High-strength and high-wear-resistance polycrystalline diamond compact and preparation method thereof

Abstract

The application discloses a kind of high-strength high-wear-resistance polycrystalline diamond compact and preparation method thereof, belong to diamond and hard alloy composite material technical field.The polycrystalline diamond compact includes hard alloy matrix and transition composite coating, powder transition layer and polycrystalline diamond layer sequentially arranged on hard alloy matrix from inside to outside.The graphite and fullerene material are added in polycrystalline diamond layer, and diamond micro powder and fullerene coated diamond micro powder are coated with titanium carbide and silicon carbide, which greatly promotes the combination of diamond and diamond, deposits transition composite coating on the surface of hard alloy matrix, and sets powder transition layer between the transition composite coating and polycrystalline diamond layer, reduces the interface stress between polycrystalline diamond layer and hard alloy matrix, improves the bonding strength of polycrystalline diamond layer and hard alloy matrix, so that it has excellent mechanical and thermal properties.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of diamond and hard alloy composite materials, and particularly relates to a high-strength and high-wear-resistance polycrystalline diamond compact and a preparation method thereof. BACKGROUND

[0002] The polycrystalline diamond compact is a kind of composite superhard material with excellent performance, which is formed by micron-sized diamond particles and a binder under high temperature and high pressure on a hard alloy substrate. It has high hardness and wear resistance of diamond and strength and impact toughness of hard alloy, and is mainly used in the fields of drilling bits and cutting tools.

[0003] In the prior art, the polycrystalline diamond compact prepared from ordinary diamond micro powder has a series of advantages of diamond single crystal, but has a deficiency in high-temperature wear resistance in actual application. For example, in the cutting process of hard and strong abrasive materials, high contact pressure of the tool and high abrasiveness of the processed material result in excessively high friction temperature of the action surface between the polycrystalline diamond layer of the polycrystalline diamond compact tool and the processed material, which reduces the strength of the polycrystalline diamond layer and accelerates the wear, thereby reducing the service life of the polycrystalline diamond compact cutting tool and sharply decreasing the mechanical properties of the polycrystalline diamond compact tool. Therefore, it is very important to improve the high-temperature wear resistance of the polycrystalline diamond compact.

[0004] With the continuous progress of technology and the increasing complexity of processing environment, higher requirements are put forward for the comprehensive performance of the polycrystalline diamond compact whether for drilling or for cutting tools. Therefore, it is necessary to improve the polycrystalline diamond compact and the preparation method thereof SUMMARY

[0005] In order to overcome the problems in the prior art, the present application provides a high-strength and high-wear-resistance polycrystalline diamond compact and a preparation method thereof, which can solve the problem of low strength and wear resistance of the polycrystalline diamond compact, thereby improving the service life and performance of the tool.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0007] A high-strength and high-wear-resistance polycrystalline diamond compact comprises a hard alloy substrate and a transition composite coating, a powder transition layer and a polycrystalline diamond layer arranged on the hard alloy substrate from inside to outside, wherein the polycrystalline diamond layer comprises the following raw materials in percentage by weight: titanium carbide and silicon carbide coated diamond micro powder 50-65%, fullerene coated diamond micro powder 25-30%, diamond micro powder 5-10%, graphdiyne 0.3-0.5%, fullerene 0.3-0.5% and a binder 4.4-9%. The thickness of the polycrystalline diamond layer is 0.5 mm-0.7 mm.

[0008] Preferably, the transition composite coating is in the order from inside to outside: a rare earth coating, a cubic boron nitride coating, wherein the rare earth coating is arranged between the surface of the cemented carbide substrate and the cubic boron nitride coating; the material of the rare earth coating is selected from one of the rare earth elements Sm, Dy, Lu, Tm; the thickness of the rare earth coating is 2-4 μm; the thickness of the cubic boron nitride coating is 3-5 μm; the cemented carbide substrate is a boronized cemented carbide substrate; the thickness of the boronized layer on the surface of the cemented carbide substrate is 1-3 μm.

[0009] Preferably, the powder transition layer is composed of the following raw materials in the weight percentage: titanium carbide and silicon carbide coated diamond micro powder 40-50%, cubic boron nitride micro powder 40-45%, magnesium carbonitride powder 2-4%, graphdiyne 0.25-0.5%, fullerene 0.25-0.5%, and binder 7.5-10%; the particle size of the cubic boron nitride micro powder is 5-10 μm; the particle size of the magnesium carbonitride powder is 40-60 nm; the thickness of the powder transition layer is 0.2-0.4 mm.

[0010] Preferably, the particle size of the titanium carbide and silicon carbide coated diamond micro powder is 20-30 μm; the thickness of the titanium carbide and silicon carbide coating layer is 100-200 nm; the particle size of the fullerene coated diamond micro powder is 10-15 μm; the particle size of the diamond micro powder is 5-10 μm; the diamond micro powder is titanium and nitrogen ion implanted diamond.

[0011] Preferably, the particle size of the graphdiyne is 500-800 nm; the particle size of the fullerene is 500-700 nm. The graphdiyne and the fullerene in the present application can be directly purchased from ordinary commercially available products, such as from Beijing Deke Dao Gold Technology Co., Ltd.

[0012] Preferably, the binder is composed of the following raw materials in the weight percentage: Co powder 94-97%, Li powder 1.8-4%, Ti powder 0.2-0.5%, Eu powder 0.2-0.3%, TiC powder 0.2-0.3%, Li3N powder 0.2-0.3%, Li3BN2 powder 0.2-0.3%, and TiN powder 0.2-0.3%. Each of the raw material powders involved in the present application is an ordinary commercially available product that can be directly purchased.

[0013] Further preferably, the particle size of each of the Co powder, the Li powder, the Ti powder, the Eu powder, the TiC powder, the Li3N powder, the Li3BN2 powder, and the TiN powder is 40-50 nm.

[0014] The fullerene-coated diamond powder can be prepared by using the existing technology, for example, referring to Chinese patent CN202011526764.6 (publication number CN112746814 A, a high-temperature-resistant diamond composite sheet and a preparation method thereof). Specifically, the fullerene-coated diamond powder can be obtained by using a magnetron sputtering technology to coat a fullerene layer on the surface of the diamond, wherein the particle size of the diamond powder is 10-15 μm, and the thickness of the fullerene layer is 0.1-0.2 μm; the process parameters of the reaction magnetron sputtering are as follows: the cathode target is a pure graphite target, the sputtering gas is argon with a purity of 99.9%, the reaction gas is nitrogen with a purity of 99.9%, the power of the graphite target is 1250 W, the substrate bias is-100 V, the argon flow rate is 36 mL / min, and the nitrogen flow rate is 18 mL / min.

[0015] The preparation method of the high-strength wear-resistant polycrystalline diamond composite sheet includes the following steps:

[0016] 1) Purification of the cemented carbide substrate: first, the cemented carbide substrate is subjected to ultrasonic alkaline cleaning to remove surface oil stains, ultrasonic pure water rinsing to remove impurities, and then ultrasonic acid cleaning to remove rust, followed by ultrasonic deionized water purification and drying; then, the cleaned cemented carbide substrate is fixed on a rotating shaft in an ion source / arc ion plating device, argon or hydrogen is introduced into the vacuum chamber, when argon is introduced, the gas flow rate is 300-500 sccm, the working pressure is 1-1.7 Pa, and the substrate bias is-500 to-700 V, the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 10-20 min; when hydrogen is introduced, the gas flow rate is 200-400 sccm, the working pressure is 0.8-1.6 Pa, and the substrate bias is-500 to-700 V, the surface of the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 10-20 min, to obtain a clean cemented carbide substrate;

[0017] 2) Boronizing of the cemented carbide substrate: the clean cemented carbide substrate obtained in step 1) is placed in a vacuum tube-type drying oven for boronizing treatment to obtain a surface-boronized cemented carbide substrate;

[0018] 3) Transition composite coating: the surface boronized cemented carbide substrate of step 2) is fixed on a rotating stand in an ion source / arc ion plating film device, argon gas is first introduced into the ion source / arc ion device at a flow rate of 50-400 sccm, the pressure in the vacuum chamber is adjusted to 0.2-1.3 Pa, the arc target current of the rare earth element is adjusted to 80-200 A, the substrate bias is 100-300 V, and a rare earth coating is deposited on the surface of the boronized cemented carbide substrate; then argon gas is introduced into the vacuum chamber, the pressure in the vacuum chamber is adjusted to 0.4-1.0 Pa, the arc target voltage of cubic boron nitride is adjusted to 15-25 V, the target current is reduced to 10-30 A, and the substrate bias is 30-200 V, and a cubic boron nitride coating is deposited on the surface of the rare earth coating to obtain a cemented carbide substrate containing a transition composite coating;

[0019] 4) Deposition of titanium carbide and silicon carbide: diamond micro-powder is placed on a substrate table in the chamber of a film plating machine, and vacuum is extracted to a vacuum degree of 1x10 -3 Pa-3x10 -3 Pa; the substrate table is heated to 550-600℃, the substrate table rotates at a speed of 10-15 rad / min, the deposition current is 100 A, and hydrogen gas carrying acetone is introduced into the film plating machine at a flow rate of 50-65 sccm; titanium and titanium-silicon (the surface area ratio of titanium element to silicon element is 5:1) are used as target materials, and titanium and titanium-silicon are deposited at a deposition power of 1000-1500 W for 1-2 h to form a composite coating of titanium carbide and silicon carbide on the surface of the diamond micro-powder, thereby obtaining titanium carbide and silicon carbide coated diamond micro-powder;

[0020] 5) Ion implantation into diamond surface: ordinary diamond micro-powder is placed in the vacuum working cavity of an ion implantation machine, monovalent titanium ions are first separated from the ions supplied by the ion source through a mass spectrometer, and then implanted into the diamond surface at an ion density of 3x10 14 -3x10 17 ions / cm 2 and an energy of 60-90 keV; then monovalent nitrogen ions are separated from the ions supplied by the ion source, and then implanted into the diamond surface at an ion density of 3x10 15 -3x10 17 ions / cm 2 and an energy of 60-90 keV, thereby obtaining titanium and nitrogen ion implanted diamond micro-powder;

[0021] 6) Powder transition layer mixing: Weigh out graphylene, fullerene, binder, magnesium carbonitride powder, cubic boron nitride micro powder, and titanium carbide and silicon carbide coated diamond micro powder according to the proportion, and disperse them in anhydrous ethanol in sequence. Mechanically stir and ultrasonically vibrate for 30-50 min, and the mass content of the powder is 0.2-0.6 g / ml; then weigh out polyethylene glycol and add it to the anhydrous ethanol dispersion, mechanically stir and ultrasonically vibrate for 50-70 min, and the concentration of polyethylene glycol is 1-4 g / L. Then pour it into a cemented carbide ball mill jar with cemented carbide balls, the mass ratio of balls to powder is 10-12:1, and ball mill for 30-40 h after purging with nitrogen as a protective gas. After mixing, place it in a vacuum dryer and vacuum dry at 50-60℃ for 4-6 h to obtain the powder transition layer mixed powder.

[0022] 7) Polycrystalline diamond layer mixing: Weigh fullerene, graphylene, binder, diamond micro powder, fullerene-coated diamond micro powder, titanium carbide and silicon carbide-coated diamond micro powder according to the proportion, and disperse them in anhydrous ethanol in sequence. Mechanically stir and ultrasonically vibrate for 50-80 min, and the mass content of the powder is 0.4-1 g / ml; then weigh polyethylene glycol and add it to the anhydrous ethanol dispersion, mechanically stir and ultrasonically vibrate for 70-90 min, and the concentration of polyethylene glycol is 2-5 g / L. Then pour it into a cemented carbide ball milling jar with cemented carbide balls, the mass ratio of balls to powder is 8-10:1, and ball mill for 35-40 h after purging with nitrogen as a protective gas. After mixing, place it in a vacuum dryer and vacuum dry at 50-60℃ for 3-6 h to obtain polycrystalline diamond layer mixed powder.

[0023] 8) Composite assembly: First, the polycrystalline diamond layer mixed powder described in step 7) and the powder transition layer mixed powder described in step 6) are sequentially loaded into a high-temperature resistant metal cup, layered and compacted to shape. Then, the hard alloy substrate containing the transition composite coating from step 3) is placed flat on the powder transition layer mixed powder with the coating side facing down. Then, a high-temperature resistant metal cup is inserted from the opposite direction to obtain the composite assembly. The high-temperature resistant metal cup is made of one or more of tantalum, molybdenum, niobium, and zirconium.

[0024] 9) Composite preloading: Place the composite component from step 8) into the pyrophyllite block, and then place the pyrophyllite block into a high-temperature, high-pressure apparatus.

[0025] During preparation, the pressure is increased to 3.5-4 GPa and held for 90-110 seconds without heating. Then, the pressure is reduced to standard atmospheric pressure using a high-temperature and high-pressure equipment to obtain a pre-compressed composite component.

[0026] 10) Composite purification: Place the pre-compressed composite component from step 9) into a vacuum sintering furnace for sintering. During sintering, first perform a rough vacuum evacuation until the furnace pressure reaches 7×10⁻⁶. -2Pa, the temperature is raised to 1300-1350℃ for 10-18 min, vacuuming is stopped, and a mixed gas of carbon monoxide, ammonia and argon is filled in, hydrogen, carbon monoxide and argon are uniformly mixed at a mass ratio of 0.3:0.8:1, and are kept for 1.0-1.5 h, and then vacuuming is performed until the gas pressure in the furnace is 3x10 -5 Pa, the temperature is raised to 1300-1350℃ for 10-18 min, vacuuming is stopped, and a mixed gas of carbon monoxide, ammonia and argon is filled in, hydrogen, carbon monoxide and argon are uniformly mixed at a mass ratio of 0.3:0.8:1, and are kept for 1.0-1.5 h, and then vacuuming is performed until the gas pressure in the furnace is 3x10 -5 Pa, the temperature is raised to 1300-1350℃ for 10-18 min, vacuuming is stopped, and a mixed gas of carbon monoxide, ammonia and argon is filled in, hydrogen, carbon monoxide and argon are uniformly mixed at a mass ratio of 0.3:0.8:1, and are kept for 1.0-1.5 h, and then vacuuming is performed until the gas pressure in the furnace is 3x10

[0027] 11) High-temperature and high-pressure sintering: the purified composite assembly of step 10) is assembled with a block of leaf talc, and is placed in a cubic anvil press for sintering, is raised to a sintering pressure of 6.5-7.0 GPa at a rate of 0.1-1 GPa / min, is heated at a heating rate of 20-30℃ / S for high-temperature sintering, and is kept at 1450℃ for 100-150 S, is raised to a sintering temperature of 1500-1550℃ within 20-30 S, is kept at the sintering temperature for 100-150 S, is cooled at a cooling rate of 15-20℃ / S to 600℃, is kept at 600℃ for 10-15 min, and is cooled to room temperature, and is depressurized to normal pressure at a depressurizing rate of 0.6-0.7 GPa / min. The assembled block is taken out of the cubic anvil press, the surface wrapping layer is removed, and a sintered polycrystalline diamond compact blank is obtained.

[0028] 12) Stress relief aging: the sintered polycrystalline diamond compact blank of step 11) is assembled with a block of leaf talc again, is placed in a cubic anvil press, is pressurized to 7.0 GPa, is adjusted to a temperature of 600-700℃, is kept for 10-15 min, is cooled to 500-550℃, is kept for 10-15 min, is then further cooled to 400-450℃, is kept for 15-20 min, is then further cooled to 300-350℃, is kept for 15-20 min, and is finally cooled to room temperature at a cooling rate of 10-20℃ / S, and is depressurized to normal pressure at a depressurizing rate of 0.5-0.7 GPa / min. The aged polycrystalline diamond compact blank is taken out of the assembled block, is processed to a required size by grinding equipment, and is subjected to surface polishing treatment, and a high-strength and high-wear-resistance polycrystalline diamond compact is obtained.

[0029] In step 1), the alkaline washing liquid for ultrasonic washing is selected from a concentrated solution of one of potassium ferricyanide, potassium hydroxide and sodium hydroxide, but is not limited thereto; the mass percentage concentration of the alkaline washing liquid is 35-45%; the acidic washing liquid for ultrasonic washing is selected from one of sulfuric acid, nitric acid, hydrochloric acid and hydrogen peroxide, but is not limited thereto; the mass percentage concentration of the acidic washing liquid is 8-12%; the alkaline washing time is 5-15 min; the acidic washing time is 3-10 min; and the ultrasonic power is 30-50 W.

[0030] In step 2), the boronizing treatment gas is a mixed gas of 9% B2H6 and 91% H2 by volume, the flow rate of the mixed gas is 9-12sccm, the pressure is 8-10kPa, and the reaction time is 3-5h.

[0031] In steps 6) and 7), the ultrasonic oscillation power is 40-50W; and the molecular weight of the polyethylene glycol is 1000-5000.

[0032] Compared with the prior art, the present application has the following advantages:

[0033] 1. The present application uses titanium carbide and silicon carbide to coat diamond powder, which makes up the defects of "micro-cracks" and micro-cavities in the diamond, thereby improving the strength of the abrasive particles, and also plays a role in oxygen protection and reducing the degree of thermal damage. The wear-resistant titanium carbide and silicon carbide coating on the surface of the diamond particles has good bonding strength with the binder and the diamond, and can connect the binder and the diamond particles, increase the holding force, and prevent premature shedding. Fullerene is used to coat the diamond powder, which has the dual properties of diamond and fullerene, good lubrication, improved wettability of the diamond particles and the binder, effectively increased contact area of the diamond and the binder, and is beneficial to form a more tightly bonded interface. Titanium ions and nitrogen ions are implanted on the surface of the diamond by ion beam implantation method, which makes up the structural defects on the surface of ordinary diamond particles, makes the structure more smooth, improves the compressive strength of the diamond crystal, and also improves the thermal stability. In addition, the polycrystalline layer of titanium ions and nitrogen ions in diamond softens the diamond particles to some extent during high-temperature and high-pressure sintering, so that these particles can be squeezed more tightly and have larger contact area, thereby enhancing their binding ability, reducing the existence of pores, and helping to sinter and improve the volume ratio of the polycrystalline diamond compact, which is beneficial to improve the strength, heat resistance and impact toughness of the polycrystalline diamond compact at high temperature.

[0034] 2. The present application adds graphdiyne and fullerene materials in the polycrystalline diamond layer, which can activate diamond particles and promote direct bonding between diamond particles. At the same time, due to the addition of a certain proportion of graphdiyne and fullerene, it can play a good lubricating effect between diamond particles, reduce the frictional resistance between particles under high pressure conditions, promote the filling of crushed diamond space, improve the uniform distribution of binder phase, and increase the fine grains, so that a more dense and uniform structure is formed in the polycrystalline diamond. In the process of preparing polycrystalline diamond, it is divided into carbon atom phase change process and diamond dissolution and precipitation process. In the sintering process, graphdiyne and fullerene are filled between diamond particles, forming a uniform pressure field inside. When the pressure reaches the stable interval of diamond precipitation, the carbon in the solvent-carbon system will precipitate in the form of diamond in these gaps, so that the fine particle powder grows up and overlaps with the surrounding particles, reducing the surface free energy of the particles, forming a stable and dense polycrystalline sintered body, and increasing the strength and wear resistance of the polycrystalline diamond layer.

[0035] 3. The present application deposits a transition composite coating on the boronized surface of the cemented carbide substrate and sets a powder transition layer between the transition composite coating and the polycrystalline diamond layer. Due to the gradient change of the thermal expansion coefficient from the cemented carbide substrate-surface boronized layer-transition composite coating-powder transition layer-polycrystalline diamond layer, it gradually decreases, so that the cemented carbide substrate and the polycrystalline diamond layer realize gradient transition, and the interface stress is small, which improves the delamination problem of the polycrystalline diamond composite sheet. At the same time, the boronized layer on the surface of the cemented carbide substrate and the transition composite coating can effectively block the diffusion of metal cobalt in the cemented carbide to the diamond layer during the high-temperature and high-pressure sintering process of the polycrystalline diamond composite sheet, reduce the metal content of the polycrystalline diamond layer, and improve the thermal stability and reduce the delamination probability of the cemented carbide substrate polycrystalline diamond composite sheet with surface boronization and transition composite coating.

[0036] 4. The high-strength and high-wear-resistance polycrystalline diamond composite sheet prepared by the present application has the performance indexes of wear ratio of 450-480 million, impact toughness of 64-67 times, and thermal stability characterization temperature of 730-760℃. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the high-strength and high-wear-resistance polycrystalline diamond composite sheet.

[0038] In the figure: 1, polycrystalline diamond layer; 2, powder transition layer; 3, transition composite coating; 4, substrate surface boronized layer; 5,

[0039] Cemented carbide substrate.

[0040] Figure 2 It is a physical picture of the high-strength and high-wear-resistance polycrystalline diamond composite sheet prepared in Example 1. Detailed Implementation

[0041] The present invention will be further described below with reference to embodiments, but these are not intended to limit the invention. To determine and compare the performance of the composite sheets prepared in the embodiments and comparative examples, the diameter of the composite sheets in the following embodiments and comparative examples is φ55mm, the thickness is 3mm, and the thickness of the polycrystalline diamond layer is 0.5mm. The cemented carbide matrix refers to a tungsten-cobalt cemented carbide YG12 (WC 88% and cobalt 12%) matrix. The molecular weight of polyethylene glycol is 2000.

[0042] Example 1

[0043] The high-strength, high-wear-resistant polycrystalline diamond composite sheet of this embodiment, such as Figure 1 As shown, the system includes a cemented carbide substrate 5 and, from the inside out, a transition composite coating 3, a powder transition layer 2, and a polycrystalline diamond layer 1 sequentially disposed on the cemented carbide substrate 5. The polycrystalline diamond layer 1 is composed of the following raw materials in weight percentages: 50% titanium carbide and silicon carbide coated diamond powder, 30% fullerene coated diamond powder, 10% diamond powder, 0.5% graphynylene, 0.5% fullerene, and 9% binder. The transition composite coating 3, from the inside out, consists of a rare earth coating and a cubic boron nitride coating. The rare earth coating is disposed on the cemented carbide substrate 5. Between the gold substrate surface and the cubic boron nitride coating; the rare earth coating material is selected from rare earth element Sm; the thickness of the rare earth coating is 2 μm; the thickness of the cubic boron nitride coating is 3 μm; the cemented carbide substrate 5 is a surface-boronized cemented carbide substrate; the thickness of the boron-infiltrated layer 4 on the surface of the cemented carbide substrate is 1 μm; the powder transition layer 2 is composed of the following raw materials in weight percentages: 40% titanium carbide and silicon carbide coated diamond micro powder, 45% cubic boron nitride micro powder, 4% magnesium carbonitride powder, 0.5% graphynylene, and fullerene. ~0.5% and binder 10%; the particle size of the cubic boron nitride micro powder is 5-10 μm; the particle size of the magnesium carbonitride powder is 40-60 nm; the thickness of the powder transition layer 2 is 0.2 mm; the particle size of the titanium carbide and silicon carbide coated diamond micro powder is 20-30 μm; the thickness of the titanium carbide and silicon carbide coating layer is 100-200 nm; the particle size of the fullerene coated diamond micro powder is 10-15 μm; the particle size of the diamond micro powder is 5-10 μm; the diamond micro powder is titanium and nitrogen ion implanted diamond. The graphdiyne has a particle size of 500–800 nm; the fullerene has a particle size of 500–700 nm; the binder is composed of the following raw materials in weight percentage: 94% Co powder, 4% Li powder, 0.5% Ti powder, 0.3% Eu powder, 0.3% TiC powder, 0.3% Li3N powder, 0.3% Li3BN2 powder, and 0.3% TiN powder; the particle size of the Co powder, Li powder, Ti powder, Eu powder, TiC powder, Li3N powder, Li3BN2 powder, and TiN powder is 40–50 nm.

[0044] The preparation method of the high-strength and high-wear-resistance polycrystalline diamond compact comprises the following steps:

[0045] 1) Purification of the cemented carbide substrate: first, ultrasonic alkaline washing is performed on the cemented carbide substrate to remove surface oil stains, ultrasonic pure water rinsing is performed to remove impurities, then ultrasonic acid washing is performed to remove rust, and ultrasonic deionized water purification and drying are performed; the alkaline washing solution used in the ultrasonic alkaline washing is a 35wt% potassium ferricyanide solution; the acid washing solution used in the ultrasonic acid washing is an 8wt% sulfuric acid solution, the alkaline washing time is 5 min, the acid washing time is 3 min, and the ultrasonic power is 30 W. Then, the cleaned cemented carbide substrate is fixed on a rotating stand in an ion source / arc ion plating device, argon or hydrogen is introduced into a vacuum chamber, when argon is introduced, the argon flow is 300 sccm, the working pressure is 1 Pa, and the substrate bias is -500 V, the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 10 min; when hydrogen is introduced, the gas flow is 200 sccm, the working pressure is 0.8 Pa, and the substrate bias is -500 V, the surface of the cemented carbide substrate is subjected to glow cleaning, the cleaning time is 10 min, and a clean cemented carbide substrate is obtained;

[0046] 2) Boronizing of the cemented carbide substrate: the clean cemented carbide substrate in step 1) is placed in a vacuum tube drying furnace for boronizing treatment; the boronizing treatment gas is a mixed gas of 9% B2H6 and 91% H2 by volume, the flow of the mixed gas is 9 sccm, the pressure is 8 kPa, and the reaction time is 3 h, and a cemented carbide substrate with a boronized surface is obtained;

[0047] 3) Transition composite coating: the cemented carbide substrate with a boronized surface in step 2) is fixed on a rotating stand in an ion source / arc ion plating device, argon is first introduced into the ion source / arc ion device, the flow is 50 sccm, the vacuum chamber pressure is adjusted to 0.2 Pa, the rare earth element arc target current is turned on to 80 A, and the substrate bias is 100 V, a rare earth coating is deposited on the boronized surface of the cemented carbide substrate; then argon is introduced into the vacuum chamber, the vacuum chamber pressure is adjusted to 0.4 Pa, the cubic boron nitride arc target voltage is adjusted to 15 V, the target current is reduced to 10 A, and the substrate bias is 30 V, a cubic boron nitride coating is deposited on the surface of the rare earth coating, and a cemented carbide substrate with a transition composite coating is obtained;

[0048] 4) Deposition of titanium carbide and silicon carbide: diamond micro powder is placed on a substrate table in a plating machine chamber, and vacuum is extracted to a vacuum degree of 1×10 -3 Pa~3×10 -3Pa; the substrate table is heated to 550℃, the substrate table rotation speed is 10 rad / min, the deposition current is 100 A, and hydrogen carrying acetone is introduced into the coating machine at a flow rate of 50 seem; titanium and titanium silicon (the surface area ratio of titanium element to silicon element is 5:1) are used as target materials, titanium and titanium silicon targets with a deposition power of 1000 W are used for deposition at the same time for 1 h, a composite coating of titanium carbide and silicon carbide is formed on the surface of the diamond micro powder, and titanium carbide and silicon carbide coated diamond micro powder is obtained;

[0049] 5) Ion implantation on the surface of the diamond: the ordinary diamond micro powder is placed in the vacuum working cavity of the ion implantation machine, the ions supplied by the ion source are first separated into monovalent titanium ions by a mass spectrometer, and then implanted into the surface of the diamond at an ion density of 3×10 14 ~ 3×10 17 ions / cm 2 and an energy of 60 keV, and then the ions supplied by the ion source are separated into monovalent nitrogen ions, and then implanted into the surface of the diamond at an ion density of 3×10 15 ~ 3×10 17 ions / cm 2 and an energy of 60 keV, to obtain titanium and nitrogen ion implanted diamond micro powder;

[0050] 6) Powder transition layer mixing: graphite alkyne, fullerene, binder, magnesium carbonitride powder, cubic boron nitride micro powder, and titanium carbide and silicon carbide coated diamond micro powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in turn, respectively, mechanically stirred and ultrasonically (power 40 W) oscillated and dispersed for 30 min, and the mass content of the powder material is 0.2 g / ml; polyethylene glycol is weighed and added to the anhydrous ethanol dispersion, mechanically stirred and ultrasonically (power 40 W) oscillated and dispersed for 50 min, and the concentration of polyethylene glycol is 1 g / L, then poured into a hard alloy ball milling tank with hard alloy balls, the ball-to-material mass ratio is 10:1, nitrogen gas is filled as a protective gas, and then ball milled for 30 h, and after mixing, placed in a vacuum dryer, vacuum dried at 50℃ for 4 h, to obtain a powder transition layer mixed powder;

[0051] 7) Polycrystalline diamond layer mixing: Fullerene, graphyne, binder, diamond powder, fullerene-coated diamond powder, titanium carbide-coated diamond powder, and silicon carbide-coated diamond powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in turn, mechanically stirred and ultrasonically (power 40W) oscillated and dispersed for 50 min, the mass content of the powder is 0.4 g / ml; polyethylene glycol is weighed and added into the anhydrous ethanol dispersion, mechanically stirred and ultrasonically (power 40W) oscillated and dispersed for 70 min, the concentration of polyethylene glycol is 2 g / L, then poured into a hard alloy ball mill tank with hard alloy balls, the ball-to-material mass ratio is 8:1, nitrogen is filled as a protective gas, and then ball milling is performed for 35 h, the mixed powder is placed in a vacuum dryer and vacuum dried at 50°C for 3 h, and a polycrystalline diamond layer mixed powder is obtained;

[0052] 8) Composite assembly: the polycrystalline diamond layer mixed powder of step 7 and the powder transition layer mixed powder of step 6 are sequentially loaded into a high-temperature-resistant metal tantalum cup, layered, compacted, and shaped, then the hard alloy substrate with a transition coating of step 3 is placed on the powder transition layer mixed powder with the coating facing down, and then a high-temperature-resistant metal tantalum cup is sleeved from the opposite direction to obtain a composite assembly;

[0053] 9) Composite pre-pressing: the composite assembly of step 8 is placed in a pyrophyllite block, the pyrophyllite block is placed in a high-temperature high-pressure device, the pressure is increased to 3.5 GPa, and the temperature is kept at 90s without heating, then the high-temperature high-pressure device is depressurized to standard atmospheric pressure, and a pre-pressed composite assembly is obtained;

[0054]

[0055] 10) Composite purification: the pre-pressed composite assembly of step 9 is placed in a vacuum sintering furnace for sintering, during sintering, the furnace is first rough-pumped to a pressure of 7×10 -2 Pa, heated to 280°C for 10 min, and then vacuumed to a pressure of 3×10 -5 Pa, the temperature is increased to 1300°C for 10 min, and then the vacuum is stopped, a mixed gas of carbon monoxide, ammonia and argon is filled, the hydrogen, carbon monoxide and argon are uniformly mixed in a mass ratio of 0.3:0.8:1, and the mixture is kept for 1.0 h, then the furnace is vacuumed to a pressure of 3×10 -5 Pa, and a purified composite assembly is obtained;

[0056] ​11) High temperature and high pressure sintering: the assembly of step 10) and the beryllosite assembly block are assembled and placed in a cubic anvil press for sintering, first increased to a sintering pressure of 6.5 GPa at a rate of 0.1 GPa / min, and then heated at a rate of 20 ℃ / S for high temperature sintering, and then increased to a sintering temperature of 1500 ℃ within 20 S after holding at 1450 ℃ for 100 S, and then held for 100 S, and then cooled to 600 ℃ at a rate of 15 ℃ / S, and then held for 10 min, and then cooled to room temperature, and then decreased to atmospheric pressure at a rate of 0.6 GPa / min. The assembly block is removed from the cubic anvil press, and the surface wrapping layer is removed to obtain a sintered polycrystalline diamond compact blank.

[0057] 12) Stress relief aging: the sintered polycrystalline diamond compact blank of step 11) is assembled again with the beryllosite assembly block, and placed in a cubic anvil press, and then pressurized to 7.0 GPa, and then adjusted to a temperature of 600 ℃, and then held for 10 min, and then the beryllosite block is cooled to 500 ℃, and then held for 10 min, and then further cooled to 400 ℃, and then held for 15 min, and then further cooled to 300 ℃, and then held for 15 min, and then cooled to room temperature at a rate of 10 ℃ / S, and then decreased to atmospheric pressure at a rate of 0.5 GPa / min. The aged polycrystalline diamond compact blank is removed from the assembly block, and then processed to the required size using grinding equipment, and then surface polished to obtain the high strength and high wear resistance polycrystalline diamond compact.

[0058] The high strength and wear resistance polycrystalline diamond compact prepared in this example is tested for wear resistance according to the standard JB / T3235-2013 "Abrasion ratio test method for sintered diamond abrasive body", first placed in a tube furnace and heated at a temperature of 690 ℃ for 1 min, and then tested for impact toughness using a drop hammer impact method (i.e. a 1 kg hammer is dropped freely from a height of 30 cm to impact the corners of the sample, and the impact toughness value is obtained when a micro crack appears on the surface); the thermal stability test is performed using a thermogravimetric-differential thermal analysis method, and the initial oxidation temperature of the differential thermal curve is used as the thermal stability characterization temperature, and the higher the initial oxidation temperature, the better the thermal stability. The test results are as follows: the abrasion ratio is 460,000, the impact toughness is 66 times, and the thermal stability characterization temperature is 740 ℃. The high strength and wear resistance polycrystalline diamond compact has excellent heat resistance, wear resistance and impact toughness.

[0059] Example 2

[0060] The high strength and wear resistance polycrystalline diamond compact of this example is prepared according to the method of Example 1, and the difference is that the sintering temperature is 1550 ℃, and the sintering pressure is 6.5 GPa. Figure 1As shown, it comprises a cemented carbide substrate 5, and a transition composite coating 3, a powder transition layer 2 and a polycrystalline diamond layer 1 arranged on the cemented carbide substrate 5 from inside to outside, the polycrystalline diamond layer 1 is composed of the following raw materials in weight percentage: titanium carbide and silicon carbide coated diamond powder 65%, fullerene coated diamond powder 25%, diamond powder 5%, graphdiyne 0.3%, fullerene 0.3% and binder 4.4%; the transition composite coating 3 is in the order of rare earth coating, cubic boron nitride coating from inside to outside, wherein the rare earth coating is arranged between the surface of the cemented carbide substrate and the cubic boron nitride coating; the material of the rare earth coating is selected from rare earth element Dy; the thickness of the rare earth coating is 4 μm; the thickness of the cubic boron nitride coating is 5 μm; the cemented carbide substrate 5 is a boronized cemented carbide substrate; the thickness of the boronized layer 4 on the surface of the cemented carbide substrate is 3 μm; the powder transition layer 2 is composed of the following raw materials in weight percentage: titanium carbide and silicon carbide coated diamond powder 50%, cubic boron nitride powder 40%, magnesium carbonitride powder 2%, graphdiyne 0.25%, fullerene 0.25% and binder 7.5%; the particle size of the cubic boron nitride powder is 5-10 μm; the particle size of the magnesium carbonitride powder is 40-60 nm; the thickness of the powder transition layer 2 is 0.4 mm; the particle size of the titanium carbide and silicon carbide coated diamond powder is 20-30 μm; the thickness of the titanium carbide and silicon carbide coated layer is 100-200 nm; the particle size of the fullerene coated diamond powder is 10-15 μm; the particle size of the diamond powder is 5-10 μm; the diamond powder is titanium and nitrogen ion implanted diamond; the particle size of the graphdiyne is 500-800 nm; the particle size of the fullerene is 500-700 nm; the binder is composed of the following raw materials in weight percentage: Co powder 97%, Li powder 1.8%, Ti powder 0.2%, Eu powder 0.2%, TiC powder 0.2%, Li3N powder 0.2%, Li3BN2 powder 0.2% and TiN powder 0.2%; the particle size of the Co powder, the Li powder, the Ti powder, the Eu powder, the TiC powder, the Li3N powder, the Li3BN2 powder and the TiN powder is 40-50 nm.

[0061] The preparation method of the high-strength and high-wear-resistance polycrystalline diamond compact described above comprises the following steps:

[0062] 1) Cemented carbide substrate cleaning: first, the cemented carbide substrate is subjected to ultrasonic alkaline cleaning to remove surface oil, ultrasonic pure water rinsing to remove impurities, then ultrasonic acid cleaning to remove rust, followed by ultrasonic deionized water cleaning and drying; the alkaline cleaning solution used in the ultrasonic alkaline cleaning is a 45wt% potassium hydroxide solution; the acid cleaning solution used in the ultrasonic acid cleaning is a 12wt% nitric acid solution, the alkaline cleaning time is 15 min, the acid cleaning time is 10 min, and the ultrasonic power is 50 W. Then the cleaned cemented carbide substrate is fixed on a rotating stand in an ion source / arc ion plating film equipment, argon or hydrogen is introduced into the vacuum chamber, when argon is introduced, the argon flow is 500 sccm, the working pressure is 1.7 Pa, and the substrate bias is -700 V, the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 20 min; when hydrogen is introduced, the gas flow is 400 sccm, the working pressure is 1.6 Pa, and the substrate bias is -700 V, the surface of the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 20 min, to obtain a clean cemented carbide substrate;

[0063] 2) Cemented carbide substrate boronizing: the clean cemented carbide substrate in step 1) is placed in a vacuum tube drying furnace for boronizing treatment; the boronizing treatment gas is a mixed gas of 9% B2H6 and 91% H2 by volume, the flow rate of the mixed gas is 12 sccm, the pressure is 10 kPa, and the reaction time is 5 h, to obtain a cemented carbide substrate with a boronized surface;

[0064] 3) Transition composite coating: the cemented carbide substrate with a boronized surface in step 2) is fixed on a rotating stand in an ion source / arc ion plating film equipment, argon is first introduced into the ion source / arc ion equipment, the flow rate is 400 sccm, the vacuum chamber pressure is adjusted to 1.3 Pa, the rare earth element arc target current is turned on to 200 A, and the substrate bias is 300 V, to deposit a rare earth coating on the boronized surface of the cemented carbide substrate; then argon is introduced into the vacuum chamber, the vacuum chamber pressure is adjusted to 1.0 Pa, the cubic boron nitride arc target voltage is adjusted to 25 V, the target current is reduced to 30 A, and the substrate bias is 200 V, to deposit a cubic boron nitride coating on the rare earth coating, to obtain a cemented carbide substrate with a transition composite coating;

[0065] 4) Depositing titanium carbide and silicon carbide: diamond micro powder is placed on a substrate table in the chamber of a film plating machine, and vacuum is pumped to a vacuum degree of 1×10 -3 Pa~3×10 -3Pa; the substrate table is heated to 600℃, the substrate table rotation speed is 15 rad / min, the deposition current is 100 A, hydrogen carries acetone into the coating machine at a flow rate of 65 seem; titanium and titanium silicon (the surface area ratio of titanium element to silicon element is 5:1) are used as target materials, titanium and titanium silicon targets are deposited at a deposition power of 1500 W at the same time for 2 h, a composite coating of titanium carbide and silicon carbide is formed on the surface of the diamond micro powder, and titanium carbide and silicon carbide coated diamond micro powder is obtained;

[0066] 5) Ion implantation on the surface of the diamond: the ordinary diamond micro powder is placed in the vacuum working cavity of the ion implantation machine, the ions supplied by the ion source are first separated into monovalent titanium ions by a mass spectrometer, and then implanted into the surface of the diamond at an ion density of 3×10 14 ~ 3×10 17 ions / cm 2 and an energy of 90 keV, and then the ions supplied by the ion source are separated into monovalent nitrogen ions, and then implanted into the surface of the diamond at an ion density of 3×10 15 ~ 3×10 17 ions / cm 2 and an energy of 90 keV, to obtain titanium and nitrogen ion implanted diamond micro powder;

[0067] 6) Powder transition layer mixing: graphite alkyne, fullerene, binder, magnesium carbonitride powder, cubic boron nitride micro powder, and titanium carbide and silicon carbide coated diamond micro powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in turn, respectively, mechanically stirred and ultrasonically (power 50 W) oscillated and dispersed for 50 min, the mass content of the powder material is 0.6 g / ml; polyethylene glycol is weighed and added to the anhydrous ethanol dispersion, mechanically stirred and ultrasonically (power 50 W) oscillated and dispersed for 70 min, the concentration of polyethylene glycol is 4 g / L, then poured into a hard alloy ball milling tank with hard alloy balls, the ball-to-material mass ratio is 12:1, nitrogen gas is filled as a protective gas, and then ball milled for 40 h, after mixing, placed in a vacuum dryer, vacuum dried at 60℃ for 6 h, to obtain a powder transition layer mixed powder;

[0068] 7) Polycrystalline diamond layer mixing: Fullerene, graphyne, binder, diamond powder, fullerene-coated diamond powder, titanium carbide-coated diamond powder, and silicon carbide-coated diamond powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in turn, mechanically stirred and ultrasonically (power 50W) oscillated for 80 min, the mass content of the powder is 1 g / ml; polyethylene glycol is weighed and added to the anhydrous ethanol dispersion, mechanically stirred and ultrasonically (power 50W) oscillated for 90 min, the concentration of polyethylene glycol is 5 g / L, then poured into a hard alloy ball mill tank with hard alloy balls, the ball-to-material mass ratio is 10:1, nitrogen is filled as a protective gas, and then ball milled for 40 h, the mixed powder is placed in a vacuum dryer and vacuum dried at 60°C for 6 h, to obtain a polycrystalline diamond layer mixed powder;

[0069] 8) Composite assembly: the polycrystalline diamond layer mixed powder of step 7 and the powder transition layer mixed powder of step 6 are sequentially loaded into a high-temperature-resistant metal molybdenum cup, layered, compacted, and shaped, then the hard alloy substrate with a transition coating of step 3 is placed on the powder transition layer mixed powder with the coating facing down, and then a high-temperature-resistant metal molybdenum cup is sleeved from the opposite direction to obtain a composite assembly;

[0070] 9) Composite pre-pressing: the composite assembly of step 8 is placed in a pyrophyllite block, the pyrophyllite block is placed in a high-temperature high-pressure device, the pressure is increased to 4 GPa, and the temperature is kept at 110°C without heating, then the high-temperature high-pressure device is depressurized to standard atmospheric pressure to obtain a pre-pressed composite assembly;

[0071]

[0072] 10) Composite purification: the pre-pressed composite assembly of step 9 is placed in a vacuum sintering furnace for sintering, during sintering, the furnace is first rough-pumped to a pressure of 7×10 -2 Pa, heated to 350°C for 15 min, and then vacuumed to a pressure of 3×10 -5 Pa, the temperature is increased to 1350°C for 18 min, then the vacuum is stopped, a mixed gas of carbon monoxide, ammonia, and argon is filled, the hydrogen, carbon monoxide, and argon are uniformly mixed in a mass ratio of 0.3:0.8:1, and the mixture is kept for 1.5 h, then the furnace is vacuumed to a pressure of 3×10 -5 Pa, to obtain a purified composite assembly;

[0073] ​11) High temperature and high pressure sintering: the assembly of step 10) and the beryllosite assembly block are assembled and placed in a cubic press for sintering, first increased to a sintering pressure of 7.0 GPa at a rate of 1 GPa / min, and then heated at a rate of 30 ℃ / S for high temperature sintering, and then increased to a sintering temperature of 1550 ℃ within 30 S after holding at 1450 ℃ for 150 S, and then held for 150 S, and then cooled to 600 ℃ at a rate of 20 ℃ / S, and then held for 15 min, and then cooled to room temperature, and then decreased to atmospheric pressure at a rate of 0.7 GPa / min. The assembly block is removed from the cubic press, and the surface coating layer is removed to obtain a sintered polycrystalline diamond compact blank.

[0074] 12) Stress relief aging: the sintered polycrystalline diamond compact blank of step 11) is assembled again with the beryllosite assembly block, and placed in a cubic press, and then pressurized to 7.0 GPa, and then adjusted to a temperature of 700 ℃, and then held for 15 min, and then the beryllosite block is cooled to 550 ℃, and then held for 15 min, and then further cooled to 450 ℃, and then held for 20 min, and then further cooled to 350 ℃, and then held for 20 min, and then cooled to room temperature at a rate of 20 ℃ / S, and then decreased to atmospheric pressure at a rate of 0.7 GPa / min. The aged polycrystalline diamond compact blank is removed from the assembly block, and then processed to the required size using grinding equipment, and then surface polished to obtain the high strength and high wear resistance polycrystalline diamond compact.

[0075] The high strength and wear resistance polycrystalline diamond compact prepared in this embodiment is tested for wear resistance according to the standard JB / T3235-2013 "Abrasion Resistance Test Method for Artificial Diamond Sintered Body", first placed in a tube furnace and heated at a temperature of 690 ℃ for 1 min, and then tested for impact toughness using a drop hammer impact method (i.e., a 1 kg mass hammer is dropped freely from a height of 30 cm, and the energy is used to impact the corners of the sample for testing, and the impact toughness value is obtained when a micro crack appears on the surface); the thermal stability test is performed using a thermogravimetric-differential thermal analysis method, and the initial oxidation temperature of the differential thermal curve is used as the thermal stability characterization temperature, and the higher the initial oxidation temperature, the better the thermal stability. The test results are as follows: the abrasion ratio is 470,000, the impact toughness is 67 times, and the thermal stability characterization temperature is 760 ℃. The high strength and wear resistance polycrystalline diamond compact has excellent heat resistance, wear resistance and impact toughness.

[0076] Example 3

[0077] The high strength and wear resistance polycrystalline diamond compact of this embodiment is prepared according to the method of the present application, and has the advantages of Figure 1As shown, it comprises a cemented carbide substrate 5, and a transition composite coating 3, a powder transition layer 2 and a polycrystalline diamond layer 1 arranged on the cemented carbide substrate 5 from inside to outside, the polycrystalline diamond layer 1 is composed of the following raw materials in weight percentage: titanium carbide and silicon carbide coated diamond powder 57.5%, fullerene coated diamond powder 27.5%, diamond powder 7.5%, graphdiyne 0.4%, fullerene 0.4% and binder 6.7%; the transition composite coating 3 is in the order of rare earth coating, cubic boron nitride coating from inside to outside, wherein the rare earth coating is arranged between the surface of the cemented carbide substrate and the cubic boron nitride coating; the material of the rare earth coating is selected from rare earth element Lu; the thickness of the rare earth coating is 3 μm; the thickness of the cubic boron nitride coating is 4 μm; the cemented carbide substrate 5 is a boronized cemented carbide substrate; the thickness of the boronized layer 4 on the surface of the cemented carbide substrate is 2 μm; the powder transition layer 2 is composed of the following raw materials in weight percentage: titanium carbide and silicon carbide coated diamond powder 45%, cubic boron nitride powder 42.5%, magnesium carbonitride powder 3%, graphdiyne 0.375%, fullerene 0.375% and binder 8.75%; the particle size of the cubic boron nitride powder is 5-10 μm; the particle size of the magnesium carbonitride powder is 40-60 nm; the thickness of the powder transition layer 2 is 0.3 mm; the particle size of the titanium carbide and silicon carbide coated diamond powder is 20-30 μm; the thickness of the titanium carbide and silicon carbide coated layer is 100-200 nm; the particle size of the fullerene coated diamond powder is 10-15 μm; the particle size of the diamond powder is 5-10 μm; the diamond powder is titanium and nitrogen ion implanted diamond; the particle size of the graphdiyne is 500-800 nm; the particle size of the fullerene is 500-700 nm; the binder is composed of the following raw materials in weight percentage: Co powder 95.5%, Li powder 2.9%, Ti powder 0.35%, Eu powder 0.25%, TiC powder 0.25%, Li3N powder 0.25%, Li3BN2 powder 0.25% and TiN powder 0.25%; the particle size of the Co powder, Li powder, Ti powder, Eu powder, TiC powder, Li3N powder, Li3BN2 powder and TiN powder is 40-50 nm.

[0078] The preparation method of the high-strength and high-wear-resistance polycrystalline diamond compact described above comprises the following steps:

[0079] 1) Cemented carbide substrate cleaning: first, the cemented carbide substrate is subjected to ultrasonic alkaline cleaning to remove surface oil, ultrasonic pure water rinsing to remove impurities, then ultrasonic acid cleaning to remove rust, followed by ultrasonic deionized water cleaning and drying; the alkaline cleaning solution used in the ultrasonic alkaline cleaning is a 40wt% sodium hydroxide solution; the acid cleaning solution used in the ultrasonic acid cleaning is a 10wt% hydrochloric acid solution, the alkaline cleaning time is 10 min, the acid cleaning time is 6.5 min, and the ultrasonic power is 40 W. Then the cleaned cemented carbide substrate is fixed on a rotating stand in an ion source / arc ion plating film equipment, argon or hydrogen is introduced into the vacuum chamber, when argon is introduced, the argon flow is 400 sccm, the working pressure is 1.35 Pa, and the substrate bias is -600 V, the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 15 min; when hydrogen is introduced, the gas flow is 300 sccm, the working pressure is 1.2 Pa, and the substrate bias is -600 V, the surface of the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 15 min, to obtain a clean cemented carbide substrate;

[0080] 2) Cemented carbide substrate boronizing: the clean cemented carbide substrate in step 1) is placed in a vacuum tube drying furnace for boronizing treatment; the boronizing treatment gas is a mixed gas of 9% B2H6 and 91% H2 by volume, the flow rate of the mixed gas is 10 sccm, the pressure is 9 kPa, and the reaction time is 4 h, to obtain a surface boronized cemented carbide substrate;

[0081] 3) Transition composite coating: the surface boronized cemented carbide substrate in step 2) is fixed on a rotating stand in an ion source / arc ion plating film equipment, argon is first introduced into the ion source / arc ion equipment, the flow rate is 225 sccm, the vacuum chamber pressure is adjusted to 0.75 Pa, the rare earth element arc target current is turned on to 140 A, and the substrate bias is 200 V, to deposit a rare earth coating on the boronized surface of the cemented carbide substrate; then argon is introduced into the vacuum chamber, the vacuum chamber pressure is adjusted to 0.7 Pa, the cubic boron nitride arc target voltage is adjusted to 20 V, the target current is reduced to 20 A, and the substrate bias is 160 V, to deposit a cubic boron nitride coating on the surface of the rare earth coating, to obtain a cemented carbide substrate containing a transition composite coating;

[0082] 4) Depositing titanium carbide and silicon carbide: diamond micro powder is placed on a substrate table in a plating film machine chamber, and vacuum is pumped to a vacuum degree of 1×10 -3 Pa~3×10 -3Pa; the substrate table is heated to 575℃, the substrate table rotation speed is 12.5 rad / min, the deposition current is 100 A, hydrogen carrying acetone is introduced into the coating machine at a flow rate of 57.5 seem; titanium and titanium silicon (the surface area ratio of titanium element to silicon element is 5:1) are used as target materials, titanium and titanium silicon targets are deposited at a deposition power of 1250 W at the same time for 1.5 h, a composite coating of titanium carbide and silicon carbide is formed on the surface of the diamond micro powder, and titanium carbide and silicon carbide coated diamond micro powder is obtained;

[0083] 5) Ion implantation on the surface of the diamond: the ordinary diamond micro powder is placed in the vacuum working cavity of the ion implantation machine, the ions supplied by the ion source are first separated into monovalent titanium ions by the mass spectrometer, and then the ions supplied by the ion source are separated into monovalent nitrogen ions, and the ion density is 3×10 14 ~ 3×10 17 ions / cm 2 and the energy is 75 keV, and then the ions supplied by the ion source are separated into monovalent nitrogen ions, and the ion density is 3×10 15 ~ 3×10 17 ions / cm 2 and the energy is 75 keV, and the titanium and nitrogen ion implanted diamond micro powder is obtained;

[0084] 6) Powder transition layer mixing: graphite acetylene, fullerene, binder, magnesium carbonitride powder, cubic boron nitride micro powder and titanium carbide and silicon carbide coated diamond micro powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in turn, respectively, and are mechanically stirred and ultrasonic (power 45 W) oscillation dispersed for 40 min, and the mass content of the powder material is 0.4 g / ml; polyethylene glycol is weighed and added to the anhydrous ethanol dispersion, mechanically stirred and ultrasonic (power 45 W) oscillation dispersed for 60 min, and the concentration of polyethylene glycol is 2.5 g / L, then poured into a hard alloy ball milling tank with hard alloy balls, the ball-to-material mass ratio is 11:1, nitrogen gas is filled as a protective gas, and then ball milled for 35 h, and the mixed powder is placed in a vacuum dryer and vacuum dried at 55℃ for 5 h, and the powder transition layer mixed powder is obtained;

[0085] 7) Poly crystalline diamond layer mixing: Fullerene, graphyne, binder, diamond powder, fullerene coated diamond powder, titanium carbide and silicon carbide coated diamond powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in turn, respectively, and are mechanically stirred and ultrasonic (power 45W) oscillation dispersed for 65 min, the mass content of the powder material is 0.7 g / ml; polyethylene glycol is weighed and added into the anhydrous ethanol dispersion, and is mechanically stirred and ultrasonic (power 45W) oscillation dispersed for 80 min, the concentration of the polyethylene glycol is 3.5 g / L, then is poured into a hard alloy ball mill tank with hard alloy balls, the ball-to-material mass ratio is 9:1, nitrogen is filled as a protective gas, and then is ball milled for 37.5 h, after mixing, is placed in a vacuum dryer, and is vacuum dried at 55°C for 4.5 h, to obtain a poly crystalline diamond layer mixed powder;

[0086] 8) Composite assembly: the poly crystalline diamond layer mixed powder of step 7) and the powder transition layer mixed powder of step 6) are sequentially loaded into a high-temperature-resistant metal niobium cup, are layered, compacted and shaped, then the hard alloy substrate with the transition composite coating of step 3) is placed on the powder transition layer mixed powder with the coating facing down, and then a high-temperature-resistant metal niobium cup is sleeved from the opposite direction, to obtain a composite assembly;

[0087] 9) Composite pre-pressing: the composite assembly of step 8) is placed in a pyrophyllite block, the pyrophyllite block is placed in a high-temperature high-pressure device, the pressure is increased to 3.75 GPa, and is kept for 100 s without heating, then the high-temperature high-pressure device is depressurized to standard atmospheric pressure, to obtain a pre-pressed composite assembly;

[0088]

[0089] 10) Composite purification: the pre-pressed composite assembly of step 9) is placed in a vacuum sintering furnace for sintering, during sintering, the furnace is first rough-pumped to a pressure of 7x10 -2 Pa, heated to 315°C and kept for 12 min, continues to be pumped to a pressure of 3x10 -5 Pa, the temperature is increased to 1325°C and kept for 14 min, then the pumping is stopped, a mixed gas of carbon monoxide, ammonia and argon is filled, the hydrogen, carbon monoxide and argon are uniformly mixed in a mass ratio of 0.3:0.8:1, and are kept for 1.25 h, then the furnace is vacuumed to a pressure of 3x10 -5 Pa, to obtain a purified composite assembly;

[0090] ​11) High temperature and high pressure sintering: the assembly of step 10) and the block of beryllosite are assembled and placed in a cubic press for sintering, first increasing the sintering pressure to 6.75 GPa at a rate of 0.55 GPa / min, then increasing the temperature at a rate of 25 ℃ / S for high temperature sintering, and then increasing the temperature to 1525 ℃ within 25 S after holding at 1450 ℃ for 125 S, holding at 1525 ℃ for 125 S, then decreasing the temperature to 600 ℃ at a rate of 17 ℃ / S, holding for 12 min, and then decreasing to room temperature, and then decreasing the pressure to normal pressure at a rate of 0.65 GPa / min. The assembly is removed from the cubic press, the surface coating layer is removed, and a sintered polycrystalline diamond compact blank is obtained.

[0091] 12) Stress relief aging: the sintered polycrystalline diamond compact blank of step 11) is assembled again with the block of beryllosite, placed in a cubic press, pressurized to 7.0 GPa, and the temperature is adjusted to 650 ℃, holding for 12 min, then the beryllosite block is cooled to 525 ℃, holding for 12 min, then continues to cool to 425 ℃, holding for 17 min, then continues to cool to 325 ℃, holding for 17 min, and finally cooled to room temperature at a rate of 15 ℃ / S, and then decreased to normal pressure at a rate of 0.6 GPa / min. The aged polycrystalline diamond compact blank is removed from the assembly, processed to the required size using grinding equipment, and then surface polished to obtain the high strength and wear resistant polycrystalline diamond compact.

[0092] The high strength and wear resistant polycrystalline diamond compact prepared in this example is tested for wear resistance according to the standard JB / T3235-2013 "Abrasion Ratio Test Method for Artificial Diamond Sintered Body"; first, the compact sample is placed in a tube furnace and heated at 690 ℃ for 1 min, then the impact toughness is tested by the falling weight impact method (i.e. a 1 kg weight is dropped freely from a height of 30 cm, and the energy is used to impact the corners of the sample to test the impact toughness value when micro cracks appear on the surface); the thermal stability test is performed by thermogravimetric-differential thermal analysis method, and the initial oxidation temperature of the differential thermal curve is used as the thermal stability characterization temperature, and the higher the initial oxidation temperature, the better the thermal stability. The test results are as follows: the abrasion ratio is 480,000, the impact toughness is 65 times, and the thermal stability characterization temperature is 750 ℃. It has excellent heat resistance, wear resistance and impact toughness.

[0093] Comparative Example 1

[0094] The high-strength and high-wear-resistance polycrystalline diamond compact of the comparative example comprises a cemented carbide substrate and, sequentially from inside to outside of the cemented carbide substrate, a transition composite coating, a powder transition layer and a polycrystalline diamond layer, the polycrystalline diamond layer is composed of the following raw materials in percentage by weight: titanium carbide and silicon carbide coated diamond powder 49.2%, fullerene coated diamond powder 30.2%, diamond powder 10.2%, graphdiyne 0.6%, fullerene 0.6% and binder 9.2%; the transition composite coating, in order from inside to outside, is a rare earth coating and a cubic boron nitride coating, wherein the rare earth coating is arranged between the surface of the cemented carbide substrate and the cubic boron nitride coating; the material of the rare earth coating is selected from rare earth element Lu; the thickness of the rare earth coating is 1.5 μm; the thickness of the cubic boron nitride coating is 2.5 μm; the cemented carbide substrate is a boronized cemented carbide substrate; the thickness of the boronized layer on the surface of the cemented carbide substrate is 0.8 μm; the powder transition layer is composed of the following raw materials in percentage by weight: titanium carbide and silicon carbide coated diamond powder 39.2%, cubic boron nitride powder 45.2%, magnesium carbonitride powder 4.2%, graphdiyne 0.6%, fullerene 0.6% and binder 10.2%; the particle size of the cubic boron nitride powder is 5-10 μm; the particle size of the magnesium carbonitride powder is 40-60 nm; the thickness of the powder transition layer is 0.18 mm; the particle size of the titanium carbide and silicon carbide coated diamond powder is 20-30 μm; the thickness of the titanium carbide and silicon carbide coating layer is 100-200 nm; the particle size of the fullerene coated diamond powder is 10-15 μm; the particle size of the diamond powder is 5-10 μm; the diamond powder is titanium and nitrogen ion implanted diamond; the particle size of the graphdiyne is 500-800 nm; the particle size of the fullerene is 500-700 nm; the binder is composed of the following raw materials in percentage by weight: Co powder 93.2%, Li powder 4.2%, Ti powder 0.6%, Eu powder 0.4%, TiC powder 0.4%, Li3N powder 0.4%, Li3BN2 powder 0.4% and TiN powder 0.4%; the particle size of the Co powder, the Li powder, the Ti powder, the Eu powder, the TiC powder, the Li3N powder, the Li3BN2 powder and the TiN powder is 40-50 nm.

[0095] The preparation method of the above high-strength and high-wear-resistance polycrystalline diamond compact is same as that of Example 3.

[0096] The high-strength and high-wear-resistance polycrystalline diamond compact prepared in the comparative example is subjected to performance test, the test method is same as that of Example 3, the test abrasion ratio is 350,000, the impact toughness is 57 times; the thermal stability characterization temperature is 640℃, compared with Example 3, the performance index is obviously reduced.

[0097] Comparative Example 2

[0098] The high-strength and high-wear-resistance polycrystalline diamond compact of the comparative example comprises a cemented carbide substrate and, sequentially from inside to outside of the cemented carbide substrate, a transition composite coating, a powder transition layer and a polycrystalline diamond layer, the polycrystalline diamond layer is composed of the following raw materials in percentage by weight: titanium carbide and silicon carbide coated diamond powder 65.8%, fullerene coated diamond powder 24.8%, diamond powder 4.8%, graphdiyne 0.2%, fullerene 0.2% and binder 4.2%; the transition composite coating, in order from inside to outside, is a rare earth coating and a cubic boron nitride coating, wherein the rare earth coating is arranged between the surface of the cemented carbide substrate and the cubic boron nitride coating; the material of the rare earth coating is selected from rare earth element Lu; the thickness of the rare earth coating is 4.1 μm; the thickness of the cubic boron nitride coating is 5.1 μm; the cemented carbide substrate is a boronized cemented carbide substrate; the thickness of the boronized layer on the surface of the cemented carbide substrate is 3.1 μm; the powder transition layer is composed of the following raw materials in percentage by weight: titanium carbide and silicon carbide coated diamond powder 50.7%, cubic boron nitride powder 39.8%, magnesium carbonitride powder 1.8%, graphdiyne 0.2%, fullerene 0.2% and binder 7.3%; the particle size of the cubic boron nitride powder is 5-10 μm; the particle size of the magnesium carbonitride powder is 40-60 nm; the thickness of the powder transition layer is 0.42 mm; the particle size of the titanium carbide and silicon carbide coated diamond powder is 20-30 μm; the thickness of the titanium carbide and silicon carbide coating layer is 100-200 nm; the particle size of the fullerene coated diamond powder is 10-15 μm; the particle size of the diamond powder is 5-10 μm; the diamond powder is titanium and nitrogen ion implanted diamond; the particle size of the graphdiyne is 500-800 nm; the particle size of the fullerene is 500-700 nm; the binder is composed of the following raw materials in percentage by weight: Co powder 97.7%, Li powder 1.7%, Ti powder 0.1%, Eu powder 0.1%, TiC powder 0.1%, Li3N powder 0.1%, Li3BN2 powder 0.1% and TiN powder 0.1%; the particle size of the Co powder, the Li powder, the Ti powder, the Eu powder, the TiC powder, the Li3N powder, the Li3BN2 powder and the TiN powder is 40-50 nm.

[0099] The preparation method of the above high-strength and high-wear-resistance polycrystalline diamond compact is same as that of Example 3.

[0100] The high-strength and high-wear-resistance polycrystalline diamond compact prepared in the comparative example is tested for performance, and the testing method is same as that of Example 3. The test result is that the abrasion ratio is 360,000, the impact toughness is 56 times, the thermal stability characterization temperature is 670℃, and the performance index is obviously reduced compared with that of Example 3.

[0101] Comparative Example 3

[0102] The high-strength and high-wear-resistance polycrystalline diamond compact of the comparative example has the same material and ratio as those of Example 3.

[0103] The preparation method comprises the following steps:

[0104] 1) Purification of the cemented carbide substrate: the cemented carbide substrate is first subjected to ultrasonic alkaline cleaning to remove surface oil stains, ultrasonic pure water rinsing to remove impurities, and then ultrasonic acid cleaning to remove rust, followed by ultrasonic deionized water purification and drying. The alkaline cleaning solution used in the ultrasonic alkaline cleaning is a 33wt% sodium hydroxide solution; the acid cleaning solution used in the ultrasonic acid cleaning is a 7wt% hydrochloric acid solution. The alkaline cleaning time is 8 min, the acid cleaning time is 6 min, and the ultrasonic power is 40 W. The cleaned cemented carbide substrate is then fixed on a rotating stand in an ion source / arc ion plating device, argon or hydrogen is introduced into the vacuum chamber, when argon is introduced, the argon flow rate is 295 sccm, the working pressure is 0.9 Pa, and the substrate bias is -495 V, the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 9 min; when hydrogen is introduced, the gas flow rate is 195 sccm, the working pressure is 0.7 Pa, and the substrate bias is -495 V, the surface of the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 9 min, to obtain a clean cemented carbide substrate;

[0105] 2) Boronizing of the cemented carbide substrate: the clean cemented carbide substrate obtained in step 1) is placed in a vacuum tube-type drying furnace for boronizing treatment. The boronizing treatment gas is a mixture of 9% B2H6 and 91% H2 by volume, the flow rate of the mixture is 8 sccm, the pressure is 7 kPa, and the reaction time is 2.5 h, to obtain a cemented carbide substrate with a boronized surface;

[0106] 3) Transition composite coating: the cemented carbide substrate with a boronized surface obtained in step 2) is fixed on a rotating stand in an ion source / arc ion plating device, argon is first introduced into the ion source / arc ion device, the flow rate is 49.5 sccm, the vacuum chamber pressure is adjusted to 0.1 Pa, the rare earth element arc target current is turned on to 79 A, and the substrate bias is 99 V, to deposit a rare earth coating on the boronized surface of the cemented carbide substrate; then argon is introduced into the vacuum chamber, the vacuum chamber pressure is adjusted to 0.3 Pa, the cubic boron nitride arc target voltage is adjusted to 14 V, the target current is reduced to 9 A, and the substrate bias is 29 V, to deposit a cubic boron nitride coating on the surface of the rare earth coating, to obtain a cemented carbide substrate with a transition composite coating;

[0107] 4) Deposition of titanium carbide and silicon carbide: diamond micro powder is placed on a substrate table in the chamber of a plating machine, and vacuum is pumped to a vacuum degree of 1×10 -3 Pa~3×10 -3Pa; the substrate table is heated to 540℃, the substrate table rotation speed is 9 rad / min, the deposition current is 100 A, and hydrogen carrying acetone is introduced into the coating machine at a flow rate of 49 seem; titanium and titanium silicon (the surface area ratio of titanium element to silicon element is 4:1) are used as target materials, and titanium and titanium silicon targets are deposited at a deposition power of 995 W for 0.5 h to form a composite coating of titanium carbide and silicon carbide on the surface of the diamond micro powder, thereby obtaining titanium carbide and silicon carbide coated diamond micro powder;

[0108] 5) Ion implantation on the surface of the diamond: the ordinary diamond micro powder is placed in the vacuum working cavity of the ion implantation machine, and the ions supplied by the ion source are first separated into monovalent titanium ions by a mass spectrometer, and then implanted into the surface of the diamond at an ion density of 3×10 14 ~ 3×10 17 ions / cm 2 and an energy of 59 keV, and then the ions supplied by the ion source are separated into monovalent nitrogen ions, and then implanted into the surface of the diamond at an ion density of 3×10 15 ~ 3×10 17 ions / cm 2 and an energy of 59 keV, thereby obtaining titanium and nitrogen ion implanted diamond micro powder;

[0109] 6) Powder transition layer mixing: graphite alkyne, fullerene, binder, magnesium carbonitride powder, cubic boron nitride micro powder, and titanium carbide and silicon carbide coated diamond micro powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in sequence, respectively, and are mechanically stirred and ultrasonically (power 42 W) oscillated and dispersed for 35 min, and the mass content of the powder material is 0.1 g / ml; polyethylene glycol is weighed and added to the anhydrous ethanol dispersion, and is mechanically stirred and ultrasonically (power 42 W) oscillated and dispersed for 59 min, and the concentration of polyethylene glycol is 0.8 g / L, and then is poured into a hard alloy ball milling tank with hard alloy balls, and the ball-to-material mass ratio is 9:1, and nitrogen gas is filled as a protective gas, and then is ball milled for 29 h, and after mixing, is placed in a vacuum dryer, and is vacuum dried at 49℃ for 3.5 h, thereby obtaining powder transition layer mixed powder;

[0110] 7) Polycrystalline diamond layer mixing: Fullerene, graphyne, binder, diamond powder, fullerene-coated diamond powder, titanium carbide-coated diamond powder, and silicon carbide-coated diamond powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in turn, mechanically stirred and ultrasonically (power 42W) oscillated for 55 min, and the mass content of the powder is 0.3 g / ml; polyethylene glycol is weighed and added to the anhydrous ethanol dispersion, mechanically stirred and ultrasonically (power 42W) oscillated for 79 min, and the concentration of polyethylene glycol is 1.5 g / L, then poured into a hard alloy ball mill tank with hard alloy balls, the ball-to-material mass ratio is 7:1, nitrogen is filled as a protective gas, and then ball milling is performed for 34 h, the mixed material is placed in a vacuum dryer, vacuum drying is performed at 49°C for 2.5 h, and a polycrystalline diamond layer mixed powder is obtained;

[0111] 8) Composite assembly: the polycrystalline diamond layer mixed powder of step 7 and the powder transition layer mixed powder of step 6 are sequentially loaded into a high-temperature-resistant metal niobium cup, layered, compacted, and shaped, then the hard alloy substrate with a transition coating of step 3 is placed on the powder transition layer mixed powder with the coating facing down, and then a high-temperature-resistant metal niobium cup is sleeved from the opposite direction to obtain a composite assembly;

[0112] 9) Composite pre-pressing: the composite assembly of step 8 is placed in a pyrophyllite block, the pyrophyllite block is placed in a high-temperature high-pressure device, the pressure is increased to 3.3 GPa, and the temperature is kept at 89 s without heating, then the high-temperature high-pressure device is depressurized to standard atmospheric pressure, and a pre-pressed composite assembly is obtained;

[0113]

[0114] 10) Composite purification: the pre-pressed composite assembly of step 9 is placed in a vacuum sintering furnace for sintering, during sintering, the furnace is first rough-pumped to a pressure of 7×10 -2 Pa, heated to 275°C for 9 min, and then vacuumed to a pressure of 3×10 -5 Pa, the temperature is increased to 1295°C for 9 min, and then the vacuum is stopped, a mixed gas of carbon monoxide, ammonia, and argon is filled, the hydrogen, carbon monoxide, and argon are uniformly mixed in a mass ratio of 0.3:0.8:1, and the mixture is kept for 0.5 h, then the furnace is vacuumed to a pressure of 3×10 -5 Pa, and a purified composite assembly is obtained;

[0115] ​11) High temperature and high pressure sintering: the assembly of step 10) and the block of beryl are assembled and placed in a cubic press for sintering, first increasing the sintering pressure to 6.3 GPa at a rate of 0.08 GPa / min, and then increasing the temperature at a rate of 19 ℃ / S for high temperature sintering, and then increasing the temperature to 1495 ℃ at a rate of 19 ℃ / S within 99 S after keeping the temperature at 1450 ℃ for 99 S, and then decreasing the temperature to 600 ℃ at a rate of 14 ℃ / S, keeping the temperature for 9 min, and then decreasing the temperature to room temperature, and then decreasing the pressure to normal pressure at a rate of 0.5 GPa / min. The assembly is taken out of the cubic press, the surface wrapping layer is removed, and a sintered polycrystalline diamond compact blank is obtained.

[0116] 12) Stress relief aging: the sintered polycrystalline diamond compact blank of step 11) is assembled again with the block of beryl, and placed in a cubic press, and then pressurized to 7.0 GPa, and then the temperature is adjusted to 595 ℃, and then kept for 9 min, and then the temperature of the beryl block is decreased to 495 ℃, and then kept for 9 min, and then the temperature is further decreased to 395 ℃, and then kept for 14 min, and then the temperature is further decreased to 295 ℃, and then kept for 14 min, and then the temperature is decreased to room temperature at a rate of 9 ℃ / S, and then the pressure is decreased to normal pressure at a rate of 0.4 GPa / min. The aged polycrystalline diamond compact blank is taken out of the assembly, and then processed to the required size using grinding equipment, and then surface polished to obtain the high strength and high wear resistance polycrystalline diamond compact.

[0117] The high strength and high wear resistance polycrystalline diamond compact prepared in the comparative example is tested for performance, and the testing method is the same as that of example 3. The test results show that the wear ratio is 340,000, the impact toughness is 53 times, the thermal stability characterization temperature is 640 ℃, and the performance indicators are obviously lower than those of example 3.

[0118] Comparative example 4

[0119] The high strength and high wear resistance polycrystalline diamond compact of the comparative example is prepared using the same materials and their proportions as in example 3.

[0120] The preparation method comprises the following steps:

[0121] 1) Cemented carbide substrate cleaning: first, the cemented carbide substrate is subjected to ultrasonic alkaline cleaning to remove surface oil, ultrasonic pure water rinsing to remove impurities, then ultrasonic acid cleaning to remove rust, followed by ultrasonic deionized water cleaning and drying, the alkaline cleaning solution used in the ultrasonic alkaline cleaning is a 46wt% sodium hydroxide solution, the acid cleaning solution used in the ultrasonic acid cleaning is a 13wt% hydrochloric acid solution, the alkaline cleaning time is 8min, the acid cleaning time is 6min, and the ultrasonic power is 40W. Then the cleaned cemented carbide substrate is fixed on a rotating stand in an ion source / arc ion plating film equipment, argon or hydrogen is introduced into the vacuum chamber, when argon is introduced, the argon flow is 505sccm, the working pressure is 1.8Pa, and the substrate bias is -705V, the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 22min; when hydrogen is introduced, the gas flow is 405sccm, the working pressure is 1.7Pa, and the substrate bias is -705V, the surface of the cemented carbide substrate is subjected to glow cleaning, and the cleaning time is 22min, to obtain a clean cemented carbide substrate;

[0122] 2) Cemented carbide substrate boronizing: the clean cemented carbide substrate in step 1) is placed in a vacuum tube drying furnace for boronizing treatment, the boronizing treatment gas is a mixed gas of 9% B2H6 and 91% H2 by volume, the flow of the mixed gas is 13sccm, the pressure is 11kPa, and the reaction time is 6h. A cemented carbide substrate with a boronized surface is obtained;

[0123] 3) Transition composite coating: the cemented carbide substrate with a boronized surface in step 2) is fixed on a rotating stand in an ion source / arc ion plating film equipment, argon is first introduced into the ion source / arc ion equipment, the flow is 405sccm, the vacuum chamber pressure is adjusted to 1.4Pa, the rare earth element arc target current is turned on to 205A, and the substrate bias is 305V, to deposit a rare earth coating on the boronized surface of the cemented carbide substrate; then argon is introduced into the vacuum chamber, the vacuum chamber pressure is adjusted to 1.1Pa, the cubic boron nitride arc target voltage is adjusted to 26V, the target current is reduced to 31A, and the substrate bias is 205V, to deposit a cubic boron nitride coating on the rare earth coating, to obtain a cemented carbide substrate with a transition composite coating;

[0124] 4) Depositing titanium carbide and silicon carbide: diamond micro powder is placed on a substrate table in a plating film machine chamber, and vacuum is pumped to a vacuum degree of 1×10 -3 Pa~3×10 -3Pa; the substrate table is heated to 605℃, the substrate table rotation speed is 16 rad / min, the deposition current is 100 A, and hydrogen carrying acetone is introduced into the coating machine at a flow rate of 66 seem; titanium and titanium silicon (the surface area ratio of titanium element to silicon element is 6:1) are used as target materials, titanium and titanium silicon targets with a deposition power of 1505 W are used at the same time, and the diamond micro powder surface is formed with a titanium carbide and silicon carbide composite coating by depositing for 2.5 h, to obtain titanium carbide and silicon carbide coated diamond micro powder;

[0125] 5) Ion implantation on the diamond surface: the ordinary diamond micro powder is placed in the vacuum working cavity of the ion implantation machine, the ions supplied by the ion source are first separated into monovalent titanium ions by a mass spectrometer, and then implanted into the diamond surface at an ion density of 3×10 14 ~ 3×10 17 ions / cm 2 and an energy of 92 keV, and then the ions supplied by the ion source are separated into monovalent nitrogen ions, and then implanted into the diamond surface at an ion density of 3×10 15 ~ 3×10 17 ions / cm 2 and an energy of 92 keV, to obtain titanium and nitrogen ion implanted diamond micro powder;

[0126] 6) Powder transition layer mixing: graphite alkyne, fullerene, binder, magnesium carbonitride powder, cubic boron nitride micro powder, and titanium carbide and silicon carbide coated diamond micro powder are weighed according to the proportion, and are dispersed into anhydrous ethanol in turn, respectively, mechanically stirred and ultrasonically (power 43 W) oscillated and dispersed for 35 min, and the mass content of the powder material is 0.7 g / ml; polyethylene glycol is weighed and added to the anhydrous ethanol dispersion, mechanically stirred and ultrasonically (power 43 W) oscillated and dispersed for 59 min, and the concentration of polyethylene glycol is 4.2 g / L, then poured into a hard alloy ball milling tank with hard alloy balls, the ball-to-material mass ratio is 12.5:1, nitrogen gas is filled as a protective gas, and then ball milled for 41 h, and after mixing, placed in a vacuum dryer, vacuum dried at 61℃ for 6.5 h, to obtain a powder transition layer mixed powder;

[0127] 7) Polycrystalline diamond layer mixing: Weigh fullerene, graphylene, binder, diamond micro powder, fullerene-coated diamond micro powder, titanium carbide and silicon carbide-coated diamond micro powder according to the proportion, and disperse them in anhydrous ethanol in sequence. Mechanically stir and ultrasonically vibrate (power 43W) for 55 min. The mass content of the powder is 1.1 g / ml. Then weigh polyethylene glycol and add it to the anhydrous ethanol dispersion. Mechanically stir and ultrasonically vibrate (power 43W) for 79 min. The concentration of polyethylene glycol is 5.2 g / L. Then pour it into a cemented carbide ball mill jar with cemented carbide balls. The mass ratio of ball to powder is 10.5:1. After filling with nitrogen as a protective gas, ball mill for 41 h. After mixing, place it in a vacuum dryer and vacuum dry at 61℃ for 6.5 h to obtain polycrystalline diamond layer mixed powder.

[0128] 8) Composite assembly: First, the polycrystalline diamond layer mixed powder described in step 7) and the powder transition layer mixed powder described in step 6) are sequentially loaded into a high-temperature resistant niobium cup, and then compacted and shaped in layers. Then, the hard alloy substrate containing the transition composite coating from step 3) is placed flat on the powder transition layer mixed powder with the coating side facing down. Then, a high-temperature resistant niobium cup is inserted from the opposite direction to obtain the composite component.

[0129] 9) Composite preloading: Place the composite component from step 8) into the pyrophyllite block, and then place the pyrophyllite block into a high-temperature, high-pressure apparatus.

[0130] During preparation, the pressure is increased to 4.5 GPa and held for 115 seconds without heating. Then, the pressure is reduced to standard atmospheric pressure using a high-temperature and high-pressure equipment to obtain a pre-compressed composite component.

[0131] 10) Composite purification: Place the pre-compressed composite component from step 9) into a vacuum sintering furnace for sintering. During sintering, first perform a rough vacuum evacuation until the furnace pressure reaches 7×10⁻⁶. -2 Below Pa, heat to 351℃ and hold for 16 minutes, then continue evacuating until the furnace pressure is 3×10⁻⁶. -5 Below Pa, the temperature was raised to 1355℃ and held for 19 minutes, then the vacuum was stopped. A mixture of carbon monoxide, ammonia, and argon was introduced, with hydrogen, carbon monoxide, and argon uniformly mixed in a mass ratio of 0.3:0.8:1, and maintained for 1.6 hours. Then, the vacuum was evacuated until the furnace pressure was 3 × 10⁻⁶. -5 Below Pa, a purification composite component is obtained;

[0132] 11) High temperature and high pressure sintering: the assembly of the purified composite body and the block of beryllosite in step 10) is assembled and placed in a cubic press for sintering, first increased to a sintering pressure of 7.2 GPa at a rate of 1.1 GPa / min, and then increased to a high temperature sintering temperature at a rate of 31 ℃ / S, and then held at 1450 ℃ for 151 S, and then increased to a sintering temperature of 1555 ℃ within 32 S, and then held at 1555 ℃ for 151 S, and then decreased to 600 ℃ at a rate of 21 ℃ / S, and then held at 600 ℃ for 16 min, and then decreased to room temperature, and then decreased to atmospheric pressure at a rate of 0.8 GPa / min. The assembly block is taken out of the cubic press, and the surface wrapping layer is removed to obtain a sintered polycrystalline diamond compact blank.

[0133] 12) Stress relief aging: the sintered polycrystalline diamond compact blank in step 11) is assembled again with the block of beryllosite, and placed in a cubic press, and then pressurized to 7.0 GPa, and then adjusted to a temperature of 705 ℃, and then held for 16 min, and then the beryllosite block is cooled to 555 ℃, and then held for 16 min, and then further cooled to 451 ℃, and then held for 21 min, and then further cooled to 351 ℃, and then held for 21 min, and then cooled to room temperature at a rate of 21 ℃ / S, and then decreased to atmospheric pressure at a rate of 0.8 GPa / min. The aged polycrystalline diamond compact is taken out of the assembly block, and processed to the required size using grinding equipment, and then surface polished to obtain the high-strength and high-wear-resistance polycrystalline diamond compact.

[0134] The high-strength and high-wear-resistance polycrystalline diamond compact prepared in the comparative example is tested for performance, and the testing method is the same as that in example 3. The test results show that the wear ratio is 370,000, the impact toughness is 55 times, and the thermal stability characterization temperature is 665 ℃. Compared with example 3, the performance indicators are obviously reduced.

[0135] Through comparison and analysis of the technical performance indicators of the above examples and the comparative example, it can be obviously concluded that the high-strength and high-wear-resistance polycrystalline diamond compact produced by the technical scheme of the present application has the advantages of high heat resistance, wear resistance and impact toughness.

[0136] It should be noted that the materials used in the present application are commercially available, and the manufacturers and models are not mentioned. The manufacturers in the examples and the diameter, thickness, and thickness of the polycrystalline diamond layer are not limitations of the present application.

[0137] Finally, it should be noted that the above examples are used for illustration only and do not limit the technical scheme of the present application. Any equivalent replacement, modification or partial replacement of the present application without departing from the spirit and scope of the present application should be covered within the scope of protection of the claims of the present application.

Claims

1. A high-strength, high-wear-resistant polycrystalline diamond composite sheet, characterized in that, The material includes a cemented carbide substrate and, from the inside out, a transition composite coating, a powder transition layer, and a polycrystalline diamond layer sequentially disposed on the cemented carbide substrate. The polycrystalline diamond layer is composed of the following raw materials by weight percentage: 50-65% titanium carbide and silicon carbide-coated diamond powder, 25-30% fullerene-coated diamond powder, 5-10% diamond powder, 0.3-0.5% graphynylene, 0.3-0.5% fullerene, and 4.4-9% binder. The transition composite coating, from the inside out, consists of rare earth coatings... The cemented carbide substrate comprises a cubic boron nitride coating layer, wherein a rare earth coating is disposed on the surface of the cemented carbide substrate and between the cubic boron nitride coating layer; the rare earth coating material is selected from one of the rare earth elements Sm, Dy, Lu, and Tm; the thickness of the rare earth coating is 2-4 μm; the thickness of the cubic boron nitride coating is 3-5 μm; the cemented carbide substrate is a surface-boronized cemented carbide substrate; the thickness of the boronized layer on the surface of the cemented carbide substrate is 1-3 μm; the powder transition layer is composed of the following raw materials in weight percentages: The composition comprises 40-50% titanium carbide and silicon carbide-coated diamond micropowder, 40-45% cubic boron nitride micropowder, 2-4% magnesium carbonitride powder, 0.25-0.5% graphynylene, 0.25-0.5% fullerene, and 7.5-10% binder; the particle size of the cubic boron nitride micropowder is 5-10 μm; the particle size of the magnesium carbonitride powder is 40-60 nm; the thickness of the powder transition layer is 0.2-0.4 mm; the diamond micropowder is titanium and nitrogen ion implanted diamond; the binder... It is composed of the following raw materials by weight percentage: Co powder 94-97%, Li powder 1.8-4%, Ti powder 0.2-0.5%, Eu powder 0.2-0.3%, TiC powder 0.2-0.3%, Li3N powder 0.2-0.3%, Li3BN2 powder 0.2-0.3%, and TiN powder 0.2-0.3%; wherein the particle size of Co powder, Li powder, Ti powder, Eu powder, TiC powder, Li3N powder, Li3BN2 powder, and TiN powder is 40-50 nm.

2. The high-strength, high-wear-resistant polycrystalline diamond composite sheet according to claim 1, characterized in that, The titanium carbide and silicon carbide coated diamond micropowder has a particle size of 20-30 μm and a coating thickness of 100-200 nm; the fullerene coated diamond micropowder has a particle size of 10-15 μm; the diamond micropowder has a particle size of 5-10 μm; the graphyne has a particle size of 500-800 nm; and the fullerene has a particle size of 500-700 nm.

3. The method for preparing the high-strength, high-wear-resistant polycrystalline diamond composite sheet according to claim 1 or 2, characterized in that, Includes the following steps: 1) Cleaning of cemented carbide substrate: First, the cemented carbide substrate is subjected to ultrasonic alkaline cleaning to remove surface oil stains, followed by ultrasonic rinsing with pure water to remove impurities. Subsequently, it is subjected to ultrasonic acid pickling to remove rust, and then ultrasonically purified with deionized water and dried. Next, the cleaned cemented carbide substrate is fixed on a rotating frame in an ion source or arc ion plating equipment. Argon or hydrogen gas is introduced into the vacuum chamber. When argon gas is introduced, the gas flow rate is 300-500 sccm, the working pressure is 1-1.7 Pa, and the substrate bias voltage is -500 to -700 V. The cemented carbide substrate is then subjected to glow discharge cleaning for 10-20 minutes. When hydrogen gas is introduced, the gas flow rate is 200-400 sccm, the working pressure is 0.8-1.6 Pa, and the substrate bias voltage is -500 to -700 V. The surface of the cemented carbide substrate is then subjected to glow discharge cleaning for 10-20 minutes, resulting in a clean cemented carbide substrate. 2) Boronizing the cemented carbide substrate: The clean cemented carbide substrate described in step 1) is placed in a vacuum tube drying oven for boronizing treatment to obtain a cemented carbide substrate with surface boronizing. 3) Transitional composite coating: The boron-diffused cemented carbide substrate described in step 2) is fixed on a rotating frame in an ion source or arc ion plating equipment. Argon gas is first introduced into the ion source or arc ion plating equipment at a flow rate of 50–400 sccm. The vacuum chamber pressure is adjusted to 0.2–1.3 Pa, the rare earth element arc target current is turned on to 80–200 A, and the substrate bias voltage is 100–300 V. A rare earth coating is deposited on the surface of the boron-diffused layer on the cemented carbide substrate. Then, argon gas is introduced into the vacuum chamber, the vacuum chamber pressure is adjusted to 0.4–1.0 Pa, the cubic boron nitride arc target voltage is adjusted to 15–25 V, the target current is reduced to 10–30 A, and the substrate bias voltage is 30–200 V. A cubic boron nitride coating is deposited on the surface of the rare earth coating to obtain a cemented carbide substrate with a transitional composite coating. 4) Deposition of titanium carbide and silicon carbide: Diamond micro powder is placed on the substrate stage in the coating machine chamber, and a vacuum is drawn to a vacuum level of 1×10⁻⁶. -3 Pa~3×10 -3 Pa; The substrate stage is heated to 550-600°C, the stage rotation speed is 10-15 rad / min, the deposition current is 100 A, and hydrogen gas carrying acetone is introduced into the coating machine at a flow rate of 50-65 sccm; Titanium and titanium silicon are used as targets, with a surface area ratio of titanium to silicon of 5:1, and titanium and titanium silicon targets are deposited simultaneously with a deposition power of 1000-1500 W for 1-2 hours to form a composite coating of titanium carbide and silicon carbide on the surface of the diamond micro powder, thus obtaining titanium carbide and silicon carbide coated diamond micro powder; 5) Ion implantation onto diamond surface: Ordinary diamond micropowder is placed in the vacuum working chamber of an ion implanter. The ions supplied by the ion source are first separated into monovalent titanium ions using a mass spectrometer at a concentration of 3 × 10⁻⁶. 14 ~3×10 17 ions / cm 2 The ion density and energy of 60–90 keV are injected into the diamond surface, and then the ions supplied by the ion source are separated into monovalent nitrogen ions, at a density of 3 × 10⁻⁶. 15 ~3×10 17 ions / cm 2 The ion density and energy of 60-90 keV were injected into the diamond surface to obtain diamond micro powder implanted with titanium ions and nitrogen ions. 6) Powder transition layer mixing: Weigh out graphylene, fullerene, binder, magnesium carbonitride powder, cubic boron nitride micro powder, titanium carbide and silicon carbide coated diamond micro powder according to the proportion, and disperse them in anhydrous ethanol in sequence. Mechanically stir and ultrasonically vibrate for 30-50 min, and the mass content of the powder is 0.2-0.6 g / mL. Then weigh out polyethylene glycol and add it to the anhydrous ethanol dispersion. Mechanically stir and ultrasonically vibrate for 50-70 min, and the concentration of polyethylene glycol is 1-4 g / L. Then pour it into a cemented carbide ball mill jar with cemented carbide balls. The mass ratio of ball to powder is 10-12:

1. After filling with nitrogen as a protective gas, ball mill for 30-40 h. After mixing, place it in a vacuum dryer and vacuum dry at 50-60℃ for 4-6 h to obtain the powder transition layer mixed powder. 7) Polycrystalline diamond layer mixing: Weigh fullerene, graphylene, binder, diamond micro powder, fullerene-coated diamond micro powder, titanium carbide and silicon carbide-coated diamond micro powder according to the proportion, and disperse them in anhydrous ethanol in sequence. Mechanically stir and ultrasonically vibrate for 50-80 min, and the mass content of the powder is 0.4-1 g / mL; then weigh polyethylene glycol and add it to the anhydrous ethanol dispersion, mechanically stir and ultrasonically vibrate for 70-90 min, and the concentration of polyethylene glycol is 2-5 g / L. Then pour it into a cemented carbide ball mill jar with cemented carbide balls, the mass ratio of balls to powder is 8-10:1, and ball mill for 35-40 h after purging with nitrogen as a protective gas. After mixing, place it in a vacuum dryer and vacuum dry at 50-60℃ for 3-6 h to obtain polycrystalline diamond layer mixed powder. 8) Composite assembly: First, the polycrystalline diamond layer mixed powder described in step 7) and the powder transition layer mixed powder described in step 6) are sequentially loaded into a high-temperature resistant metal cup, layered and compacted to shape. Then, the hard alloy substrate containing the transition composite coating from step 3) is placed flat on the powder transition layer mixed powder with the coating side facing down. Then, a high-temperature resistant metal cup is inserted from the opposite direction to obtain the composite assembly. The high-temperature resistant metal cup is made of one or more of tantalum, molybdenum, niobium, and zirconium. 9) Composite preloading: Place the composite component from step 8) into the pyrophyllite block, and then place the pyrophyllite block into a high-temperature, high-pressure apparatus. During preparation, the pressure is increased to 3.5-4 GPa and held for 90-110 seconds without heating. Then, the pressure is reduced to standard atmospheric pressure using a high-temperature and high-pressure equipment to obtain a pre-compressed composite component. 10) Composite purification: Place the pre-compressed composite assembly from step 9) into a vacuum sintering furnace for sintering. During sintering, first roughly evacuate the furnace until the internal pressure reaches 7×10⁻⁶. -2 Below Pa, heat to 280–350℃ and hold for 10–15 minutes, then continue evacuating until the furnace pressure is 3 × 10⁻⁶. -5 Below Pa, raise the temperature to 1300–1350℃ and hold for 10–18 minutes, then stop evacuation. Introduce a mixture of carbon monoxide, hydrogen, and argon, with a mass ratio of 0.3:0.8:1, and maintain this mixture for 1.0–1.5 hours. Then evacuate again until the furnace pressure is 3 × 10⁻⁶ Pa. -5 Below Pa, a purification composite component is obtained; 11) High-temperature and high-pressure sintering: Assemble the purification composite component from step 10) with the pyrophyllite assembly block, place it in a six-sided press for sintering, first raise the temperature to 6.5-7.0 GPa at a rate of 0.1-1 GPa / min, and then raise the temperature at a rate of 20-30℃ / s for high-temperature sintering. After holding at 1450℃ for 100-150s, raise the temperature to 1500-1550℃ within 20-30s and hold for 100-150s. After sintering, lower the temperature to 600℃ at a rate of 15-20℃ / s, hold for 10-15min, and then lower the temperature to room temperature. Then, reduce the pressure to atmospheric pressure at a rate of 0.6-0.7 GPa / min. Remove the pyrophyllite assembly block from the six-sided press, remove the surface coating layer, and obtain the sintered polycrystalline diamond composite blank. 12) Stress-relief aging: The sintered polycrystalline diamond composite blank from step 11) is reassembled with the pyrophyllite assembly block and placed in a six-sided press. The pressure is increased to 7.0 GPa, the temperature is adjusted to 600-700℃ and held for 10-15 min. The pyrophyllite block is then cooled to 500-550℃ and held for 10-15 min. The temperature is then further reduced to 400-450℃ and held for 15-20 min. The temperature is then reduced to 300-350℃ and held for 15-20 min. Finally, the temperature is reduced to room temperature at a rate of 10-20℃ / s and then reduced to atmospheric pressure at a rate of 0.5-0.7 GPa / min. The aged polycrystalline diamond composite blank is removed from the pyrophyllite assembly block, processed to the required dimensions using a grinding machine, and then surface polished to obtain the high-strength, high-wear-resistant polycrystalline diamond composite sheet.

4. The method for preparing the high-strength, high-wear-resistant polycrystalline diamond composite sheet according to claim 3, characterized in that, In step 1), the alkaline cleaning solution used for ultrasonic alkaline cleaning is selected from one of potassium ferricyanide, potassium hydroxide, and sodium hydroxide; the mass percentage concentration of the alkaline cleaning solution is 35-45%. The acidic cleaning solution used for ultrasonic acid cleaning is selected from one of sulfuric acid, nitric acid, hydrochloric acid, and hydrogen peroxide; the mass percentage concentration of the acidic cleaning solution is 8-12%. The alkaline cleaning time is 5-15 min, the acid cleaning time is 3-10 min, and the ultrasonic power is 30-50 W.

5. The method for preparing the high-strength, high-wear-resistant polycrystalline diamond composite sheet according to claim 3, characterized in that, In step 2), the boronizing gas is a mixture of 9% B2H6 and 91% H2 by volume, with a flow rate of 9-12 sccm, a pressure of 8-10 kPa, and a reaction time of 3-5 h.

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