Tungsten carbide-cubic boron nitride composite powder and preparation method thereof, hard alloy composite material and cutting tool

Abstract

The invention discloses tungsten carbide-cubic boron nitride composite powder and a preparation method thereof, a hard alloy composite material and a cutting tool, and belongs to the field of hard alloy materials.The tungsten carbide-cubic boron nitride composite powder comprises tungsten carbide powder, a binder and modified cubic boron nitride powder; the modified cubic boron nitride powder comprises cubic boron nitride particles and a nanometer multilayer coating film located on the surfaces of the cubic boron nitride particles, and the nanometer multilayer coating film comprises a cobalt layer, a titanium carbide layer, a titanium nitride layer and the like, wherein the titanium carbide layer, the titanium nitride layer and the like are sequentially and alternately arranged on the surface of the cobalt layer. According to the tungsten carbide-cubic boron nitride composite powder provided by the invention, the comprehensive performance such as hardness, fracture toughness and high-temperature stability of a hard alloy composite material can be remarkably improved, so that the use requirements of the modern manufacturing industry on cutting tools are met, and the application prospect is wide.

Description

Technical Field

[0001] This application belongs to the field of cemented carbide materials, specifically relating to a tungsten carbide-cubic boron nitride composite powder and its preparation method, cemented carbide composite materials, and cutting tools. Background Technology

[0002] In the rapid development of modern manufacturing, cemented carbide materials and related products play a crucial role, especially those used in cutting tools. Their performance directly determines key indicators such as machining efficiency, machining accuracy, and product quality. Meanwhile, with the continuous advancement of industries such as aerospace, automotive manufacturing, and mold processing, increasingly stringent requirements are being placed on the performance of cutting tools. These tools not only need high hardness to handle various difficult-to-machine materials but also good fracture toughness to withstand complex and changing cutting conditions, thereby ensuring the stability and reliability of high-temperature cutting processes.

[0003] Therefore, it is particularly important to develop a cemented carbide composite material that combines high hardness, excellent fracture toughness, and high-temperature stability to meet the growing demand for cutting tools in modern manufacturing. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in related technologies. Therefore, the purpose of this application is to provide a tungsten carbide-cubic boron nitride composite powder and its preparation method, a cemented carbide composite material, and a cutting tool. The tungsten carbide-cubic boron nitride composite powder provided by this application can significantly improve the comprehensive properties of cemented carbide composite materials, such as hardness, fracture toughness, and high-temperature stability, thereby meeting the needs of modern manufacturing for cutting tools and showing broad application prospects.

[0005] The first aspect of this application discloses a tungsten carbide-cubic boron nitride composite powder. According to embodiments of this application, the tungsten carbide-cubic boron nitride composite powder comprises tungsten carbide powder, a binder, and modified cubic boron nitride powder; The modified cubic boron nitride powder includes cubic boron nitride particles and a nano-multilayer coating on the surface of the cubic boron nitride particles. The nano-multilayer coating includes a cobalt layer and titanium carbide and titanium nitride layers alternately disposed on the surface of the cobalt layer. The total thickness of the titanium carbide layer and the titanium nitride layer is 16-32 nm. The modified cubic boron nitride powder has a volume percentage of 20-45 vol.

[0006] The tungsten carbide-cubic boron nitride composite powder of the above embodiments of this application can significantly improve the comprehensive properties of cemented carbide composite materials, such as hardness, fracture toughness and high temperature stability, thereby meeting the needs of modern manufacturing for cutting tools and having broad application prospects.

[0007] In addition, the tungsten carbide-cubic boron nitride composite powder according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the particle size of the cubic boron nitride particles is 50-100 nm; And / or, the particle size of the tungsten carbide powder is 10-15 μm; And / or, the binder comprises cobalt powder with a particle size of 1.0-1.5 μm; And / or, the particle size of the tungsten carbide-cubic boron nitride composite powder is 50-80 μm.

[0008] In some embodiments of this application, the thickness of the cobalt layer is 30-50 nm; And / or, the thickness of the titanium carbide layer is 4-8 nm; And / or, the thickness of the titanium nitride layer is 4-8 nm.

[0009] In some embodiments of this application, the tungsten carbide powder accounts for 50-88% by volume percentage. And / or, by volume percentage, the adhesive accounts for 2-5 vol%.

[0010] The second aspect of this application provides a method for preparing the tungsten carbide-cubic boron nitride composite powder described in the first aspect above. According to embodiments of this application, the method for preparing the tungsten carbide-cubic boron nitride composite powder includes the following steps: A cobalt layer was deposited on the surface of cubic boron nitride by chemical plating, and then titanium carbide and titanium nitride layers were deposited alternately on the surface of the cobalt layer by chemical vapor deposition to obtain the modified cubic boron nitride powder. Tungsten carbide powder, binder and modified cubic boron nitride powder are mixed to obtain a mixture; Add dispersant and water to the mixture and stir to obtain a suspension; The suspension was spray-dried to obtain the tungsten carbide-cubic boron nitride composite powder.

[0011] The method for preparing tungsten carbide-cubic boron nitride composite powder according to the above embodiments of this application first forms a nano-multilayer coating structure on the surface of cubic boron nitride by electroless plating and chemical vapor deposition, which is beneficial to the interfacial compatibility of the two heterogeneous materials, cubic boron nitride and tungsten carbide. Subsequently, the raw materials are mixed and spray-dried to achieve the preparation of tungsten carbide-cubic boron nitride composite powder. The operation is simple, requires no additional specific equipment, and is suitable for industrial mass production.

[0012] In addition, the method for preparing tungsten carbide-cubic boron nitride composite powder according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the steps of depositing a cobalt layer on the surface of cubic boron nitride using chemical plating, followed by alternating deposition of titanium carbide and titanium nitride layers on the surface of the cobalt layer using chemical vapor deposition to obtain the modified cubic boron nitride powder include the following processes: The cubic boron nitride was placed in a cobalt sulfate solution and a sodium hypophosphite system and reacted for 20-40 minutes at a temperature of 70-90℃ and a pH of 8-10. After filtration, nano-cobalt plating intermediate powder was obtained. Under an inert gas atmosphere, the nano-cobalt-plated intermediate powder is annealed at 150-250°C for 0.5-2 hours to obtain cubic boron nitride containing a cobalt-plated layer. The modified cubic boron nitride powder is obtained by sequentially and alternately performing a first chemical vapor deposition and a second chemical vapor deposition on the surface of the cubic boron nitride containing the cobalt-plated layer. The working conditions for the first chemical vapor deposition include a temperature of 780-820°C and reaction gases including titanium tetrachloride and methane. The working conditions for the second chemical vapor deposition include a temperature of 780-820°C and reaction gases including titanium tetrachloride, nitrogen, and hydrogen. And / or, the dispersant comprises polyacrylic acid, and the concentration of the dispersant in the suspension is 2-5 mg / L; And / or, based on 100g of the mixture, the volume of water added is 75~90ml; And / or, the operating conditions of the spray dryer include: an inlet temperature of 180-220℃, an outlet temperature of 80-120℃, and an atomization pressure of 0.2-0.5MPa.

[0013] A third aspect of this application discloses a cemented carbide composite material. According to embodiments of this application, the cemented carbide composite material comprises the tungsten carbide-cubic boron nitride composite powder described in the first aspect, or tungsten carbide-cubic boron nitride composite powder prepared using the method described in the second aspect. This significantly improves the hardness, fracture toughness, and other properties of the cemented carbide composite material.

[0014] In addition, the cemented carbide composite material according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the method for preparing the cemented carbide composite material includes the following steps: The tungsten carbide-cubic boron nitride composite powder is pressed and molded to obtain a green body; The green body is subjected to vacuum heat treatment to obtain a preform; The preform is sintered to obtain the cemented carbide composite material.

[0015] In some embodiments of this application, the working conditions parameters for the compression molding include: cold isostatic pressing, pressure of 380-450 MPa, and holding time of 1.5-3 min; And / or, the working conditions parameters of the vacuum heat treatment include: temperature of 900-1000℃ and time of 1-2h; And / or, the working conditions parameters of the sintering treatment include: pressure of 4-5.5 GPa, temperature of 1300-1450℃, and time of 6-10 min.

[0016] A fourth aspect of this application discloses a cutting tool. According to embodiments of this application, the cutting tool comprises the tungsten carbide-cubic boron nitride composite powder described in the first aspect, tungsten carbide-cubic boron nitride composite powder prepared using the method described in the second aspect, or the cemented carbide composite material described in the third aspect. This significantly improves the service life and wear resistance of the cutting tool.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the process for preparing tungsten carbide-cubic boron nitride composite powder in the embodiments of this application.

[0019] Figure 2 This is a schematic diagram of the sintering assembly structure during the sintering process in the preparation of cemented carbide composite materials in the embodiments of this application.

[0020] Figure 3 This is a schematic diagram of the structure of the modified cubic boron nitride powder in the embodiments of this application.

[0021] Figure 4 The tool face wear diagram is for a cutting tool made using the cemented carbide composite material provided in Example 1 of this application.

[0022] Figure 5 This is a wear diagram of the cutting surface of a YG6 carbide insert.

[0023] Figure label: Figure 2 In the middle: 1-Pyrophyllite plugging ring, 2-Conductive graphite sheet, 3-Conductive steel ring, 4-Conductive metal sheet, 5-Pyrophyllite composite block, 6-Dolomite inner lining tube, 7-Insulation layer, 8-Conductive layer, 9-Insulating layer, 10-Crystal bed plate, 11-Pressure transfer plate, 12-Composite material growth reaction zone. Detailed Implementation

[0024] The embodiments of this application are described in detail below by way of example, and are intended to explain this application, but should not be construed as limiting this application.

[0025] Tungsten carbide (WC)-based cemented carbide is one of the most widely used cemented carbide materials. However, despite its advantages of low cost and good toughness, it is limited by its hardness and high-temperature resistance, making it difficult to handle high-speed precision machining of high-hardness materials. Cubic boron nitride (CBN), as an ultrahard material, can overcome the bottlenecks in hard material machining, but its high brittleness and cost prevent it from covering conventional roughing and low-cost machining scenarios. Therefore, the preparation of tungsten carbide-cubic boron nitride composites has gradually become a research hotspot in recent years. However, the hardness, fracture toughness, and stability under high-temperature conditions of existing tungsten carbide-cubic boron nitride-based cemented carbide composites need further improvement to meet the growing demands of modern manufacturing for cutting tools.

[0026] The first aspect of this application discloses a tungsten carbide-cubic boron nitride composite powder. According to embodiments of this application, the tungsten carbide-cubic boron nitride composite powder comprises tungsten carbide powder, a binder, and modified cubic boron nitride powder; The modified cubic boron nitride powder includes cubic boron nitride particles and a nano-multilayer coating on the surface of the cubic boron nitride particles. The nano-multilayer coating includes a cobalt layer and titanium carbide and titanium nitride layers alternately disposed on the surface of the cobalt layer. The total thickness of the titanium carbide layer and the titanium nitride layer is 16-32 nm. The modified cubic boron nitride powder has a volume percentage of 20-45 vol.

[0027] The tungsten carbide-cubic boron nitride composite powder of the above embodiments of this application can significantly improve the comprehensive properties of cemented carbide composite materials, such as hardness, fracture toughness, and high-temperature stability, thereby meeting the needs of modern manufacturing for cutting tools and showing broad application prospects. Specifically: On the one hand, by setting a specific nano-multilayer coating structure on the surface of cubic boron nitride powder, the cobalt layer in this nano-multilayer coating structure can adapt to the difference in thermal expansion coefficients between cubic boron nitride and tungsten carbide substrates. By alleviating the thermal stress caused by the mismatch in thermal expansion characteristics between the two, it can effectively avoid cracks caused by stress concentration during subsequent sintering and cooling, thus ensuring the structural integrity of the sintered body. On the other hand, by alternately setting titanium carbide and titanium nitride layers on the surface of the cobalt layer and controlling the thickness of the titanium carbide and titanium nitride layers in the coating, as well as the amount of modified cubic boron nitride powder, it can not only significantly improve the interfacial compatibility between cubic boron nitride and tungsten carbide, further improving the hardness and fracture toughness of the cemented carbide composite material, but also effectively suppress the high-temperature softening phenomenon of Co element in the cobalt layer, improving the high-temperature stability of the cemented carbide composite material, thereby meeting the requirements for use under high-temperature conditions.

[0028] In the embodiments of this application, the total thickness of the titanium carbide layer and the titanium nitride layer is controlled within 16-32 nm, which is beneficial to improving the comprehensive properties of the cemented carbide composite material, such as hardness and fracture toughness. Specifically, it can be 16 nm, 20 nm, 24 nm, 28 nm, 32 nm, or any value between any two of the above. If the total thickness of the titanium carbide layer and the titanium nitride layer is too thick, microcracks will appear at the interface due to thermal stress, reducing fracture toughness. In addition, the thickness of both the titanium carbide layer and the titanium nitride layer can be measured using existing detection methods such as electron microscopy.

[0029] In the embodiments of this application, the amount of the modified cubic boron nitride powder is controlled within 20-45 vol%, which is beneficial to improving the comprehensive properties of the cemented carbide composite material, such as hardness and fracture toughness. Specifically, it can be 20 vol%, 30 vol%, 40 vol%, 45 vol%, or any value between any two of the above. If the amount of modified cubic boron nitride powder is too large, it will hinder the continuity of the binder phase and weaken the fracture toughness.

[0030] According to some specific embodiments of this application, the particle size of the cubic boron nitride particles is 50-100 nm, for example, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm or any range between any two of the above values; and / or, the particle size of the tungsten carbide powder is 10-15 μm, for example, 10 μm, 12 μm, 15 μm or any range between any two of the above values; and / or, the binder includes cobalt powder with a particle size of 1.0-1.5 μm, for example, 0.5 μm, 1.0 μm, 1.5 μm or any range between any two of the above values; and / or, the particle size of the tungsten carbide-cubic boron nitride composite powder is 50-80 μm, for example, 55 μm, 65 μm, 75 μm or any range between any two of the above values. Therefore, by using cubic boron nitride particles, tungsten carbide powder, and binders in combination within different particle size ranges to form a mixture with gradient particle sizes, it is beneficial to improve the compactness of the tungsten carbide-cubic boron nitride composite powder. Furthermore, the aforementioned particle sizes can all be determined using existing detection methods such as laser diffraction.

[0031] According to some specific embodiments of this application, the thickness of the cobalt layer is 30-50 nm, for example, 35 nm, 45 nm, 50 nm, or any value between two of the above; and / or, the thickness of the titanium carbide layer is 4-8 nm, for example, 5 nm; and / or, the thickness of the titanium nitride layer is 4-8 nm, for example, 5 nm. Thus, by sequentially setting cobalt-titanium carbide / titanium nitride alternating layers on the surface of cubic boron nitride particles, this application not only alleviates the thermal stress caused by the mismatch in thermal expansion characteristics between cubic boron nitride and tungsten carbide, but also effectively suppresses the high-temperature softening phenomenon of Co element in the cobalt layer, thereby effectively improving the high-temperature stability and fracture toughness of the cemented carbide composite material. Furthermore, the above thicknesses can all be measured using existing detection methods such as electron microscopy; and the number of alternating titanium carbide and titanium nitride layers on the cobalt layer surface can be multiple, such as two layers of each.

[0032] According to some specific embodiments of this application, the volume percentage of the tungsten carbide powder is 50-88 vol%, for example, 50 vol%, 60 vol%, 65 vol%, 70 vol%, 75 vol%, or any range between the above two values; and / or, the volume percentage of the binder is 2-5 vol%, for example, 2 vol%, 3 vol%, 4.5 vol%, 5 vol%, or any range between the above two values. Therefore, the proportion of each component in the tungsten carbide-cubic boron nitride composite powder improved by this application is appropriate, which is beneficial to improving the overall comprehensive performance of the tungsten carbide-cubic boron nitride composite powder.

[0033] The second aspect of this application discloses a method for preparing the tungsten carbide-cubic boron nitride composite powder described in the first aspect above. According to embodiments of this application, such as... Figure 1 As shown, the preparation method of the tungsten carbide-cubic boron nitride composite powder includes the following steps: A cobalt layer was deposited on the surface of cubic boron nitride by chemical plating, and then titanium carbide and titanium nitride layers were deposited alternately on the surface of the cobalt layer by chemical vapor deposition to obtain the modified cubic boron nitride powder. Tungsten carbide powder, binder and modified cubic boron nitride powder are mixed to obtain a mixture; Add dispersant and water to the mixture and stir to obtain a suspension; The suspension was spray-dried to obtain the tungsten carbide-cubic boron nitride composite powder.

[0034] The method for preparing tungsten carbide-cubic boron nitride composite powder according to the above embodiments of this application first forms a nano-multilayer coating structure on the surface of cubic boron nitride by electroless plating and chemical vapor deposition, which is beneficial to the interfacial compatibility of the two heterogeneous materials, cubic boron nitride and tungsten carbide. Subsequently, the raw materials are mixed and spray-dried to achieve the preparation of tungsten carbide-cubic boron nitride composite powder. The operation is simple, requires no additional specific equipment, and is suitable for industrial mass production.

[0035] According to some specific embodiments of this application, the modified cubic boron nitride powder is obtained by electroless plating to deposit a cobalt layer on the surface of cubic boron nitride, followed by alternating deposition of titanium carbide and titanium nitride layers on the surface of the cobalt layer using chemical vapor deposition. The process includes the following steps: placing the cubic boron nitride in a cobalt sulfate solution and sodium hypophosphite system, and reacting it for 20-40 minutes at a temperature of 70-90℃ (e.g., 75℃, 80℃, 85℃, etc.) and a pH of 8-10 (e.g., 7.5, 9.0, 9.5, etc.). (e.g., for 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.) Filter to obtain nano-cobalt-plated intermediate powder; anneal the nano-cobalt-plated intermediate powder at 150-250℃ for 0.5-2 hours in an inert gas atmosphere to obtain cubic boron nitride containing a cobalt-plated layer; sequentially and alternately perform first chemical vapor deposition and second chemical vapor deposition on the surface of the cubic boron nitride containing the cobalt-plated layer to obtain the modified cubic boron nitride powder; wherein the working conditions parameters for the first chemical vapor deposition include: temperature 780-820℃. (e.g., 790℃, 800℃, 810℃, etc.), the reactant gases include titanium tetrachloride and methane; the operating conditions for the second chemical vapor deposition include: a temperature of 780-820℃ (e.g., 790℃, 800℃, 810℃, etc.), reactant gases including titanium tetrachloride, nitrogen, and hydrogen; and / or, the dispersant includes polyacrylic acid, and the concentration of the dispersant in the suspension is 2~5 mg / L (e.g., 2 mg / L, 3 mg / L, 4 mg / L, 5 mg / L, etc.); / or, using 100g of the mixture The volume of water added is 75-90 ml (e.g., 80 ml, 85 ml, 90 ml, etc.); and / or, the operating conditions of the spray drying include: an inlet temperature of 180-220℃ (e.g., 185℃, 190℃, 195℃, 215℃, etc.), an outlet temperature of 80-120℃ (e.g., 85℃, 90℃, 95℃, 105℃, 110℃, etc.), and an atomization pressure of 0.2-0.5 MPa (e.g., 0.2 MPa, 0.3 MPa, 0.5 MPa, etc.). Thus, this application prepares modified cubic boron nitride powder, and through appropriate dispersant concentration and spray parameters, ensures uniform powder composition and no segregation, which is beneficial for improving the flowability and density of the tungsten carbide-cubic boron nitride composite powder. Furthermore, the conditions and parameters in the above-mentioned electroless plating and chemical vapor deposition that are not specifically limited or described can be carried out according to the existing conventional processes in the field, as long as the preset coating thickness is achieved.

[0036] A third aspect of this application discloses a cemented carbide composite material. According to embodiments of this application, the cemented carbide composite material comprises the tungsten carbide-cubic boron nitride composite powder described in the first aspect, or tungsten carbide-cubic boron nitride composite powder prepared using the method described in the second aspect. This significantly improves the hardness, fracture toughness, and other properties of the cemented carbide composite material.

[0037] According to some specific embodiments of this application, the preparation method of the cemented carbide composite material includes the following steps: pressing the tungsten carbide-cubic boron nitride composite powder into a green blank; subjecting the green blank to vacuum heat treatment to obtain a preform; and sintering the preform to obtain the cemented carbide composite material. Specifically, in actual operation, the above-mentioned cemented carbide composite material can be prepared using existing publicly available preparation processes in combination with conventional equipment. For example, during pressing, the tungsten carbide-cubic boron nitride composite powder can be placed in a container such as a molybdenum cup and pressed to form a metal box-shaped green blank; furthermore, during vacuum heat treatment, the green blank can be placed in a high-temperature vacuum furnace, such as an ultimate vacuum of 1×10⁻⁶. -3 Vacuum heat treatment under vacuum conditions such as Pa effectively removes organic residues and activates the powder surface, serving as a vacuum purification process. This provides a preform with high purity and high reactivity for subsequent high-pressure sintering. Alternatively, during sintering, equipment such as a six-sided press high-temperature and high-pressure device can be used. The vacuum-heat-treated preform is assembled according to conventional high-temperature and high-pressure sintering assembly structures in the field and sintered within the six-sided press high-temperature and high-pressure device. This allows the preform to complete sintering and forming within the growth reaction zone of the six-sided press high-temperature and high-pressure device, resulting in a hard alloy composite material. A schematic diagram of the sintering assembly structure is shown below. Figure 2 ( Figure 2The structure, as shown in the diagram, consists of: 1-pyrophyllite plugging ring, 2-conductive graphite sheet, 3-conductive steel ring, 4-conductive metal sheet, 5-pyrophyllite composite block, 6-dolomite liner tube, 7-insulation layer, 8-conductive layer, 9-insulating layer, 10-crystal bed plate, 11-pressure transmitting plate, 12-composite material growth reaction zone). Along the radial direction from the outer layer to the inner layer, the sintered assembly structure is arranged as follows: a pyrophyllite composite block with a hollow cylindrical cavity for pressure transmission and sealing; a dolomite liner tube with a tightly fitted hollow cylindrical inner hole of the pyrophyllite composite block for heat insulation and pressure transmission; and an insulation layer tightly fitted to the inner hole of the dolomite liner tube. Typically, the structure consists of zirconium oxide, a conductive graphite tube tightly fitted to the inner pores of the insulation layer, and an insulating layer, typically magnesium oxide, tightly fitted to the inner pores of the conductive layer. Along the axial direction from the outer layer to the inner layer, the sintered assembly structure is symmetrically arranged at both ends of a hollow cylindrical cavity in pyrophyllite: a conductive steel ring connecting the top hammer and the composite block circuitry, a conductive metal sheet fitted to the conductive steel ring, a conductive graphite sheet fitted to the conductive metal sheet, a pyrophyllite plugging ring surrounding the conductive metal sheet and the conductive graphite sheet, and a pressure-transmitting sheet fitted to the conductive graphite sheet, typically made of dolomite. The insulation layer and the pressure-transmitting layer together form a growth reaction zone for the composite material. This composite material is located within the growth reaction zone of the device. Externally, the device, along with the top hammer and a six-sided press, applies high-temperature and high-pressure conditions to the composite material, causing it to sinter and achieve high densification.

[0038] According to some specific embodiments of this application, the working conditions parameters for the pressing molding include: cold isostatic pressing, a pressure of 380-450 MPa (e.g., 380 MPa, 400 MPa, 410 MPa, 420 MPa, 435 MPa, 450 MPa, etc.), and a holding time of 1.5-3 min (e.g., 1.5 min, 2 min, 2.5 min, 3 min, etc.); and / or, the working conditions parameters for the vacuum heat treatment include: a temperature of The sintering temperature is 900-1000℃ (e.g., 900℃, 950℃, 1000℃, etc.), and the time is 1-2h (e.g., 1h, 1.5h, 2h, etc.); and / or, the working conditions of the sintering treatment include: pressure of 4-5.5GPa (e.g., 4GPa, 4.5GPa, 5.0GPa, 5.5GPa, etc.), temperature of 1300-1450℃ (e.g., 1300℃, 1350℃, 1400℃, 1450℃, etc.), and time of 6-10 min (e.g., 6 min, 8 min, 10 min, etc.). Therefore, this application achieves the preparation of cemented carbide composite materials under the above working conditions.

[0039] A fourth aspect of this application discloses a cutting tool. According to embodiments of this application, the cutting tool comprises the tungsten carbide-cubic boron nitride composite powder described in the first aspect, tungsten carbide-cubic boron nitride composite powder prepared using the method described in the second aspect, or the cemented carbide composite material described in the third aspect. This significantly improves the service life and wear resistance of the cutting tool.

[0040] The embodiments of this application are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0041] Example 1 This embodiment provides a tungsten carbide-cubic boron nitride composite powder. By volume fraction, the tungsten carbide-cubic boron nitride composite powder comprises: 30 vol% modified cubic boron nitride powder, which includes cubic boron nitride particles with a particle size of 50-100 nm (D50=80 nm), and a cobalt layer with a thickness of 40 nm and alternating titanium carbide and titanium nitride layers (specifically, sequentially, a titanium carbide layer with a thickness of 5 nm, a titanium nitride layer with a thickness of 5 nm, a titanium carbide layer with a thickness of 5 nm, and a titanium nitride layer with a thickness of 5 nm, for a total thickness of 20 nm) on the surface of the cubic boron nitride particles. Figure 3 As shown; the binder is 5 vol%, specifically cobalt powder with a particle size of 1.0 μm; tungsten carbide powder is 65 vol%, 15 μm.

[0042] This example also applies the above-mentioned tungsten carbide-cubic boron nitride composite powder to the preparation of cemented carbide composite materials, including the following steps: Step 1. Cobalt layer is deposited on the surface of cubic boron nitride using chemical plating: CBN powder (i.e., cubic boron nitride powder) with a particle size of 50-100nm (D50=80nm) and a purity ≥99.9% is used. In a cobalt sulfate solution (concentration 0.1mol / L) and sodium hypophosphite (concentration 0.3mol / L) reducing agent system, the powder is reacted at 80±2℃ and pH=9 (adjusted with ammonia) for 30 minutes to form a uniform cobalt layer of 40nm. In the post-treatment stage, the powder is annealed at 200℃ for 1 hour under nitrogen protection to obtain cubic boron nitride containing the cobalt layer.

[0043] Step 2. Deposition of TiC / TiN (titanium carbide / titanium nitride) alternating multilayer coatings using chemical vapor deposition: Cubic boron nitride containing a cobalt layer is placed in a CVD furnace. A mixture of TiCl4, CH4, and N2 / H2 gases is introduced as needed, with the following gas purity: TiCl4 purity ≥ 99.99%, and the purity of CH4, N2, and H2 all ≥ 99.999%. Deposition is performed at 800℃, with the following steps: First, a 5nm TiC layer is deposited (reaction gas: TiCl4 + CH4); then a 5nm TiN layer is deposited (reaction gas: TiCl4 + N2 / H2); after deposition, the layer is rapidly cooled (10℃ / min) to room temperature to avoid interlayer diffusion; the above steps are repeated to form a 20nm thick alternating multilayer of titanium carbide / titanium nitride.

[0044] Step 3. Preparation of tungsten carbide-cubic boron nitride composite powder by spray drying: Modified cubic boron nitride powder (30 vol%, particle size 50-100 nm), tungsten carbide powder (65 vol%, 15 μm), and cobalt powder binder (5 vol%, 1 μm) were weighed and mixed in proportion. Polyacrylic acid dispersant (3 mg / L) and deionized water (80 ml / 100 g powder) were added, and the mixture was ultrasonically stirred for 30 minutes to form a uniform suspension. Subsequently, a centrifugal spray dryer was used to dry the powder under the conditions of inlet temperature 200 ± 5 ℃, outlet temperature 100 ± 5 ℃, atomization pressure 0.3 MPa, and feed rate 10 ml / min to obtain spherical tungsten carbide-cubic boron nitride composite powder with a particle size of 50-80 μm (D50=65 μm).

[0045] Step 4. Pressing and molding: The tungsten carbide-cubic boron nitride composite powder is loaded into a molybdenum cup and cold isostatically pressed under a pressure of 400MPa for 2 minutes to obtain a metal box-shaped green blank with a density of 68% of the theoretical density.

[0046] Step 5. Vacuum heat treatment: Place the pressed green body in a high-temperature vacuum furnace and heat it under an ultimate vacuum of 1×10⁻⁶. -3 Under Pa conditions, the temperature is increased to 950℃ at a heating rate of 5℃ / min and held for 1 hour to complete the vacuum heat treatment and obtain the preform.

[0047] Step 6. Assembly and high-temperature high-pressure sintering of sintered blocks: The preform is assembled with pyrophyllite, dolomite, zirconia tubes, graphite sheets, etc. into a synthetic sintered block. The block is then sintered using a six-sided top press high-temperature high-pressure device at a sintering pressure of 5 GPa, a temperature of 1400℃, and a holding time of 8 minutes to form a hard alloy composite material.

[0048] Example 2 This embodiment provides a tungsten carbide-cubic boron nitride composite powder and a cemented carbide composite material, which differs from Embodiment 1 only in that: (1) The total thickness of the alternating titanium carbide and titanium nitride layers in the modified cubic boron nitride powder is 32 nm, specifically in the order of titanium carbide layer with a thickness of 8 nm, titanium nitride layer with a thickness of 8 nm, titanium carbide layer with a thickness of 8 nm, and titanium nitride layer with a thickness of 8 nm.

[0049] Example 3 This embodiment provides a tungsten carbide-cubic boron nitride composite powder and a cemented carbide composite material, which differs from Embodiment 1 only in that: (1) By volume fraction, the tungsten carbide-cubic boron nitride composite powder comprises: 40 vol% modified cubic boron nitride powder, 5 vol% binder, and 55 vol% tungsten carbide powder.

[0050] Example 4 This embodiment provides a tungsten carbide-cubic boron nitride composite powder and a cemented carbide composite material, which differs from Embodiment 1 only in that: (1) The total thickness of the alternating titanium carbide and titanium nitride layers in the modified cubic boron nitride powder is 24 nm, specifically in the order of titanium carbide layer with a thickness of 6 nm, titanium nitride layer with a thickness of 6 nm, titanium carbide layer with a thickness of 6 nm, and titanium nitride layer with a thickness of 6 nm. (2) By volume fraction, the tungsten carbide-cubic boron nitride composite powder comprises: 35 vol% modified cubic boron nitride powder, 5 vol% binder, and 60 vol% tungsten carbide powder.

[0051] Example 5 This embodiment provides a tungsten carbide-cubic boron nitride composite powder, which, by volume fraction, comprises: 20 vol% modified cubic boron nitride powder, which includes cubic boron nitride particles with a particle size of 50-100 nm (D50=80 nm), and a cobalt layer with a thickness of 30 nm and alternating titanium carbide and titanium nitride layers (specifically, a titanium carbide layer with a thickness of 4 nm, a titanium nitride layer with a thickness of 4 nm, a titanium carbide layer with a thickness of 4 nm, and a titanium nitride layer with a thickness of 4 nm, for a total thickness of 16 nm) sequentially disposed on the surface of the cubic boron nitride particles; 2 vol% binder, specifically cobalt powder with a particle size of 1.5 μm; and 88 vol% tungsten carbide powder with a particle size of 10 μm.

[0052] This example also applies the above-mentioned tungsten carbide-cubic boron nitride composite powder to the preparation of cemented carbide composite materials, including the following steps: Step 1. Cobalt layer is deposited on the surface of cubic boron nitride using chemical plating: CBN powder (i.e., cubic boron nitride powder) with a particle size of 50-100nm (D50=80nm) and a purity ≥99.9% is used. In a cobalt sulfate solution (concentration 0.1mol / L) and sodium hypophosphite (concentration 0.3mol / L) reducing agent system, the powder is reacted at 70℃ and pH=8 (adjusted with ammonia) for 20 minutes to form a uniform cobalt layer of 30nm. In the post-treatment stage, the powder is annealed at 250℃ for 0.5 hours under nitrogen protection to obtain cubic boron nitride containing the cobalt layer.

[0053] Step 2. Deposition of TiC / TiN (titanium carbide / titanium nitride) alternating multilayer coatings using chemical vapor deposition: Cubic boron nitride containing a cobalt layer is placed in a CVD furnace. A mixture of TiCl4, CH4, and N2 / H2 gases is introduced as needed, with the following gas purity: TiCl4 purity ≥ 99.99%, and the purity of CH4, N2, and H2 all ≥ 99.999%. Deposition is performed at 800℃, with the following steps: First, a 4nm TiC layer is deposited (reaction gas: TiCl4 + CH4); then a 4nm TiN layer is deposited (reaction gas: TiCl4 + N2 / H2); after deposition, the layer is rapidly cooled (10℃ / min) to room temperature to avoid interlayer diffusion; the above steps are repeated to form a 16nm thick alternating multilayer titanium carbide / titanium nitride coating.

[0054] Step 3. Preparation of tungsten carbide-cubic boron nitride composite powder by spray drying: Modified cubic boron nitride powder, tungsten carbide powder, and cobalt powder binder are weighed and mixed in proportion, and polyacrylic acid dispersant (2 mg / L) and deionized water (75 ml / 100 g powder) are added. The mixture is ultrasonically stirred for 30 minutes to form a uniform suspension. Subsequently, a centrifugal spray dryer is used to dry the powder under the conditions of inlet temperature 180℃, outlet temperature 80℃, atomization pressure 0.2 MPa, and feed rate 10 ml / min to obtain spherical tungsten carbide-cubic boron nitride composite powder.

[0055] Step 4. Pressing: The tungsten carbide-cubic boron nitride composite powder is loaded into a molybdenum cup and cold isostatically pressed at 380 MPa for 3 minutes to obtain a metal box-shaped green blank.

[0056] Step 5. Vacuum heat treatment: Place the pressed green body in a high-temperature vacuum furnace and heat it under an ultimate vacuum of 1×10⁻⁶. -3 Under Pa conditions, the temperature is increased to 900℃ at a heating rate of 5℃ / min and held for 2 hours to complete the vacuum heat treatment and obtain the preform.

[0057] Step 6. Assembly and high-temperature high-pressure sintering of sintered blocks: The preform is assembled with pyrophyllite, dolomite, zirconia tubes, graphite sheets, etc. into a synthetic sintered block. The block is then sintered using a six-sided top press high-temperature high-pressure device at a sintering pressure of 4 GPa, a temperature of 1450℃, and a holding time of 10 minutes to obtain a hard alloy composite material.

[0058] Example 6 This embodiment provides a tungsten carbide-cubic boron nitride composite powder, which, by volume fraction, comprises: 45 vol% modified cubic boron nitride powder, which includes cubic boron nitride particles with a particle size of 50-100 nm (D50=80 nm), and a cobalt layer with a thickness of 50 nm and alternating titanium carbide and titanium nitride layers (specifically, a titanium carbide layer with a thickness of 6 nm, a titanium nitride layer with a thickness of 6 nm, a titanium carbide layer with a thickness of 6 nm, and a titanium nitride layer with a thickness of 6 nm, for a total thickness of 24 nm) sequentially disposed on the surface of the cubic boron nitride particles; 5 vol% binder, specifically cobalt powder with a particle size of 1.0 μm; and 50 vol% tungsten carbide powder with a particle size of 15 μm.

[0059] This example also applies the above-mentioned tungsten carbide-cubic boron nitride composite powder to the preparation of cemented carbide composite materials, including the following steps: Step 1. Cobalt layer is deposited on the surface of cubic boron nitride using chemical plating: CBN powder (i.e., cubic boron nitride powder) with a particle size of 50-100nm (D50=80nm) and a purity ≥99.9% is used. In a cobalt sulfate solution (concentration 0.1mol / L) and sodium hypophosphite (concentration 0.3mol / L) reducing agent system, the powder is reacted at 90℃ and pH=10 (adjusted with ammonia) for 40 minutes to form a uniform cobalt layer of 50nm. In the post-treatment stage, the powder is annealed at 150℃ for 2 hours under nitrogen protection to obtain cubic boron nitride containing the cobalt layer.

[0060] Step 2. Deposition of TiC / TiN (titanium carbide / titanium nitride) alternating multilayer coatings using chemical vapor deposition: Cubic boron nitride containing a cobalt layer is placed in a CVD furnace. A mixture of TiCl4, CH4, and N2 / H2 gases is introduced as needed, with the following gas purity: TiCl4 purity ≥ 99.99%, and the purity of CH4, N2, and H2 all ≥ 99.999%. Deposition is performed at 800℃, with the following steps: First, a 6nm TiC layer is deposited (reaction gas: TiCl4 + CH4); then a 6nm TiN layer is deposited (reaction gas: TiCl4 + N2 / H2); after deposition, the layer is rapidly cooled (10℃ / min) to room temperature to avoid interlayer diffusion; the above steps are repeated to form a 24nm thick alternating multilayer titanium carbide / titanium nitride coating.

[0061] Step 3. Preparation of tungsten carbide-cubic boron nitride composite powder by spray drying: Modified cubic boron nitride powder, tungsten carbide powder, and cobalt powder binder are weighed and mixed in proportion, and polyacrylic acid dispersant (5 mg / L) and deionized water (90 ml / 100 g powder) are added. The mixture is ultrasonically stirred for 30 minutes to form a uniform suspension. Subsequently, a centrifugal spray dryer is used to dry the powder under the conditions of inlet temperature 220℃, outlet temperature 120℃, atomization pressure 0.5 MPa, and feed rate 10 ml / min to obtain spherical tungsten carbide-cubic boron nitride composite powder.

[0062] Step 4. Pressing: The tungsten carbide-cubic boron nitride composite powder is loaded into a molybdenum cup and cold isostatically pressed at 450 MPa for 1.5 minutes to obtain a metal box-shaped green blank.

[0063] Step 5. Vacuum heat treatment: Place the pressed green body in a high-temperature vacuum furnace and heat it under an ultimate vacuum of 1×10⁻⁶. -3 Under Pa conditions, the temperature is increased to 1000℃ at a heating rate of 5℃ / min and held for 1 hour to complete the vacuum heat treatment and obtain the preform.

[0064] Step 6. Assembly and high-temperature high-pressure sintering of sintered blocks: The preform is assembled with pyrophyllite, dolomite, zirconia tubes, graphite sheets, etc. into a synthetic sintered block. The block is then sintered using a six-sided top press high-temperature high-pressure device at a sintering pressure of 5.5 GPa, a temperature of 1350℃, and a holding time of 6 minutes to form a hard alloy composite material.

[0065] Comparative Example 1 This comparative example provides a tungsten carbide-cubic boron nitride composite powder and a cemented carbide composite material, which differs from Example 1 only in that: (1) By volume fraction, the tungsten carbide-cubic boron nitride composite powder comprises: 55 vol% modified cubic boron nitride powder, 5 vol% binder, and 40 vol% tungsten carbide powder.

[0066] Comparative Example 2 This comparative example provides a tungsten carbide-cubic boron nitride composite powder and a cemented carbide composite material, which differs from Example 1 only in that: (1) The total thickness of the alternating titanium carbide and titanium nitride layers in the modified cubic boron nitride powder is 40 nm, specifically in the order of titanium carbide layer with a thickness of 10 nm, titanium nitride layer with a thickness of 10 nm, titanium carbide layer with a thickness of 10 nm, and titanium nitride layer with a thickness of 10 nm.

[0067] Comparative Example 3 This comparative example provides a tungsten carbide-cubic boron nitride composite powder and a cemented carbide composite material, which differs from Example 1 only in that: (1) Only a cobalt layer with a thickness of 40 nm is set on the surface of the modified cubic boron nitride powder (i.e., no alternating multilayer of titanium carbide / titanium nitride with a total thickness of 20 nm is set).

[0068] Comparative Example 4 This comparative example provides an existing cemented carbide composite material, specifically YG6 cemented carbide.

[0069] Test Example 1 This test example performs performance tests on the cemented carbide composite materials obtained in the above embodiments and comparative examples; the hardness is measured using a Vickers hardness tester, and the fracture toughness is tested using a standard three-point bending test specimen and a universal testing machine.

[0070] The test results are shown in Table 1.

[0071] Table 1

[0072] As shown in Table 1: 1) Compared with comparative examples 1 to 4, the cemented carbide composite materials provided in Examples 1 to 6 of this application are superior in terms of hardness and fracture toughness.

[0073] 2) The test results of Example 1 and Comparative Example 1 show that when the amount of modified cubic boron nitride powder in the tungsten carbide-cubic boron nitride composite powder is too large, it will hinder the continuity of the binder phase, weaken the fracture toughness, and reduce the performance of the resulting cemented carbide composite material.

[0074] 3) The test results of Example 1 and Comparative Example 2 show that when the total thickness of the titanium carbide layer and the titanium nitride layer is too thick, microcracks will appear at the interface due to thermal stress, which will reduce the fracture toughness and reduce the performance of the resulting cemented carbide composite material.

[0075] 4) The test results of Example 1 and Comparative Example 3 show that the performance of the obtained cemented carbide composite material is reduced when the surface of the modified cubic boron nitride powder is not provided with alternating layers of titanium carbide / titanium nitride.

[0076] Test Example 2 This test example demonstrates the high-temperature resistance of the cemented carbide composite materials obtained in the above embodiments and comparative examples.

[0077] The test method is as follows: Referring to GB / T 4342-1991 Metal Micro Vickers Hardness Test Method, the sample is kept at a specified high temperature for 1 hour, then cooled to room temperature, and its hardness retention rate (hardness after high temperature / initial hardness × 100%) is measured, and the surface morphology is observed.

[0078] The test results are shown in Table 2.

[0079] Table 2

[0080] As shown in Table 2: The embodiments of the present invention exhibit a much better hardness retention rate than conventional YG6 alloys at high temperatures. At 800°C, the hardness retention rate of Example 1 reaches 84%, while that of Comparative Example 4 is only 56.7%, showing a drastic performance degradation.

[0081] The high-temperature performance of Comparative Example 3 (without TiC / TiN coating) decreased significantly, which directly proves that the TiC / TiN nano-multilayer coating acts as a "barrier" to effectively inhibit the diffusion, oxidation and softening of the Co binder phase at high temperatures, and is a key structure for improving the high-temperature stability of the material.

[0082] Test Example 3 In this test example, the cemented carbide composite materials provided in Example 1 and Comparative Example 4 were used to make cutting inserts for cutting wear resistance testing.

[0083] Test method: Gray cast iron bars were used as the cutting object. YG6 cemented carbide inserts made of cemented carbide composite material provided in Comparative Example 4 and cutting inserts made of cemented carbide composite material provided in Example 1 were used as cutting tools to conduct cutting performance tests. The hardness of the gray cast iron bar workpiece was 180HB. The machining parameters were: depth of cut 0.3mm, linear speed 600m / min, and feed 0.2mm / r.

[0084] The cutting wear resistance test results show that the cutting edge wear of the cutting insert made of the cemented carbide composite material provided in Example 1 is 0.35 mm (e.g., ...). Figure 4 As shown), the face wear of the YG6 carbide insert is 0.98mm (as shown). Figure 5 (As shown). This demonstrates that the wear resistance of the cemented carbide composite material prepared in this embodiment is significantly improved compared to the wear resistance of YG6 cemented carbide cutting tools.

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0086] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A tungsten carbide-cubic boron nitride composite powder, characterized in that, Includes tungsten carbide powder, binder, and modified cubic boron nitride powder; The modified cubic boron nitride powder includes cubic boron nitride particles and a nano-multilayer coating on the surface of the cubic boron nitride particles. The nano-multilayer coating includes a cobalt layer and titanium carbide and titanium nitride layers alternately disposed on the surface of the cobalt layer. The total thickness of the titanium carbide layer and the titanium nitride layer is 16-32 nm. The modified cubic boron nitride powder has a volume percentage of 20-45 vol.

2. The tungsten carbide-cubic boron nitride composite powder according to claim 1, characterized in that, The cubic boron nitride particles have a particle size of 50-100 nm; And / or, the particle size of the tungsten carbide powder is 10-15 μm; And / or, the binder comprises cobalt powder with a particle size of 1.0-1.5 μm; And / or, the particle size of the tungsten carbide-cubic boron nitride composite powder is 50-80 μm.

3. The tungsten carbide-cubic boron nitride composite powder according to claim 1, characterized in that, The thickness of the cobalt layer is 30-50 nm; And / or, the thickness of the titanium carbide layer is 4-8 nm; And / or, the thickness of the titanium nitride layer is 4-8 nm.

4. The tungsten carbide-cubic boron nitride composite powder according to claim 1, characterized in that, The tungsten carbide powder has a volume percentage of 50-88 vol%. And / or, by volume percentage, the adhesive accounts for 2-5 vol%.

5. A method for preparing tungsten carbide-cubic boron nitride composite powder according to any one of claims 1 to 4, characterized in that, The preparation method of the tungsten carbide-cubic boron nitride composite powder includes the following steps: A cobalt layer was deposited on the surface of cubic boron nitride by chemical plating, and then titanium carbide and titanium nitride layers were deposited alternately on the surface of the cobalt layer by chemical vapor deposition to obtain the modified cubic boron nitride powder. Tungsten carbide powder, binder and modified cubic boron nitride powder are mixed to obtain a mixture; Add dispersant and water to the mixture and stir to obtain a suspension; The suspension was spray-dried to obtain the tungsten carbide-cubic boron nitride composite powder.

6. The method for preparing tungsten carbide-cubic boron nitride composite powder according to claim 5, characterized in that, The modified cubic boron nitride powder is obtained by electroless plating to deposit a cobalt layer on the surface of cubic boron nitride, followed by alternating deposition of titanium carbide and titanium nitride layers on the cobalt layer surface using chemical vapor deposition. Includes the following processes: The cubic boron nitride was placed in a cobalt sulfate solution and a sodium hypophosphite system and reacted for 20-40 minutes at a temperature of 70-90℃ and a pH of 8-10. After filtration, nano-cobalt plating intermediate powder was obtained. Under an inert gas atmosphere, the nano-cobalt-plated intermediate powder is annealed at 150-250°C for 0.5-2 hours to obtain cubic boron nitride containing a cobalt-plated layer. The modified cubic boron nitride powder is obtained by sequentially and alternately performing a first chemical vapor deposition and a second chemical vapor deposition on the surface of the cubic boron nitride containing the cobalt-plated layer. The working conditions for the first chemical vapor deposition include a temperature of 780-820°C and reaction gases including titanium tetrachloride and methane. The working conditions for the second chemical vapor deposition include a temperature of 780-820°C and reaction gases including titanium tetrachloride, nitrogen, and hydrogen. And / or, the dispersant comprises polyacrylic acid, and the concentration of the dispersant in the suspension is 2-5 mg / L; And / or, based on 100g of the mixture, the volume of water added is 75~90ml; And / or, the operating conditions of the spray dryer include: an inlet temperature of 180-220℃, an outlet temperature of 80-120℃, and an atomization pressure of 0.2-0.5MPa.

7. A cemented carbide composite material, characterized in that, The cemented carbide composite material includes the tungsten carbide-cubic boron nitride composite powder according to any one of claims 1 to 4, or the tungsten carbide-cubic boron nitride composite powder prepared by the method of preparing tungsten carbide-cubic boron nitride composite powder according to any one of claims 5 to 6.

8. The cemented carbide composite material according to claim 7, characterized in that, The preparation method of the cemented carbide composite material includes the following steps: The tungsten carbide-cubic boron nitride composite powder is pressed and molded to obtain a green body; The green body is subjected to vacuum heat treatment to obtain a preform; The preform is sintered to obtain the cemented carbide composite material.

9. The cemented carbide composite material according to claim 8, characterized in that, The working conditions parameters for the compression molding include: cold isostatic pressing, pressure of 380-450MPa, and holding time of 1.5-3min. And / or, the working conditions parameters of the vacuum heat treatment include: temperature of 900-1000℃ and time of 1-2h; And / or, the working conditions parameters of the sintering treatment include: pressure of 4-5.5 GPa, temperature of 1300-1450℃, and time of 6-10 min.

10. A cutting tool, characterized in that, The cutting tool includes the tungsten carbide-cubic boron nitride composite powder according to any one of claims 1 to 4, the tungsten carbide-cubic boron nitride composite powder prepared by the preparation method of the tungsten carbide-cubic boron nitride composite powder according to any one of claims 5 to 6, or the cemented carbide composite material according to any one of claims 7 to 9.

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