WC-Co hard alloy and preparation method and application thereof

Abstract

The invention provides a WC-Co hard alloy, which is prepared from the following raw materials in percentage by mass: 8.0 to 18.0 percent of binding agent, 0.2 to 5.0 percent of polycarbosilane, 0.2 to 0.9 percent of inhibitor and the balance of tungsten carbide. The raw materials of the hard alloy contain polycarbosilane, the polycarbosilane serves as a strengthening phase precursor, the strengthening phase in the prepared alloy is distributed more uniformly, and the strength of the hard alloy can be improved. The invention further provides a preparation method and application of the WC-Co hard alloy.

Description

Technical Field

[0001] The invention belongs to the technical field of cemented carbide, and in particular relates to a WC-Co cemented carbide and a preparation method and application thereof. Background Art

[0002] WC-Co cemented carbide is a type of composite material prepared by powder metallurgy with WC as the hard phase and transition metal Co as the bonding phase. WC with high melting point and high hardness provides the alloy with the ability to bear loads, while the bonding metal Co gives the cemented carbide a certain toughness. Cemented carbide combines the advantages of both the hard phase and the bonding metal, and has a series of excellent properties, such as: high hardness and wear resistance, especially at 600°C, the hardness can still exceed the room temperature strength of high-speed steel; good chemical stability, and better oxidation resistance and corrosion resistance than steel. This series of advantages makes cemented carbide widely used in mining, petrochemical, material processing, mold manufacturing, national defense and military industries, and is known as the "teeth of industry".

[0003] Traditional cemented carbide mainly strengthens the Co phase through solid solution strengthening, such as adding elements such as Ni and Cr to cause lattice distortion of the Co phase, thereby increasing the resistance to dislocation movement and improving the strength and hardness of the alloy. With the rapid development of industries such as material processing, alloys prepared by this strengthening method have gradually failed to meet the requirements. In recent years, some scholars have begun to strengthen the cobalt phase through dispersion strengthening. Dispersion strengthening is the introduction of second phase particles into the alloy. These particles play a hindering role in dislocation movement, and the strengthening effect is usually better than solid solution strengthening.

[0004] Patent CN112609116A adds SiC particles to WC-Co-Ni alloy, and its ordered strengthening phase is dispersed in the Co-Ni bonding phase, and the room temperature and high temperature bending strength of the alloy is increased by more than 20%. Patent CN112430769A adds Ti3SiC2 powder to WC-Co cemented carbide, and utilizes the advantages of self-lubrication and good wear resistance of Ti3SiC2 material to improve the wear resistance and hardness of the cemented carbide. Although the above method improves the strength or hardness of the alloy to a certain extent, the strengthening phase is added in the form of solid phase, which is not easy to mix evenly with other raw material powders during the ball milling process, causing the second phase particles in the alloy after sintering to easily agglomerate and unevenly distribute, greatly reducing the strengthening effect. Summary of the invention

[0005] Based on the above, the main purpose of the present invention is to provide a WC-Co cemented carbide and a preparation method and application thereof. The strengthening phase in the WC-Co cemented carbide of the present invention is evenly distributed in the raw material, which can improve the strength of the cemented carbide.

[0006] To this end, in a first aspect, the present invention proposes a WC-Co cemented carbide, whose raw materials include, by mass percentage: 8.0-18.0% of a binder, 0.2-5.0% of polycarbosilane (PCS), 0.2-0.9% of an inhibitor and the remainder of tungsten carbide, and the sum of the contents of the above components is 100%.

[0007] The cemented carbide raw material of the present invention contains polycarbosilane, which serves as a reinforcement phase precursor. The reinforcement phase in the prepared alloy is more evenly distributed, and the strength of the cemented carbide can be improved.

[0008] As a specific implementation of the present invention, the binder is cobalt powder.

[0009] As a specific embodiment of the present invention, the binder has a Fisher particle size of 0.5 μm to 2.0 μm.

[0010] As a specific embodiment of the present invention, the number average molecular weight of the polycarbosilane is 1000-1500 g / mol.

[0011] As a specific embodiment of the present invention, the inhibitor is selected from one of Cr3C2 and VC, preferably Cr3C2.

[0012] As a specific embodiment of the present invention, the inhibitor has a Fresnel particle size of 0.5 μm to 2.0 μm.

[0013] As a specific embodiment of the present invention, the tungsten carbide includes medium-grained tungsten carbide and fine-grained tungsten carbide; preferably, the tungsten carbide consists of medium-grained tungsten carbide and fine-grained tungsten carbide.

[0014] As a specific embodiment of the present invention, the medium-grained tungsten carbide has a Fisher particle size of 2.8 μm to 5.4 μm, preferably 3.0 μm to 4.0 μm.

[0015] As a specific embodiment of the present invention, the fine particle size of tungsten carbide is 0.8 μm to 2.0 μm, preferably 1.0 μm to 1.5 μm.

[0016] As a specific embodiment of the present invention, the mass ratio of the medium-grained tungsten carbide to the fine-grained tungsten carbide is 1:0.45-2.5, preferably 1:0.65-1.5.

[0017] As a specific embodiment of the present invention, the average grain size of the cemented carbide is 1.0 μm to 2.0 μm, and / or the bending strength is 2800 MPa to 3300 MPa, and / or the Rockwell hardness is 86 HRA to 92 HRA, and / or the fracture toughness is 12.0 MPa·m 1 / 2 ~33.0MPa·m 1 / 2 .

[0018] To this end, in a second aspect, the present invention provides a method for preparing the above-mentioned WC-Co cemented carbide, comprising the following steps:

[0019] S1: wet grinding the raw materials with wet grinding media and forming agents;

[0020] S2: spray drying and pressing the mixture obtained in step S1 and then sintering it at low pressure;

[0021] S3: The compacted green body pressed in step S3 is subjected to tempering treatment, and then naturally cooled after the tempering treatment is completed.

[0022] As a specific embodiment of the present invention, the wet grinding medium is xylene, alcohol or hexane, preferably alcohol or hexane.

[0023] As a specific implementation of the present invention, the volume concentration of the alcohol is 90% to 100%.

[0024] As a specific embodiment of the present invention, the molding agent is paraffin or PEG.

[0025] As a specific embodiment of the present invention, in step S1, the ratio of the wet grinding medium to the raw material is 200ml / kg to 400ml / kg, preferably 250ml / kg to 350ml / kg.

[0026] As a specific embodiment of the present invention, the added amount of the molding agent is 0.5% to 5% of the mass of the raw material, preferably 1% to 3%.

[0027] As a specific embodiment of the present invention, in step S1, the wet grinding conditions are: the ball-to-material mass ratio is 2.0:1-5:1, and the time is 20h-30h. The ball-to-material ratio refers to the mass ratio of the grinding balls / rods to the raw material powder.

[0028] As a specific embodiment of the present invention, the conditions of the low-pressure sintering include: a pressure of 4 to 8 MPa, a sintering temperature of 1380 to 1450° C., and a sintering time of 30 to 300 min.

[0029] As a specific embodiment of the present invention, the tempering treatment conditions include: in a vacuum environment, a tempering temperature of 300 to 600° C., and a tempering time of 4 h to 12 h, preferably 6 to 8 h.

[0030] To this end, in a third aspect, the present invention proposes an application of the above-mentioned WC-Co cemented carbide or the WC-Co cemented carbide prepared by the above-mentioned preparation method in wear-resistant parts, cutting tools and drilling tools.

[0031] The beneficial effects of the present invention are:

[0032] (1) The cemented carbide raw material of the present invention contains polycarbosilane, which serves as a strengthening phase precursor. The strengthening phase in the prepared alloy is more evenly distributed, which can improve the bending strength and fracture toughness of the cemented carbide.

[0033] (2) In the cemented carbide of the present invention, polycarbosilane is used as a reinforcing phase precursor. During wet grinding, polycarbosilane will dissolve into the wet grinding medium and mix with other raw materials in the form of a liquid phase. Compared with directly adding a solid reinforcing phase, the mixing is more uniform, so that the reinforcing phase is more evenly distributed in the Co phase, which can improve the strength and fracture toughness of the cemented carbide.

[0034] (3) In the cemented carbide of the present invention, polycarbosilane as a reinforcement phase precursor will be cracked to generate SiC particles in situ during subsequent sintering. The dispersion strengthening effect is more significant than directly adding reinforcement phase SiC particles, thereby improving the strength and fracture toughness of the cemented carbide. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 3 is a scanning electron microscope photograph of the WC-Co cemented carbide prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0036] The technical scheme of the present invention is further described below by specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0037] Test Method

[0038] (1) Average grain size: GB / T 3488.2-2018 Metallographic determination of cemented carbide microstructure Part 2: Measurement of WC grain size;

[0039] (2) Flexural strength: GB / T 3851-2015 Determination method for transverse fracture strength of cemented carbide;

[0040] (3) Rockwell hardness: GB / T 3849.1-2015 Rockwell hardness of cemented carbide (A scale) Part 1: Test method;

[0041] (4) Fracture toughness: GB / T 33819-2017 Cemented carbide Babbitt toughness test.

[0042] Example 1

[0043] The in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide comprises the following raw materials by weight percentage: Co powder content is 9%, the Co powder has a Fischer-Strauss particle size of 1.0 μm, PCS content is 0.5%, the number average molecular weight of PCS is 1200 g / mol, Cr3C2 powder content is 0.2%, the Cr3C2 powder has a Fischer-Strauss particle size of 1.0 μm, WC powder content is 90.3%, and the mass ratio of medium-grained WC powder to fine-grained WC powder is 4:6, wherein the medium-grained WC powder has a Fischer-Strauss particle size of 3.4 μm, and the fine-grained WC powder has a Fischer-Strauss particle size of 1.0 μm.

[0044] The preparation method of the above-mentioned SiC dispersion strengthened WC-Co cemented carbide comprises the following steps: weighing 1000g of raw material according to the above-mentioned proportion, adding it together with wet grinding medium and forming agent into a ball mill for wet grinding for 30 hours. Among them, the wet grinding ball-to-material ratio is 3:1, the wet grinding medium is alcohol with a volume concentration of 92%, the ratio of alcohol to raw material powder is 300ml:1kg, the forming agent is paraffin, and the amount of paraffin added is 2% of the total mass of the raw material powder. The wet-milled mixture is spray-dried and pressed into shape, and then sintered in a 5MPa pressure furnace, the sintering temperature is 1450℃, and the sintering time is 60min. The sintered cemented carbide is placed in a tempering furnace for vacuum tempering treatment, the tempering temperature is 500℃, the tempering time is 8h, and it is naturally cooled to room temperature after tempering.

[0045] After testing, the average grain size of the cemented carbide prepared by the above process is 1.2μm, the bending strength is 2900MPa, the Rockwell hardness is 90.2HRA, and the fracture toughness is 12.9MPa·m 1 / 2 .

[0046] Example 2

[0047] The in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide comprises the following raw materials by weight percentage: Co powder content is 14%, the Co powder has a Fischer-Strauss particle size of 1.0 μm, PCS content is 1%, the number average molecular weight of PCS is 1200 g / mol, Cr3C2 powder content is 0.5%, the Cr3C2 powder has a Fischer-Strauss particle size of 1.0 μm, WC powder content is 84.5%, and the mass ratio of medium-grained WC powder to fine-grained WC powder is 5:5, wherein the medium-grained WC powder has a Fischer-Strauss particle size of 3.4 μm, and the fine-grained WC powder has a Fischer-Strauss particle size of 1.0 μm.

[0048] The preparation method of the above-mentioned in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide is as follows: weigh 1000g of the above-mentioned raw materials in proportion, add them together with the wet grinding medium and the molding agent into a ball mill for wet grinding for 22 hours. Among them, the wet grinding ball-to-material ratio is 3:1, the wet grinding medium is alcohol with a volume concentration of 92%, the ratio of alcohol to raw material powder is 300ml:1kg, the molding agent is paraffin, and the amount of paraffin added is 2% of the total mass of the raw material powder. The wet-milled mixture is spray-dried and pressed into shape, and then sintered in a 5MPa pressure furnace, the sintering temperature is 1450℃, and the sintering time is 120min. The sintered cemented carbide is placed in a tempering furnace for vacuum tempering treatment, the tempering temperature is 500℃, the tempering time is 8h, and it is naturally cooled to room temperature after tempering.

[0049] The alloy prepared by the above process has an average grain size of 1.6 μm, a bending strength of 3200 MPa, a Rockwell hardness of 88.6 HRA, and a fracture toughness of 29.3 MPa·m. 1 / 2 .

[0050] The microstructure of the cemented carbide prepared in this embodiment is characterized. Figure 1 shown.

[0051] Example 3

[0052] The in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide comprises the following raw materials by weight percentage: Co powder content is 14%, the Fischer-Strauss particle size of the Co powder is 1.0 μm, PCS content is 2%, the number average molecular weight of the PCS is 1100 g / mol, Cr3C2 powder content is 0.5%, the Fischer-Strauss particle size of the Cr3C2 powder is 1.5 μm, WC powder content is 83.5%, and the mass ratio of medium-grained WC powder to fine-grained WC powder is 5:5, wherein the Fischer-Strauss particle size of the medium-grained WC powder is 3.4 μm, and the Fischer-Strauss particle size of the fine-grained WC powder is 1.0 μm.

[0053] The preparation method of the above-mentioned in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide is as follows: weigh 1000g of the above-mentioned raw materials in proportion, add them together with the wet grinding medium and the molding agent into a ball mill for wet grinding for 22 hours. Among them, the wet grinding ball-to-material ratio is 3:1, the wet grinding medium is alcohol with a volume concentration of 92%, the ratio of alcohol to raw material powder is 300ml:1kg, the molding agent is paraffin, and the amount of paraffin added is 2% of the total mass of the raw material powder. The wet-milled mixture is spray-dried and pressed into shape, and then sintered in a 5MPa pressure furnace, the sintering temperature is 1450℃, and the sintering time is 180min. The sintered cemented carbide is placed in a tempering furnace for vacuum tempering treatment, the tempering temperature is 500℃, the tempering time is 8h, and it is naturally cooled to room temperature after tempering.

[0054] The alloy prepared by the above process has an average grain size of 1.6 μm, a bending strength of 3180 MPa, a Rockwell hardness of 88.8 HRA, and a fracture toughness of 29.0 MPa·m. 1 / 2 .

[0055] Example 4

[0056] The in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide comprises the following raw materials by weight percentage: Co powder content is 16%, the Fischer-Strauss particle size of the Co powder is 1.5 μm, PCS content is 2%, the number average molecular weight of the PCS is 1350 g / mol, Cr3C2 powder content is 0.5%, the Fischer-Strauss particle size is 1.5 μm, WC powder content is 81.5%, and the mass ratio of medium-grained WC powder to fine-grained WC powder is 6:4, wherein the Fischer-Strauss particle size of the medium-grained WC powder is 3.6 μm, and the Fischer-Strauss particle size of the fine-grained WC powder is 1.5 μm.

[0057] The preparation method of the above-mentioned in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide is as follows: weigh 1000g of the above-mentioned raw materials in proportion, add them together with the wet grinding medium and the molding agent into a ball mill for wet grinding for 20 hours. Among them, the wet grinding ball-to-material ratio is 3:1, the wet grinding medium is alcohol with a volume concentration of 92%, the ratio of alcohol to raw material powder is 300ml:1kg, the molding agent is paraffin, and the amount of paraffin added is 2% of the total mass of the raw material powder. The wet-milled mixture is spray-dried and pressed into shape, and then sintered in a 5MPa pressure furnace, the sintering temperature is 1410℃, and the sintering time is 240min. The sintered cemented carbide is placed in a tempering furnace for vacuum tempering treatment, the tempering temperature is 550℃, the tempering time is 6h, and it is naturally cooled to room temperature after tempering.

[0058] The average grain size of the alloy prepared by the above process is 1.8μm, the bending strength is 3230MPa, the Rockwell hardness is 88.4HRA, and the fracture toughness is 32.5MPa·m 1 / 2 .

[0059] Example 5

[0060] The in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide comprises the following raw materials by weight percentage: Co powder content is 16%, the Fischer-Strauss particle size of Co powder is 1.5 μm, PCS content is 4%, the number average molecular weight of PCS is 1450 g / mol, Cr3C2 powder content is 0.8%, the Fischer-Strauss particle size is 1.5 μm, WC powder content is 79.2%, and the mass ratio of medium-grained WC powder to fine-grained WC powder is 6:4, wherein the Fischer-Strauss particle size of the medium-grained WC powder is 3.6 μm, and the Fischer-Strauss particle size of the fine-grained WC powder is 1.5 μm.

[0061] The preparation method of the above-mentioned in-situ SiC nanoparticle dispersion strengthened WC-Co cemented carbide is as follows: weigh 1000g of the above-mentioned raw materials in proportion, add them together with the wet grinding medium and the molding agent into a ball mill for wet grinding for 20 hours. Among them, the wet grinding ball-to-material ratio is 3:1, the wet grinding medium is anhydrous alcohol, the ratio of alcohol to raw material powder is 300ml:1kg, the molding agent is paraffin, and the amount of paraffin added is 2% of the total mass of the raw material powder. The wet-milled mixture is spray-dried and pressed into shape, and then sintered in a 5MPa pressure furnace, the sintering temperature is 1410℃, and the sintering time is 240min. The sintered cemented carbide is placed in a tempering furnace for vacuum tempering treatment, the tempering temperature is 550℃, the tempering time is 6h, and it is naturally cooled to room temperature after tempering.

[0062] The alloy prepared by the above process has an average grain size of 1.8 μm, a bending strength of 3070 MPa, a Rockwell hardness of 88.7 HRA, and a fracture toughness of 30.9 MPa·m. 1 / 2 .

[0063] Comparative Example 1

[0064] The reinforced WC-Co cemented carbide comprises, by weight percentage, 9% Co powder content, 0.5% SiC powder content, 0.2% Cr3C2 powder content, 1.0 μm Fischer particle size of Cr3C2 powder, 90.3% WC powder content, and a mass ratio of medium-grained WC powder to fine-grained WC powder of 4:6, wherein the Fischer particle size of the medium-grained WC powder is 3.4 μm, and the Fischer particle size of the fine-grained WC powder is 1.0 μm.

[0065] The preparation method of the above-mentioned strengthened WC-Co cemented carbide is as follows: weigh 1000g of the above-mentioned raw materials in proportion, add them together with the wet grinding medium and the molding agent into a ball mill for wet grinding for 30 hours. Among them, the wet grinding ball-to-material ratio is 3:1, the wet grinding medium is alcohol with a volume concentration of 92%, the ratio of alcohol to raw material powder is 300ml:1kg, the molding agent is paraffin, and the amount of paraffin added is 2% of the total mass of the raw material powder. The wet-milled mixture is spray-dried and pressed into shape, and then sintered in a 5MPa pressure furnace, the sintering temperature is 1450℃, and the sintering time is 60min. The sintered cemented carbide is placed in a tempering furnace for vacuum tempering treatment, the tempering temperature is 500℃, the tempering time is 8h, and it is naturally cooled to room temperature after tempering.

[0066] The alloy prepared by the above process has an average grain size of 1.2 μm, a bending strength of 2630 MPa, a Rockwell hardness of 90.0 HRA, and a fracture toughness of 11.2 MPa·m. 1 / 2 .

[0067] Table 1 Performance test results of Examples 1-5 and Comparative Example 1

[0068] Serial number Hardness (HRA) Flexural strength(MPa) <![CDATA[Fracture toughness (MPa·m 1 / 2 )]]> Example 1 90.2 2900 12.9 Example 2 88.6 3200 29.3 Example 3 88.8 3180 29.0 Example 4 88.4 3230 32.5 Example 5 88.7 3070 30.9 Comparative Example 1 90.0 2630 11.2

[0069] As shown in Table 1, the average grain size of the cemented carbides prepared in Examples 1-5 of the present invention is 1.0 μm to 2.0 μm, the bending strength is 2800 MPa to 3300 MPa, the Rockwell hardness is 86 HRA to 92 HRA, and the fracture toughness is 12.0 MPa·m 1 / 2 ~33.0MPa·m 1 / 2 .

[0070] Compared with Example 1, Comparative Example 1 uses SiC powder instead of PCS, and the rest of the raw material ratios and preparation methods are the same as those of Example 1. In the present invention, PCS is used as a SiC precursor. During ball milling, the precursor will dissolve into the wet grinding medium and mix with other raw materials in the form of a liquid phase, which is more uniform than directly adding SiC powder to mix in the traditional process. In addition, SiC in the present invention is generated in situ by pyrolysis of the precursor, and the SiC particles formed in situ are nanometer-sized (see Figure 1 ), the bending strengthening effect is more obvious, so Example 1 has better performance than Comparative Example 1.

[0071] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A WC-Co cemented carbide, characterized in that: The raw materials include, by mass percentage, 8.0-18.0% of a binder, 0.2-5.0% of polycarbosilane, 0.2-0.9% of an inhibitor and the balance of tungsten carbide.

2. The cemented carbide according to claim 1, characterized in that: The binder is cobalt powder, and / or the binder has a Fisher particle size of 0.5 μm to 2.0 μm; and / or the polycarbosilane has a number average molecular weight of 1000 to 1500 g / mol.

3. The cemented carbide according to claim 1 or 2, characterized in that: The inhibitor is selected from one of Cr3C2 and VC, preferably Cr3C2; and / or, The inhibitor has a Fresnel particle size of 0.5 μm to 2.0 μm.

4. The cemented carbide according to any one of claims 1 to 3, characterized in that: The tungsten carbide includes medium-grained tungsten carbide and fine-grained tungsten carbide. The medium-grained tungsten carbide has a Fisher grain size of 2.8 μm to 5.4 μm, preferably 3.0 μm to 4.0 μm; the fine-grained tungsten carbide has a Fisher grain size of 0.8 μm to 2.0 μm, preferably 1.0 μm to 1.5 μm.

5. The cemented carbide according to claim 4, characterized in that: The mass ratio of the medium-grained tungsten carbide to the fine-grained tungsten carbide is 1:0.45-2.5, preferably 1:0.65-1.

5.

6. The cemented carbide according to any one of claims 1 to 5, characterized in that: The cemented carbide has an average grain size of 1.0 μm to 2.0 μm, and / or a flexural strength of 2800 MPa to 3300 MPa, and / or a Rockwell hardness of 86 HRA to 92 HRA, and / or a fracture toughness of 12.0 MPa·m 1 / 2 ~33.0MPa·m 1 / 2 .

7. A method for preparing the WC-Co cemented carbide according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: wet grinding the raw materials with wet grinding media and forming agents; S2: spray drying and pressing the mixture obtained in step S1 and then sintering it at low pressure; S3: The compacted green body pressed in step S3 is subjected to tempering treatment, and then naturally cooled after the tempering treatment is completed.

8. The preparation method according to claim 7, characterized in that: The wet grinding medium is xylene, alcohol or hexane, preferably alcohol or hexane; preferably, the volume concentration of the alcohol is 90% to 100%; and / or, the molding agent is paraffin or PEG.

9. The preparation method according to claim 7 or 8, characterized in that: In step S1, the ratio of the wet grinding medium to the raw material is 200ml / kg to 400ml / kg, preferably 250ml / kg to 350ml / kg; and / or, the amount of the molding agent added is 0.5% to 5% of the mass of the raw material, preferably 1% to 3%; and / or, In step S1, the wet grinding conditions are: ball-to-material ratio of 2.5:1 to 5:1, time of 20h to 30h; and / or, The low-pressure sintering conditions include: pressure 4-8 MPa, sintering temperature 1380-1450° C., sintering time 30-300 min; and / or, The tempering treatment conditions include: in a vacuum environment, a tempering temperature of 300 to 600° C., and a tempering time of 4 to 12 hours, preferably 6 to 8 hours.

10. Use of the WC-Co cemented carbide according to any one of claims 1 to 6 or the WC-Co cemented carbide prepared by the preparation method according to any one of claims 7 to 9 in wear-resistant parts, cutting tools and drilling tools.

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