022] Preferably, in step S4, the vacuum drying temperature is 100~120℃, the time is 36~50 h, and the sieving is done using a 200-mesh sieve.

[0023] Preferably, in step S5, the sintering temperature of the discharge plasma sintering is 1500~1575℃, and the sintering pressure is 30 MPa.

[0024] Preferably, in step S5, the temperature rise procedure for the discharge plasma sintering is as follows:

[0025] 570~600℃: 30℃ / min;

[0026] 600~900℃: 100℃ / min;

[0027] 900~1200℃: 75℃ / min;

[0028] 1200℃ to final sintering temperature: 50℃ / min;

[0029] Incubation time: 10 min.

[0030] A third aspect of the present invention provides an application of the multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure described in the first aspect in the fields of cutting tool materials and precision machining.

[0031] The beneficial effects achieved by one or more of the above technical solutions of the present invention are as follows:

[0032] (1) By adding ZrC, the present invention induces the formation of a second solid solution phase (Ti,Zr,Nb)(C,N) rich in Zr and Nb elements during the cooling process. Its dispersed distribution within the grains and at the grain boundaries effectively pins the grain boundaries, inhibits abnormal grain growth during the sintering process, realizes the leap from a single solid solution to a multiphase ceramic, and significantly improves the comprehensive mechanical properties of Ti(C,N) based ceramic materials.

[0033] (2) The mechanical properties of the Ti(C,N)-based ceramic material samples obtained in this invention, after cutting, rough grinding, polishing and finishing, are as follows: flexural strength 914~1269 MPa, fracture toughness 6.37~6.83 MPa. m 1 / 2 The hardness is 19.06~19.75 GPa. At the optimal sintering temperature, the flexural strength of the prepared dual solid solution microstructure multiphase Ti(C,N)-based ceramic material is increased by 77.7%, 8.6% and 5.4% respectively compared with the traditional single solid solution microstructure Ti(C,N)-based ceramic material without ZrC prepared at the same temperature.

[0034] (3) The present invention uses spark plasma sintering (SPS) technology, combined with a staged heating program (e.g., 1200℃ followed by 50℃ / min), to achieve high density at a lower temperature (1550℃) and a shorter time (10 minutes of holding).

[0035] (4) The dual solid solution microstructure multiphase Ti(C,N) based ceramic material prepared by the present invention has high hardness, high strength and toughness, and is suitable for fields with demanding mechanical properties such as tool materials and precision machining. Moreover, the metal-free design expands its application scenarios in corrosive or high-temperature environments. Attached Figure Description

[0036] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0037] Figure 1XRD analysis of Ti(C,N)-based ceramic materials prepared in Examples 1-3 and Comparative Example 2 of the present invention is shown below. (a) is the XRD pattern of the Ti(C,N)-based ceramic material with a single solid solution microstructure prepared in Comparative Example 2; (b) is the XRD pattern of the multiphase Ti(C,N)-based ceramic material with a double solid solution microstructure prepared in Example 2; (c) is the XRD pattern of the multiphase Ti(C,N)-based ceramic material with a double solid solution microstructure prepared in Example 1; and (d) is the XRD pattern of the multiphase Ti(C,N)-based ceramic material with a double solid solution microstructure prepared in Example 3.

[0038] Figure 2 XRD images of Ti(C,N)-based ceramic materials with different ZrC contents and dual solid solution microstructures are shown in the figures. (a) is the XRD pattern of the Ti(C,N)-based ceramic material with a single solid solution microstructure prepared in Comparative Example 1; (b) is the XRD pattern of the multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure prepared in Example 4; (c) is the XRD pattern of the multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure prepared in Example 1; (d) is the XRD pattern of the multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure prepared in Example 5; and (e) is the XRD pattern of the multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure prepared in Example 6.

[0039] Figure 3 The images show cross-sectional and surface SEM images of the Ti(C,N)-based ceramic materials prepared in Example 1 and Comparative Example 1 of this invention, wherein (a) is a cross-sectional SEM image of the Ti(C,N)-based ceramic material with a single solid solution microstructure prepared in Comparative Example 1; (b) is a cross-sectional SEM image of the Ti(C,N)-based ceramic material with a double solid solution microstructure prepared in Example 1; (c) is a surface SEM image of the Ti(C,N)-based ceramic material with a single solid solution microstructure prepared in Comparative Example 1; and (d) is a surface SEM image of the Ti(C,N)-based ceramic material with a double solid solution microstructure prepared in Example 1. Detailed Implementation

[0040] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0041] As mentioned above, existing Ti(C,N)-based cermets suffer from reduced hardness and strength due to the softening of the metal binder phase (such as Ni or Co) at high temperatures (>800°C); while pure Ti(C,N) ceramics, although heat-resistant, have poor strength and toughness. Single-solid-solution or high-entropy ceramics require high-temperature, long-term sintering and are prone to grain coarsening. Therefore, this invention provides a multiphase Ti(C,N)-based ceramic material with a dual-solid-solution microstructure that balances grain refinement, high strength, and high-temperature stability.

[0042] A first typical embodiment of the present invention provides a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure, which is composed of the following raw materials by mass percentage: 70%~85% Ti(C,N) powder, 5%~20% ZrC powder, 5% NbC powder, and 5% Mo2C powder; and the multiphase Ti(C,N)-based ceramic material comprises a matrix phase (Ti,Zr,Nb,Mo)(C,N) and a dispersed second solid solution phase (Ti,Zr,Nb)(C,N).

[0043] In one or more embodiments of this implementation, the average particle size of the Ti(C,N) powder is 0.5 μm, and the average particle size of the ZrC powder, NbC powder, and Mo2C powder is 1~3 μm.

[0044] A second typical embodiment of the present invention provides a method for preparing the above-mentioned multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure, comprising the following steps:

[0045] S1. Dissolve polyethylene glycol in anhydrous ethanol, heat in a water bath, and stir to obtain a polyethylene glycol-anhydrous ethanol dispersion.

[0046] S2. Add the ceramic powder obtained by mixing Ti(C,N) powder, ZrC powder, NbC powder and Mo2C powder to the dispersion prepared in step S1, and disperse by ultrasonic stirring to obtain a ceramic powder mixed solution.

[0047] S3. The mixed solution is subjected to high-energy ball milling under nitrogen protection to obtain a ball milling slurry;

[0048] S4. Vacuum dry and sieve the ball-milled slurry to obtain a mixed powder;

[0049] S5. The mixed powder is placed in a mold and subjected to discharge plasma sintering under vacuum conditions to obtain a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure.

[0050] In one or more embodiments of this implementation, in step S1, the polyethylene glycol is PEG6000, and its addition amount is 1% of the total mass of the ceramic powder.

[0051] In one or more embodiments of this implementation, in step S1, the temperature of the water bath heating is 55~65℃, and the stirring speed is 1200~1600 r / min.

[0052] In one or more embodiments of this implementation, in step S2, the ultrasonic time is 25-40 min and the stirring speed is 350-400 r / min.

[0053] In one or more embodiments of this implementation, in step S3, the ball-to-material mass ratio of the high-energy ball mill is 10:1, the grinding balls are cemented carbide balls with diameters of 5 mm and 10 mm, the mass ratio of which is 2:5, and the rotation speed of the ball mill is 350~450 r / min.

[0054] In one or more embodiments of this implementation, in step S4, the vacuum drying temperature is 100~120℃ and the time is 36~50 h, and the sieving is done using a 200-mesh sieve.

[0055] In one or more embodiments of this implementation, in step S5, the sintering temperature of the discharge plasma sintering is 1500~1575℃, and the sintering pressure is 30 MPa.

[0056] In one or more embodiments of this implementation, the heating procedure for the discharge plasma sintering in step S5 is as follows:

[0057] 570~600℃: 30℃ / min;

[0058] 600~900℃: 100℃ / min;

[0059] 900~1200℃: 75℃ / min;

[0060] 1200℃ to final sintering temperature: 50℃ / min;

[0061] Incubation time: 10 min.

[0062] A third typical embodiment of the present invention provides an application of the multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure described in the first aspect in the fields of cutting tool materials and precision machining.

[0063] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0064] Example 1: This example provides a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure and its preparation method.

[0065] In this embodiment, the dual solid solution microstructure multiphase Ti(C,N)-based ceramic material comprises the following components (by mass percentage): 80% Ti(C,N) powder, 10% ZrC powder, 5% NbC powder, and 5% Mo2C powder;

[0066] The specific preparation method is as follows:

[0067] (1) Add 200 mL of anhydrous ethanol to a beaker, weigh and add 1% of the total mass of polyethylene glycol (a ceramic powder obtained by mixing Ti(C,N) powder, ZrC powder, NbC powder and Mo2C powder), place the beaker in a water bath, and stir magnetically at 1500 r / min at 60°C until the polyethylene glycol is completely dissolved. Cool to room temperature to obtain a polyethylene glycol-anhydrous ethanol mixture.

[0068] (2) Mix Ti(C,N) powder, ZrC powder, NbC powder and Mo2C powder according to the above mass ratio, add them to the polyethylene glycol-anhydrous ethanol mixture obtained in step (1), and ultrasonically stir and disperse at 380 r / min for 30 min to obtain a mixed solution.

[0069] (3) The prepared mixed solution was placed in a ball milling jar, wherein the ball used for ball milling was a cemented carbide grinding ball, and the cemented carbide grinding ball was a mixture of cemented carbide grinding balls with diameters of 5 mm and 10 mm, with a mass ratio of 2:5 and a ball-to-material mass ratio of 10:1. The ball was milled at a high energy speed of 400 r / min for 48 h under a nitrogen protective atmosphere.

[0070] (4) The ball-milled slurry was dried under vacuum at 120℃ for 48 h and passed through a 200-mesh sieve to obtain Ti(C,N)-based ceramic mixed powder;

[0071] (5) The Ti(C,N)-based ceramic mixed powder was placed in a graphite mold and subjected to spark plasma sintering under a vacuum atmosphere. The sintering temperature was 1550℃, the sintering pressure was 30 MPa, the heating rate was 30℃ / min when the temperature was 570~600℃, 100℃ / min when the temperature was 600~900℃, 75℃ / min when the temperature was 900~1200℃, and 50℃ / min when the temperature was 1200~1500℃. The temperature was held for 10 min and then cooled to room temperature to obtain the dual solid solution microstructure multiphase Ti(C,N)-based ceramic material.

[0072] The mechanical properties of the prepared dual-solid-solution microstructure multiphase Ti(C,N)-based ceramic material samples were measured after cutting, rough grinding, polishing, and grinding: flexural strength 1269 MPa, fracture toughness 6.83 MPa. m 1 / 2 Hardness 19.75 GPa.

[0073] Example 2:

[0074] The difference between this embodiment and embodiment 1 is that in step (5), the sintering temperature in the plasma sintering process is set to 1525℃, while the other components and preparation methods are the same as in embodiment 1.

[0075] The specific preparation method of step (5) is as follows: Ti(C,N) based ceramic mixed powder is placed in a graphite mold and subjected to discharge plasma sintering under vacuum atmosphere. The sintering temperature is 1525℃, the sintering pressure is 30 MPa, the heating rate is 30℃ / min when the temperature is 570~600℃, 100℃ / min when the temperature is 600~900℃, 75℃ / min when the temperature is 900~1200℃, and 50℃ / min when the temperature is 1200~1525℃. The temperature is held for 10 min and then cooled to room temperature to obtain the dual solid solution microstructure multiphase Ti(C,N) based ceramic material.

[0076] The mechanical properties of the prepared dual-solid-solution microstructure multiphase Ti(C,N)-based ceramic material samples were measured after cutting, rough grinding, lapping, and polishing: flexural strength 950 MPa, fracture toughness 6.53 MPa. m 1 / 2 Hardness 19.26 GPa.

[0077] Example 3:

[0078] The difference between this embodiment and Embodiment 1 is that the sintering temperature in the plasma sintering process is set to 1575℃, while the other components and preparation methods are the same as in Embodiment 1.

[0079] The specific preparation method of step (5) is as follows: Ti(C,N) based ceramic mixed powder is placed in a graphite mold and subjected to discharge plasma sintering under vacuum atmosphere. The sintering temperature is 1575℃, the sintering pressure is 30 MPa, the heating rate is 30℃ / min when the temperature is 570~600℃, 100℃ / min when the temperature is 600~900℃, 75℃ / min when the temperature is 900~1200℃, and 50℃ / min when the temperature is 1200~1575℃. The temperature is held for 10 min and then cooled to room temperature to obtain the dual solid solution microstructure multiphase Ti(C,N) based ceramic material.

[0080] The mechanical properties of the prepared dual-solid-solution microstructure multiphase Ti(C,N)-based ceramic material samples were measured after cutting, rough grinding, lapping, and polishing: flexural strength 1035 MPa, fracture toughness 6.77 MPa. m 1 / 2 Hardness 19.57 GPa.

[0081] Example 4:

[0082] The difference between this embodiment and Embodiment 1 is that:

[0083] The dual solid solution microstructured multiphase Ti(C,N)-based ceramic material comprises the following components (by mass percentage): 85% Ti(C,N) powder, 5% ZrC powder, 5% NbC powder, and 5% Mo2C powder; other components and preparation methods are the same as in Example 1.

[0084] The mechanical properties of the prepared dual-solid-solution microstructure multiphase Ti(C,N)-based ceramic material samples were measured after cutting, rough grinding, polishing, and grinding: flexural strength 931 MPa, fracture toughness 6.47 MPa. m 1 / 2 Hardness 19.33 GPa.

[0085] Example 5:

[0086] The difference between this embodiment and Embodiment 1 is that:

[0087] The dual solid solution microstructured multiphase Ti(C,N)-based ceramic material comprises the following components (by mass percentage): 75% Ti(C,N) powder, 15% ZrC powder, 5% NbC powder, and 5% Mo2C powder; other components and preparation methods are the same as in Example 1.

[0088] The mechanical properties of the prepared dual-solid-solution microstructure multiphase Ti(C,N)-based ceramic material samples were measured after cutting, rough grinding, polishing, and grinding: flexural strength 1028 MPa, fracture toughness 6.54 MPa. m 1 / 2 Hardness 19.42 GPa.

[0089] Example 6:

[0090] The difference between this embodiment and Embodiment 1 is that:

[0091] The dual solid solution microstructured multiphase Ti(C,N)-based ceramic material comprises the following components (by mass percentage): 70% Ti(C,N) powder, 20% ZrC powder, 5% NbC powder, and 5% Mo2C powder; other components and preparation methods are the same as in Example 1.

[0092] The mechanical properties of the prepared dual-solid-solution microstructure multiphase Ti(C,N)-based ceramic material samples were measured after cutting, rough grinding, lapping, and polishing: flexural strength 914 MPa, fracture toughness 6.37 MPa. m 1 / 2 Hardness 19.06 GPa.

[0093] Comparative Example 1:

[0094] The difference between this comparative example and Example 1 is that the Ti(C,N) based ceramic material contains the following components (by mass percentage): 90% Ti(C,N) powder, 5% NbC powder, and 5% Mo2C powder; the other components and preparation methods are the same as in Example 1.

[0095] The mechanical properties of the prepared Ti(C,N)-based ceramic material sample with a single solid micro-solid structure were measured after cutting, rough grinding, polishing, and grinding: flexural strength 714 MPa, fracture toughness 6.29 MPa. m 1 / 2 Hardness 18.73 GPa.

[0096] Comparative Example 2:

[0097] The difference between this comparative example and Example 1 is that the sintering temperature in the plasma sintering process is set to 1500℃, while the other components and preparation methods are the same as in Example 1.

[0098] The mechanical properties of the prepared Ti(C,N)-based ceramic material sample with a single solid micro-solid structure were measured after cutting, rough grinding, polishing, and grinding: flexural strength 744 MPa, fracture toughness 6.27 MPa. m 1 / 2 Hardness 18.13 GPa.

[0099] In summary, a comparison of Examples 1-3 shows that when the ZrC content is 10 wt.%, the mechanical properties of the prepared dual solid solution microstructure multiphase Ti(C,N)-based ceramic material are significantly improved with increasing sintering temperature. When the sintering temperature is 1550℃, the prepared dual solid solution microstructure multiphase Ti(C,N)-based ceramic material exhibits the best comprehensive mechanical properties.

[0100] A comparison of Examples 1 and 3 shows that when the ZrC content is 10 wt.%, further increases in sintering temperature actually reduce the mechanical properties of the dual solid solution microstructure multiphase Ti(C,N)-based ceramic materials to some extent.

[0101] As can be seen from the comparison between Example 1 and Comparative Example 1, at the same sintering temperature, the mechanical properties of the prepared multiphase Ti(C,N)-based ceramic material with dual solid solution microstructure are significantly improved compared with the traditional Ti(C,N)-based ceramic material with single solid solution microstructure.

[0102] As can be seen from the comparison between Examples 1 and Examples 4-6, the mechanical properties of the dual solid solution microstructure multiphase Ti(C,N)-based ceramic material are optimal when the ZrC content is 10 wt.%.

[0103] Experimental Example 1: This experimental example performs structural analysis on the Ti(C,N)-based ceramic materials prepared in the examples and comparative examples.

[0104] like Figure 1 As shown, Figure 1 (a) XRD image of Ti(C,N) ceramics prepared at 1500℃ with 10% ZrC addition, showing no formation of a double solid solution microstructure; when the sintering temperature is increased to 1525~1575℃, Figure 1 In the XRD images of the dual solid solution microstructure multiphase Ti(C,N)-based ceramics in (b) to (d), the diffraction peaks of Ti(C,N) disappear and the diffraction peaks of (Ti,Zr,Nb,Mo)(C,N) and (Ti,Zr,Nb)(C,N) appear.

[0105] like Figure 2 As shown, compared to Figure 2 In (a) without the addition of ZrC, only the diffraction peaks of the matrix Ti(C,N) and the diffraction peaks of the solid solution (Ti,Nb,Mo)(C,N) are observed. Figure 2 When the ZrC addition amount in (b) is 5%, the Ti(C,N) diffraction peak of the dual solid solution microstructure multiphase Ti(C,N)-based ceramic disappears, and (Ti,Zr,Nb,Mo)(C,N) diffraction peak and (Ti,Zr,Nb)(C,N) diffraction peak appear. Figure 2 In (c)~(e), as the ZrC content increases, the diffraction peak angle gradually shifts to the left, and the lattice constant increases. Therefore, the mechanical properties are optimal at a ZrC content of 10%.

[0106] like Figure 3 As shown, Figure 3 In the middle (a) and (c), SEM images of Ti(C,N) ceramics with a single solid solution structure prepared at 1550℃ without the addition of ZrC are shown. The grain size is relatively large and there are many pores. Figure 3 (b) and (d) are SEM images of the dual solid solution microstructure multiphase Ti(C,N)-based ceramics prepared at 1550℃ with 10% ZrC addition. The formation of the dual solid solution microstructure significantly refines the grain size, thus improving the mechanical properties of the Ti(C,N)-based ceramic materials prepared in the examples.

[0107] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure, characterized in that, The material is composed of the following raw materials by mass percentage: 70%~85% Ti(C,N) powder, 5%~20% ZrC powder, 5% NbC powder, and 5% Mo2C powder; and the multiphase Ti(C,N) based ceramic material comprises a matrix phase (Ti,Zr,Nb,Mo)(C,N) and a dispersed second solid solution phase (Ti,Zr,Nb)(C,N); The multiphase Ti(C,N)-based ceramic material is prepared by spark plasma sintering at a temperature of 1525~1575℃ and a sintering pressure of 30 MPa.

2. The multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure as described in claim 1, characterized in that, The average particle size of the Ti(C,N) powder is 0.5 μm, and the average particle size of the ZrC powder, NbC powder and Mo2C powder are all 1~3 μm.

3. A method for preparing a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Dissolve polyethylene glycol in anhydrous ethanol, heat in a water bath, and stir to obtain a polyethylene glycol-anhydrous ethanol dispersion. S2. Add the ceramic powder obtained by mixing Ti(C,N) powder, ZrC powder, NbC powder and Mo2C powder to the dispersion prepared in step S1, and disperse by ultrasonic stirring to obtain a ceramic powder mixed solution. S3. The mixed solution is subjected to high-energy ball milling under nitrogen protection to obtain a ball milling slurry; S4. Vacuum dry and sieve the ball-milled slurry to obtain a mixed powder; S5. The mixed powder is placed in a mold and subjected to discharge plasma sintering under vacuum conditions to obtain a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure.

4. The preparation method according to claim 3, characterized in that, In step S1, the polyethylene glycol is PEG6000, and its addition amount is 1% of the total mass of the ceramic powder.

5. The preparation method according to claim 3, characterized in that, In step S1, the water bath heating temperature is 55~65℃, and the stirring speed is 1200~1600 r / min.

6. The preparation method according to claim 3, characterized in that, In step S2, the ultrasonic time is 25-40 minutes, and the stirring speed is 350-400 r / min.

7. The preparation method according to claim 3, characterized in that, In step S3, the ball-to-material mass ratio of the high-energy ball mill is 10:1, the grinding balls are cemented carbide balls with diameters of 5 mm and 10 mm, and their mass ratio is 2:

5. The rotation speed of the ball mill is 350~450 r / min.

8. The preparation method according to claim 3, characterized in that, In step S4, the vacuum drying temperature is 100~120℃ and the time is 36~50 h, and the sieving is done using a 200-mesh sieve.

9. The preparation method according to claim 3, characterized in that, In step S5, the temperature rise procedure for the discharge plasma sintering is as follows: 570~600℃: 30℃ / min; 600~900℃: 100℃ / min; 900~1200℃: 75℃ / min; 1200℃ to final sintering temperature: 50℃ / min; Incubation time: 10 min.

10. The application of a multiphase Ti(C,N)-based ceramic material with a dual solid solution microstructure as described in claim 1 or 2 in cutting tool materials.

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