Ceramic cutting tool surface high temperature strong magnetic heat plasma treatment method and obtained cutting tool

Abstract

The application relates to the field of surface treatment of ceramic cutters and specifically discloses a high-temperature strong-magnetic heat plasma treatment method for a ceramic cutter surface and a cutter obtained through the method, which comprises the following steps: step 1, placing the ceramic cutter into a vacuum chamber after cleaning and drying; step 2, uniformly preheating the surface of the ceramic cutter through an argon plasma beam, so that the surface of the ceramic cutter is heated to a set treatment temperature zone within a set time, and heat stable transmission and microstructure activation in the preheating temperature zone are realized; step 3, continuously maintaining the high-temperature state to perform short-time heat treatment on the ceramic cutter, so that the grain boundary migration of the Al2O3-TiCN ceramic surface is enhanced, the subgrain structure is rearranged, and the particles are densified, the original micropores are partially closed, the surface structure is significantly densified, and compression residual stress is introduced into the near surface layer; and step 4, cutting off the plasma beam flow and performing furnace cooling treatment on the ceramic cutter in a vacuum or inert atmosphere.

Description

Technical Field

[0001] This invention relates to the field of surface treatment of ceramic cutting tools, and specifically to a method for high-temperature strong magnetothermal plasma treatment of ceramic cutting tool surfaces and the resulting cutting tools. Background Technology

[0002] Ceramic matrix composites, due to their high hardness, high wear resistance, and excellent high-temperature stability, have been widely used in high-performance cutting tools, wear-resistant components, and structural ceramics. Among them, Al2O3–TiCN composite ceramics, combining the high thermal stability of alumina with the reinforcing and toughening effects of titanium carbonitride, have become one of the most frequently used advanced ceramic tool materials in industry. However, these materials generally suffer from high brittleness and low fracture toughness, limiting their application under high loads or interrupted cutting conditions. To address this issue, existing technologies have proposed various surface modification or structural optimization methods for ceramic tools, mainly including high-temperature annealing heat treatment, chemical vapor deposition (CVD) and physical vapor deposition (PVD) coating technologies, laser cladding, and plasma spraying technologies. Among these, high-temperature annealing heat treatment promotes grain growth and phase structure stability through long-term high-temperature sintering or post-heat treatment, improving the internal stress state of the material. For example, controlling the heat treatment temperature in the range of 1500–1700°C and maintaining it for several hours can promote the densification and homogenization of Al2O3 to a certain extent. However, this method has the following drawbacks: long processing cycle, poor heating uniformity, and low efficiency; prolonged high temperature can easily cause abnormal grain growth, leading to a decrease in strength and toughness. Summary of the Invention

[0003] This invention addresses the problems existing in the high-temperature annealing heat treatment technology in the prior art by proposing a high-temperature strong magnetothermal plasma treatment method for ceramic cutting tools and the resulting cutting tools.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, the present invention proposes a method for high-temperature strong magnetothermal plasma treatment of ceramic cutting tool surfaces, comprising the following steps:

[0006] Step 1. After cleaning and drying the ceramic cutting tool, place it in a vacuum chamber;

[0007] Step 2. Use an argon plasma beam to homogenize and preheat the surface of the ceramic cutting tool, raising the surface of the ceramic cutting tool to the set treatment temperature zone, so as to achieve stable heat transfer and microstructure activation within the preheating temperature zone;

[0008] Step 3. Continue to maintain the high temperature state to perform short-time heat treatment on the ceramic cutting tool to achieve enhanced grain boundary migration, subgrain structure rearrangement and particle densification on the Al2O3–TiCN ceramic surface, so that the original micropores are partially closed and the surface structure is significantly densed, while introducing compressive residual stress in the near-surface layer.

[0009] Step 4. Cut off the argon plasma beam and perform furnace cooling on the ceramic cutting tool under vacuum or inert atmosphere to avoid microcracks caused by thermal stress concentration, while maintaining the stability of the residual compressive stress layer, thereby further enhancing the tool's resistance to crack propagation and fracture toughness.

[0010] As a further technical solution, ultrasonic cleaning is used in step 1.

[0011] As a further technical solution, in step 2, the set processing temperature range is 1900℃~2150℃.

[0012] As a further technical solution, the discharge power of the plasma beam is 8-20 kW, the operating voltage is 200-400 V, and the current is 40-80 A.

[0013] As a further technical solution, in step 3, the short-time heat treatment time is 15 to 60 seconds.

[0014] As a further technical solution, in step 3, the heat treatment temperature is 1900℃ and the short-time heat treatment time is 30 seconds.

[0015] As a further technical solution, in step 4, the cooling process is carried out in an argon protective atmosphere.

[0016] As a further technical solution, in step 4, the cooling rate is controlled at 10-30℃ / min.

[0017] As a further technical solution, in step 3, the heat treatment temperature is 1900℃ and the short-time heat treatment time is 30 seconds.

[0018] Secondly, the present invention also provides a cutting tool, which is obtained by the high-temperature strong magnetothermal plasma treatment method for ceramic cutting tool surfaces described above.

[0019] As a further technical solution, the fracture toughness of the ceramic cutting tool is increased to 7.22–9.68 MPa·m¹. / ².

[0020] Compared with existing ceramic cutting tool surface modification technologies, the beneficial effects of this invention are as follows:

[0021] This invention significantly optimizes the microstructure and mechanical properties of Al2O3–TiCN composite ceramic cutting tools by employing short-time high-temperature non-contact treatment with argon plasma beams. It exhibits particularly excellent effects in improving fracture toughness, homogenizing the microstructure, and enhancing densification, as detailed below:

[0022] 1. Significantly improved processing efficiency, avoiding grain coarsening.

[0023] This invention uses an argon plasma beam to reconstruct and optimize the microstructure of ceramic surfaces within a set temperature and time, effectively avoiding problems such as abnormal grain growth and microstructure coarsening caused by long-term processing, and improving processing efficiency by more than an order of magnitude.

[0024] 2. Fracture toughness is comprehensively improved, and the material's crack resistance is enhanced.

[0025] The ceramic cutting tools treated by the method of this invention exhibit significantly improved fracture toughness to 7.22–9.68 MPa·m1 / 2, with a maximum improvement of 40.5%. Specifically, α-Al2O3 grains grow preferentially, grain boundary density decreases, and crack propagation paths are blocked; crystal defects are reduced, C / N orderly distribution is enhanced, and the solid solution structure is more complete; a residual compressive stress field is formed on the surface, effectively closing the microcrack tips and improving crack propagation resistance; surface particle rearrangement and melting and resolidification processes enhance density, forming a uniform honeycomb structure.

[0026] 3. Optimize comprehensive mechanical properties to obtain the best processing window.

[0027] Preferably, the present invention extends the processing time to 30 seconds under the processing condition of 1900°C, so that the material properties reach the optimal state, the density increases to 4.829 g / cm³, the hardness is 23.11 GPa, and the fracture toughness is as high as 9.68 MPa·m¹ / ². Toughening is achieved without sacrificing hardness. Therefore, argon plasma beam treatment can achieve synergistic densification and toughening, which helps to improve the service life and fracture resistance of the tool.

[0028] 4. The microstructure is highly controllable, and the stability of the phase composition is enhanced.

[0029] After treatment with the method proposed in this invention, the α-Al2O3 grain size increased, the crystallinity improved, the diffraction peaks of Ti(C,N) solid solution were enhanced, and the lattice distortion was reduced. This indicates that the treatment process did not induce any unfavorable new phases, but instead improved the integrity of the crystal structure. Attached Figure Description

[0030] 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.

[0031] Figure 1 This is a flowchart of the processing of the present invention;

[0032] Figure 2 These are the XRD patterns of Al2O3-TiCN composite ceramics at different treatment temperatures;

[0033] Figure 3 These are SEM images of the sample surfaces after being treated at different temperatures for 15 seconds, and at a magnification of 500x. Among them, (a) is the SEM image of the sample surface before treatment; (b) is the SEM image of the sample surface after treatment at 1900℃; (c) is the SEM image of the sample surface after treatment at 2000℃; (d) is the SEM image of the sample surface after treatment at 2050℃; (e) is the SEM image of the sample surface after treatment at 2100℃; and (f) is the SEM image of the sample surface after treatment at 2150℃.

[0034] Figure 4 These are SEM images of the sample surfaces after being treated at different temperatures for 15 seconds, and at a magnification of 2000x. Among them, (a) is the SEM image of the sample surface before treatment; (b) is the SEM image of the sample surface after treatment at 1900℃; (c) is the SEM image of the sample surface after treatment at 2000℃; (d) is the SEM image of the sample surface after treatment at 2050℃; (e) is the SEM image of the sample surface after treatment at 2100℃; and (f) is the SEM image of the sample surface after treatment at 2150℃.

[0035] Figure 5 These are SEM surface morphology images at 1900℃ for different processing times; (a) is the SEM surface morphology image at 500x magnification for a processing time of 15s; (b) is the SEM surface morphology image at 2000x magnification for a processing time of 15s; (c) is the SEM surface morphology image at 500x magnification for a processing time of 30s; (d) is the SEM surface morphology image at 2000x magnification for a processing time of 30s; (e) is the SEM surface morphology image at 500x magnification for a processing time of 60s; and (f) is the SEM surface morphology image at 2000x magnification for a processing time of 60s. Detailed Implementation

[0036] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] As described in the background section, existing methods for surface modification of ceramic cutting tools suffer from drawbacks such as long processing times and grain coarsening, making it difficult to achieve directional surface control; CVD / PVD coatings suffer from insufficient adhesion and high risk of peeling, failing to provide long-term stable improvement in the crack resistance of the ceramic matrix; laser or plasma cladding methods, when applied to ceramic surfaces, easily generate thermal stress concentration and crack defects, negatively impacting the overall fracture toughness and structural integrity of the material. To address these technical problems, this invention proposes a high-temperature, high-intensity magnetothermal plasma treatment method for ceramic cutting tool surfaces and the resulting cutting tool. The technical problems it aims to solve include: First, providing an efficient, non-contact, and short-time surface heat treatment method suitable for structural control and performance enhancement of ceramic cutting tools, avoiding problems such as grain coarsening, insufficient modification depth, and low processing efficiency inherent in traditional heat treatment processes; Second, significantly improving the surface resistance of Al2O3–TiCN. The fracture toughness of ceramic cutting tools, while maintaining or optimizing hardness and density, improves the material's resistance to crack initiation and propagation, enhancing its service reliability under high-load cutting environments; third, it solves the common problems of "difficulty in toughening" and "poor structural controllability" in existing technologies, providing a new process path for large-scale strengthening of ceramic cutting tools.

[0039] Specifically, the high-temperature, high-intensity magnetothermal plasma treatment method for ceramic cutting tool surfaces proposed in this embodiment provides a surface heat treatment method suitable for alumina-titanium carbonitride (Al2O3–TiCN) composite ceramic cutting tools. This method aims to reconstruct the microstructure of the ceramic cutting tool surface through a short-time, high-energy, and highly controlled processing procedure, thereby improving its fracture toughness, hardness, and overall mechanical properties. This method can significantly optimize the service life and reliability of ceramic materials without introducing additional coatings or impurities. Figure 1 As shown, the specific steps include:

[0040] Step S1: Clean the ceramic knife, dry it, and place it in a vacuum chamber;

[0041] Step S2: Using a plasma emission device, the surface of the ceramic tool is preheated to a uniform temperature by using the argon plasma beam of the plasma emission device, so that the surface of the ceramic tool is heated to the set treatment temperature zone, and the heat is stably transferred and the microstructure is activated within the preheating temperature zone.

[0042] Step S3: Continue to maintain the high temperature state to perform short-term heat treatment on the ceramic cutting tool. Through the action of high temperature, the grain boundary migration of Al2O3–TiCN ceramic surface is enhanced, the subgrain structure is rearranged and the particles are densified, so that the original micropores are partially closed and the surface structure is significantly densed. At the same time, compressive residual stress is introduced in the near-surface layer.

[0043] Step S4: After the treatment is completed, the plasma beam is cut off, and the ceramic tool is cooled in the furnace under vacuum or inert atmosphere to avoid microcracks caused by thermal stress concentration, while maintaining the stability of the residual compressive stress layer, thereby further enhancing the tool's resistance to crack propagation and fracture toughness.

[0044] Furthermore, in step 1 of this embodiment, ultrasonic cleaning is used. Ultrasonic waves can peel off, emulsify, and disperse various contaminants such as oil, grease, dust, particles, polishing paste, fingerprints, and biofilms attached to the surface of ceramic knives, thereby achieving the purpose of cleaning.

[0045] Furthermore, in step 2 of this embodiment, the processing temperature range is set to 1900℃~2150℃. This can be achieved by adjusting the discharge power, operating voltage, and current of the plasma beam. Specifically, the discharge power of the plasma beam can be adjusted to 8~20kW, the operating voltage to 200~400V, and the current to 40~80A.

[0046] Furthermore, in step 3 of this embodiment, the short-time heat treatment lasts for 15–60 seconds. Experimental results show that the method of the present invention, under the conditions of a temperature range of 1900–2150°C and a treatment time of 15–60 seconds, can induce partial degradation of TiCN to generate beneficial phases (such as TiN), and achieve significant toughening of ceramic cutting tools through mechanisms such as grain structure rearrangement, reduction of defect numbers, formation of residual compressive stress, and densification enhancement. Specifically, the fracture toughness of the treated material increases from 6.89 MPa·m¹ / ² in the untreated state to 7.22–9.68 MPa·m¹ / ², showing a significant performance improvement. Parameter verification and characterization data accumulation for key process windows have been completed, demonstrating feasibility for industrial promotion and technology implementation. Preferably, the short-time heat treatment time is 30 seconds; preferably, the surface heating temperature of the ceramic cutting tool is 2050°C.

[0047] As a further technical solution, in step 4, the cooling process is carried out in an argon protective atmosphere with a gas purity of not less than 99.999%. The cooling process in this step under an argon protective atmosphere is mainly to create an inert environment for the cooling of the tool, to prevent the ceramic tool from reacting harmfully with oxygen (O2), nitrogen (N2), water vapor (H2O) in the air at high temperatures, thereby ensuring material performance and surface quality.

[0048] As a further technical solution, in step 4, the cooling rate is controlled at 10-30℃ / min; to avoid microcracks caused by thermal stress concentration, while maintaining the stable existence of the residual compressive stress layer, thereby further enhancing the tool's resistance to crack propagation and fracture toughness.

[0049] The following describes the specific processing procedure using a ceramic cutting tool sample of a certain model as an example. Specifically, the sample cutting tool is model AN5, with a square blade and dimensions of 12.7 mm × 12.7 mm × 4.76 mm. The processing method mainly includes the following steps:

[0050] Step 1. Sample preparation and pretreatment

[0051] To ensure uniform heat treatment and the effectiveness of subsequent energy application, this method involves cleaning and pre-treating the surface of the ceramic cutting tool before heat treatment, including:

[0052] Use anhydrous ethanol to ultrasonically clean the surface of the tool. Set the ultrasonic temperature to 70°C and the duration to 5–10 minutes to remove surface oil, dust and residual impurities.

[0053] After cleaning, place the sample in a clean environment to air dry naturally, or use hot air to dry (temperature not higher than 100℃).

[0054] This step helps improve the consistency of grain reconstruction after heat treatment and reduces the risk of local microcrack formation.

[0055] Step 2. High-temperature short-time strong magnetothermal plasma treatment

[0056] This step is a key technical measure of the present invention. Its core lies in reconstructing the microstructure of the ceramic tool surface through short-time, high-temperature, non-contact magnetron thermal plasma treatment, thereby improving fracture toughness and crack propagation resistance. The technical principle is as follows: Utilizing a plasma beam to provide strong instantaneous thermal energy input in a high vacuum, inert atmosphere, without causing overheating of the tool substrate, it activates grain boundary migration and densification processes, inducing preferential grain growth, solid solution ordering, and the introduction of residual compressive stress, thereby enhancing the overall crack resistance and thermal shock stability of the ceramic. Specifically, this step is explained in detail based on high-power, high-intensity magnetic vortex thermal plasma (MRTP) ultra-high temperature equipment:

[0057] (2-1) Opening the hatch and placing the sample:

[0058] Open the sealed chamber door of the vacuum heat treatment device, and place the pretreated ceramic tool sample on the high-purity graphite platform in the center of the chamber. The sample must be centered to ensure the uniformity and repeatability of the subsequent beam action and avoid heterogeneous ablation.

[0059] (2-2) Close the hatch and evacuate the vacuum:

[0060] After closing the hatch, the vacuum system is activated, employing a staged evacuation method (rough evacuation → high vacuum) to control the vacuum level inside the chamber at ≤10 Pa, thereby eliminating oxygen and water vapor and preventing grain boundary damage induced by high-temperature oxidation. Simultaneously, high-purity argon (purity ≥99.999%) is introduced as the process gas to create a stable, inert atmosphere, which facilitates uniform heat conduction.

[0061] (2-3) Mechanical positioning:

[0062] The stepper motor built into the starting device controls the mechanical conveying platform to move the sample to the designated position, directly below the plasma emission nozzle (beam core region). This process enables relative movement control between the local beam action area and the surface to be treated, thereby controlling the width and heating consistency of the local heat-affected zone.

[0063] (2-4) Argon gas filling and gas flow stabilization:

[0064] Turn on the argon flow control system to fill the cavity with high-purity argon gas (purity ≥99.999%), set the gas flow rate to 10–3000 L / min, and monitor the pressure fluctuations in the cavity in real time to ensure the formation of a stable plasma atmosphere environment.

[0065] (2-5) Plasma beam startup and power control:

[0066] The magnetron plasma beam is activated, and the voltage (200–400 V), current (40–80 A), and jet power (8–20 kW) are adjusted to rapidly heat the sample surface to 1900–2150 °C. This temperature range promotes the directional growth of α-Al₂O₃ grains and reduces the tendency for intergranular fracture.

[0067] (2-6) Temperature setting and real-time feedback adjustment:

[0068] Set the target processing temperature (recommended 1900–2150℃), and obtain the real-time surface temperature feedback signal through the built-in infrared high-temperature thermometer (measurement accuracy ±10℃). The control system automatically adjusts the electrode voltage or gas flux to dynamically maintain the stability of the set temperature range.

[0069] (2-7) Insulation time control:

[0070] The heat treatment time should be controlled between 15 and 60 seconds. The longer the time, the more complete the grain growth, but too long a time may cause grain coarsening or increased porosity. Experiments show that treatment at 1900°C for 30 seconds can obtain the best honeycomb structure, balancing toughness and density. See Table 1 for details.

[0071] Table 1 Processing parameters

[0072]

[0073] (2-8) Cooling and Sampling:

[0074] After processing, shut off the plasma beam and argon flow, keep the chamber under static argon protection or maintain a vacuum, and allow the sample to cool naturally to below 100°C. Then open the chamber door, use an insulated clamp to remove the sample, and place it in a clean environment to cool naturally to room temperature.

[0075] Through comprehensive mechanical property optimization, the optimal processing window was obtained through the above experiments. Extending the processing time to 30 seconds at 1900°C resulted in optimal material properties, with density increasing to 4.829 g / cm³, hardness reaching 23.11 GPa, and fracture toughness reaching 9.68 MPa·m¹ / ², achieving toughening without sacrificing hardness. This result demonstrates that MRTP plasma...

[0076] The bulk treatment can achieve a synergistic effect of densification and toughening, which helps to improve the service life and fracture resistance of the tool. For specific data, please refer to Table 2.

[0077] Table 2. Comprehensive Data Table of Temperature-Time-Density-Hardness-Fracture Toughness

[0078]

[0079] The experimental data above show that the fracture toughness of the untreated sample is 6.89 MPa·m. 1 / 2 After treatment with the method of this invention, the fracture toughness is significantly improved to 7.22–9.68 MPa·m. 1 / 2 The maximum increase reached 40.5%; its improvement mechanism mainly includes:

[0080] Preferred growth of α-Al2O3 grains reduces grain boundary density and hinders crack propagation paths; crystal defects are reduced, C / N orderly distribution is enhanced, and the solid solution structure is more complete; residual compressive stress field is formed on the surface, effectively closing the microcrack tip and increasing crack propagation resistance; surface particle rearrangement and melting and resolidification processes enhance compactness and form a uniform honeycomb structure.

[0081] SEM analysis revealed that the surface morphology changes of the tool under the processing of this invention can be divided into three stages: low temperature and short time (1900–2000°C, ≤15s): surface micropores are formed, and scratches are passivated; medium temperature and moderate time (2050°C, 15–30s): honeycomb structure is formed, and grain fusion is enhanced; high temperature and long time (≥2150°C, >30s): severe ablation occurs, an open porous network is formed, and the structure degrades. See details. Figure 4 , Figure 5 ;

[0082] XRD analysis showed that the treated α-Al₂O₃ grain size increased, crystallinity improved, Ti(C,N) solid solution diffraction peaks were enhanced, and lattice distortion decreased. This indicates that the treatment did not induce any unfavorable new phases, but rather improved the integrity of the crystal structure. (See details...) Figure 2 .

[0083] Through the above experiments, compared with existing ceramic tool surface modification technologies, the present invention significantly optimizes the microstructure and mechanical properties of Al2O3–TiCN composite ceramic tools by using high-power magnetic vortex thermal plasma (MRTP) for short-time high-temperature non-contact treatment, especially showing excellent effects in improving fracture toughness, homogenizing microstructure, and enhancing densification.

[0084] Traditional heat treatment processes (such as conventional annealing) typically require several hours of high-temperature holding time, resulting in long processing cycles and difficulty in precisely controlling grain growth, which can easily lead to material embrittlement. This invention utilizes an MRTP device, requiring only 15–60 seconds of processing time within a temperature range of 1900–2150°C to reconstruct the microstructure and optimize the performance of ceramic surfaces. This effectively avoids problems such as abnormal grain growth and microstructure coarsening caused by prolonged processing, significantly improving processing efficiency by more than an order of magnitude.

[0085] Furthermore, the plasma treatment method proposed in this embodiment is applicable to the standard geometry of conventional ceramic cutting tools. It does not require complex pretreatment processes such as pre-coating and doping, and can directly carry out rapid modification on the original ceramic surface. The process is clean, energy consumption is controllable, and it has good adaptability to large-scale applications.

[0086] Example 2

[0087] This embodiment also provides a cutting tool, obtained by the high-temperature strong magnetothermal plasma treatment method for ceramic cutting tool surface described in Embodiment 1. The fracture toughness of this ceramic cutting tool is improved to 7.22–9.68 MPa·m¹. / ².

[0088] 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 method for treating the surface of ceramic cutting tools with high-temperature strong magnetothermal plasma, characterized in that, Includes the following steps: Step 1. After cleaning and drying the ceramic knives, place them in a vacuum chamber; Step 2. Using a magnetron thermal plasma source, an argon plasma beam is used to homogenize and preheat the surface of the ceramic cutting tool, raising the surface of the ceramic cutting tool to 1900℃ within a set time, and achieving stable heat transfer and microstructure activation within the preheating temperature zone. Step 3. Continue to maintain a high temperature of 1900℃ to perform a short heat treatment of 30 seconds on the ceramic cutting tool to achieve enhanced grain boundary migration, subgrain structure rearrangement and particle densification on the Al2O3–TiCN ceramic surface, so that the original micropores are partially closed and the surface structure is significantly denser, while introducing compressive residual stress in the near-surface layer. Step 4. Cut off the plasma beam and perform furnace cooling treatment on the ceramic cutting tool under vacuum or inert atmosphere.

2. The high-temperature strong magnetothermal plasma treatment method for ceramic cutting tool surfaces as described in claim 1, characterized in that, In step 1, ultrasonic cleaning is used to clean the ceramic cutting tool.

3. The high-temperature strong magnetothermal plasma treatment method for ceramic cutting tool surfaces as described in claim 1, characterized in that, In step 2, the discharge power of the plasma beam is 8–20 kW, the operating voltage is 200–400 V, and the current is 40–80 A.

4. The high-temperature strong magnetothermal plasma treatment method for ceramic cutting tool surfaces as described in claim 1, characterized in that, In step 4, the cooling process is carried out in an argon protective atmosphere.

5. The high-temperature strong magnetothermal plasma treatment method for ceramic cutting tool surfaces as described in claim 1, characterized in that, In step 4, the cooling rate is controlled at 10–30 °C / min.

6. A cutting tool, characterized in that, Obtained by the high-temperature strong magnetothermal plasma treatment method for the surface of ceramic cutting tools as described in any one of claims 1-5.

7. The cutting tool as described in claim 6, characterized in that, The fracture toughness of the ceramic cutting tool is increased to 9.68 MPa·m¹ ².

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