High wear-resistant cemented carbide drill bit and preparation method thereof

Abstract

This invention relates to the field of tungsten carbide-based cemented carbide technology, and in particular to a high wear-resistant cemented carbide drill bit and its preparation method. The high wear-resistant cemented carbide drill bit is made of 0.05-0.50 wt% sintering aid, 8-12 wt% M1 / M2 binder, and the balance being high wear-resistant cemented carbide powder; the high wear-resistant cemented carbide powder consists of 80-90 wt% cemented carbide powder and 10-20 wt% M1 / M2 binder; the cemented carbide powder is M1 / M2 ... x C y M is selected from any one of W, V, Cr, Ti, Hf, Ta, and Nb; the binder used in PM is selected from at least one of nickel powder, cobalt powder, nickel alloy powder, nickel-cobalt alloy powder, nickel-chromium alloy powder, nickel-copper alloy powder, and cobalt-based alloy powder. The carbide drill bit prepared by the MIM process of this invention has the advantages of high hardness, high wear resistance, and high bending strength, and also possesses good impact toughness, with a fracture toughness ≥10.0 MPa. 1 / 2 .

Description

Technical Field

[0001] This invention relates to the field of tungsten carbide-based cemented carbide technology, and in particular to a high wear-resistant cemented carbide drill bit and its preparation method. Background Technology

[0002] Carbide is mainly made of hard compounds of refractory metals and a binder metal. The resulting carbide possesses excellent properties such as high hardness and good wear resistance, making it widely used in important industrial fields such as machining, mold making, and wear- and corrosion-resistant parts. Carbide drills play a vital role in machining and are suitable for cutting various alloy materials, including aluminum alloys, copper alloys, and stainless steel.

[0003] Currently, cemented carbide is typically produced using powder metallurgy, with tungsten carbide (WC) as the hard compound and Ni and / or Co as the binder phase. For example, the production process of cemented carbide drill bits involves: ball milling WC and the binder phase to refine them, filling them into a mold, and pressing them at 50-200 MPa to obtain a cylindrical blank; the resulting cylindrical blank is sintered at 1400-1600℃ for 2-4 hours, cooled in the furnace, and demolded to obtain a semi-finished cemented carbide drill bit; finally, the semi-finished cemented carbide drill bit is machined and polished using diamond tools to obtain the finished cemented carbide drill bit. In existing technologies, cemented carbide drill bits prepared using powder metallurgy involve machining and polishing processes in the later stages. This not only prolongs the production time and increases production costs, but also causes internal stress in the drill bit during cutting, increasing the risk of tool breakage and hindering the improvement of drill bit quality.

[0004] Metal injection molding is a novel metallurgical process combining powder metallurgy and injection molding, suitable for one-time molding of complex structural parts. The metal injection molding process involves mixing metal powder and a binder to prepare a feedstock. This feedstock is then injected under pressure into a mold using injection molding equipment to create a blank. The blank is then debonded and sintered to obtain a complex structural part in one step. Using metal injection molding, carbide drill bits can be produced in a single step, effectively reducing the time required for subsequent machining and grinding processes, thus improving the quality of carbide drill bits. In practice, the inventors discovered that fine-grained (D) feedstock is ideal for carbide drill bits. 50 Pure nickel or cobalt powder (≤1μm) is prone to agglomeration. While the overall density is relatively good, the dispersion uniformity of the binder phase is poor, resulting in cemented carbide prepared by MIM having an impact toughness lower than 8.0 MPa. 1 / 2 The impact toughness deviation limits its application and promotion. However, if D is used... 50Using 5-20μm pure nickel or cobalt powder can improve the uniformity of feed distribution in carbide drill bits to some extent, but it will affect the sintering density, resulting in a decrease in the hardness, bending strength and impact toughness of carbide drill bits.

[0005] To this end, the inventors optimized the composition of the binder phase, providing a high wear-resistant cemented carbide drill bit suitable for metal injection molding and its preparation method. Summary of the Invention

[0006] To address the technical challenge of impact toughness deviation in cemented carbide drill bits manufactured using metal injection molding, this invention provides a high wear-resistant cemented carbide drill bit and its preparation method.

[0007] The high wear-resistant carbide drill bit provided by this invention is achieved through the following technical solution:

[0008] A high wear-resistant carbide drill bit is made from the following raw materials in weight percentages: 0.05-0.50 wt% sintering aid and 8-12 wt% binder for MIM, with the balance being high wear-resistant carbide powder; the high wear-resistant carbide powder consists of 80-90 wt% carbide powder and 10-20 wt% binder for PM; the carbide powder is M... x C y M is selected from any one of W, V, Cr, Ti, Hf, Ta, and Nb; the binder for PM is selected from at least one of nickel powder, cobalt powder, nickel alloy powder, nickel-cobalt alloy powder, nickel-chromium alloy powder, nickel-copper alloy powder, and cobalt-based alloy powder.

[0009] The cemented carbide drill bit prepared by the present invention using the MIM process has the advantages of high hardness, high wear resistance, and high bending strength, and also has good impact toughness, with a fracture toughness ≥10.0 MPa.m 1 / 2 .

[0010] Preferably, the cemented carbide powder includes a main cemented carbide powder and an auxiliary alloy powder with grain refining effect, wherein the mass ratio of the main cemented carbide powder to the auxiliary alloy powder is (90-99):(1-10); the main cemented carbide powder is tungsten carbide (WC); and the auxiliary alloy powder is at least one of VC, TaC, NbC, and Cr3C2, which imparts excellent hardness, wear resistance, bending strength, and impact toughness to the cemented carbide drill bit.

[0011] The sintering aid is ultrafine boron powder, which can improve the overall hardness, wear resistance, mechanical properties and impact toughness of high wear-resistant cemented carbide drill bits.

[0012] Preferably, the cemented carbide powder further includes toughening carbides, which account for 1-5 wt% of the total mass of the cemented carbide powder; the toughening carbides are at least one of HfC and layered two-dimensional materials.

[0013] By adopting the above technical solutions, the bending strength and impact toughness of cemented carbide drill bits can be improved.

[0014] Preferably, the main cemented carbide powder is composed of tungsten carbide with different particle sizes: 5-20 wt% of tungsten carbide with a particle size of 50-500 nm, 10-30 wt% of tungsten carbide with a particle size of 20-45 μm, and the balance being tungsten carbide with a particle size of 1-15 μm.

[0015] Preferably, the median diameter D of the auxiliary alloy powder 50 =2-15μm.

[0016] Preferably, the median diameter D of the toughening carbide 50 =0.05-15μm.

[0017] Preferably, the cemented carbide powder is composed of WC, Cr3C2, and HfC in a mass ratio of (90-95):(4-8):(1-2), which endows the cemented carbide drill bit with excellent hardness, wear resistance, bending strength, and impact toughness.

[0018] Preferably, the binder for PM is selected from at least one of Inconel 713LC alloy spherical powder, Inconel 738 alloy spherical powder, Haynes 188 alloy spherical powder, Aloy R41 alloy spherical powder, and Rene '88DT alloy spherical powder.

[0019] Commercial alloy spherical powder is used as a binder for PM to ensure the high hardness, high wear resistance, high bending strength and good impact toughness of carbide drill bits, while reducing overall production costs.

[0020] The present invention provides a method for preparing a high wear-resistant cemented carbide drill bit, which is achieved through the following technical solution:

[0021] A method for preparing a high wear-resistant cemented carbide drill bit includes the following steps:

[0022] S1. Preparation of cemented carbide powder;

[0023] S2. Place the accurately measured cemented carbide powder and PM binder into a planetary ball mill and perform planetary ball milling for 1-4 hours to obtain high wear-resistant cemented carbide powder.

[0024] S3. The high wear-resistant cemented carbide powder, sintering aid, and MIM binder are placed in an internal mixer and mixed to obtain a high wear-resistant cemented carbide feedstock; the sintering aid is ultrafine boron powder.

[0025] S4. Drill bit blanks are obtained by injection molding using high wear-resistant cemented carbide feedstock;

[0026] S5. High wear-resistant cemented carbide drill bits can be obtained by vacuum sintering after catalytic degreasing of the drill bit blank.

[0027] Preferably, the catalytic degreasing method in S5 is fuming nitric acid degreasing; the vacuum sintering parameters in S5 are as follows: under vacuum conditions, heat from room temperature to 550±50℃ at a heating rate of 10±2℃ / min and hold for 2-4 hours, heat to 1850±150℃ at a heating rate of 15-20℃ / min and hold for 0.5-1 hours, cool with the furnace to 1400±150℃ and hold for 2-6 hours, and then cool with the furnace to room temperature to obtain a high wear-resistant cemented carbide drill bit.

[0028] By adopting the above technical solutions, the density of carbide drill bits can be effectively guaranteed, thereby ensuring that carbide drill bits have high hardness, high wear resistance, high bending strength and good impact toughness.

[0029] Preferably, the process further includes S6. Heat treatment of the high wear-resistant cemented carbide drill bit: Under vacuum conditions, heating from room temperature to 1050-1250℃ at a heating rate of 15-20℃ / min and holding for 10-20 min, introducing a reducing gas, wherein the reducing gas is any one of hydrogen, carbon monoxide, a hydrogen / carbon monoxide mixture, a hydrogen / nitrogen mixture, or a carbon monoxide / nitrogen mixture; under the reducing gas atmosphere, the furnace pressure is controlled at 1-3MPa, and the temperature is held at 1400-1450℃ for 60-120 min, followed by gas quenching and cooling to room temperature.

[0030] By adopting the above technical solutions, the bending strength and fracture toughness of cemented carbide drill bits can be improved.

[0031] In summary, the present invention has the following advantages:

[0032] 1. The cemented carbide drill bit prepared by the MIM process of this invention has the advantages of high hardness, high wear resistance, and high bending strength, and also has good impact toughness, with a fracture toughness ≥10.0 MPa.m 1 / 2 .

[0033] 2. In this invention, the cemented carbide powder is composed of main cemented carbide powder, auxiliary alloy powder, and toughening carbide. The cemented carbide drill bit prepared by this invention has excellent hardness, wear resistance, bending strength and impact toughness.

[0034] 3. The metal injection molding (MIM) process provided in this invention is relatively mature, which can form complex structural parts in one step, reduce the labor time of subsequent machining and grinding processes, improve the quality of carbide drill bits, and facilitate the industrial mass production of carbide drill bits.

[0035] 4. In the heat treatment process of the present invention, by controlling the temperature and atmosphere, boron B in the sintered cemented carbide matrix reacts with nitrogen to produce boron nitride BN, which strengthens and toughens the whole. Tungsten oxide in the sintered cemented carbide matrix reacts with boron B to produce tungsten diboride WB2, eliminating tungsten oxide impurities and producing reinforcing phase WB2, which can improve the hardness, wear resistance, bending strength and impact toughness of cemented carbide drill bits. Detailed Implementation

[0036] To further understand the inventiveness and technical advancements of this invention, the preferred embodiments of this invention will be discussed in detail below with reference to examples and comparative examples.

[0037] Example: A high wear-resistant carbide drill bit is made from the following raw materials by weight percentage: 0.05-0.50 wt% sintering aid and 8-12 wt% binder for MIM, with the balance being high wear-resistant carbide powder.

[0038] The sintering aid is any one of ultrafine boron powder, ultrafine silicon powder, or a mixed sintering aid formed from ultrafine boron powder and ultrafine silicon powder, preferably boron powder. The sintering aid can play a toughening and reinforcing role: in a nitrogen atmosphere at 1050-1250℃, boron (B) in the sintered cemented carbide matrix reacts with nitrogen to produce boron nitride (BN), which toughens and reinforces the entire structure. In a reducing atmosphere and at a furnace temperature of 1400-1450℃, tungsten oxide in the sintered cemented carbide matrix reacts with boron (B) to produce tungsten diboride (WB2), eliminating tungsten oxide impurities and producing the reinforcing phase WB2, which can improve the overall hardness, wear resistance, mechanical properties, and impact toughness.

[0039] The adhesive used for MIM is made of polyoxymethylene (POM) (Kocetalk K900 type POM copolymer from Korea), maleic anhydride grafted polypropylene resin (MAH-g-PP, ADMER Japan Mitsui, model QF500T), and ethylene bis-stearamide (EBS, Maclean, CAS: 110-30-5). Specifically, the adhesive for MIM consists of 85 parts of K900 type POM, 8 parts of MAH-g-PP model QF500T, and 7 parts of ethylene bis-stearamide (EBS), with an MFR (g / min) of 554.

[0040] Preferably, the high wear-resistant carbide drill bit is made from the following raw materials in weight percentages: 0.15-0.30 wt% high-purity boron powder and 9-10 wt% MIM binder, with the balance being high wear-resistant carbide powder.

[0041] High wear-resistant cemented carbide powder consists of 80-90 wt% cemented carbide powder and 10-20 wt% PM binder.

[0042] cemented carbide powder is M x C y M is selected from any one of W, V, Cr, Ti, Hf, Ta, and Nb.

[0043] The cemented carbide powder comprises a main cemented carbide powder and an auxiliary alloy powder that has a grain-refining effect. The mass ratio of the main cemented carbide powder to the auxiliary alloy powder is (90-99):(1-10). Specifically, the main cemented carbide powder is tungsten carbide (WC), and the auxiliary alloy powder is at least one selected from VC, TaC, NbC, and Cr3C2. Preferably, the cemented carbide powder also includes toughening carbides, which account for 1-5 wt% of the total mass of the cemented carbide powder. The toughening carbides are at least one selected from HfC and layered two-dimensional materials.

[0044] Preferably, the main cemented carbide powder consists of 5-20 wt% tungsten carbide with a particle size of 50-500 nm, 10-30 wt% tungsten carbide with a particle size of 20-45 μm, and the balance being tungsten carbide with a particle size of 1-15 μm. The median diameter D of the auxiliary alloying powder... 50 =2-15μm. Median diameter D of the toughening carbide. 50 =0.05-15μm. More preferably, the cemented carbide powder is composed of WC, Cr3C2, and HfC in a mass ratio of (90-95):(4-8):(1-2).

[0045] The binder for PM is selected from one or more combinations of nickel powder, cobalt powder, nickel alloy powder, nickel-cobalt alloy powder, nickel-chromium alloy powder, nickel-copper alloy powder, and cobalt-based alloy powder. Preferably, the binder for PM is selected from at least one of Inconel 713LC alloy spherical powder, Inconel 738 alloy spherical powder, Haynes 188 alloy spherical powder, Aloy R41 alloy spherical powder, and Rene '88DT alloy spherical powder.

[0046] A method for preparing a high wear-resistant cemented carbide drill bit includes the following steps:

[0047] S1. Preparation of cemented carbide powder;

[0048] S2. Place the accurately measured cemented carbide powder and PM binder into a planetary ball mill and perform planetary ball milling for 1-4 hours to obtain high wear-resistant cemented carbide powder.

[0049] S3. The high wear-resistant cemented carbide powder, sintering aid and MIM binder are placed in an internal mixer for internal mixing and homogenization to obtain high wear-resistant cemented carbide feed.

[0050] S4. Drill bit blanks are obtained by injection molding using high wear-resistant cemented carbide feedstock;

[0051] S5. After degreasing by fuming nitric acid, the drill bit blank is vacuum sintered: Under vacuum conditions, it is heated from room temperature to 550±50℃ at a heating rate of 10±2℃ / min and held for 2-4 hours, then heated to 1850±150℃ at a heating rate of 15-20℃ / min and held for 0.5-1 hours, then cooled in the furnace to 1400±150℃ and held for 2-6 hours, and finally cooled in the furnace to room temperature to obtain a high wear-resistant cemented carbide drill bit;

[0052] S6. Heat treatment of high wear-resistant cemented carbide drill bits: Under vacuum conditions, heat from room temperature to 1050-1250℃ at a heating rate of 15-20℃ / min and hold for 10-20min. Introduce a reducing gas, which can be any one of hydrogen, carbon monoxide, hydrogen / carbon monoxide mixture, hydrogen / nitrogen mixture, or carbon monoxide / nitrogen mixture. Under the reducing gas atmosphere, control the furnace pressure at 1-3MPa, heat to 1400-1450℃ and hold for 60-120min. Then, quench the drill bits in gas and cool to room temperature to obtain the finished high wear-resistant cemented carbide drill bits.

[0053] Example 1: The high wear-resistant carbide drill bit is made from the following raw materials in weight percentages: 0.25 wt% high-purity boron powder, 9.15 wt% binder for MIM, and 90.6 wt% high wear-resistant carbide powder.

[0054] The MIM adhesive consists of 85 parts of K900 type polyoxymethylene POM, 8 parts of QF500T type MAH-g-PP, and 7 parts of ethylene bis-stearamide EBS, with an MFR (g / min) of 554.

[0055] The adhesive for MIM is prepared as follows: 85 parts by weight of K900 type polyoxymethylene POM, 8 parts by weight of QF500T type MAH-g-PP, and 7 parts by weight of ethylene bis-stearamide EBS are dispersed at high speed of 600 rpm for 15 min to obtain the adhesive for MIM.

[0056] High-purity boron powder A, microstructure: near-spherical, product specification 100nm, item number XT-B-03, Shanghai Xiangtian Nanomaterials Co., Ltd. High-purity boron powder B, microstructure: irregular, product specification 1μm, item number XT-B-06, Shanghai Xiangtian Nanomaterials Co., Ltd. 0.25wt% of high-purity boron powder contains 0.1wt% high-purity boron powder A and 0.15wt% high-purity boron powder B.

[0057] The high wear-resistant cemented carbide powder consists of 89.5 wt% cemented carbide powder and 11.5 wt% PM binder.

[0058] The cemented carbide powder is composed of WC, Cr3C2, and HfC in a mass ratio of 95:4:1.

[0059] WC is composed of 20 wt% tungsten carbide with an average particle size of 60 nm (model CW-WC-001, Shanghai Chaowei Nanotechnology Co., Ltd.), 10 wt% tungsten carbide with an average particle size of 35 μm (model XT-WC-10), 30 wt% tungsten carbide with an average particle size of 1 μm (model XT-WC-08), and 40 wt% tungsten carbide with an average particle size of 5 μm (model XT-WC-9). The tungsten carbide powders of models XT-WC-10, XT-WC-09, and XT-WC-08 were purchased from Shanghai Xiangtian Nanomaterials Co., Ltd.

[0060] Chromium carbide (Cr3C2): Shanghai Chaowei Nanotechnology Co., Ltd., model CW-Cr3C2-001, nano-chromium carbide with an average particle size of 100nm. Hafnium carbide (HfC): Zhejiang Yamei Nanotechnology Co., Ltd., model AM-HfC-061-2, particle size (APS): 200nm. PM binder is Inconel 713LC alloy spherical powder, powder size 5-15um (3000~800 mesh), Zhuangmai (Shanghai) Additive Manufacturing Technology Co., Ltd.

[0061] A method for preparing a high wear-resistant cemented carbide drill bit includes the following steps:

[0062] S1. Preparation of cemented carbide powder:

[0063] S1.1. Preparation of main cemented carbide powder: 20 parts by weight of tungsten carbide CW-WC-001 with an average particle size of 60 nm, 10 parts by weight of tungsten carbide XT-WC-10 with an average particle size of 35 μm, 30 parts by weight of tungsten carbide XT-WC-08 with an average particle size of 1 μm, and 40 parts by weight of tungsten carbide XT-WC-09 with an average particle size of 5 μm were placed in a dual planetary mixer LDPPM-5L and dispersed at high speed of 600 rpm for 2 hours under nitrogen protection. The powder was then vacuum packaged to obtain the main cemented carbide powder.

[0064] S1.2. Take 95 parts by weight of the main cemented carbide powder, 4 parts by weight of chromium carbide Cr3C2, and 1 part by weight of hafnium carbide HfC and add them to a dual planetary power mixer LDPPM-5L. Under nitrogen protection, disperse at high speed of 600 rpm for 2 hours to obtain cemented carbide powder of model HFC-95WC / 4Cr3C2 / 1HfC.

[0065] S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of Inconel 713LC alloy spherical powder from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Ni713LC-01.

[0066] S3.90.6 parts by weight of high wear-resistant cemented carbide powder in S2, 0.1 parts by weight of high-purity boron powder A, 0.15 parts by weight of high-purity boron powder B, and 9.15 parts by weight of MIM are mixed in an internal mixer at a mixing temperature of 190°C for 40 minutes to obtain high wear-resistant cemented carbide feed.

[0067] S4. Add the high wear-resistant cemented carbide feedstock from S3 into the injection molding machine. Inject the plasticized high wear-resistant cemented carbide feedstock into the drill bit forming mold through the injection molding machine. After cooling and forming, demold and remove burrs to obtain the drill bit blank.

[0068] S5. Drill bit blanks are first catalytically degreased and then vacuum sintered to obtain high wear-resistant cemented carbide drill bits. The parameters for catalytic degreasing are as follows: 98% fuming nitric acid is used as the catalyst, the fuming nitric acid inlet rate is 6.5 mL / min, the catalytic degreasing temperature is 120℃, and the catalytic degreasing time is 4 hours. After catalytic degreasing, the blanks are transferred to a vacuum pressure atmosphere sintering furnace for vacuum sintering. The vacuum sintering parameters are as follows: under vacuum conditions, the temperature is increased from room temperature to 600℃ at a heating rate of 10℃ / min and held for 2 hours, followed by thermal catalytic degreasing at 600℃ for 2 hours. The binder used to effectively remove MIM reduces the residual carbon content of the finished high wear-resistant carbide drill bit. Then, the temperature is increased from 600℃ to 1800℃ at a rate of 20℃ / min and held for 45min. At 1800℃, the residual carbon reacts with boron powder to produce high-hardness boron carbide B4C, which further reduces the residual carbon content of the finished high wear-resistant carbide drill bit. After furnace cooling, the temperature is reduced from 1800℃ to 1400℃ after 60min and vacuum sintered for 4.0h. After vacuum sintering, the drill bit is cooled to room temperature to obtain the high wear-resistant carbide drill bit.

[0069] S6. Heat treatment of high wear-resistant cemented carbide drill bits: Under vacuum conditions, heat from room temperature to 1100℃ and hold for 15 minutes at a heating rate of 20℃ / min. A reducing gas is introduced, which is a mixture of carbon monoxide and nitrogen (CO:N2 volume ratio of 1:1). Under the reducing gas atmosphere, the furnace pressure is controlled at 1.0MPa, and the temperature is increased from 1100℃ to 1450℃ and held for 120 minutes at a heating rate of 20℃ / min. Tungsten oxide in the sintered cemented carbide matrix reacts with boron B to produce tungsten diboride WB2, and boron B reacts with nitrogen to produce boron nitride BN. Then, the part is quenched to room temperature with nitrogen gas (nitrogen gas pressure 8 bar), removed, and the burrs are removed to obtain the finished high wear-resistant cemented carbide drill bit.

[0070] The difference between Example 2 and Example 1 is that the cemented carbide powder is composed of WC and Cr3C2 in a mass ratio of 96:4. The difference in the preparation method of the high wear-resistant cemented carbide drill bit is that: S1.2. Take 96 parts by weight of the main cemented carbide powder and 4 parts by weight of chromium carbide Cr3C2 and add them to a dual planetary power mixer LDPPM-5L. Under nitrogen protection, disperse at high speed of 600 rpm for 2 hours to obtain cemented carbide powder of model HFC-96WC / 4Cr3C2;

[0071] S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of Inconel 713LC alloy spherical powder from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process the powder at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Ni 713LC-02.

[0072] The difference between Example 3 and Example 1 is that the cemented carbide powder is composed of WC, VC, TaC, and HfC in a mass ratio of 95:3.5:0.5:1. Vanadium carbide (VC): Shanghai Chaowei Nanotechnology Co., Ltd., model CW-VC-001 nano-chromium carbide, with an average particle size of 80 nm. Tantalum carbide (TaC): Shanghai Chaowei Nanotechnology Co., Ltd., model CW-TaC-001 nano-chromium carbide, with an average particle size of 100 nm.

[0073] The difference in the preparation method of high wear-resistant cemented carbide drill bit is as follows: S1.2. Take 95 parts by weight of main cemented carbide powder, 3 parts by weight of vanadium carbide VC, 0.5 parts by weight of tantalum carbide TaC, and 1 part by weight of hafnium carbide HfC and add them to a dual planetary power mixer LDPPM-5L. Under nitrogen protection, disperse at high speed of 600 rpm for 2 hours to obtain cemented carbide powder of model HFC-95WC / 3.5VC / 0.5TaC / 1HfC;

[0074] S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of Inconel 713LC alloy spherical powder from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them by planetary ball milling at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Ni713LC-03.

[0075] The difference between Example 4 and Example 1 is that the main cemented carbide powder consists of 15 wt% tungsten carbide XT-WC-10 with an average particle size of 35 μm, 45 wt% tungsten carbide XT-WC-08 with an average particle size of 1 μm, and 40 wt% tungsten carbide XT-WC-9 with an average particle size of 5 μm.

[0076] The difference in the preparation methods of high wear-resistant cemented carbide drill bits lies in: S1.1. Preparation of main cemented carbide powder: 15 parts by weight of tungsten carbide XT-WC-10 with an average particle size of 35 μm, 45 parts by weight of tungsten carbide XT-WC-08 with an average particle size of 1 μm, and 40 parts by weight of tungsten carbide XT-WC-09 with an average particle size of 5 μm are placed in a dual planetary mixer LDPPM-5L and dispersed at a high speed of 600 rpm for 2 hours under nitrogen protection. The resulting product is then vacuum packaged to obtain the main cemented carbide powder. S1.2. Take 95 parts by weight of the main cemented carbide powder, 4 parts by weight of chromium carbide Cr3C2, and 1 part by weight of hafnium carbide HfC and add them to a dual planetary mixer LDPPM-5L. Under nitrogen protection, disperse at high speed of 600 rpm for 2 hours to obtain cemented carbide powder of model HFC-95WC' / 4Cr3C2 / 1HfC; S2. Take 89.5 parts by weight of the cemented carbide powder from S1.2 and 11.5 parts by weight of Inconel 713LC alloy spherical powder and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them by planetary ball milling at 300 rpm for 4.0 hours to obtain high wear-resistant cemented carbide powder of model HFC-WC-Ni713LC-04.

[0077] The difference between Example 5 and Example 1 is that the binder used in PM is Inconel 738 alloy spherical powder with a powder size of 5-15um (3000-800 mesh), manufactured by Zhuangmai (Shanghai) Additive Manufacturing Technology Co., Ltd.

[0078] The difference in the preparation method of high wear-resistant cemented carbide drill bits is as follows: S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of Inconel 738 alloy spherical powder from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Inconel 738-01.

[0079] The difference between Example 6 and Example 1 is that the binder used in PM is Haynes 188 alloy spherical powder with a powder size of 5-15um (3000-800 mesh), manufactured by Zhuangmai (Shanghai) Additive Manufacturing Technology Co., Ltd.

[0080] The difference in the preparation method of high wear-resistant cemented carbide drill bits is as follows: S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of Haynes188 alloy spherical powder from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Haynes188-01.

[0081] The difference between Example 7 and Example 1 is that the binder used in PM is Aloy R41 alloy spherical powder with a powder size of 5-15um (3000-800 mesh), manufactured by Zhuangmai (Shanghai) Additive Manufacturing Technology Co., Ltd.

[0082] The difference in the preparation method of high wear-resistant cemented carbide drill bits lies in: S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of AloyR41 alloy spherical powder from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them at 300 rpm for 4.0 hours to obtain high wear-resistant cemented carbide powder of model HFC-WC-AloyR41-01.

[0083] The difference between Example 8 and Example 1 is that the binder used in PM is Rene'88DT alloy spherical powder with a powder size of 5-15um (3000-800 mesh), manufactured by Zhuangmai (Shanghai) Additive Manufacturing Technology Co., Ltd.

[0084] The difference in the preparation method of high wear-resistant cemented carbide drill bits is as follows: S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of Rene'88DT alloy spherical powder from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Rene'88DT-01.

[0085] The difference between Comparative Example 1 and Example 1 is that the high wear-resistant carbide drill bit is made from the following raw materials by weight percentage: 9.15 wt% binder for MIM and 90.85 wt% high wear-resistant carbide powder.

[0086] The differences in the manufacturing methods of high wear-resistant carbide drill bits are as follows:

[0087] S3.90.85 parts by weight of high wear-resistant cemented carbide powder in S2 and 9.15 parts by weight of MIM binder are placed in an internal mixer for internal mixing and homogenization. The mixing temperature is 190℃ and the material is discharged after 40 minutes to obtain high wear-resistant cemented carbide feed.

[0088] S4. Add the high wear-resistant cemented carbide feedstock from S3 into the injection molding machine. Inject the plasticized high wear-resistant cemented carbide feedstock into the drill bit forming mold through the injection molding machine. After cooling and forming, demold and remove burrs to obtain the drill bit blank.

[0089] S5. The drill bit blank is first catalytically degreased and then vacuum sintered to obtain a high wear-resistant cemented carbide drill bit: The parameters for catalytic degreasing are as follows: 98% fuming nitric acid is used as the catalyst, the acid inlet rate of fuming nitric acid is 6.5 mL / min, the catalytic degreasing temperature is 120℃, and the catalytic degreasing time is 4 h; After catalytic degreasing, the blank is transferred to a vacuum pressure atmosphere sintering furnace for vacuum sintering. The vacuum sintering parameters are as follows: Under vacuum conditions, the temperature is increased from room temperature to 600℃ at a heating rate of 10℃ / min and held for 2 h. The thermal catalytic degreasing at 600℃ for 2 h can effectively remove the binder used for MIM and reduce the residual carbon content of the finished high wear-resistant cemented carbide drill bit. Then, the temperature is increased from 600℃ to 1400℃ at a heating rate of 20℃ / min and held for 285 min. After vacuum sintering, the blank is cooled to room temperature with the furnace to obtain a high wear-resistant cemented carbide drill bit. The remaining steps are the same.

[0090] The difference between Comparative Example 2 and Example 1 is that the cemented carbide powder consists of 20 wt% tungsten carbide CW-WC-001 with an average particle size of 60 nm, 10 wt% tungsten carbide XT-WC-10 with an average particle size of 35 μm, 30 wt% tungsten carbide XT-WC-08 with an average particle size of 1 μm, and 40 wt% tungsten carbide XT-WC-9 with an average particle size of 5 μm. The difference in the preparation methods of the high wear-resistant cemented carbide drill bit is as follows:

[0091] S1. Preparation of cemented carbide powder: 20 parts by weight of tungsten carbide CW-WC-001 with an average particle size of 60 nm, 10 parts by weight of tungsten carbide XT-WC-10 with an average particle size of 35 μm, 30 parts by weight of tungsten carbide XT-WC-08 with an average particle size of 1 μm, and 40 parts by weight of tungsten carbide XT-WC-09 with an average particle size of 5 μm were placed in a dual planetary mixer LDPPM-5L and dispersed at high speed of 600 rpm for 2 hours under nitrogen protection. The powder was then vacuum-packed to obtain cemented carbide powder of model HFC-100WC.

[0092] S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of Inconel 713LC alloy spherical powder from S1 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process the powder at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Ni 713LC-05.

[0093] The difference between Comparative Example 3 and Example 1 is that the high wear-resistant carbide drill bit is made from the following raw materials by weight percentage: 9.15 wt% MIM binder and 90.85 wt% high wear-resistant carbide powder. The carbide powder consists of 80 parts by weight of tungsten carbide XT-WC-9 with an average particle size of 5 μm and 20 parts by weight of tungsten carbide XT-WC-10 with an average particle size of 35 μm.

[0094] The differences in the manufacturing methods of high wear-resistant carbide drill bits are as follows:

[0095] S1. Preparation of cemented carbide powder: 20 parts by weight of tungsten carbide XT-WC-10 with an average particle size of 35 μm and 80 parts by weight of tungsten carbide XT-WC-09 with an average particle size of 5 μm were placed in a dual planetary mixer LDPPM-5L and dispersed at high speed of 600 rpm for 2 hours under nitrogen protection. The powder was then vacuum-packed to obtain cemented carbide powder of model HFC-100WC.

[0096] S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of Inconel 713LC alloy spherical powder from S1 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Ni 713LC-06.

[0097] S3.90.85 parts by weight of high wear-resistant cemented carbide powder in S2 and 9.15 parts by weight of MIM binder are placed in an internal mixer for internal mixing and homogenization. The mixing temperature is 190℃ and the material is discharged after 40 minutes to obtain high wear-resistant cemented carbide feed.

[0098] S4. Add the high wear-resistant cemented carbide feedstock from S3 into the injection molding machine. Inject the plasticized high wear-resistant cemented carbide feedstock into the drill bit forming mold through the injection molding machine. After cooling and forming, demold and remove burrs to obtain the drill bit blank.

[0099] S5. The drill bit blank is first catalytically degreased and then vacuum sintered to obtain a high wear-resistant cemented carbide drill bit: The parameters for catalytic degreasing are as follows: 98% fuming nitric acid is used as the catalyst, the acid inlet of fuming nitric acid is 6.5 mL / min, the catalytic degreasing temperature is 120℃, and the catalytic degreasing time is 4 h; After catalytic degreasing, the blank is transferred to a vacuum pressure atmosphere sintering furnace for vacuum sintering. The vacuum sintering parameters are as follows: Under vacuum conditions, the temperature is increased from room temperature to 600℃ at a heating rate of 10℃ / min and held for 2 h. The thermal catalytic degreasing at 600℃ for 2 h can effectively remove the binder used for MIM and reduce the residual carbon content of the finished high wear-resistant cemented carbide drill bit. Then, the temperature is increased from 600℃ to 1400℃ at a heating rate of 20℃ / min and held for 285 min. After vacuum sintering, the blank is cooled to room temperature with the furnace to obtain a high wear-resistant cemented carbide drill bit. The remaining steps S6 are the same as in Example 1.

[0100] The difference between Comparative Example 4 and Example 1 is that the binder used in PM is nano-grade nickel powder, model CW-Ni-002, spherical, with an average particle size of 600nm, manufactured by Shanghai Chaowei Nanotechnology Co., Ltd.

[0101] The differences in the preparation methods of cemented carbide drill bits are as follows: S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of nano-grade nickel powder CW-Ni-002 from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Ni-01. The remaining steps are the same.

[0102] The difference between Comparative Example 5 and Example 1 is that the high wear-resistant carbide drill bit was made from the following raw materials by weight percentage: 9.15 wt% binder for MIM and 90.85 wt% high wear-resistant carbide powder. The carbide powder consisted of 80 parts by weight of tungsten carbide XT-WC-9 with an average particle size of 5 μm and 20 parts by weight of tungsten carbide XT-WC-10 with an average particle size of 35 μm. The binder for PM was selected as nano-grade nickel powder, model CW-Ni-002, spherical, with an average particle size of 600 nm, manufactured by Shanghai Chaowei Nanotechnology Co., Ltd.

[0103] The differences in the manufacturing methods of high wear-resistant carbide drill bits are as follows:

[0104] S1. Preparation of cemented carbide powder: 20 parts by weight of tungsten carbide XT-WC-10 with an average particle size of 35 μm and 80 parts by weight of tungsten carbide XT-WC-09 with an average particle size of 5 μm were placed in a dual planetary mixer LDPPM-5L and dispersed at high speed of 600 rpm for 2 hours under nitrogen protection. The powder was then vacuum-packed to obtain cemented carbide powder of model HFC-100WC.

[0105] S2. Take 89.5 parts by weight of cemented carbide powder and 11.5 parts by weight of nano-grade nickel powder CW-Ni-002 from S1.2 and place them in a ZQM planetary ball mill YXQM-8L. Under nitrogen protection, process them by planetary ball milling at 300 rpm for 4.0 h to obtain high wear-resistant cemented carbide powder of model HFC-WC-Ni-01.

[0106] S3.90.85 parts by weight of high wear-resistant cemented carbide powder in S2 and 9.15 parts by weight of MIM binder are placed in an internal mixer for internal mixing and homogenization. The mixing temperature is 190℃ and the material is discharged after 40 minutes to obtain high wear-resistant cemented carbide feed.

[0107] S4. Add the high wear-resistant cemented carbide feedstock from S3 into the injection molding machine. Inject the plasticized high wear-resistant cemented carbide feedstock into the drill bit forming mold through the injection molding machine. After cooling and forming, demold and remove burrs to obtain the drill bit blank.

[0108] S5. The drill bit blank is first catalytically degreased and then vacuum sintered to obtain a high wear-resistant cemented carbide drill bit: The parameters for catalytic degreasing are as follows: 98% fuming nitric acid is used as the catalyst, the acid inlet of fuming nitric acid is 6.5 mL / min, the catalytic degreasing temperature is 120℃, and the catalytic degreasing time is 4h; After catalytic degreasing, the blank is transferred to a vacuum pressure atmosphere sintering furnace for vacuum sintering. The vacuum sintering parameters are as follows: Under vacuum conditions, the temperature is increased from room temperature to 600℃ at a heating rate of 10℃ / min and held for 2h. The thermal catalytic degreasing at 600℃ for 2h can effectively remove the binder used for MIM and reduce the residual carbon content of the finished high wear-resistant cemented carbide drill bit. Then, the temperature is increased from 600℃ to 1400℃ at a heating rate of 20℃ / min and held for 285min. After vacuum sintering, the blank is cooled to room temperature with the furnace to obtain the high wear-resistant cemented carbide drill bit.

[0109] Performance testing: 1. Hardness was measured using a Vickers hardness tester. 2. Bending strength was measured using a three-point bending test. 3. Fracture toughness was measured according to GB / T 1817-2017 "Test Method for Impact Toughness of Hard Alloys at Room Temperature". 4. Wear rate was measured according to ISO 20808, with a loading force of 50 N, a wear time of 100 min, and a wear speed of 15 m / min.

[0110] Table 1: Test parameters of high wear-resistant carbide drill bits in Examples 1-8 and Comparative Examples 1-5

[0111]

[0112] According to Example 1 and Comparative Example 1, and in conjunction with Table 1, adding an appropriate amount of boron powder as a sintering aid can improve the hardness, wear resistance, bending strength, and impact toughness of high wear-resistant cemented carbide drill bits.

[0113] Based on Examples 1-3 and Comparative Example 2, and referring to Table 1, it can be seen that the high-wear-resistant cemented carbide drill bit prepared from cemented carbide powder composed of main cemented carbide powder and auxiliary cemented carbide powder with grain-refining effect exhibits better hardness, wear resistance, bending strength, and impact toughness. HfC, as a toughening carbide, can improve the fracture toughness of the prepared high-wear-resistant cemented carbide drill bit, resulting in cemented carbide materials with better impact toughness.

[0114] Based on Examples 1 and 4, and Comparative Examples 2-3, and in conjunction with Table 1, it can be seen that the high wear-resistant cemented carbide drill bit prepared by the main cemented carbide powder consisting of 5-20 wt% tungsten carbide with a particle size of 50-500 nm, 10-30 wt% tungsten carbide with a particle size of 20-45 μm, and the balance being tungsten carbide with a particle size of 1-15 μm has better hardness, wear resistance, bending strength, and impact toughness.

[0115] Based on Examples 1, 5-8, and Comparative Examples 4-5, and in conjunction with Table 1, it can be seen that any one of Inconel 713LC alloy spherical powder, Inconel 738 alloy spherical powder, Haynes 188 alloy spherical powder, Aloy R41 alloy spherical powder, and Rene'88DT alloy spherical powder, when used as a binder for PM, produces high-wear-resistant carbide drill bits with characteristics of high hardness, high wear resistance, high bending strength, and high impact toughness.

[0116] As can be seen from Examples 1, 5-8, and Comparative Examples 4-5, and Table 1, using commercial alloy spherical powder as a binder for PM ensures the high hardness, high wear resistance, high bending strength, and good impact toughness of carbide drill bits, while reducing the production cost of high wear-resistant carbide drill bits.

[0117] In summary, the carbide drill bit prepared using the manufacturing process provided in this invention combined with the high wear-resistant carbide drill bit formulation exhibits high hardness (≥1600HV) and high wear resistance (≤5*10). -5 mm 3 It possesses high strength (≥3500MPa) and high flexural strength (≥3500MPa), while also exhibiting good impact toughness and fracture toughness ≥10.0MPa.m. 1 / 2 .

[0118] It should be noted that this specific embodiment is merely an explanation of the technical solution of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A high wear resistant cemented carbide drill bit characterized in that: The high wear-resistant carbide drill bit is made from the following raw materials by MIM process in the following weight percentages: 0.05-0.50 wt% sintering aid and 8-12 wt% MIM binder, with the balance being high wear-resistant carbide powder; the high wear-resistant carbide powder consists of 80-90 wt% carbide powder and 10-20 wt% PM binder; The sintering aid is ultrafine boron powder; the binder for MIM is composed of 85 parts of K900 type polyoxymethylene POM, 8 parts of QF500T maleic anhydride grafted polypropylene resin MAH-g-PP, and 7 parts of ethylene bis-stearamide EBS. The cemented carbide powder comprises main cemented carbide powder (WC), auxiliary alloy powder with grain refining effect, and toughening carbide (HfC). The mass ratio of the main cemented carbide powder to the auxiliary alloy powder is (90-99):(1-10). The auxiliary alloy powder is at least one of VC, TaC, NbC, and Cr3C2. The toughening carbide (HfC) accounts for 1-5 wt% of the total mass of the cemented carbide powder. The binder for PM is selected from at least one of Inconel 713LC alloy spherical powder, Inconel 738 alloy spherical powder, Haynes 188 alloy spherical powder, Aloy R41 alloy spherical powder, and Rene '88DT alloy spherical powder.

2. A high wear resistant carbide drill bit according to claim 1, characterized in that: The main cemented carbide powder is composed of tungsten carbide with the following different particle sizes: 5-20 wt% tungsten carbide with a particle size of 50-500 nm, 10-30 wt% tungsten carbide with a particle size of 20-45 μm, and the balance being tungsten carbide with a particle size of 1-15 μm.

3. A high wear resistant carbide drill bit according to claim 1, characterized in that: The median diameter D50 of the auxiliary alloy powder is 2-15 μm; the median diameter D50 of the toughening carbide is 0.05-15 μm.

4. The high wear-resistant carbide drill bit according to claim 1, characterized in that: The high wear-resistant carbide drill bit is made from the following raw materials by the MIM process in the following mass percentages: 0.15-0.30 wt% high-purity boron powder and 9-10 wt% MIM binder, with the balance being high wear-resistant carbide powder.

5. A high wear-resistant carbide drill bit according to claim 1, characterized in that: The cemented carbide powder is composed of WC, Cr3C2, and HfC in a mass ratio of (90-95):(4-8):(1-2).

6. A method for preparing a high wear-resistant cemented carbide drill bit according to any one of claims 1-5, characterized in that: Includes the following steps: S1. Preparation of cemented carbide powder; S2. Place the accurately measured cemented carbide powder and PM binder into a planetary ball mill and perform planetary ball milling for 1-4 hours to obtain high wear-resistant cemented carbide powder. S3. The high wear-resistant cemented carbide powder, sintering aid, and MIM binder are placed in an internal mixer and mixed to obtain a high wear-resistant cemented carbide feedstock; the sintering aid is ultrafine boron powder. S4. Drill bit blanks are obtained by injection molding using high wear-resistant cemented carbide feedstock; S5. High wear-resistant cemented carbide drill bits can be obtained by vacuum sintering after catalytic degreasing of the drill bit blank.

7. The method for preparing a high wear-resistant cemented carbide drill bit according to claim 6, characterized in that: The catalytic degreasing method in S5 is fuming nitric acid degreasing; the vacuum sintering parameters in S5 are as follows: under vacuum conditions, heat from room temperature to 550±50℃ at a heating rate of 10±2℃ / min and hold for 2-4 hours, heat to 1850±150℃ at a heating rate of 15-20℃ / min and hold for 0.5-1 hours, cool with the furnace to 1400±150℃ and hold for 2-6 hours, and then cool with the furnace to room temperature to obtain a high wear-resistant cemented carbide drill bit.

8. The method for preparing a high wear-resistant cemented carbide drill bit according to claim 6, characterized in that: It also includes S6. Heat treatment of high wear-resistant cemented carbide drill bits: Under vacuum conditions, heat from room temperature to 1050-1250℃ at a heating rate of 15-20℃ / min and hold for 10-20min, introduce a reducing gas, wherein the reducing gas is any one of hydrogen, carbon monoxide, hydrogen / carbon monoxide mixture, hydrogen / nitrogen mixture, or carbon monoxide / nitrogen mixture; under the reducing gas atmosphere, control the furnace pressure at 1-3MPa, heat to 1400-1450℃ and hold for 60-120min, and then gas quench and cool to room temperature.

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