A multi-zone gradient cemented carbide material and a method for producing the same

Abstract

The present application provides a kind of multi-zone gradient hard alloy material, it is related to the field of hard alloy material, including drill tip area, transition area and drill handle area from outer layer to inner layer, drill tip area composition includes AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C, transition area composition includes WC, Co, ZrC, nanoparticle, NbC and carbon nanotube, drill handle area composition includes WC, Co, Ni and ZrC.The material is designed by gradient structure, effectively reduce the interface stress concentration in sintering process, improve material hardness and wear resistance, so as to improve the overall crack resistance of structure, service stability and service life, suitable for the field of complex impact load such as mine drilling, geological survey.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cemented carbide material, and particularly relates to a multi-region gradient cemented carbide material and a preparation method thereof. BACKGROUND

[0002] The cemented carbide drill bit is a high-performance drilling tool mainly composed of tungsten carbide (WC) and cobalt (Co) as a binder, and is manufactured through a powder metallurgy process. The cemented carbide drill bit has high hardness (HRA 89-93), excellent wear resistance and thermal stability, and is widely used in the fields of mechanical manufacturing, aerospace, mine drilling and geological exploration. However, under the conditions of mine drilling and geological exploration, due to uneven strata (i.e., alternating appearance of quartz particles in hard rock and argillaceous interlayer in soft rock, resulting in sudden change of cutting resistance), poor chip removal (for example, rock powder is accumulated at the bottom of the hole, and when the rock powder is extruded, the reaction force impacts the drill bit, causing “secondary impact”), and dynamic response lag of equipment, the cemented carbide drill bit is subjected to complex impact load (including impact stress peak value far exceeding the bending strength limit of ordinary cemented carbide, alternating stress caused by alternating strata of hard interlayer and soft rock layer, and three-dimensional composite stress field formed by axial impact, radial vibration and circumferential torque fluctuation). The traditional double-layer composite structure of the cemented carbide drill bit is prone to interface stress concentration due to composition mutation, which not only increases the risk of crack propagation and fracture, reduces the service life and reliability of the drill bit, but also easily causes deformation of the drill bit, leading to sticking of the drill bit, thereby reducing the drilling and exploration efficiency, and even causing safety hazards in the drilling and exploration process. SUMMARY

[0003] In view of the problems existing in the prior art, the present application aims to provide a multi-region gradient cemented carbide material. The material is designed with a gradient structure, which effectively reduces the interface stress concentration in the sintering process and improves the hardness and wear resistance of the material, thereby improving the crack resistance, service stability and service life of the overall structure, and is suitable for fields with complex impact load such as mine drilling and geological exploration.

[0004] Another object of the present application is to provide a preparation method of the multi-region gradient cemented carbide material.

[0005] The object of the present application is achieved by the following technical solutions.

[0006] A multi-region gradient cemented carbide material comprises a drill tip region, a transition region and a drill shank region from the outer layer (i.e., the front end of the drill bit) to the inner layer (i.e., the rear end). The drill tip region comprises AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C. The transition region comprises WC, Co, ZrC, nano-particles, NbC and carbon nanotubes. The drill shank region comprises WC, Co, Ni and ZrC. The drill tip region comprises AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C. The transition region comprises WC, Co, ZrC, nano-particles, NbC and carbon nanotubes. The drill shank region comprises WC, Co, Ni and ZrC.

[0007] Further optimization based on the above scheme, the drill tip area thickness is 0.3 μm ~ 0.9 μm, the transition zone thickness is 0.3 μm ~ 1.0 μm, the drill handle area thickness is 0.9 μm ~ 3.0 μm.

[0008] Further optimization based on the above scheme, the content of each component (i.e. AlTiN, TiCN, ZrC, SiC-B4C composite particles and Mo2C) in the drill tip area is: 3 ~ 5wt%, 88 ~ 92wt%, 1 ~ 2wt%, 2.5 ~ 3.5wt%, 0.3 ~ 0.7wt%, TaC is set on the side of the drill tip area close to the transition zone, the thickness is 40 ~ 60 μm; wherein, the powder particle size of AlTiN, TiCN, ZrC is 0.1 ~ 0.2 μm; the particle size of SiC-B4C composite particles is 0.1 ~ 0.3 μm, the mass ratio of SiC to B4C in the composite particles is 1:1; the particle size of TaC powder is 50 ~ 100 nm; the particle size of Mo2C powder is 0.1 ~ 0.3 μm.

[0009] Further optimization based on the above scheme, the content of each component (i.e. WC, Co, ZrC, nanoparticles and carbon nanotubes) in the transition zone is: 75 ~ 79wt%, 14 ~ 18wt%, 3 ~ 5wt%, 2 ~ 3wt%, 0.4 ~ 0.6wt%, NbC is set on the side of the transition zone close to the drill tip area, the thickness is 40 ~ 60 μm; wherein, the powder particle size of WC, Co, ZrC is 0.5 ~ 1.0 μm; the particle size of the particles is 50 ~ 80 nm; the particle size of NbC powder is 50 ~ 100 nm; the length of the carbon nanotube is 5 ~ 10 μm.

[0010] Further optimization based on the above scheme, the content of each component (i.e. WC, Co, Ni and ZrC) in the drill handle area is: 65 ~ 69wt%, 24 ~ 28wt%, 3 ~ 4wt%, 3 ~ 4wt%; wherein, the powder particle size of WC, Co, Ni, ZrC is 2 ~ 5 μm.

[0011] A preparation method of a multi-region gradient cemented carbide material, comprising:

[0012] Step S1, drill tip area preparation: first, the components of the drill tip area are proportioned, and the SiC-B4C composite particles and TaC powder are pretreated; then, in the high-energy planetary grinding machine under the protection of inert gas, the grinding ball is a WC-Co alloy ball with a diameter of 5 mm, the dispersion medium is anhydrous ethanol and oleic acid, first add TiCN, ZrC, Mo2C for ball milling, then add AlTiN and SiC-B4C composite particles, ultrasonic dispersion and then ball milling; the slurry after ball milling is vacuum dried to obtain the drill tip area preparation powder;

[0013] Step S2, transition zone preparation: first, prepare (W, Zr)C solid solution powder in proportion; then, mix part of (W, Zr)C solid solution powder, Co powder and carbon nanotubes to generate in-situ adsorbed carbon nanotube nanoparticles; nanoparticles; then, add Co powder and the remaining (W, Zr)C solid solution powder, and mix and mill in an argon atmosphere; after vacuum drying of the mixed powder, reduce in a tube furnace by passing hydrogen gas; after reduction, vacuum mill, spray dry, and obtain transition zone preliminary powder;

[0014] Step S3, shank zone preparation: using gas atomization, melt Co powder and Ni powder in proportion to obtain Co-Ni pre-alloy powder; mix (W, Zr)C solid solution powder prepared in proportion with Co-Ni pre-alloy powder, add grain inhibitors in ethanol as medium, and mix and mill in an argon atmosphere; after vacuum drying of the mixed powder, reduce in a tube furnace by passing hydrogen gas; after reduction, vacuum mill, spray dry, and obtain shank zone preliminary powder;

[0015] Step S4, material forming: layer by layer press the shank zone preliminary powder, transition zone preliminary powder and drill tip zone preliminary powder in order of shank zone, transition zone and drill tip zone; during layer by layer pressing, lay NbC layer and TaC layer on the surface of the transition zone away from the shank zone in turn; finally, perform gradient hot isostatic pressing diffusion in a nitrogen atmosphere to obtain a cemented carbide material.

[0016] Based on further optimization of the above scheme, the specific method for "pretreating SiC-B4C composite particles and TaC powder" in step S1 is: surface modification of the milled SiC-B4C composite particles using silane coupling agent (KH550), with silane coupling agent accounting for 0.8-1.2wt% of SiC-B4C composite particles; vacuum drying of TaC powder at a temperature of 110-130℃ for 1.5-2.5h.

[0017] Based on further optimization of the above scheme, the rotation speed for ball milling after first adding TiCN, ZrC and Mo2C in step S1 is 280-320rpm for 0.8-1.2h; the rotation speed for ball milling after adding AlTiN and SiC-B4C composite particles is 380-420rpm for 1.8-2.2h, and the frequency for ultrasonic dispersion is 18-22kHz for 28-32min.

[0018] Based on further optimization of the above scheme, the preparation process of (W,Zr)C solid solution powder in steps S2 and S3 is as follows: tungsten powder, zirconium powder, and graphite powder are weighed separately, rare earth element oxides are added, and then the raw materials and tungsten carbide balls are loaded into a stainless steel vacuum ball mill jar for high-energy ball milling at a speed of 480–520 rpm for 7.5–8.5 h. The milled product is then placed in a high-temperature atmosphere furnace and subjected to a thermochemical reaction at 800–900°C for 1.5–2.5 h under a nitrogen-hydrogen mixed gas atmosphere (nitrogen to hydrogen volume ratio of 5–10:1–2) for 1.5–2.5 h to obtain (W,Zr)C solid solution powder.

[0019] Based on further optimization of the above scheme, the rare earth element is any one of La, Ce, Pr, Nd, Pm, Sm, and Eu.

[0020] Based on further optimization of the above scheme, in step S2, the in-situ generation of surface-adsorbed carbon nanotubes... The nanoparticles specifically consist of a portion of (W, Zr)C solid solution powder mixed with Co powder according to... The mixture was prepared with an atomic ratio of Co:W = 1:1, and nano-tungsten powder (approximately 50 nm in particle size) and carbon nanotubes were added. The mixture was then ball-milled in an argon atmosphere to obtain a precursor. The precursor was then placed in a tube furnace, through which hydrogen gas was introduced, and heated to generate carbon nanotubes adsorbed on the surface. Nanoparticles.

[0021] Based on further optimization of the above scheme, the ball milling speed for the precursor preparation step is 280-320 rpm and the time is 3.5-4.5 h; the heating temperature for hydrogen reduction in the tube furnace is 830-870℃ and the holding time is 1.8-2.2 h.

[0022] Based on further optimization of the above scheme, the preparation of Co-Ni pre-alloyed powder by gas atomization in step S3 is specifically as follows: Co powder and Ni powder are melted at 1550-1650℃ in proportion, and then atomized with argon gas at a pressure of 0.45-0.55MPa to obtain pre-alloyed powder with a particle size of 2-5μm.

[0023] Based on further optimization of the above scheme, the crystal inhibitor in step S3 is VC, with a content of 0.3wt%.

[0024] Based on further optimization of the above scheme, in step S4, the layer pressing is pre-pressed using cold isostatic pressing, with a pressing pressure of 250-300 MPa and a time of 8-12 min.

[0025] Based on the further optimization of the above scheme, the gradient hot isostatic pressing diffusion in the step S4 is specifically: first, at 1080-1120 DEG C, 90-110 MPa, heat preservation 0.9-1.1 h; then at 1330-1370 DEG C, 115-135 MPa, heat preservation 1.9-2.1 h; finally at 1380-1420 DEG C, 140-160 MPa, heat preservation 1.9-2.1 h.

[0026] The following is the technical effect of the present scheme:

[0027] The present application is composed of the drill tip area of AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C, and the transition area of WC, Co, ZrC, nanoparticles, NbC and carbon nanotubes, which are matched, first, the glass phase generated by the SiC-B4C composite particles is used for crack filling and crack propagation inhibition to form self-repair, avoid the aging acceleration of the hard alloy under complex impact load and the cracks or delamination caused by the chemical bond difference of each component in the drill tip area, and at the same time, the hard and brittle phase formed between the composite particles and AlTiN, TiCN is used for cooperation and enhancement of the overall hardness of the material surface (hardness ≥ 95HRA); second, the in-situ generated nanoparticles form a grain boundary pinning phase, which not only inhibits grain growth, maintains the fine grain structure of the transition area, avoids the agglomeration between powders, but also effectively inhibits the decomposition of nanoparticles at high temperature, improves the overall bending strength of the material (bending strength ≥ 3600 MPa); third, the solid solution formed by TaC and NbC under hot isostatic pressing diffusion, not only uses the solid solution to pin the grain boundary migration and "bridge" the interface on both sides to relieve the interface stress concentration and enhance the bonding strength between the drill tip area and the transition area, but also effectively avoids the diffusion of elements (such as Ti and Al) in the drill tip area to the transition area and the diffusion of elements (such as Co) in the transition area to the drill tip area, ensuring the strength and toughness of the overall hard alloy material; fourth, the cooperation between the plastic phase Mo2C and TaC, NbC effectively buffers the interface thermal stress while pinning the grain boundary, further improves the interface bonding strength, and avoids the problems of cracks, fractures or delamination between the drill tip area (TiCN with a thermal expansion coefficient of 7-8x10 -6 / K) and the transition area (WC-based transition area with a thermal expansion coefficient of 5-6x10 -6 / K) due to the large difference in expansion coefficient. In addition, through the three-layer structure setting of the drill tip area, the transition area and the shank area, not only the bonding strength between the layers is improved through the cooperation of the transition area (the gradient composition design of the transition area and the shank area ensures the bonding strength), but also the hard alloy has high fracture toughness (fracture toughness ≥ 21 MPa·m 1 / 2 ), ensuring the service life and reliability of the drill bit. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the cemented carbide material in an embodiment of the present invention. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] Example 1:

[0031] A multi-region gradient cemented carbide material includes a drill tip region, a transition region, and a drill shank region from the outer layer (i.e., the front end of the drill bit) to the inner layer (i.e., the rear end). The thickness of the drill tip region is 0.3 μm, the thickness of the transition region is 0.3 μm, and the thickness of the drill shank region is 0.9 μm. The drill tip region comprises AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC, and Mo2C. The contents of each component (AlTiN, TiCN, ZrC, SiC-B4C composite particles, and Mo2C) are 3 wt%, 92 wt%, 1 wt%, 3.5 wt%, and 0.5 wt%, respectively. TaC is placed on the side of the drill tip region near the transition zone, with a thickness of 40 μm. The particle size of AlTiN, TiCN, and ZrC powders is 0.1–0.2 μm; the particle size of the SiC-B4C composite particles is 0.1–0.3 μm, with a SiC to B4C mass ratio of 1:1; the particle size of the TaC powder is 50–100 nm; and the particle size of the Mo2C powder is 0.1–0.3 μm. The transition zone comprises WC, Co, ZrC, and... Nanoparticles, NbC, and carbon nanotubes, each component (i.e., WC, Co, ZrC, ... The contents of nanoparticles and carbon nanotubes are 75wt%, 18wt%, 5wt%, 1.6wt%, and 0.4wt%, respectively. NbC is placed on the side of the transition zone near the drill tip with a thickness of 40μm. The powder particle size of WC, Co, and ZrC is 0.5-1.0μm. The particle size is 50–80 nm; the NbC powder particle size is 50–100 nm; and the carbon nanotube length is 5–10 μm. The drill shank region composition includes WC, Co, Ni, and ZrC, with the contents of each component (i.e., WC, Co, Ni, and ZrC) being 65 wt%, 28 wt%, 4 wt%, and 3 wt%, respectively; among them, the powder particle size of WC, Co, Ni, and ZrC is 2–5 μm.

[0032] A method for preparing a multi-region gradient cemented carbide material includes:

[0033] Step S1, drill tip zone preparation: first, the components of the drill tip zone are proportioned, and the SiC-B4C composite particles and TaC powder are pretreated; specifically: the SiC-B4C composite particles (i.e., SiC particles and B4C particles are mixed and ball milled at a mass ratio of 1:1 to obtain SiC-B4C composite particles with a particle size of 0.1-0.3 μm) after ball milling are surface modified with a silane coupling agent (KH550), and the silane coupling agent accounts for 0.8 wt% of the SiC-B4C composite particles (enhancing wettability); the TaC powder is vacuum dried at a temperature of 110°C for 2.5 h (to remove adsorbed water and avoid the formation of pores during the sintering process).

[0034] Then, in a high-energy planetary mill under the protection of an inert gas (such as argon), the ball-to-material ratio is 10:1, the grinding balls are WC-Co alloy balls with a diameter of 5 mm, the dispersion medium is anhydrous ethanol (solid-to-liquid ratio 1:1.2) and oleic acid (amount 0.3 wt%), TiCN, ZrC, and Mo2C are first ball milled, the ball milling speed is 280 rpm, and the time is 1.2 h; then AlTiN and SiC-B4C composite particles are added, ultrasonic dispersion is performed, the ultrasonic dispersion frequency is 18 kHz, the time is 32 min, the rotation speed is 380 rpm, and the time is 2.2 h; the slurry after ball milling is vacuum dried (vacuum drying temperature is 100°C, time is 2.5 h), and the drill tip zone preliminary powder is obtained.

[0035] Step S2, transition zone preparation: first, the (W, Zr)C solid solution powder is prepared according to the proportions, specifically: tungsten powder, zirconium powder, and graphite powder are weighed according to the mass ratio of WC and ZrC in the transition zone, rare earth oxides are added, and the rare earth element is La, then the raw materials and tungsten carbide balls are loaded into a stainless steel vacuum ball mill jar for high-energy ball milling (ball-to-material ratio is 8:1), the ball milling speed is 480 rpm, and the time is 8.5 h; then the ball-milled product is placed in a high-temperature atmosphere furnace, and a hot combination reaction is carried out at a temperature of 800°C in an atmosphere of nitrogen-hydrogen mixed gas (volume ratio of nitrogen to hydrogen is 5:1), and the reaction time is 2.5 h, to obtain the (W, Zr)C solid solution powder.

[0036] Then, part of the (W, Zr)C solid solution powder (the amount of W element in the (W, Zr)C solid solution powder here is consistent with the amount of W element in the nanometer particles) and Co powder are mixed according to a mass ratio of 1:1, and the mixture is vacuum dried at a temperature of 100°C for 2.5 h to obtain the transition zone preliminary powder. atom ratio (i.e. Co:W = 1:1) and nano-tungsten powder (particle size of about 50 nm, the atom ratio of nano-tungsten powder to cobalt powder is 1:1, used for supplementing tungsten) and carbon nanotubes are mixed and ball milled in an argon atmosphere, the ball milling speed is 280 rpm, and the ball milling time is 4.5 h, to obtain a precursor; the precursor is placed in a tube furnace, hydrogen is introduced into the tube furnace (hydrogen flow is 6 L / min), and the surface adsorbed carbon nanotube nanoparticle is generated by heating at 830 ℃ for 2.2 h.

[0037] Then, Co powder and the remaining (W, Zr)C solid solution powder are added, mixed and ball milled in an argon atmosphere, the ball milling speed is 280 rpm, and the ball milling time is 3 h; the mixed powder is vacuum dried (vacuum drying temperature is 100 ℃, and the time is 2.5 h), and then reduced in a tube furnace by introducing hydrogen (hydrogen flow is 8 L / min, and the holding time is 600 ℃ for 2.5 h); after reduction, vacuum ball milling (ball milling speed is 280 rpm, and the time is 3 h) and spray drying (conventional spray drying method can be used) are performed, to obtain a transition zone preparation powder.

[0038] Step S3, shank zone preparation: Co powder and Ni powder are melted in proportion by gas atomization method, to obtain Co-Ni pre-alloy powder, specifically: Co powder and Ni powder are melted in proportion at 1550 ℃, and then argon gas atomization is used to prepare pre-alloy powder with a particle size of 2-5 μm under a pressure of 0.45 MPa. At the same time, (W, Zr)C solid solution powder is prepared according to the mass ratio of WC to ZrC in the shank zone (the preparation method is the same as step S2).

[0039] (W, Zr)C solid solution powder prepared by mixing in proportion and Co-Ni pre-alloy powder are mixed and ball milled in an argon atmosphere with ethanol as a medium and VC as a grain inhibitor, the content of VC is 0.3 wt%, the ball milling ratio is 8:1, the ball milling speed is 180 rpm, and the ball milling time is 2.2 h; the mixed powder is vacuum dried (vacuum drying temperature is 100 ℃, and the time is 2.5 h), and then reduced in a tube furnace by introducing hydrogen (hydrogen flow is 8 L / min, and the holding time is 600 ℃ for 2.5 h); after reduction, vacuum ball milling (ball milling speed is 180 rpm, and the time is 2.2 h) and spray drying (conventional spray drying method can be used) are performed, to obtain a shank zone preparation powder.

[0040] Step S4, material forming: the drill shank area, transition area, drill tip area in order to drill shank area, transition area, drill tip area of the preparation of the powder layering pressing, layering pressing process, transition area away from the drill shank area on the side surface of NbC layer and TaC layer (i.e. first pressing drill shank area, then pressing transition, then NbC layer and TaC layer, and finally pressing drill tip area) ; Layering pressing using cold isostatic pressing pre-pressing, pressing pressure is 250 MPa, time is 12 min.

[0041] Finally, under nitrogen atmosphere, gradient hot isostatic pressing diffusion, specifically: first at 1080℃, 90 MPa, 1.1 h; Then at 1330℃, 115 MPa, 2.1 h; Finally at 1380℃, 140 MPa, 2.1 h; Obtain the hard alloy material.

[0042] Example 2:

[0043] A multi-region gradient hard alloy material, from the outer layer (i.e. drill bit front end) to the inner layer (i.e. rear end) includes drill tip area, transition area and drill shank area, drill tip area thickness is 0.6 μm, transition area thickness is 0.6 μm, drill shank area thickness is 2.0 μm. Drill tip area composition includes AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C, the content of each component (i.e. AlTiN, TiCN, ZrC, SiC-B4C composite particles and Mo2C) is: 4wt%, 90wt%, 1.5wt%, 3wt%, 0.5wt%, TaC is set on the side of the drill tip area close to the transition area, the thickness is 50 μm; Among them, the powder particle size of AlTiN, TiCN, ZrC is 0.1-0.2 μm; The particle size of SiC-B4C composite particles is 0.1-0.3 μm, the mass ratio of SiC to B4C in the composite particles is 1:1; The particle size of TaC powder is 50-100 nm; The particle size of Mo2C powder is 0.1-0.3 μm. Transition area composition includes WC, Co, ZrC, nanoparticles, NbC and carbon nanotubes, the content of each component (i.e. WC, Co, ZrC, nanoparticles and carbon nanotubes) is: 77wt%, 16wt%, 4wt%, 2.5wt%, 0.5wt%, NbC is set on the side of the transition area close to the drill tip area, the thickness is 50 μm; Among them, the powder particle size of WC, Co, ZrC is 0.5-1.0 μm; The particle size of the particles is 50-80 nm; the particle size of the NbC powder is 50-100 nm; and the length of the carbon nanotube is 5-10 μm. The shank region composition comprises WC, Co, Ni and ZrC, and the content of each component (i.e. WC, Co, Ni and ZrC) is 67 wt%, 26 wt%, 3.5 wt% and 3.5 wt% respectively; wherein the powder particle size of WC, Co, Ni and ZrC is 2-5 μm.

[0044] A preparation method of a multi-region gradient cemented carbide material, comprising:

[0045] Step S1, drill tip region preparation: first, the components of the drill tip region are proportioned, and SiC-B4C composite particles and TaC powder are pretreated; specifically: the surface of the ball-milled SiC-B4C composite particles (i.e. SiC particles and B4C particles are mixed and ball-milled at a mass ratio of 1:1 to obtain SiC-B4C composite particles with a particle size of 0.1-0.3 μm) is modified with a silane coupling agent (KH550), and the silane coupling agent accounts for 1 wt% of the SiC-B4C composite particles (enhancing wettability); the TaC powder is vacuum dried at a temperature of 120°C for 2 h (to remove adsorbed water and avoid the formation of pores during the sintering process).

[0046] Then, in a high-energy planetary mill under the protection of an inert gas (such as argon), the ball-to-powder ratio is 10:1, the grinding balls are WC-Co alloy balls with a diameter of 5 mm, the dispersion medium is anhydrous ethanol (solid-liquid ratio 1:1.2) and oleic acid (amount 0.3 wt%), TiCN, ZrC and Mo2C are first ball-milled, the ball-milling speed is 300 rpm and the time is 1 h; then AlTiN and SiC-B4C composite particles are ball-milled after ultrasonic dispersion, the ultrasonic dispersion frequency is 20 kHz and the time is 30 min, the ball-milling speed is 400 rpm and the time is 2 h; the ball-milled slurry is vacuum dried (vacuum drying temperature is 110°C and the time is 2 h) to obtain the drill tip region preliminary powder.

[0047] Step S2, transition region preparation: first, the (W, Zr)C solid solution powder is prepared in proportion, specifically: tungsten powder, zirconium powder and graphite powder are weighed according to the mass ratio of WC and ZrC in the transition region, rare earth oxides are added, and the rare earth element is Ce, then the raw materials and tungsten carbide balls are loaded into a stainless steel vacuum ball mill pot for high-energy ball milling (ball-to-powder ratio is 8:1), the ball-milling speed is 500 rpm and the time is 8 h; then the ball-milled product is placed in a high-temperature atmosphere furnace and subjected to a thermal combination reaction in a nitrogen-hydrogen mixed gas atmosphere (volume ratio of nitrogen to hydrogen is 7:1.5) at a temperature of 850°C for 2 h to obtain the (W, Zr)C solid solution powder.

[0048] Then, a portion of the (W, Zr)C solid solution powder (the amount of W in the (W, Zr)C solid solution powder here is related to...) (The W element content in the nanoparticles remains consistent) and is consistent with that of the Co powder. The mixture was prepared with a Co:W ratio of 1:1, and nano-tungsten powder (approximately 50 nm in particle size, with an atomic ratio of 1:1 to cobalt powder to supplement tungsten) and carbon nanotubes were added. The mixture was then ball-milled in an argon atmosphere at 300 rpm for 4 hours to obtain a precursor. The precursor was then placed in a tube furnace, which was purged with hydrogen gas (6 L / min) and heated to generate carbon nanotubes adsorbed on the surface. Nanoparticles were heated to 850℃ and held for 2 hours.

[0049] Subsequently, Co powder and the remaining (W, Zr)C solid solution powder were added and mixed and ball-milled under an argon atmosphere at a speed of 300 rpm for 2.5 h. The mixed powder was then vacuum-dried (at a temperature of 110 °C for 2 h) and reduced again in a tube furnace by hydrogen (hydrogen flow rate of 8 L / min, holding time of 700 °C for 2 h). After reduction, the powder was vacuum-ball-milled (at a speed of 300 rpm for 2.5 h) and spray-dried (using conventional spray drying methods) to obtain the transition zone preparatory powder.

[0050] Step S3, Drill Shank Region Preparation: Co powder and Ni powder are melted in a specific ratio using an air atomization method to obtain Co-Ni pre-alloyed powder. Specifically, Co powder and Ni powder are melted at 1600℃ in a specific ratio, and then atomized with argon gas at a pressure of 0.5 MPa to obtain pre-alloyed powder with a particle size of 2–5 μm. Simultaneously, (W, Zr)C solid solution powder is prepared according to the mass ratio of WC to ZrC in the drill shank region (preparation method is described in step S2).

[0051] (W, Zr)C solid solution powder and Co-Ni pre-alloy powder were mixed in proportion, and ethanol was used as the medium with the addition of a grain inhibitor, VC (0.3 wt%), and the mixture was ball-milled under an argon atmosphere at a ball-to-powder ratio of 8:1, a ball milling speed of 200 rpm, and a ball milling time of 2 h. The mixed powder was then vacuum dried (vacuum drying temperature of 110℃ for 2 h) and reduced in a tube furnace with hydrogen (hydrogen flow rate of 8 L / min, holding time of 700℃ for 2 h). After reduction, the powder was vacuum ball-milled (ball milling speed of 200 rpm for 2 h) and spray-dried (using conventional spray drying methods) to obtain the pre-powder for the drill shank area.

[0052] Step S4, material forming: the drill shank area, transition area, drill tip area in order to drill shank area, transition area, drill tip area of the preparation of powder layering pressing, layering pressing process, transition area away from the drill shank area, one side surface of NbC layer and TaC layer (i.e. first pressing drill shank area, then pressing transition, then NbC layer and TaC layer, finally pressing drill tip area) ; Layering pressing using cold isostatic pressing pre-pressing, pressing pressure is 275 MPa, time is 10 min.

[0053] Finally, under nitrogen atmosphere, gradient hot isostatic pressing diffusion, specifically: first at 1100 DEG C, 100 MPa, 1 h; Then at 1350 DEG C, 125 MPa, 2 h; Finally at 1400 DEG C, 150 MPa, 2 h; Obtain the hard alloy material.

[0054] Example 3:

[0055] A multi-region gradient hard alloy material, from the outer layer (i.e. drill bit front end) to the inner layer (i.e. rear end) includes drill tip area, transition area and drill shank area, drill tip area thickness is 0.9 μm, transition area thickness is 1.0 μm, drill shank area thickness is 3.0 μm. Drill tip area composition includes AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C, the content of each component (i.e. AlTiN, TiCN, ZrC, SiC-B4C composite particles and Mo2C) is: 5wt%, 89wt%, 2wt%, 3.3wt%, 0.7wt%, TaC is set on the side of the drill tip area close to the transition area, the thickness is 60 μm; Among them, the powder particle size of AlTiN, TiCN, ZrC is 0.1-0.2 μm; The particle size of SiC-B4C composite particles is 0.1-0.3 μm, the mass ratio of SiC to B4C in the composite particles is 1:1; The particle size of TaC powder is 50-100 nm; The particle size of Mo2C powder is 0.1-0.3 μm. Transition area composition includes WC, Co, ZrC, nanoparticles, NbC and carbon nanotubes, the content of each component (i.e. WC, Co, ZrC, nanoparticles and carbon nanotubes) is: 79wt%, 14wt%, 4.6wt%, 2wt%, 0.4wt%, NbC is set on the side of the transition area close to the drill tip area, the thickness is 60 μm; Among them, the powder particle size of WC, Co, ZrC is 0.5-1.0 μm; The particle size of the particles is 50-80 nm; the particle size of the NbC powder is 50-100 nm; and the length of the carbon nanotube is 5-10 μm. The shank region composition comprises WC, Co, Ni and ZrC, and the content of each component (i.e. WC, Co, Ni and ZrC) is 69 wt%, 24 wt%, 4 wt% and 3 wt% in turn; wherein the powder particle size of WC, Co, Ni and ZrC is 2-5 μm.

[0056] A preparation method of a multi-region gradient cemented carbide material, comprising:

[0057] Step S1, drill tip region preparation: first, the components of the drill tip region are proportioned, and SiC-B4C composite particles and TaC powder are pretreated; specifically: the surface of the ball-milled SiC-B4C composite particles (i.e. SiC particles and B4C particles are mixed and ball-milled at a mass ratio of 1:1 to obtain SiC-B4C composite particles with a particle size of 0.1-0.3 μm) is modified by using a silane coupling agent (KH550), and the silane coupling agent accounts for 1.2 wt% of the SiC-B4C composite particles (enhancing wettability); the TaC powder is vacuum dried at a temperature of 130°C for 1.5 h (to remove adsorbed water and avoid the generation of pores during the sintering process).

[0058] Then, in a high-energy planetary mill under the protection of an inert gas (such as argon), the ball-to-powder ratio is 10:1, the grinding balls are WC-Co alloy balls with a diameter of 5 mm, the dispersion medium is anhydrous ethanol (solid-liquid ratio 1:1.2) and oleic acid (amount 0.3 wt%), TiCN, ZrC and Mo2C are first ball-milled, the ball-milling speed is 320 rpm and the time is 0.8 h; then AlTiN and SiC-B4C composite particles are ball-milled after ultrasonic dispersion, the ultrasonic dispersion frequency is 22 kHz and the time is 28 min, the ball-milling speed is 420 rpm and the time is 1.8 h; the ball-milled slurry is vacuum dried (vacuum drying temperature 120°C, time 1.5 h) to obtain the drill tip region preliminary powder.

[0059] Step S2, transition region preparation: first, the (W, Zr)C solid solution powder is prepared in proportion, specifically: tungsten powder, zirconium powder and graphite powder are weighed according to the mass ratio of WC and ZrC in the transition region, a rare earth element oxide is added, the rare earth element is Eu, then the raw materials and tungsten carbide balls are loaded into a stainless steel vacuum ball mill pot for high-energy ball milling (ball-to-powder ratio 8:1), the ball-milling speed is 520 rpm and the time is 7.5 h; then the ball-milled product is placed in a high-temperature atmosphere furnace and subjected to a thermal combination reaction in a nitrogen-hydrogen mixed gas atmosphere (volume ratio of nitrogen to hydrogen 5:2) at a temperature of 900°C for 1.5 h to obtain the (W, Zr)C solid solution powder.

[0060] Then, a portion of the (W, Zr)C solid solution powder (the amount of W in the (W, Zr)C solid solution powder here is related to...) (The W element content in the nanoparticles remains consistent) and is consistent with that of the Co powder. The mixture was prepared with a Co:W ratio of 1:1, and nano-tungsten powder (particle size of about 50 nm, with an atomic ratio of 1:1 to cobalt powder to supplement tungsten) and carbon nanotubes were added. The mixture was then ball-milled in an argon atmosphere at 320 rpm for 3.5 hours to obtain a precursor. The precursor was then placed in a tube furnace, which was purged with hydrogen gas (hydrogen flow rate 6 L / min) and heated to generate carbon nanotubes adsorbed on the surface. Nanoparticles were heated to 870℃ and held for 1.8 hours.

[0061] Subsequently, Co powder and the remaining (W, Zr)C solid solution powder were added and mixed and ball-milled under an argon atmosphere at a speed of 320 rpm for 2 hours. The mixed powder was then vacuum-dried (at a temperature of 120°C for 1.5 hours) and reduced again in a tube furnace by purging with hydrogen (hydrogen flow rate of 8 L / min, holding time of 800°C for 1.5 hours). After reduction, the powder was vacuum-ball-milled (at a speed of 320 rpm for 2 hours) and spray-dried (using conventional spray drying methods) to obtain the transition zone preparatory powder.

[0062] Step S3, Drill Shank Region Preparation: Co powder and Ni powder are melted in a specific ratio using an air atomization method to obtain Co-Ni pre-alloyed powder. Specifically, Co powder and Ni powder are melted at 1650℃ in a specific ratio, and then atomized with argon gas at a pressure of 0.55 MPa to obtain pre-alloyed powder with a particle size of 2–5 μm. Simultaneously, (W, Zr)C solid solution powder is prepared according to the mass ratio of WC to ZrC in the drill shank region (preparation method is described in step S2).

[0063] (W, Zr)C solid solution powder and Co-Ni pre-alloy powder were mixed in proportion, and ethanol was used as the medium with the addition of a grain inhibitor, VC (0.3 wt%), and the mixture was ball-milled under an argon atmosphere at a ball-to-powder ratio of 8:1, a ball milling speed of 220 rpm, and a ball milling time of 1.8 h. The mixed powder was then vacuum dried (vacuum drying temperature of 120℃ for 1.5 h) and reduced in a tube furnace by hydrogen (hydrogen flow rate of 8 L / min, holding time of 800℃ for 1.5 h). After reduction, the powder was vacuum ball-milled (ball milling speed of 220 rpm for 1.8 h) and spray-dried (using conventional spray drying methods) to obtain the pre-powder for the drill shank area.

[0064] Step S4, material forming: the drill shank area, transition area, drill tip area in order to prepare the powder, transition area, drill tip area of the prepared powder layering pressing, layering pressing process, transition area away from the drill shank area on the side surface in turn laying NbC layer and TaC layer (i.e. first pressing drill shank area, then pressing transition, then laying NbC layer and TaC layer in turn, and finally pressing drill tip area); layering pressing using cold isostatic pressing for pre-pressing, the pressing pressure is 300 MPa, the time is 8 min.

[0065] Finally, gradient hot isostatic pressing diffusion under nitrogen atmosphere, specifically: first at 1120℃, 110 MPa, 0.9 h; then at 1370℃, 135 MPa, 1.9 h; finally at 1420℃, 160 MPa, 1.9 h; obtain cemented carbide material.

[0066] Comparative example 1:

[0067] A kind of cemented carbide material, from outer layer (i.e. drill bit front end) to inner layer (i.e. rear end) includes drill tip area, transition area and drill shank area, drill tip area thickness is 0.6 μm, transition area thickness is 0.6 μm, drill shank area thickness is 2.0 μm. Drill tip area composition includes AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C, the content of each component (i.e. AlTiN, TiCN, ZrC, SiC-B4C composite particles and Mo2C) is: 4wt%, 90wt%, 1.5wt%, 3wt%, 0.5wt%, TaC is set on the side of drill tip area close to transition area, thickness is 50 μm;Among them, the powder particle size of AlTiN, TiCN, ZrC is 0.1-0.2 μm;The particle size of SiC-B4C composite particles is 0.1-0.3 μm, the mass ratio of SiC and B4C in composite particles is 1:1;The particle size of TaC powder is 50-100 nm;The particle size of Mo2C powder is 0.1-0.3 μm. Transition area composition includes WC, Co, ZrC, nanoparticles and carbon nanotubes, the content of each component (i.e. WC, Co, ZrC, nanoparticles and carbon nanotubes) is: 77wt%, 16wt%, 4wt%, 2.5wt%, 0.5wt%;Among them, the powder particle size of WC, Co, ZrC is 0.5-1.0 μm; The particle size of the particles is 50-80 nm;The length of carbon nanotubes is 5-10 μm. Drill shank area composition includes WC, Co, Ni and ZrC, the content of each component (i.e. WC, Co, Ni and ZrC) is: 67wt%, 26wt%, 3.5wt%, 3.5wt%;Among them, the powder particle size of WC, Co, Ni, ZrC is 2-5 μm.

[0068] Comparative Example 2:

[0069] A cemented carbide material, comprising a tip region, a transition region and a shank region from the outer layer (i.e. the front end of the drill) to the inner layer (i.e. the rear end), the thickness of the tip region is 0.6 μm, the thickness of the transition region is 0.6 μm, and the thickness of the shank region is 2.0 μm. The tip region comprises AlTiN, TiCN, ZrC, SiC-B4C composite particles and Mo2C, and the content of each component (i.e. AlTiN, TiCN, ZrC, SiC-B4C composite particles and Mo2C) is 4wt%, 90wt%, 1.5wt%, 3wt% and 0.5wt% respectively; wherein the powder particle size of AlTiN, TiCN and ZrC is 0.1-0.2 μm; the particle size of SiC-B4C composite particles is 0.1-0.3 μm, and the mass ratio of SiC to B4C in the composite particles is 1:1; the particle size of Mo2C powder is 0.1-0.3 μm. The transition region comprises WC, Co, ZrC, nanoparticles, NbC and carbon nanotubes, and the content of each component (i.e. WC, Co, ZrC, nanoparticles and carbon nanotubes) is 77wt%, 16wt%, 4wt%, 2.5wt% and 0.5wt% respectively; the NbC is arranged on the side of the transition region close to the tip region, and the thickness is 50 μm; wherein the powder particle size of WC, Co and ZrC is 0.5-1.0 μm; the particle size of the nanoparticles is 50-80 nm; the particle size of the NbC powder is 50-100 nm; and the length of the carbon nanotubes is 5-10 μm. The shank region comprises WC, Co, Ni and ZrC, and the content of each component (i.e. WC, Co, Ni and ZrC) is 67wt%, 26wt%, 3.5wt% and 3.5wt% respectively; wherein the powder particle size of WC, Co, Ni and ZrC is 2-5 μm.

[0070] Comparative Example 3:

[0071] A cemented carbide material, from the outer layer (i.e. the front end of the drill bit) to the inner layer (i.e. the rear end), comprises a drill tip area, a transition area and a shank area, the thickness of the drill tip area is 0.6 μm, the thickness of the transition area is 0.6 μm, and the thickness of the shank area is 2.0 μm. The drill tip area comprises AlTiN, TiCN, ZrC, B4C particles, TaC and Mo2C, the content of each component (i.e. AlTiN, TiCN, ZrC, B4C particles and Mo2C) is 4wt%, 90wt%, 1.5wt%, 3wt% and 0.5wt% respectively, TaC is arranged on the side of the drill tip area close to the transition area, and the thickness is 50 μm; wherein the powder particle size of AlTiN, TiCN and ZrC is 0.1-0.2 μm; the particle size of B4C particles is 0.1-0.3 μm; the particle size of TaC powder is 50-100 nm; and the particle size of Mo2C powder is 0.1-0.3 μm. The transition area comprises WC, Co, ZrC, nanoparticles, NbC and carbon nanotubes, the content of each component (i.e. WC, Co, ZrC, nanoparticles and carbon nanotubes) is 77wt%, 16wt%, 4wt%, 2.5wt% and 0.5wt% respectively, NbC is arranged on the side of the transition area close to the drill tip area, and the thickness is 50 μm; wherein the powder particle size of WC, Co and ZrC is 0.5-1.0 μm; the particle size of the particles is 50-80 nm; the particle size of NbC powder is 50-100 nm; and the length of the carbon nanotubes is 5-10 μm. The shank area comprises WC, Co, Ni and ZrC, the content of each component (i.e. WC, Co, Ni and ZrC) is 67wt%, 26wt%, 3.5wt% and 3.5wt% respectively; wherein the powder particle size of WC, Co, Ni and ZrC is 2-5 μm.

[0072] Comparative Example 4:

[0073] A cemented carbide material, from the outer layer (i.e. the front end of the drill bit) to the inner layer (i.e. the rear end), comprises a drill tip area, a transition area and a shank area, the thickness of the drill tip area is 0.6 μm, the thickness of the transition area is 0.6 μm, and the thickness of the shank area is 2.0 μm. The drill tip area comprises AlTiN, TiCN, ZrC, SiC-B4C composite particles and TaC, the content of each component (i.e. AlTiN, TiCN, ZrC and SiC-B4C composite particles) is 4wt%, 90wt%, 1.5wt% and 3.5wt% respectively; TaC is arranged on the side of the drill tip area close to the transition area, and the thickness is 50 μm; wherein the powder particle size of AlTiN, TiCN and ZrC is 0.1-0.2 μm; the particle size of SiC-B4C composite particles is 0.1-0.3 μm, and the mass ratio of SiC to B4C in the composite particles is 1:1; the particle size of TaC powder is 50-100 nm. The transition area comprises WC, Co, ZrC, nanoparticles, NbC and carbon nanotubes, the content of each component (i.e. WC, Co, ZrC, nanoparticles and carbon nanotubes) is 77wt%, 16wt%, 4wt%, 2.5wt% and 0.5wt% respectively; NbC is arranged on the side of the transition area close to the drill tip area, and the thickness is 50 μm; wherein the powder particle size of WC, Co and ZrC is 0.5-1.0 μm; the particle size of the nanoparticles is 50-80 nm; the particle size of NbC powder is 50-100 nm; the length of the carbon nanotubes is 5-10 μm. The shank area comprises WC, Co, Ni and ZrC, and the content of each component (i.e. WC, Co, Ni and ZrC) is 67wt%, 26wt%, 3.5wt% and 3.5wt% respectively; wherein the powder particle size of WC, Co, Ni and ZrC is 2-5 μm.

[0074] Comparative Example 5:

[0075] A cemented carbide material, from the outer layer (i.e. the front end of the drill bit) to the inner layer (i.e. the rear end), comprises a drill tip area, a transition area and a shank area, the thickness of the drill tip area is 0.6 μm, the thickness of the transition area is 0.6 μm, and the thickness of the shank area is 2.0 μm. The drill tip area comprises AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C, and the content of each component (i.e. AlTiN, TiCN, ZrC, SiC-B4C composite particles and Mo2C) is 4wt%, 90wt%, 1.5wt%, 3wt% and 0.5wt% respectively; TaC is arranged on the side of the drill tip area close to the transition area, and the thickness is 50 μm; wherein the powder particle size of AlTiN, TiCN and ZrC is 0.1-0.2 μm; the particle size of SiC-B4C composite particles is 0.1-0.3 μm, and the mass ratio of SiC to B4C in the composite particles is 1:1; the particle size of TaC powder is 50-100 nm; and the particle size of Mo2C powder is 0.1-0.3 μm. The transition area comprises WC, Co, ZrC, NbC and carbon nanotubes, and the content of each component (i.e. WC, Co, ZrC and carbon nanotubes) is 77wt%, 16wt%, 4wt% and 3wt% respectively; NbC is arranged on the side of the transition area close to the drill tip area, and the thickness is 50 μm; wherein the powder particle size of WC, Co and ZrC is 0.5-1.0 μm; the particle size of NbC powder is 50-100 nm; and the length of the carbon nanotubes is 5-10 μm. The shank area comprises WC, Co, Ni and ZrC, and the content of each component (i.e. WC, Co, Ni and ZrC) is 67wt%, 26wt%, 3.5wt% and 3.5wt% respectively; wherein the powder particle size of WC, Co, Ni and ZrC is 2-5 μm.

[0076] Comparative Example 6:

[0077] A cemented carbide material, from outer layer (i.e. drill bit front end) to inner layer (i.e. rear end) comprises a drill tip area, a transition area and a shank area, the drill tip area has a thickness of 0.6 μm, the transition area has a thickness of 0.6 μm, and the shank area has a thickness of 2.0 μm. The drill tip area comprises AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C, the content of each component (i.e. AlTiN, TiCN, ZrC, SiC-B4C composite particles and Mo2C) is 4wt%, 90wt%, 1.5wt%, 3wt% and 0.5wt% respectively, TaC is arranged on the side of the drill tip area close to the transition area and has a thickness of 50 μm; wherein the powder particle size of AlTiN, TiCN and ZrC is 0.1-0.2 μm; the particle size of SiC-B4C composite particles is 0.1-0.3 μm, the mass ratio of SiC to B4C in the composite particles is 1:1; the particle size of TaC powder is 50-100 nm; and the particle size of Mo2C powder is 0.1-0.3 μm. The transition area comprises WC, Co, ZrC, nanoparticles and NbC, the content of each component (i.e. WC, Co, ZrC and nanoparticles) is 77wt%, 16wt%, 4wt% and 3wt% respectively, NbC is arranged on the side of the transition area close to the drill tip area and has a thickness of 50 μm; wherein the powder particle size of WC, Co and ZrC is 0.5-1.0 μm; the particle size of the nanoparticles is 50-80 nm; and the particle size of NbC powder is 50-100 nm. The shank area comprises WC, Co, Ni and ZrC, the content of each component (i.e. WC, Co, Ni and ZrC) is 67wt%, 26wt%, 3.5wt% and 3.5wt% respectively; wherein the powder particle size of WC, Co, Ni and ZrC is 2-5 μm.

[0078] The cemented carbide materials prepared in Example 1-Example 3 and Comparative Example 1-6 are respectively tested for hardness, bending strength, cyclic wear resistance, fracture toughness and high temperature stability:

[0079] The hardness, bending strength and fracture toughness can be tested by using conventional testing methods in the art;

[0080] Cyclic wear resistance: wet corrosion wear is carried out in a 30% quartz sand aqueous solution (pH=3), the impact frequency is 5 Hz and the impact energy is 2 J, and the cycle is 200 h;

[0081] High temperature stability: thermal shock cycle is carried out at 800℃;

[0082] The test results are shown in the following table:

[0083]

[0084] In summary: the hard alloy material prepared by the method has high hardness, large bending strength and high fracture toughness, has excellent wear resistance and high temperature stability, has small internal stress and high bonding strength between layers, can realize near net forming of complex components, and has no cobalt phase enrichment, good dispersity, effectively eliminates brittle phase, and improves overall service reliability.

Claims

1. A multi-zone gradient cemented carbide material, characterized in that: The drill bit region consists of a drill tip area, a transition area, and a drill shank area, from the outermost layer to the innermost layer. The drill tip area is composed of AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC, and Mo2C. The contents of AlTiN, TiCN, ZrC, SiC-B4C composite particles, and Mo2C in the drill tip area are, in descending order: 3–5 wt%, 88–92 wt%, 1–2 wt%, 2.5–3.5 wt%, and 0.3–0.7 wt%. TaC is located on the side of the drill tip area near the transition area with a thickness of 40–60 μm. The particle size of AlTiN, TiCN, and ZrC powder is 0.1–0.2 μm; the particle size of SiC-B4C composite particles is 0.1–0.3 μm, and the mass ratio of SiC to B4C in the composite particles is 1:1; the particle size of TaC powder is 50–100 nm; and the particle size of Mo2C powder is 0.1–0.3 μm. The transition zone comprises WC, Co, ZrC, Co3W3C nanoparticles, NbC, and carbon nanotubes. The contents of WC, Co, ZrC, Co3W3C nanoparticles, and carbon nanotubes in the transition zone are, in descending order: 75–79 wt%, 14–18 wt%, 3–5 wt%, 2–3 wt%, and 0.4–0.6 wt%. NbC is located on the side of the transition zone closest to the drill tip, with a thickness of 40–60 μm. Specifically, the particle size of WC, Co, and ZrC powder is 0.5–1.0 μm; the particle size of Co3W3C particles is 50–80 nm; the particle size of NbC powder is 50–100 nm; and the length of the carbon nanotubes is 5–10 μm. The drill shank region is composed of WC, Co, Ni and ZrC, with the contents of WC, Co, Ni and ZrC in the drill shank region being 65-69 wt%, 24-28 wt%, 3-4 wt% and 3-4 wt% respectively; among which, the powder particle size of WC, Co, Ni and ZrC is 2-5 μm.

2. A method of producing a multi-zone gradient cemented carbide material according to claim 1, characterized in that: include: Step S1, Drill Tip Region Preparation: First, the components of the drill tip region are proportioned according to the specifications, and the SiC-B4C composite particles and TaC powder are pretreated. Then, in a high-energy planetary mill under inert gas protection, the grinding balls are WC-Co alloy balls with a diameter of 5 mm, and the dispersion medium is anhydrous ethanol and oleic acid. TiCN, ZrC, and Mo2C are added first for ball milling, and then AlTiN and SiC-B4C composite particles are added. After ultrasonic dispersion, they are ball milled again. The slurry after ball milling is vacuum dried to obtain the drill tip region preparation powder. Step S2, Transition Zone Preparation: First, prepare (W, Zr)C solid solution powder according to the specified ratio; then mix part of the (W, Zr)C solid solution powder, Co powder and carbon nanotubes to generate Co3W3C nanoparticles with adsorbed carbon nanotubes in situ; then, add Co powder and the remaining (W, Zr)C solid solution powder, and mix and ball mill in an argon atmosphere; after vacuum drying, the mixed powder is reduced again by hydrogen in a tube furnace, and after reduction, it is vacuum ball milled and spray dried to obtain the transition zone preparatory powder; Step S3, Drill Shank Region Preparation: Co powder and Ni powder are melted in a certain proportion using a gas atomization method to obtain Co-Ni pre-alloy powder; the (W,Zr)C solid solution powder prepared in a certain proportion is mixed with the Co-Ni pre-alloy powder, and the mixture is ball-milled under an argon atmosphere with ethanol as the medium and grain inhibitor added; the mixed powder is vacuum dried and then reduced by hydrogen in a tube furnace. After reduction, it is vacuum ball-milled and spray-dried to obtain the drill shank region preparatory powder; Step S4, Material Forming: The preparatory powders for the drill shank area, the transition area, and the drill tip area are layered and pressed in the order of drill shank area, transition area, and drill tip area. During the layer pressing process, NbC layer and TaC layer are sequentially laid on the surface of the transition area away from the drill shank area. Finally, gradient hot isostatic diffusion is carried out under nitrogen atmosphere to obtain cemented carbide material.

3. A method of producing a multi-zone gradient cemented carbide material according to claim 2, characterized in that: The specific method for "pretreatment of SiC-B4C composite particles and TaC powder" in step S1 is as follows: the surface of the ball-milled SiC-B4C composite particles is modified with a silane coupling agent, the silane coupling agent accounting for 0.8 to 1.2 wt% of the SiC-B4C composite particles; the TaC powder is vacuum dried at a temperature of 110 to 130°C for 1.5 to 2.5 hours.

4. A method of producing a multi-zone gradient cemented carbide material according to claim 2, characterized in that: In step S1, TiCN, ZrC, and Mo2C are first added and ball-milled at a speed of 280–320 rpm for 0.8–1.2 h; then AlTiN and SiC-B4C composite particles are added and ball-milled at a speed of 380–420 rpm for 1.8–2.2 h, and ultrasonically dispersed at a frequency of 18–22 kHz for 28–32 min.

5. The method for preparing a multi-region gradient cemented carbide material according to claim 2, characterized in that: In step S4, the layer pressing is pre-pressed using cold isostatic pressing, with a pressing pressure of 250-300 MPa and a time of 8-12 min.

6. The method for preparing a multi-region gradient cemented carbide material according to claim 2, characterized in that: The gradient thermal isostatic diffusion in step S4 specifically involves: first, maintaining the temperature at 1080–1120℃ and 90–110MPa for 0.9–1.1 h; then maintaining the temperature at 1330–1370℃ and 115–135MPa for 1.9–2.1 h; and finally maintaining the temperature at 1380–1420℃ and 140–160MPa for 1.9–2.1 h.

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