Polycrystalline al 2o 3-tic-diamond composite material and preparation method therefor and use thereof

Abstract

A polycrystalline Al2O3-TiC-diamond composite material and a preparation method therefor and the use thereof, which belong to the field of petroleum drilling. The polycrystalline Al2O3-TiC-diamond composite material comprises a polycrystalline diamond layer, a polycrystalline Al2O3 layer, and a polycrystalline TiC transition layer, wherein the polycrystalline diamond layer and the polycrystalline Al2O3 layer are bonded by means of the polycrystalline TiC transition layer. The preparation method comprises sintering and optionally post-processing an assembled block of a diamond compact comprising a single crystal diamond and optionally a sintering aid A, a polycrystalline TiC compact comprising polycrystalline TiC and optionally a sintering aid B, and a polycrystalline Al2O3 compact comprising a polycrystalline Al2O3 compact and optionally a sintering aid C, which are assembled in sequence. The composite material has a good thermal stability and mechanical properties, and can be used in petroleum drilling applications.

Description

Polycrystalline Al2O3-TiC-diamond composite material, preparation method and application thereof

[0001] Cross-reference to Related Applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411318412.X, filed September 20, 2024, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of oil drilling, in particular to a polycrystalline Al2O3-TiC-diamond composite material, a preparation method and application thereof. BACKGROUND

[0004] The diamond compact is sintered from diamond powder and hard alloy substrate material under ultra-high pressure and high temperature, which has high hardness, wear resistance and thermal conductivity of diamond, and also has the strength and impact toughness of hard alloy, and is an ideal material for manufacturing cutting tools, drilling bits and other wear-resistant tools. Therefore, the diamond compact plays a crucial role in the use of drilling bits in the modern drilling field. However, as the deepest drilling depth of domestic and foreign drilling platforms gradually deepens, higher requirements are put forward for the performance of the drill teeth used for oil and gas drilling. Therefore, the diamond compact on the drill bit also needs to have better performance, such as better impact strength and hardness. The traditional diamond compact sintering technology is to uniformly mix diamond powder and metal sintering aid powder, and then sinter under high temperature and high pressure. Due to the large difference in thermal expansion coefficient between the metal sintering aid and the diamond, thermal cracks are easily formed in the diamond compact under high temperature conditions, which not only affects the yield of the finished product during the synthesis of the diamond compact, but also affects the service life of the diamond compact under extreme heating conditions during use, thereby affecting the service life of the drill bit and the drilling cost. In addition, the diamond powder used to prepare polycrystalline diamond is expensive, which limits the large-scale application of polycrystalline diamond to some extent.

[0005] The interface between the diamond layer and the substrate of the conventional oil compact is often a weak area for crack propagation, which is prone to fracture, delamination and other behaviors under load. SUMMARY

[0006] The present application aims to overcome the instability of the PDC composite material in the high-temperature and high-pressure synthesis process in the prior art. In the research, the applicant of the present application proposes to combine Al2O3, TiC and polycrystalline diamond together to obtain a polycrystalline Al2O3-TiC-diamond three-layer composite material. The polycrystalline Al2O3-TiC-diamond three-layer composite material not only has the characteristics of high hardness and high fracture toughness of the diamond layer, but also has the following advantages. On the one hand, the intermediate TiC transition layer can facilitate the formation of strong chemical bonds with the diamond layer, thereby promoting the bonding strength of the composite material layer. On the other hand, the TiC transition layer enhances the interfacial strength between the two layers. The strong chemical bonds can hinder crack propagation, thereby improving the impact resistance of the overall petroleum composite sheet.

[0007] Based on this, the first aspect of the present application provides a polycrystalline Al2O3-TiC-diamond composite material. The composite material comprises a polycrystalline diamond layer, a polycrystalline Al2O3 layer and a polycrystalline TiC transition layer. The polycrystalline diamond layer and the polycrystalline Al2O3 layer are combined through the polycrystalline TiC transition layer.

[0008] Aluminum oxide has good mechanical strength and high-temperature stability, and therefore can be widely used in various fields. In the synthesis of diamond composite sheets, it can reduce internal stress cracking and improve the cutting amount. Titanium carbide is a very hard and highly wear-resistant material, and is commonly used to manufacture tools and parts with high hardness and high wear resistance. The hardness of titanium carbide is only second to diamond and boron carbide, and the hardness can reach 1400-2000 HV. The wear resistance is 5-10 times that of hard alloy. In addition, titanium carbide also has extremely high heat resistance, corrosion resistance, oxidation resistance and stability, and is an ideal reinforcing agent. Therefore, in the process of manufacturing diamond drill bits, adding an appropriate amount of titanium carbide can significantly improve the hardness, wear resistance, corrosion resistance and heat resistance of the drill bit.

[0009] The composite material formed by the combination of the polycrystalline diamond layer and the polycrystalline Al2O3 layer through the polycrystalline TiC transition layer in the present application is composed of three materials with different physical and chemical properties. In the present application, the materials in each layer can interact with each other while being independent of each other, each maintaining its inherent physical, chemical and mechanical properties, and there is a multi-phase solid material interface between them. Various materials complement each other in performance, produce a synergistic effect, and the comprehensive performance of the composite material is better than that of the original constituent materials, thereby meeting various different requirements.

[0010] The second aspect of the present application provides a preparation method of a polycrystalline Al2O3-TiC-diamond composite material. The preparation method comprises: sintering an assembled block comprising a diamond forming body containing single-crystal diamond and optionally a sintering aid A, a polycrystalline TiC forming body containing polycrystalline TiC and optionally a sintering aid B, and a polycrystalline Al2O3 forming body containing polycrystalline Al2O3 and optionally a sintering aid C, and optionally post-treating.

[0011] The third aspect of the present application provides the polycrystalline Al2O3-TiC-diamond composite material prepared by the preparation method of the second aspect of the present application.

[0012] The fourth aspect of the present application provides the application of the polycrystalline Al2O3-TiC-diamond composite material of the first aspect of the present application or the third aspect of the present application in a PDC drill bit.

[0013] Compared with the prior art, the present application has at least the following beneficial effects:

[0014] (1) The polycrystalline diamond layer and the polycrystalline Al2O3 layer in the composite material of the present application are combined through the polycrystalline TiC transition layer, which can reduce the fragmentation and delamination of the composite material caused by low interfacial strength, and improve the impact resistance of the composite material.

[0015] (2) The composite material of the present application has good thermal stability and mechanical properties, and the overall performance and impact performance of the composite material are higher than those of general commercial petroleum composite sheets.

[0016] (3) The composite material of the present application can be used in petroleum drilling applications, and the TiC and Al2O3 materials are easy to obtain and have a low price, which has great application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0017] FIG. 1 is a preparation process flow diagram of the polycrystalline Al2O3-TiC-diamond composite material in an embodiment of the present application; 3- FIG. 2 is a device diagram of a high-temperature and high-pressure assembly of a sample in an embodiment of the present application;

[0018] FIG. 3 is a super-depth electron microscope diagram of the polycrystalline Al2O3-TiC-diamond composite material of Example 1;

[0019] FIG. 4 is a scanning electron microscope analysis diagram of the polycrystalline Al2O3 layer of the polycrystalline Al2O3-TiC-diamond composite material of Example 1;

[0020] FIG. 5 is a scanning electron microscope analysis diagram of the polycrystalline TiC layer of the polycrystalline Al2O3-TiC-diamond composite material of Example 1;

[0021] FIG. 6 is a scanning electron microscope analysis diagram of the polycrystalline diamond layer of the polycrystalline Al2O3-TiC-diamond composite material of Example 1;

[0022] FIG. 7 is a super-depth electron microscope diagram of the polycrystalline Al2O3-TiC-diamond composite material of Example 2;

[0023] FIG. 7 is a super-depth electron microscope diagram of the polycrystalline Al2O3-TiC-diamond composite material of Example 2;

[0024] Figure 8 is a scanning electron microscope analysis of the polycrystalline Al203 layer of the polycrystalline Al203-TiC-diamond composite material of Example 2;

[0025] Figure 9 is a scanning electron microscope analysis of the polycrystalline TiC layer of the polycrystalline Al203-TiC-diamond composite material of Example 2;

[0026] Figure 10 is a scanning electron microscope analysis of the polycrystalline diamond layer of the polycrystalline Al203-TiC-diamond composite material of Example 2;

[0027] Figure 11 is a super depth of field electron microscope image of the polycrystalline Al203-TiC-diamond composite material of Example 3;

[0028] Figure 12 is a scanning electron microscope analysis of the polycrystalline Al203 layer of the polycrystalline Al203-TiC-diamond composite material of Example 3;

[0029] Figure 13 is a scanning electron microscope analysis of the polycrystalline TiC layer of the polycrystalline Al203-TiC-diamond composite material of Example 3;

[0030] Figure 14 is a scanning electron microscope analysis of the polycrystalline diamond layer of the polycrystalline Al203-TiC-diamond composite material of Example 3. DETAILED DESCRIPTION

[0031] The endpoints of the ranges and any values described herein are not limited to the precise values stated. The endpoints of the ranges and any values should be understood to be approximate. The exact values will depend on the specific context and should be understood accordingly. The various ranges disclosed herein are intended to serve as a disclosure door to all ranges encompassed within the ranges. Any maximum numerical limitation

[0032] A polycrystalline Al203-TiC-diamond composite material is provided, the composite material comprising a polycrystalline diamond layer, a polycrystalline Al203 layer and a polycrystalline TiC transition layer; wherein the polycrystalline diamond layer is bonded to the polycrystalline Al203 layer via the polycrystalline TiC transition layer.

[0033] The composite material in the application has high temperature stability and good mechanical properties, and the polycrystalline diamond layer and the polycrystalline Al2O3 layer are combined through the polycrystalline TiC transition layer, so that the polycrystalline diamond layer has the characteristics of high hardness and high fracture toughness, the combination strength between the polycrystalline diamond layer and the polycrystalline Al2O3 layer is promoted through the polycrystalline TiC transition layer, the crack propagation is hindered, and the thermal stability and impact resistance of the overall composite material are improved. The hardness and fracture toughness of the polycrystalline Al2O3 layer are also significantly improved, further, it is speculated that an AlTiC alloy is formed between the polycrystalline Al2O3 layer and the polycrystalline TiC transition layer, the interface strength between the two is enhanced, the strong chemical bond hinders the crack propagation, and the impact resistance of the overall petroleum composite sheet is improved.

[0034] The composite material in the application has tight combination. According to an embodiment of the application, the density of the composite material is not less than 98%.

[0035] The density of the composite material in the application is detected by using an ultra-depth-of-field electron microscope and SEM to detect the micro-morphology of the sample, the polycrystalline material has tight combination and high density, and the density of the composite material is measured by using the Archimedes principle.

[0036] According to an embodiment of the application, the chemical bond force between the polycrystalline diamond layer and the polycrystalline TiC transition layer has a chemical bond force. The aforementioned embodiment makes the composite material have better thermal stability and mechanical properties.

[0037] According to a preferred embodiment of the application, the chemical bond force includes a chemical bond force formed by bonding A and B, wherein A is selected from at least one of Fe, Ni and Al, and B is selected from at least one of Si, Co and Fe. The aforementioned embodiment makes the composite material reduce the fragmentation and delamination of the petroleum composite sheet caused by low interface strength, and improves the impact resistance of the overall petroleum composite sheet.

[0038] In the application, the chemical bond force between Fe and Si, the chemical bond force between Ni and Co, the chemical bond force between Al and Co, the chemical bond force between Ni and Fe, and the chemical bond force between Al and Fe can be listed.

[0039] According to an embodiment of the application, the grain size of the polycrystalline diamond layer, the polycrystalline Al2O3 layer and the polycrystalline TiC transition layer is independently 3 nm-500 μm. The composite material in the aforementioned embodiment has uniform grain size distribution, high temperature stability and good mechanical properties.

[0040] According to an embodiment of the present application, the grain size of the polycrystalline diamond layer is 0.1 μm-15 μm, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.5 μm, 0.8 μm, 1 μm, 1.3 μm, 1.5 μm, 3 μm, 4 μm, 5 μm, 8 μm, 10 μm, 11 μm, 13 μm, 15 μm, or a range defined by any two of the above values.

[0041] According to an embodiment of the present application, the grain size of the polycrystalline Al2O3 layer is 3 nm-100 nm, for example, 3 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 100 nm, or a range defined by any two of the above values.

[0042] According to an embodiment of the present application, the grain size of the TiC transition layer is 0.5 μm-10 μm, for example, 0.5 μm, 0.8 μm, 1 μm, 1.3 μm, 1.5 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, or a range defined by any two of the above values.

[0043] According to an embodiment of the present application, the main phase of the polycrystalline diamond layer is diamond.

[0044] According to an embodiment of the present application, the main phase of the polycrystalline Al2O3 layer is α-Al2O3.

[0045] According to an embodiment of the present application, the main phase of the polycrystalline TiC transition layer is cubic TiC.

[0046] The phase composition of each layer of the composite material layer in the present application is obtained by XRD detection.

[0047] According to a preferred embodiment of the present application, the thickness ratio of the polycrystalline diamond layer, the polycrystalline Al2O3 layer, and the polycrystalline TiC transition layer is 1:(0.1-20): (0.01-10).

[0048] According to a particularly preferred embodiment of the present application, the thickness ratio of the polycrystalline diamond layer, the polycrystalline Al2O3 layer, and the polycrystalline TiC transition layer is 1:(0.5-3):(0.1-0.2). The composite material layer of the foregoing embodiment can better interact with each other, so that the composite material has excellent heat resistance and overall impact resistance.

[0049] According to the present application, the overall thickness of the composite material and the thickness between each layer can be selected as needed as long as the purpose of the present application can be achieved. The present application gives the following exemplary description:

[0050] According to an embodiment of the present application, the thickness of the composite material is 0.3-30 mm, for example 0.3 mm, 1 mm, 5.9 mm, 6.9 mm, 7.1 mm, 7.3 mm, 20 mm or 30 mm, preferably 1-30 mm.

[0051] According to an embodiment of the present application, the thickness of the polycrystalline diamond layer is 0.1-29.7 mm, for example 0.1 mm, 2.6 mm, 3.1 mm, 3.5 mm, 3.6 mm, 7 mm, 10 mm, 15 mm, 18 mm, 22 mm, 25 mm, 29.7 mm, preferably 0.1-10 mm.

[0052] According to an embodiment of the present application, the thickness of the polycrystalline Al2O3 layer is 0.1-29.7 mm, for example 3 mm, 3.1 mm, 3.1 mm, 6 mm, 8 mm, 12 mm, 15 mm, 20 mm, 25 mm or 29.7 mm, preferably 0.1-20 mm.

[0053] According to an embodiment of the present application, the thickness of the polycrystalline TiC transition layer is 0.1-29.7 mm, for example 0.1 mm, 0.2 mm, 0.4 mm, 5 mm, 7 mm, 10 mm, 12 mm, 15 mm, 18 mm, 29.7 mm, preferably 0.1-10 mm.

[0054] The thickness of the polycrystalline diamond layer, the polycrystalline TiC transition layer, the polycrystalline Al2O3 layer and the thickness of the composite material can be measured by an ultra-depth microscope, a scanning electron microscope and a vernier caliper, etc.

[0055] According to an embodiment of the present application, the Vickers hardness of the polycrystalline diamond layer is 50-85 GPa.

[0056] According to an embodiment of the present application, the fracture toughness of the polycrystalline diamond layer is 6-15.1 MPa·m 1 / 2 .

[0057] According to an embodiment of the present application, the Vickers hardness of the polycrystalline TiC transition layer is 14-35 GPa.

[0058] According to an embodiment of the present application, the fracture toughness of the polycrystalline TiC transition layer is 3-8 MPa·m 1 / 2 .

[0059] According to an embodiment of the present application, the Vickers hardness of the polycrystalline Al2O3 layer is 19-35 GPa.

[0060] According to an embodiment of the present application, the fracture toughness of the polycrystalline Al2O3 layer is 2-4 MPa·m 1 / 2 .

[0061] The present application detects the sample cross section, and respectively measures the Vickers hardness and fracture toughness of the polycrystalline diamond layer, the polycrystalline TiC transition layer and the polycrystalline Al2O3 layer by using a Vickers hardness tester. The composite material with high hardness is obtained, and the overall impact resistance of the composite material is also improved. The cumulative impact work is 600-1500J measured by using a drop hammer impact test, which is better than that of the control sample composite sheet, and the cumulative impact work thereof is about 900J.

[0062] The second aspect of the present application provides a preparation method of a polycrystalline Al2O3-TiC-diamond composite material, which comprises:

[0063] The assembled block of the diamond forming body containing single crystal diamond and optionally sintering aid A, the polycrystalline TiC forming body containing polycrystalline TiC and optionally sintering aid B, and the polycrystalline Al2O3 forming body containing polycrystalline Al2O3 and optionally sintering aid C is sintered, and optionally post-treated.

[0064] In the present application, the intermediate TiC layer of the Al2O3-TiC-diamond composite material prepared by the preparation method of the present application respectively forms strong chemical bonds with the diamond layer and the Al2O3 layer, reduces the fragmentation and delamination of the oil composite sheet caused by low interfacial strength, improves the overall impact resistance of the oil composite sheet, and makes it have good thermal stability and mechanical properties.

[0065] Before sintering, the forming body can be cold-pressed as needed to reduce the volume collapse of the sample. The cold-pressing method is a conventional method in the art, for example, the preferred temperature during cold-pressing is 20-25℃, the preferred pressure is 1-3GPa, and the preferred pressure holding time is 10s-120s.

[0066] The diamond forming body in the present application can be obtained by a conventional method in the art, for example, single crystal diamond, optionally sintering aid A and water are mixed and then pre-pressed to form, wherein the amount of water is generally (0.8-5) : 1 of the mass of the single crystal diamond.

[0067] The polycrystalline TiC forming body containing polycrystalline TiC and optionally sintering aid B in the present application can be obtained by a conventional method in the art, for example, polycrystalline TiC, optionally sintering aid B and water are mixed and then pre-pressed to form, wherein the amount of water is generally (1-30) : 1 of the mass of the polycrystalline TiC.

[0068] The sintering of the assembled block of the polycrystalline Al2O3 and optionally sintering aid C in the present application can be carried out according to the conventional method in the art, for example, the polycrystalline Al2O3 and optionally sintering aid C and water are mixed and then pre-pressed into a shape, wherein the amount of water is generally (1-30) : 1 by mass to the mass of the polycrystalline Al2O3.

[0069] In the present application, the single crystal diamond, TiC and polycrystalline Al2O3 can each contain some impurities, and the purity is generally 95-100wt%, and the raw material can be cleaned and dried before use, for example, cleaned with anhydrous ethanol and then dried. That is, in some embodiments, the single crystal diamond, TiC and polycrystalline Al2O3 are cleaned and dried with anhydrous ethanol, respectively, and then each is independently optionally mixed with the corresponding sintering aid.

[0070] In the present application, the single crystal diamond, TiC, polycrystalline Al2O3 are all finally pre-pressed into corresponding shaped bodies, and there is no special limitation on the specific shape, which can be the conventional block or powder shape in the art.

[0071] According to an embodiment of the present application, the sintering conditions include that the sintering pressure is 3-25GPa. The grain growth affects the performance and microstructure of the material, and the high pressure can inhibit the abnormal growth of the grains under high temperature conditions.

[0072] According to an embodiment of the present application, the sintering conditions include that the sintering temperature is 600-2000℃, preferably 1200-1600℃.

[0073] According to an embodiment of the present application, the sintering conditions include that the holding time is 20s-4h, preferably 10-60min.

[0074] According to an embodiment of the present application, the sintering conditions include that the holding time is 20s-4h, preferably 10-60min.

[0075] According to an embodiment of the present application, the post-processing method includes grinding, polishing and pickling. In order to make the composite material reach the required flatness and smoothness, remove the sintering aid of the diamond layer, and improve the mechanical properties of the working layer of the sample. Among them, grinding, polishing and pickling are conventional technical means in the art, and the present application does not add more description.

[0076] In order to prevent the sample from being contaminated at high temperature in the present application, according to an embodiment of the present application, the assembled block is wrapped in a metal wrapper for sintering. The diamond shaped body, polycrystalline TiC shaped body and polycrystalline Al2O3 shaped body are layered in order and wrapped with a metal wrapper, which can prevent the sample from being contaminated in a high temperature and high pressure environment.

[0077] In this invention, specifically as shown in Figure 2, in one embodiment, Figure 2 is a diagram of the apparatus for high-temperature and high-pressure assembly of the sample. Polycrystalline Al2O3, polycrystalline TiC, and diamond are sequentially placed in a metal encapsulation. The sample with the metal encapsulation is then loaded into a high-pressure sintering unit, which is then placed in the synthesis chamber of a high-pressure equipment for sintering. Finally, the product undergoes post-processing. This invention utilizes a six-sided press for high-temperature and high-pressure sintering. After reaching the set pressure, the temperature is increased and held for a period of time. After the holding time ends, heating is stopped, and the pressure is maintained for 2 minutes before slowly reducing the pressure.

[0078] According to a preferred embodiment of the present invention, as shown in FIG1, polycrystalline Al2O is prepared. 3- The process flow diagram of TiC-diamond composite material includes the following steps: Al2O3, TiC, and diamond powder (single crystal) are taken, cleaned and dried respectively, and sintering aid C is added to Al2O3, sintering aid B is added to TiC, and sintering aid A is added to diamond. After mixing, they are pre-pressed and vacuum dried to obtain polycrystalline Al2O3, polycrystalline TiC, and diamond molded bodies respectively. Then, the polycrystalline Al2O3, polycrystalline TiC, and diamond molded bodies are laid up in a specific order and wrapped with a metal encapsulation to form a pre-pressed assembly block sample. The metal encapsulation is ground and polished, then degreased, ultrasonically cleaned, and vacuum dried. The wrapped sample is then placed in a high-pressure assembly sintering unit, and the sintering unit is placed in a drying oven and dried at a constant temperature of 120℃ for later use. High-temperature and high-pressure sintering was carried out using a six-sided top press. After that, the sample was taken out of the synthesis chamber, the metal wrapped around the sample was removed, and the synthesized sample was post-processed by grinding and polishing to obtain polycrystalline Al2O3-TiC-diamond composite material. Finally, the performance of the composite material was tested.

[0079] According to one embodiment of the present invention, the content of the sintering aid A is 1-20 wt%, for example, 1 wt%, 5 wt%, 8 wt%, 9 wt%, 10 wt%, 16 wt%, or 20 wt%, based on the mass of the single crystal diamond.

[0080] According to one embodiment of the present invention, based on polycrystalline TiC, the content of the sintering aid B is 1-15 wt%, for example, 0.5 wt%, 0.6 wt%, 3 wt%, 5 wt%, 10 wt%, or 15 wt%.

[0081] According to one embodiment of the present invention, based on polycrystalline Al2O3, the content of the sintering aid C is 1-15 wt%, for example, 0.5 wt%, 0.6 wt%, 3 wt%, 5 wt%, 10 wt%, or 15 wt%.

[0082] The present application promotes the sintering densification of the composite material by adding sintering aids and in a high temperature and high pressure environment, mainly by reducing the sintering activation energy, activating the crystal lattice, destroying the stable crystal lattice structure, and generating defects or lattice distortion, thereby promoting the sintering process. And adjust the content of the polycrystalline diamond layer, the polycrystalline TiC transition layer, and the polycrystalline Al2O3 layer in a certain range to obtain a composite material with different hardness and different fracture toughness.

[0083] According to an embodiment of the present application, the sintering aid A is selected from one or more of Fe, Co, Ni, Si, Fe2(CO3)3, CoCO3, NiCO3, Co2SiO4, NiSiO3, Fe6N3, CoN, Ni3N and Si3N4.

[0084] According to an embodiment of the present application, the sintering aid B is selected from one or more of Fe, Si, Ni, Al and Mo.

[0085] According to an embodiment of the present application, the sintering aid C is selected from one or more of W, Ni, SiC, Y2O3, La2O3, TiO2, ZrO2 and CaO.

[0086] According to an embodiment of the present application, the sintering aid A is selected from one or more of Co, Si, Fe2(CO3)3, CoCO3 and NiCO3, and is preferably Fe2(CO3)3. With the foregoing embodiment, the sintering aids between the layers can form more stable metal chemical bonds, thereby reducing the fragmentation and delamination of the composite material caused by low interfacial strength, and improving the overall impact resistance of the composite material.

[0087] According to an embodiment of the present application, the sintering aid B is selected from one or more of Fe, Al and Mo. With the foregoing embodiment, the sintering aids between the layers can form more stable metal chemical bonds, thereby reducing the fragmentation and delamination of the composite material caused by low interfacial strength, and improving the overall impact resistance of the composite material.

[0088] According to an embodiment of the present application, the sintering aid C is selected from one or more of W, Ni and CaO. With the foregoing embodiment, the sintering aids between the layers can form more stable metal chemical bonds, thereby reducing the fragmentation and delamination of the composite material caused by low interfacial strength, and improving the overall impact resistance of the composite material.

[0089] According to an embodiment of the present application, the grain size of the single crystal diamond is 3 nm-500 μm, for example, 3 nm, 100 nm, 200 nm, 1 μm, 5 μm, 10 μm, 350 μm or 500 μm.

[0090] According to an embodiment of the present application, the grain size of the polycrystalline TiC is 3 nm-500 μm, for example, 3 nm, 100 nm, 1 μm, 2 μm, 5 μm, 300 μm or 500 μm.

[0091] According to an embodiment of the present application, the grain size of the polycrystalline Al2O3 is 3 nm-500 μm, for example, 3 nm, 20 nm, 40 nm, 50 nm, 300 μm or 500 μm. The raw material is processed before the present application, the single crystal diamond is a powder with a grain size of 3 nm-500 μm, the polycrystalline TiC is a block or a powder with a grain size of 3 nm-500 μm, and the polycrystalline Al2O3 is a block or a powder with a grain size of 3 nm-500 μm.

[0092] According to an embodiment of the present application, the thickness of the diamond shaped body is 0.1-10 mm.

[0093] According to an embodiment of the present application, the thickness of the polycrystalline TiC shaped body is 0.1-10 mm.

[0094] According to an embodiment of the present application, the thickness of the polycrystalline Al2O3 shaped body is 0.1-20 mm.

[0095] The thickness of the polycrystalline diamond shaped body, the polycrystalline TiC shaped body and the polycrystalline Al2O3 shaped body is measured by an ultra-depth microscope, a scanning electron microscope and a vernier caliper, etc. The reasonable thickness design can improve the performance and quality of the product, reduce the production cost and improve the production efficiency.

[0096] The third aspect of the present application provides a polycrystalline Al2O3-TiC-diamond composite material prepared by the preparation method of the second aspect of the present application.

[0097] The composite material prepared by the preparation method of the present application has good thermal stability and mechanical properties, and the overall impact resistance of the composite material is higher than that of general commercial diamond composite sheets. In addition, the method for preparing the polycrystalline Al2O3-TiC-diamond composite material can reduce the use amount of the diamond layer, reduce the raw material cost, and realize large-scale industrial production and application.

[0098] The fourth aspect of the present application provides an application of the polycrystalline Al2O3-TiC-diamond composite material of the first aspect or the third aspect of the present application in a PDC drill bit.

[0099] The polycrystalline Al2O3-TiC-diamond composite material in the present application has excellent heat resistance and impact resistance, and the TiC and Al2O3 materials are easy to obtain and low in price, which has great application prospect in PDC drill bits.

[0100] The present application will be described in detail below by way of examples. In the following examples:

[0101] The impact energy parameter is measured by a falling weight impact test method; the control product is a diamond compact raw material composed of diamond powder and Co-containing tungsten carbide matrix, and the company's brand is 1613MJSP, which is a commercially available product.

[0102] Example 1

[0103] Take 32g of polycrystalline Al2O3 block material with a purity of 96% and an average grain size of 20nm, 4g of polycrystalline TiC block material with a purity of 98% and an average grain size of 1μm, and 30g of diamond powder with a purity of 97% and an average grain size of 1μm, and treat them with 100ml, 80ml and 100ml of anhydrous ethanol respectively. After pouring out the waste liquid, dry them in an oven at 120℃. After drying, add 3% by mass of Y2O3 powder to the Al2O3, 5% by mass of Fe powder to the TiC, and 5% by mass of Si powder to the diamond as sintering aids, respectively. After mixing, add 50ml of deionized water to each and pre-press into a shape. Vacuum dry to obtain a polycrystalline Al2O3 shaped body, a polycrystalline TiC shaped body and a diamond shaped body respectively. Then, layer the polycrystalline Al2O3 shaped body, the polycrystalline TiC shaped body and the diamond shaped body in a specific order and wrap them with a metal wrapping body. Grind and polish the metal wrapping body, then degrease, ultrasonic clean and vacuum dry. Put the wrapped sample into a high-pressure assembly sintering unit, and place the sintering unit in a drying oven for drying at 120℃. Perform high-temperature and high-pressure sintering using a cubic press. After reaching a set pressure of 4.5GPa, heat up and keep the temperature at 1400℃ for 25 minutes. After the holding time is over, stop heating and keep the pressure for 2 minutes before slowly reducing the pressure. Take out the sample from the synthesis cavity, remove the metal wrapping outside the sample, and grind, polish and acid wash the synthesized sample to obtain a polycrystalline Al2O3-TiC-diamond composite material.

[0104] The ultra-depth-of-field electron microscope image of the polycrystalline Al2O3-TiC-diamond composite material in Example 1 is shown in FIG. 3. The polycrystalline Al2O3-TiC-diamond composite material is damaged to test the performance of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline Al2O3-TiC-diamond composite material.

[0105] The scanning electron microscope analysis diagrams of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are shown in Figures 4, 5 and 6 respectively, and it can be determined that the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are all polycrystalline structures, the average grain size in the polycrystalline Al2O3 layer is 22 nm, the average grain size in the polycrystalline TiC layer is 1 μm, and the average grain size in the polycrystalline diamond layer is 1 μm.

[0106] It is obtained by XRD that the main phase of the polycrystalline diamond layer is diamond, the main phase of the polycrystalline Al2O3 layer is α-Al2O3, and the main phase of the polycrystalline TiC transition layer is cubic structure TiC.

[0107] Performance detection of the sample: the thickness of the prepared polycrystalline Al2O3-TiC-diamond composite material is 5.9 mm, the thickness of the polycrystalline Al2O3 layer is 3.1 mm, the thickness of the polycrystalline TiC layer is 0.2 mm, and the thickness of the polycrystalline diamond layer is 2.6 mm, and the sample density is 98.5%; the Vickers hardness of the polycrystalline diamond layer is 52 GPa, and the fracture toughness is 6.7 MPa·m 1 / 2 ; the Vickers hardness of the polycrystalline TiC transition layer is 25 GPa, and the fracture toughness is 3.0 MPa·m 1 / 2 ; the Vickers hardness of the polycrystalline Al2O3 layer is 20 GPa, and the fracture toughness is 2.5 MPa·m 1 / 2 . The thermal stability temperature of the composite material is 853℃, and the cumulative impact work is 1020J.

[0108] Example 2

[0109] Take the purity of 97%, the average grain size of 50 nm of polycrystalline Al2O3 block 35g, take the purity of 97%, the average grain size of 5 μm of polycrystalline TiC block 6g, take the purity of 98%, the average grain size of 200 nm of diamond powder 44g, respectively with 85ml, 90ml, 90ml absolute ethanol treatment, pour out the waste liquid, after drying in the oven 120℃; After drying, add 5% of TiO2 powder to Al2O3, add 3% of Ni powder to TiC, and add 9% of Co powder to diamond as sintering aid, respectively mix and add 60ml of deionized water and pre-press into shape, vacuum drying respectively to obtain polycrystalline Al2O3 shaped body, polycrystalline TiC shaped body and diamond shaped body, then layer the polycrystalline Al2O3 shaped body, polycrystalline TiC shaped body and diamond shaped body according to a specific order and wrap with a metal wrapping body, polish and polish the metal wrapping body, then degrease, ultrasonic cleaning, vacuum drying, put the wrapped sample into a high-pressure assembly sintering unit, put the sintering unit into a drying box and dry at 120℃ constant temperature, and standby. High temperature and high pressure sintering is carried out by using a six-surface pressing machine. After reaching the set pressure of 5.5GPa, heating is started, and the temperature is raised to 1550℃ and kept for 15 minutes. After the holding is finished, heating is stopped, and the pressure is kept for 2 minutes before slowly reducing the pressure. Remove the sample in the synthesis cavity, remove the metal wrapping outside the sample, polish, polish and acid wash the synthesized sample to obtain a polycrystalline Al2O3-TiC-diamond composite material.

[0110] The ultra-depth-of-field electron microscope image of the polycrystalline Al2O3-TiC-diamond composite material in Example 2 is shown in Figure 7. The polycrystalline Al2O3-TiC-diamond composite material is damaged to test the performance of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline Al2O3-TiC-diamond composite material.

[0111] Among them, the scanning electron microscope analysis images of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are shown in Figures 8, 9 and 10 respectively. It can be determined that the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are all polycrystalline structures, the average grain size in the polycrystalline Al2O3 layer is 62 nm, the average grain size in the polycrystalline TiC layer is 5.1 μm, and the average grain size in the polycrystalline diamond layer is 213 nm.

[0112] By XRD, it is obtained that the main phase of the polycrystalline diamond layer is diamond, the main phase of the polycrystalline Al2O3 layer is α-Al2O3, and the main phase of the polycrystalline TiC transition layer is cubic crystal system TiC.

[0113] The prepared polycrystalline Al2O3-TiC-diamond composite material has a thickness of 7.1 mm, wherein the polycrystalline Al2O3 layer has a thickness of 3.1 mm, the polycrystalline TiC transition layer has a thickness of 0.4 mm, the polycrystalline diamond layer has a thickness of 3.6 mm, the sample has a density of 99.5%, the polycrystalline diamond layer has a Vickers hardness of 75 GPa, and the fracture toughness is 11.2 MPa·m 1 / 2 The polycrystalline TiC transition layer has a Vickers hardness of 32 GPa, and the fracture toughness is 3.4 MPa·m 1 / 2 The polycrystalline Al2O3 layer has a Vickers hardness of 25 GPa, and the fracture toughness is 3.0 MPa·m 1 / 2 The high-temperature stability of the composite material is 865℃, and the cumulative impact work is 1260J.

[0114] Example 3

[0115] Take 66g of polycrystalline Al2O3 bulk material with a purity of 98% and an average grain size of 40nm, 72g of polycrystalline TiC bulk material with a purity of 98% and an average grain size of 2μm, and 75g of diamond powder with a purity of 99% and an average grain size of 10μm, and treat them with 180ml, 160ml and 170ml of anhydrous ethanol respectively. After pouring out the waste liquid, dry them in an oven at 120℃. After drying, add 3% CaO powder to the Al2O3, 5% Al powder to the TiC, and 10% Co powder to the diamond as sintering aids, respectively. After mixing, pre-press them with 100ml of deionized water respectively to form polycrystalline Al2O3, polycrystalline TiC and diamond shaped bodies. Then, layer the polycrystalline Al2O3 shaped body, the polycrystalline TiC shaped body and the diamond shaped body in a specific order and wrap them with a metal wrapping body. Grind and polish the metal wrapping body, then degrease, ultrasonic clean and vacuum dry it. Put the wrapped sample into a high-pressure assembly sintering unit, and place the sintering unit in a drying oven for constant temperature drying at 120℃. Perform high-temperature and high-pressure sintering using a cubic press. After reaching the set pressure of 7GPa, heat it up and keep it at 1300℃ for 40 minutes. After the holding period is over, stop heating and keep the pressure for 2 minutes before slowly reducing the pressure. Take out the sample from the synthesis cavity, remove the metal wrapping outside the sample, and grind, polish and acid wash the synthesized sample to obtain a polycrystalline Al2O3-TiC-diamond composite material.

[0116] The ultra-depth-of-field electron microscope image of the polycrystalline Al2O3-TiC-diamond composite material in Example 3 is shown in FIG. 11. The polycrystalline Al2O3-TiC-diamond composite material is damaged to test the performance of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline Al2O3-TiC-diamond composite material.

[0117] The scanning electron microscope analysis diagrams of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are shown in Figures 12, 13 and 14 respectively, and it can be determined that the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are all polycrystalline structures, the average grain size in the polycrystalline Al2O3 layer is 44 nm, the average grain size in the polycrystalline TiC layer is 2 μm, and the average grain size in the polycrystalline diamond layer is 10 μm.

[0118] It is obtained by XRD that the main phase of the polycrystalline diamond layer is diamond, the main phase of the polycrystalline Al2O3 layer is α-Al2O3, and the main phase of the polycrystalline TiC transition layer is cubic TiC.

[0119] The polycrystalline Al2O3-TiC-diamond composite material prepared has a thickness of 20 mm, wherein the thickness of the polycrystalline Al2O3 layer is 6 mm, the thickness of the polycrystalline TiC layer is 7 mm, and the thickness of the polycrystalline diamond layer is 7 mm, the sample density is 99.7%, the Vickers hardness of the polycrystalline diamond layer is 84 GPa, and the fracture toughness is 13.3 MPa·m 1 / 2 The Vickers hardness of the polycrystalline TiC transition layer is 38 GPa, and the fracture toughness is 4.2 MPa·m 1 / 2 The Vickers hardness of the polycrystalline Al2O3 layer is 32 GPa, and the fracture toughness is 3.9 MPa·m 1 / 2 The high-temperature stability temperature of the composite material is 956℃, and the cumulative impact work is 1180 J.

[0120] Example 4

[0121] Take the purity of 98%, the average grain size of 300 μm of polycrystalline Al2O3 block 35 g, take the purity of 98%, the average grain size of 300 μm of polycrystalline TiC block 6 g, take the purity of 99%, the average grain size of 350 μm of diamond powder 44 g, respectively with 85 ml, 90 ml, 90 ml of absolute ethanol, pour out the waste liquid, and then dry in the oven at 120 DEG C;After drying, add 3% CaO powder to Al2O3, 5% Al powder to TiC, and 10% Co powder to diamond as sintering aids, respectively, mix them, add 60 ml of deionized water to each, and pre-press into shape, and then vacuum dry to obtain polycrystalline Al2O3, polycrystalline TiC and diamond shaped bodies, respectively. Then, lay the polycrystalline Al2O3, polycrystalline TiC and diamond shaped bodies in a specific order and wrap them with a metal wrapping body. Grind and polish the metal wrapping body, then remove oil, ultrasonic clean and vacuum dry. Put the wrapped sample into a high-pressure assembly sintering unit, and place the sintering unit in a drying oven at 120 DEG C for constant temperature drying. Use a six-surface press to sinter at high temperature and high pressure. After reaching the set pressure of 5.5 GPa, heat up, and keep the temperature at 1550 DEG C for 15 minutes. After the holding period, stop heating, and keep the pressure for 2 minutes before slowly reducing the pressure. Remove the sample from the synthesis cavity, remove the metal wrapping body from the outside of the sample, and grind, polish and acid wash the synthesized sample to obtain a polycrystalline Al2O3-TiC-diamond composite material.

[0122] Destroy the polycrystalline Al2O3-TiC-diamond composite material to test the performance of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline Al2O3-TiC-diamond composite material.

[0123] The analysis of the electron microscope scanning images of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer can determine that the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are all polycrystalline structures, the average grain size in the polycrystalline Al2O3 layer is 312 μ1, the average grain size in the polycrystalline TiC layer is 326 μ2, and the average grain size in the polycrystalline diamond layer is 325 μ2.

[0124] The XRD analysis shows that the main phase of the polycrystalline diamond layer is diamond, the main phase of the polycrystalline Al2O3 layer is α-Al2O3, and the main phase of the polycrystalline TiC transition layer is cubic TiC.

[0125] The prepared polycrystalline Al2O3-TiC-diamond composite material has a thickness of 7.3 mm, wherein the thickness of the polycrystalline Al2O3 layer is 3.1 mm, the thickness of the polycrystalline TiC transition layer is 0.4 mm, the thickness of the polycrystalline diamond layer is 3.6 mm, the sample density is 96.6%, the Vickers hardness of the polycrystalline diamond layer is 56 GPa, the fracture toughness is 8.0 MPa·m 1 / 2 , the Vickers hardness of the polycrystalline TiC transition layer is 25 GPa, the fracture toughness is 3.2 MPa·m 1 / 2 , the hardness of the polycrystalline Al2O3 layer is 25 GPa, and the fracture toughness is 2.6 MPa·m 1 / 2 , the high-temperature stability temperature of the composite material is 820℃, and the cumulative impact work is 930J.

[0126] Example 5

[0127] Take 35g of polycrystalline Al2O3 bulk material with a purity of 97% and an average grain size of 50nm, 6g of polycrystalline TiC bulk material with a purity of 97% and an average grain size of 5μm, and 44g of diamond powder with a purity of 98% and an average grain size of 200nm, and treat them with 85ml, 90ml and 90ml of anhydrous ethanol respectively. After pouring out the waste liquid, dry them in an oven at 120℃. After drying, add 5% TiO2 powder to the Al2O3, 3% Ni powder to the TiC, and 16% Fe2(CO3)3 as a sintering aid to the diamond, respectively. After mixing, add 60ml of deionized water to each and pre-press into a shape. Vacuum drying separately obtains polycrystalline Al2O3, polycrystalline TiC and diamond shaped bodies. Then, according to a specific order, lay the polycrystalline Al2O3 shaped body, the polycrystalline TiC shaped body and the diamond shaped body, and wrap them with a metal wrapping body. Polish and polish the metal wrapping body, then degrease, ultrasonic cleaning, vacuum drying, and put the wrapped sample into a high-pressure assembly sintering unit. Place the sintering unit in a drying oven and dry at 120℃. High-temperature and high-pressure sintering is carried out using a six-surface press. After reaching the set pressure of 5.5GPa, heat up and heat at 1550℃ for 15 minutes. After the holding period is over, stop heating and hold pressure for 2 minutes before slowly reducing pressure. Remove the sample from the synthesis cavity, remove the metal wrapping outside the sample, and polish, polish and acid wash the synthesized sample to obtain a polycrystalline Al2O3-TiC-diamond composite material.

[0128] The polycrystalline Al2O3-TiC-diamond composite material is damaged to test the performance of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline Al2O3-TiC-diamond composite material.

[0129] The electron microscope scanning graph analysis of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer can determine that the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are all polycrystalline structures, the average grain size in the polycrystalline Al2O3 layer is 61 nm, the average grain size in the polycrystalline TiC layer is 5 μm, and the average grain size in the polycrystalline diamond layer is 196 nm.

[0130] It is obtained by XRD that the main phase of the polycrystalline diamond layer is diamond, the main phase of the polycrystalline Al2O3 layer is α-Al2O3, and the main phase of the polycrystalline TiC transition layer is cubic TiC.

[0131] Performance detection of the sample: the thickness of the prepared polycrystalline Al2O3-TiC-diamond composite material is 6.9 mm, the thickness of the polycrystalline Al2O3 layer is 3 mm, the thickness of the polycrystalline TiC layer is 0.4 mm, and the thickness of the polycrystalline diamond layer is 3.5 mm; the sample density is 99.8%; the Vickers hardness of the polycrystalline diamond layer is 85 GPa, and the fracture toughness is 14.5 MPa·m 1 / 2 ; the Vickers hardness of the polycrystalline TiC transition layer is 35 GPa, and the fracture toughness is 5.3 MPa·m 1 / 2 ; the Vickers hardness of the polycrystalline Al2O3 layer is 35 GPa, and the fracture toughness is 4 MPa·m 1 / 2 ; the high-temperature stability temperature of the composite material is 970℃, and the cumulative impact work is 1500 J.

[0132] Example 6

[0133] Take the purity of 97%, the average grain size of 50 nm of polycrystalline Al2O3 block 35 g, take the purity of 97%, the average grain size of 5 μm of polycrystalline TiC block 6 g, take the purity of 98%, the average grain size of 200 nm of diamond powder 22 g, respectively with 85 ml, 90 ml, 90 ml of absolute ethanol, pour out the waste liquid, and then dry in the oven at 120 DEG C; after drying, add 5% of TiO2 powder to Al2O3, add 3% of Ni powder to TiC, and add 8% of Ni powder to diamond as a sintering aid, respectively mix and then add 60 ml of deionized water and pre-press into a shape, vacuum dry to obtain polycrystalline Al2O3 shaped body, polycrystalline TiC shaped body and diamond shaped body, then layer the polycrystalline Al2O3 shaped body, polycrystalline TiC shaped body and diamond shaped body in a specific order and wrap with a metal wrapping body, polish and polish the metal wrapping body, then degrease, ultrasonic cleaning, vacuum drying, and load the wrapped sample into a high-pressure assembly sintering unit, place the sintering unit in a drying oven and dry at 120 DEG C for standby. High temperature and high pressure sintering is carried out by using a six-surface press, after reaching the set pressure of 5.5 GPa, heating is started, and the temperature is raised to 1550 DEG C and kept for 15 minutes, then heating is stopped, and the pressure is kept for 2 minutes, then slow pressure reduction is started. Remove the sample in the synthesis cavity, remove the metal wrapping outside the sample, polish, polish and acid wash the synthesized sample to obtain a polycrystalline Al2O3-TiC-diamond composite material.

[0134] The polycrystalline Al2O3-TiC-diamond composite material is damaged to test the performance of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline Al2O3-TiC-diamond composite material.

[0135] The polycrystalline Al2O3-TiC-diamond composite material is damaged to test the performance of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline Al2O3-TiC-diamond composite material.

[0136] By XRD, it is obtained that the main phase of the polycrystalline diamond layer is diamond, the main phase of the polycrystalline Al2O3 layer is α-Al2O3, and the main phase of the polycrystalline TiC transition layer is cubic TiC.

[0137] The prepared polycrystalline Al2O3-TiC-diamond composite material has a thickness of 5.5 mm, wherein the polycrystalline Al2O3 layer has a thickness of 3.2 mm, the polycrystalline TiC layer has a thickness of 0.5 mm, the polycrystalline diamond layer has a thickness of 1.8 mm, the sample has a density of 94.8%, the polycrystalline diamond layer has a Vickers hardness of 45 GPa, and the fracture toughness is 7.5 MPa·m 1 / 2 The polycrystalline TiC transition layer has a Vickers hardness of 18 GPa, and the fracture toughness is 2.5 MPa·m 1 / 2 The polycrystalline Al2O3 layer has a hardness of 15 GPa, and the fracture toughness is 2.3 MPa·m 1 / 2 The high-temperature stability temperature of the composite material is 850℃, and the cumulative impact work is 970J.

[0138] Example 7

[0139] Take 35g of polycrystalline Al2O3 bulk material with a purity of 97% and an average grain size of 50nm, 6g of polycrystalline TiC bulk material with a purity of 97% and an average grain size of 5μm, and 44g of diamond powder with a purity of 98% and an average grain size of 200nm, and treat them with 85ml, 90ml and 90ml of anhydrous ethanol respectively. After pouring out the waste liquid, dry them in an oven at 120℃. After drying, add 0.5% CaO powder to the Al2O3, 0.6% Al powder to the TiC, and 0.6% Co powder to the diamond as sintering aids, respectively. After mixing, add 60ml of deionized water to each and pre-press into a shape. Vacuum drying separately obtains polycrystalline Al2O3, polycrystalline TiC and diamond shaped bodies. Then, the polycrystalline Al2O3, polycrystalline TiC and diamond shaped bodies are layered in a specific order and wrapped with a metal wrapping body. The metal wrapping body is polished and polished, then oiled, ultrasonically cleaned and vacuum dried. The wrapped sample is loaded into a high-pressure assembly sintering unit, and the sintering unit is placed in a drying oven at 120℃ for constant temperature drying. High-temperature and high-pressure sintering is carried out using a six-surface press. After reaching the set pressure of 5.5GPa, heating is started, and the temperature is raised to 1550℃ and held for 15 minutes. After the holding is completed, the heating is stopped, and the pressure is maintained for 2 minutes before slowly reducing the pressure. The sample in the synthesis cavity is removed, and the metal wrapping outside the sample is removed. The synthesized sample is polished, polished and pickled to obtain a polycrystalline Al2O3-TiC-diamond composite material.

[0140] The polycrystalline Al2O3-TiC-diamond composite material is damaged to test the performance of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline Al2O3-TiC-diamond composite material.

[0141] The electron microscope scanning graph analysis of the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer can determine that the polycrystalline Al2O3 layer, the polycrystalline TiC layer and the polycrystalline diamond layer are all polycrystalline structures, the average grain size in the polycrystalline Al2O3 layer is 64 nm, the average grain size in the polycrystalline TiC layer is 5.1 μm, and the average grain size in the polycrystalline diamond layer is 236 nm.

[0142] It is obtained by XRD that the main phase of the polycrystalline diamond layer is diamond, the main phase of the polycrystalline Al2O3 layer is α-Al2O3, and the main phase of the polycrystalline TiC transition layer is cubic structure TiC.

[0143] Performance detection of the sample: the thickness of the prepared polycrystalline Al2O3-TiC-diamond composite material is 7.4 mm, the thickness of the polycrystalline Al2O3 layer is 3.2 mm, the thickness of the polycrystalline TiC layer is 0.5 mm, and the thickness of the polycrystalline diamond layer is 3.7 mm; the sample density is 95.6%; the Vickers hardness of the polycrystalline diamond layer is 49 GPa, the fracture toughness is 6.5 MPa·m 1 / 2 , the Vickers hardness of the polycrystalline TiC transition layer is 19 GPa, the fracture toughness is 2.5 MPa·m 1 / 2 , the hardness of the polycrystalline Al2O3 layer is 15 GPa, and the fracture toughness is 1.9 MPa·m 1 / 2 ; the high-temperature stability temperature of the composite material is 650℃, and the cumulative impact work is 600 J

[0144] Comparative Example 1

[0145] Take the purity of 97%, the average grain size of 50 nm of polycrystalline Al2O3 block 35 g, take the purity of 98%, the average grain size of 2 μm of polycrystalline B4C block 6 g, take the purity of 98%, the average grain size of 200 nm of diamond powder 44 g, respectively with 85 ml, 90 ml, 90 ml of absolute ethanol treatment, pour out the waste liquid, and then dry in the oven at 120 DEG C; after drying, respectively to Al2O3 add mass fraction of 3% CaO powder, B4C add mass fraction of 5% Al powder, diamond add mass fraction of 10% Co powder as sintering aid, respectively after mixing, add 60 ml of deionized water and pre-pressing, vacuum drying respectively to get polycrystalline Al2O3 forming body, polycrystalline TiC forming body and diamond forming body, then polycrystalline Al2O3 forming body, polycrystalline TiC forming body and diamond forming body according to a specific order and wrapped with metal package, polish and polish the metal package, then oil, ultrasonic cleaning, vacuum drying, the wrapped sample is loaded into a high pressure assembly sintering unit, the sintering unit is placed in a drying oven at 120 DEG C constant temperature drying standby. High temperature and high pressure sintering is carried out by using a six-surface press. After reaching the set pressure of 5.5 GPa, heating is started. The temperature is kept at 1550 DEG C for 15 minutes. After the holding period, heating is stopped. The pressure is kept for 2 minutes before slowly reducing the pressure. The sample in the synthesis cavity is taken out. The metal wrapped outside the sample is removed. The synthesized sample is polished, polished and pickled to obtain a polycrystalline Al2O3-B4C-diamond composite material.

[0146] The polycrystalline Al2O3-B4C-diamond composite material is damaged to test the performance of the polycrystalline Al2O3 layer, the polycrystalline B4C layer and the polycrystalline diamond layer in the polycrystalline Al2O3-B4C-diamond composite material.

[0147] The polycrystalline Al2O3-B4C-diamond composite material prepared has a thickness of 7.2 mm, wherein the polycrystalline Al2O3 layer has a thickness of 3.2 mm, the polycrystalline B4C layer has a thickness of 0.4 mm, the polycrystalline diamond layer has a thickness of 0.6 mm, the sample has a density of 96.3%, the polycrystalline diamond layer has a Vickers hardness of 75 GPa and a fracture toughness of 10.6 MPa·m 1 / 2 , the polycrystalline B4C transition layer has a Vickers hardness of 20 GPa and a fracture toughness of 1.5 MPa·m 1 / 2 , the polycrystalline Al2O3 layer has a hardness of 16 GPa and a fracture toughness of 1.6 MPa·m 1 / 2 , the high temperature stability temperature of the composite material is 600 DEG C, and the cumulative impact work is 470 J.

[0148] Comparative Example 2

[0149] Take 35g of polycrystalline SiC bulk material with a purity of 98% and an average grain size of 1μm, 6g of polycrystalline TiC bulk material with a purity of 97% and an average grain size of 5μm, and 44g of diamond powder with a purity of 98% and an average grain size of 200nm, and treat them with 85ml, 90ml and 90ml of anhydrous ethanol respectively, pour out the waste liquid, and then dry them in an oven at 120℃; after drying, add 5% of TiO2 powder by mass fraction to the SiC, 3% of Ni powder by mass fraction to the SiC, and 9% of Co powder by mass fraction to the diamond as sintering aids, mix them respectively, add 60ml of deionized water to each, and pre-press them into shapes, and then vacuum dry them to obtain polycrystalline SiC, polycrystalline TiC and diamond shaped bodies respectively; then, lay the polycrystalline SiC, polycrystalline TiC and diamond shaped bodies in a specific order and wrap them with a metal wrapping body, polish and polish the metal wrapping body, then remove the oil, ultrasonic clean and vacuum dry them, and then put the wrapped sample into a high-pressure assembly sintering unit, and place the sintering unit in a drying oven and dry it at 120℃ for standby. High-temperature and high-pressure sintering is carried out using a cubic press, after reaching the set pressure of 5.5GPa, heating is started, and the temperature is raised to 1550℃ and held for 15 minutes, after the holding is completed, heating is stopped, and the pressure is maintained for 2 minutes, and then the pressure is slowly reduced. Remove the sample from the synthesis cavity, remove the metal wrapping outside the sample, polish, polish and acid wash the synthesized sample to obtain a polycrystalline SiC-TiC-diamond composite material.

[0150] The polycrystalline SiC-TiC-diamond composite material is damaged to test the performance of the polycrystalline SiC layer, the polycrystalline TiC layer and the polycrystalline diamond layer in the polycrystalline SiC-TiC-diamond composite material.

[0151] Sample performance testing: The polycrystalline SiC-TiC-diamond composite material prepared has a thickness of about 7.5mm, wherein the polycrystalline SiC layer has a thickness of 3.3mm, the polycrystalline TiC transition layer has a thickness of 0.4mm, and the polycrystalline diamond layer has a thickness of 3.7mm, the sample has a density of 94.7%, the polycrystalline diamond layer has a Vickers hardness of 70GPa and a fracture toughness of 9.8MPa·m 1 / 2 , the polycrystalline TiC transition layer has a Vickers hardness of 30GPa and a fracture toughness of 2.9MPa·m 1 / 2 , the polycrystalline SiC layer has a Vickers hardness of 20GPa and a fracture toughness of 2.3MPa·m 1 / 2 , and the high-temperature stability of the composite material is 700℃ and the cumulative impact work is 500J.

[0152] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

A polycrystalline Al2O3-TiC-diamond composite material, characterized in that The composite material comprises a polycrystalline diamond layer, a polycrystalline Al2O3 layer and a polycrystalline TiC transition layer; The polycrystalline diamond layer and the polycrystalline Al2O3 layer are combined by the polycrystalline TiC transition layer. The composite material according to claim 1, wherein The polycrystalline diamond layer and the polycrystalline TiC transition layer have a chemical bond force. The composite material according to claim 2, wherein The chemical bond force comprises a chemical bond force formed by bonding of A and B, wherein A is at least one selected from Fe, Ni and Al, and B is at least one selected from Si, Co and Fe. The composite material according to claim 1, wherein The compactness of the composite material is not less than 98%. The composite material according to claim 1, wherein The grain size of the polycrystalline diamond layer, the polycrystalline Al2O3 layer and the polycrystalline TiC transition layer is independently 3 nm-500 μm. The composite material according to claim 5, wherein The grain size of the polycrystalline diamond layer is 0.1 μm-15 μm; and / or The grain size of the polycrystalline Al2O3 layer is 3 nm-100 nm; and / or The grain size of the TiC transition layer is 0.5 μm-10 μm. The composite material according to claim 1, wherein The main phase of the polycrystalline diamond layer is diamond; and / or The main phase of the polycrystalline Al2O3 layer is α-Al2O3; and / or The main phase of the polycrystalline TiC transition layer is cubic structure TiC. The composite material according to claim 1, wherein The thickness ratio of the polycrystalline diamond layer, the polycrystalline Al2O3 layer and the polycrystalline TiC transition layer is 1:(0.1-20):(0.01-10). The composite material according to claim 8, wherein The thickness ratio of the polycrystalline diamond layer, the polycrystalline Al2O3 layer and the polycrystalline TiC transition layer is 1:(0.5-3):(0.1-0.2). The composite material according to claim 8, wherein The thickness of the composite material is 0.3-30 mm; and / or The thickness of the polycrystalline diamond layer is 0.1-29.7 mm; and / or The thickness of the polycrystalline Al2O3 layer is 0.1-29.7 mm; and / or The thickness of the polycrystalline TiC transition layer is 0.1-29.7 mm. The composite material according to claim 10, wherein The thickness of the composite material is 1-30 mm; and / or The thickness of the polycrystalline diamond layer is 0.1-10 mm; and / or The thickness of the polycrystalline Al2O3 layer is 0.1-20 mm; and / or The thickness of the polycrystalline TiC transition layer is 0.1-10 mm. The composite material according to any one of claims 1-11, wherein The Vickers hardness of the polycrystalline diamond layer is 50-85 GPa; and / or The polycrystalline diamond layer has a fracture toughness of 6-15.1 MPa.m 1 / 2 . The Vickers hardness of the polycrystalline TiC transition layer is 14-35 GPa; and / or The Vickers hardness of the polycrystalline TiC transition layer is 14-35 GPa; and / or The fracture toughness of the polycrystalline TiC transition layer is 3-8 MPa·m 1 / 2 . The Vickers hardness of the polycrystalline TiC transition layer is 14-35 GPa; and / or the Vickers hardness of the polycrystalline Al2O3 layer is 19-35 GPa; and / or The polycrystalline AI2O3 layer has a fracture toughness of 2-4 MPa-m 1 / 2 . A method for producing a polycrystalline Al2O3-TiC-diamond composite material, characterized by The preparation method comprises: sintering the assembled block of the diamond compact containing single crystal diamond and optionally sintering aid A, the polycrystalline TiC compact containing polycrystalline TiC and optionally sintering aid B, and the polycrystalline Al2O3 compact containing polycrystalline Al2O3 and optionally sintering aid C, and optionally post-processing. The preparation method according to claim 15, wherein the diamond compact is obtained by mixing single crystal diamond, optionally sintering aid A and water, and then pre-pressing; and / or the polycrystalline TiC compact is obtained by mixing polycrystalline TiC, optionally sintering aid B and water, and then pre-pressing; and / or the polycrystalline Al2O3 compact is obtained by mixing polycrystalline Al2O3, optionally sintering aid C and water, and then pre-pressing. The preparation method according to claim 15, wherein the sintering conditions comprise: the sintering pressure is 3-25 GPa; and / or the sintering temperature is 600-2000 ℃; and / or the holding time is 20 s-4 h; and / or the pressure holding time is 10 s-20 min. The preparation method according to claim 17, wherein the sintering conditions comprise: the sintering temperature is 1200-1600 ℃; and / or the holding time is 10-60 min; and / or the pressure holding time is 1-5 min. The preparation method according to claim 15, wherein the post-processing method comprises grinding, polishing and pickling; and / or the assembled block is wrapped in a metal wrapper and then sintered. The preparation method according to claim 15, wherein the content of the sintering aid A is 1-20 wt% based on the mass of the single crystal diamond; and / or the content of the sintering aid B is 1-15 wt% based on the mass of the polycrystalline TiC; and / or the content of the sintering aid C is 1-15 wt% based on the mass of the polycrystalline Al2O3. The preparation method according to claim 15, wherein the sintering aid A is selected from one or more of Fe, Co, Ni, Si, Fe2(CO3)3, CoCO3, NiCO3, Co2SiO4, NiSiO3, Fe6N3, CoN, Ni3N and Si3N4; and / or the sintering aid B is selected from one or more of Fe, Si, Ni, Al and Mo; and / or the sintering aid C is selected from one or more of W, Ni, SiC, Y2O3, La2O3, TiO2, ZrO2 and CaO. The preparation method according to claim 21, wherein the sintering aid A is selected from one or more of Co, Si, Fe2(CO3)3, CoCO3 and NiCO3; and / or the sintering aid B is selected from one or more of Fe, Al and Mo; and / or the sintering aid C is selected from one or more of W, Ni and CaO. The preparation method according to claim 22, wherein the sintering aid A is Fe2(CO3)3. The production method according to any one of claims 15-23, wherein the single crystal diamond has a grain size of 3 nm to 500 μm; and / or the polycrystalline TiC has a grain size of 3 nm to 500 μm; and / or the polycrystalline Al2O3 has a grain size of 3 nm to 500 μm. The production method according to any one of claims 15-23, wherein the single crystal diamond compact has a thickness of 0.1 to 10 mm; and / or the polycrystalline TiC compact has a thickness of 0.1 to 10 mm; and / or the polycrystalline Al2O3 compact has a thickness of 0.1 to 20 mm. A polycrystalline Al2O3-TiC-diamond composite produced by the production method according to any one of claims 15-25. Use of the polycrystalline Al2O3-TiC-diamond composite according to any one of claims 1-14, 26 in a PDC drill bit.

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