CN116730737A - Diamond-cubic boron nitride composite sheet and preparation method thereof - Google Patents
Diamond-cubic boron nitride composite sheet and preparation method thereof Download PDFInfo
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- CN116730737A CN116730737A CN202310663126.6A CN202310663126A CN116730737A CN 116730737 A CN116730737 A CN 116730737A CN 202310663126 A CN202310663126 A CN 202310663126A CN 116730737 A CN116730737 A CN 116730737A
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- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 title claims abstract description 73
- 229910052582 BN Inorganic materials 0.000 title claims abstract description 49
- 239000002131 composite material Substances 0.000 title claims abstract description 46
- 238000002360 preparation method Methods 0.000 title abstract description 8
- 239000000843 powder Substances 0.000 claims abstract description 78
- 229910003460 diamond Inorganic materials 0.000 claims abstract description 74
- 239000010432 diamond Substances 0.000 claims abstract description 74
- 239000010936 titanium Substances 0.000 claims abstract description 43
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 41
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 41
- 239000011248 coating agent Substances 0.000 claims abstract description 38
- 238000000576 coating method Methods 0.000 claims abstract description 38
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000000463 material Substances 0.000 claims description 52
- 238000010438 heat treatment Methods 0.000 claims description 23
- 238000001035 drying Methods 0.000 claims description 15
- 239000000203 mixture Substances 0.000 claims description 12
- 239000002245 particle Substances 0.000 claims description 12
- 230000015572 biosynthetic process Effects 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 10
- 238000004806 packaging method and process Methods 0.000 claims description 10
- 238000003786 synthesis reaction Methods 0.000 claims description 10
- 239000000956 alloy Substances 0.000 claims description 8
- 229910045601 alloy Inorganic materials 0.000 claims description 8
- 238000004321 preservation Methods 0.000 claims description 8
- 239000011159 matrix material Substances 0.000 claims description 7
- 238000002156 mixing Methods 0.000 claims description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 5
- 239000004020 conductor Substances 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 238000007789 sealing Methods 0.000 claims description 5
- 239000003566 sealing material Substances 0.000 claims description 5
- 238000003825 pressing Methods 0.000 claims description 4
- 239000011810 insulating material Substances 0.000 claims description 3
- 230000002194 synthesizing effect Effects 0.000 claims description 2
- 238000005087 graphitization Methods 0.000 abstract description 11
- 238000003466 welding Methods 0.000 abstract description 7
- 238000005520 cutting process Methods 0.000 abstract description 3
- 235000019580 granularity Nutrition 0.000 description 8
- 238000005219 brazing Methods 0.000 description 7
- 239000011230 binding agent Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 229910017052 cobalt Inorganic materials 0.000 description 3
- 239000010941 cobalt Substances 0.000 description 3
- 239000002270 dispersing agent Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 description 3
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 description 2
- 229910009043 WC-Co Inorganic materials 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000012774 insulation material Substances 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 244000025254 Cannabis sativa Species 0.000 description 1
- 235000012766 Cannabis sativa ssp. sativa var. sativa Nutrition 0.000 description 1
- 235000012765 Cannabis sativa ssp. sativa var. spontanea Nutrition 0.000 description 1
- 235000009120 camo Nutrition 0.000 description 1
- 235000005607 chanvre indien Nutrition 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000011487 hemp Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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Abstract
The application provides a diamond-cubic boron nitride composite sheet and a preparation method thereof, wherein the diamond-cubic boron nitride composite sheet consists of titanium coating diamond micro powder, pure diamond micro powder, cubic boron nitride micro powder and cobalt powder, and the titanium coating diamond micro powder is added, and the cubic boron nitride micro powder is added according to a certain proportion, so that the diamond-cubic boron nitride composite sheet with better temperature resistance is obtained. The diamond-cubic boron nitride composite sheet obtained by the application has toughness, wear resistance and temperature resistance, and has good conductivity, and the heat-resistant temperature of the cutter can be obviously improved when the diamond-cubic boron nitride composite sheet is made into a cutting cutter; during high-temperature vacuum welding, the welding temperature range is greatly increased, the vacuum degree condition is reduced, and the graphitization probability is reduced.
Description
Technical Field
The application relates to the field of materials, and mainly relates to a diamond-cubic boron nitride composite sheet and a preparation method thereof.
Background
Polycrystalline diamond (PCD) composite sheet is a cutter blank composite material formed by sintering diamond micropowder, binder and hard alloy matrix (WC-Co) at high temperature and high pressure. Metallic cobalt (Co) is commonly used in the industry as a binder for PCD composite sheets, and PCD synthesized by using the metallic cobalt (Co) as the binder has the greatest characteristics of good toughness and high wear resistance.
PCD composite sheets synthesized by using metallic cobalt (Co) as a binder often have the following two limitations in the use process of industry, on one hand, in the processing process of certain high-temperature alloys, the tip of a cutter can generate a temperature exceeding that of diamond graphitization (PCD can be rapidly graphitized in an air environment at the temperature of more than 700 ℃), so that the cutting performance is greatly reduced, and the processing cost of enterprises is increased; on the other hand, for many small-sized cutter enterprises, the vacuum welding equipment has a great gap with the large-sized cutter enterprises in terms of vacuum degree and temperature control precision, and micro graphitization on the surface of the cutter is often caused in the process of welding the cutter head made of the PCD composite sheet, so that the service life of the cutter is greatly reduced, and certain loss is brought to the cutter enterprises. It can be seen that such conventional PCD compacts are relatively poor in temperature resistance.
Disclosure of Invention
The application provides a diamond-cubic boron nitride composite sheet and a preparation method thereof in order to solve the problem of poor heat resistance of a polycrystalline diamond composite sheet. The diamond-cubic boron nitride composite sheet comprises titanium coating diamond micro powder, pure diamond micro powder, cubic boron nitride micro powder and cobalt powder, wherein the titanium coating diamond micro powder comprises coarse-grain titanium coating diamond micro powder and fine-grain titanium coating diamond micro powder, the content of the coarse-grain titanium coating diamond micro powder is 50wt%, the content of the fine-grain titanium coating diamond micro powder is 20wt%, the content of the pure diamond micro powder is 15wt%, the content of the cubic boron nitride micro powder is 10wt%, and the content of the cobalt powder is 5wt%.
The application selects pure diamond micropowder and a certain amount of cubic boron nitride micropowder to mix, and adds a certain amount of titanium coating diamond micropowder on the basis. Because titanium can react with cubic boron nitride and diamond at high temperature and high pressure to form titanium nitride (TiN) and titanium carbide (TiC) ceramics with higher temperature resistance, the temperature resistance of the cubic boron nitride micro powder is high, and finally the diamond-cubic boron nitride composite sheet with better comprehensive performance is synthesized, and the heat resistance of the diamond-cubic boron nitride composite sheet is improved.
Optionally, the diamond-cubic boron nitride composite sheet comprises titanium coating diamond micro powder, pure diamond micro powder, cubic boron nitride micro powder and cobalt powder, wherein the titanium coating diamond micro powder comprises coarse-grain titanium coating diamond micro powder and fine-grain titanium coating diamond micro powder, the content of the coarse-grain titanium coating diamond micro powder is 50wt%, the content of the fine-grain titanium coating diamond micro powder is 30wt%, the content of the pure diamond micro powder is 10wt%, the content of the cubic boron nitride micro powder is 5wt%, and the content of the cobalt powder is 5wt%.
Optionally, the granularity of the coarse-granularity titanium coating diamond micropowder is 8-12um, and the granularity of the fine-granularity titanium coating diamond micropowder is 1-5um.
Optionally, the granularity of the cubic boron nitride micro powder is 4-8um, the granularity of the pure diamond micro powder is 0-1um, and the granularity of the cobalt powder is 1-2um.
The application also provides a preparation method of the diamond-cubic boron nitride composite sheet, which comprises the following steps:
mixing the titanium-coated diamond micropowder, the pure diamond micropowder, the cubic boron nitride micropowder, the cobalt powder and the alcohol in a three-dimensional mixer for 20 hours to obtain a wet mixed material;
placing the wet mixed material into a vacuum oven for drying to obtain a mixed material;
carrying out high-vacuum reduction on the mixture in a vacuum furnace to obtain a reduced mixture;
and packaging the reduction mixed material, assembling the reduction mixed material with other scattered auxiliary materials to form a block, and synthesizing at high temperature and high pressure to obtain the diamond-cubic boron nitride composite sheet.
Optionally, the placing the wet mixed material in a vacuum oven for drying specifically includes:
placing the wet mixed material in a vacuum box, heating to 100 ℃, and drying for 1 hour;
and (3) vacuumizing to 133Pa after 1 hour, raising the temperature to 200 ℃, and drying for 2 hours to obtain the mixture.
Optionally, the high vacuum reduction includes:
sequentially starting vacuum pumps of each stage of the vacuum furnace to perform vacuumizing treatment until reaching 2x10 8 Placing the dry blend in a vacuum degree of 2x10 until the high vacuum degree of Pa 8 Heating under Pa, heating to 300 ℃ within 20min, and then preserving heat at 300 ℃ for 60min;
heating from 300 ℃ to 700 ℃ within 60min, and then preserving heat at 700 ℃ for 120min;
naturally cooling to room temperature to obtain the reduced mixed material.
Optionally, the packaging includes:
placing the reduced mixed material in a metal wrapping cup, placing a hard alloy matrix on the reduced mixed material, and carrying out edge sealing treatment;
assembling the reduction mixed material according to the sequence of the heating material, the heat-insulating material, the conductive material and the pressure-transmitting sealing material from inside to outside to obtain an assembly block;
and placing the assembly blocks into a pressing cavity of a hexahedral top press for synthesis, wherein the synthesis conditions are that the pressure is 5.0-5.5GPa, the temperature is 1300-1600 ℃, and the heat preservation time is 5-10min.
The application provides a diamond-cubic boron nitride composite sheet and a preparation method thereof, wherein the diamond-cubic boron nitride composite sheet consists of titanium coating diamond micro powder, pure diamond micro powder, cubic boron nitride micro powder and cobalt powder, and the titanium coating diamond micro powder is added, and the cubic boron nitride micro powder is added according to a certain proportion, so that the diamond-cubic boron nitride composite sheet with better temperature resistance is obtained. The obtained diamond-cubic boron nitride composite sheet has toughness, wear resistance and temperature resistance, and good conductivity, can obviously improve the heat resistance temperature of a cutter when the cutter is manufactured, and can greatly increase the welding temperature range and reduce the vacuum degree condition and reduce the probability of PCD graphitization when the cutter is welded at high temperature under vacuum.
Drawings
In order to more clearly illustrate the technical solution of the present application, the drawings that are needed in the embodiments will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.
FIG. 1 is a flow chart of a method for preparing a diamond-cubic boron nitride composite sheet;
fig. 2 is a schematic diagram of the contents of the components of a diamond-cubic boron nitride composite sheet.
Detailed Description
Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The embodiments described in the examples below do not represent all embodiments consistent with the application. Merely exemplary of systems and methods consistent with aspects of the application as set forth in the claims.
The application provides a diamond-cubic boron nitride composite sheet prepared from titanium coating diamond micropowder, pure diamond micropowder, cubic boron nitride micropowder and cobalt powder.
The added titanium coating diamond micropowder and cubic boron nitride micropowder react with the cubic boron nitride and diamond to form titanium nitride and titanium carbide ceramics with higher temperature resistance under the high-temperature and high-pressure environment, the temperature resistance of the cubic boron nitride micropowder is very high, the diamond-cubic boron nitride composite sheet with better comprehensive performance is finally synthesized, and the heat resistance of the diamond-cubic boron nitride composite sheet is improved.
Embodiment one:
the mixed diamond micro powder is adopted, as shown in figures 1 and 2, wherein the Ti coating diamond micro powder adopts two particle sizes: coarse grain size is 8-12um, fine grain size is 1-5um. The particle size ratio is respectively 50 weight percent and 20 weight percent. The pure diamond micro powder is prepared from single particle size 0-1um, the mass is proportioned according to 15wt%, the CBN micro powder is prepared from single particle size 4-8um, the mass is proportioned according to 10wt%, the Co powder is prepared from micro powder 1-2um, and the Co powder is prepared according to 5wt%.
In order to mix materials more uniformly, wet mixing materials are used, alcohol is used as a dispersing agent, the wet mixing materials are mixed in a three-dimensional mixer for 20 hours, and then the mixture is dried in a vacuum oven, wherein the specific drying steps are as follows: firstly, placing the wet mixed material in a vacuum oven (vacuum is not pumped firstly), heating to 100 ℃, and pumping when the powder is basically in a dry state after 1 hour, wherein the vacuum degree is as follows: 133Pa, at this time, the temperature is raised to 200 ℃ and redrying is carried out for 2 hours, and after the whole drying process is finished, the powder is placed in a vacuum oven for the next high vacuum reduction.
The mixture is placed in a vacuum furnace for reduction, so as to remove oxygen and moisture adsorbed on the surface of the powder. The specific vacuum reduction steps are as follows: (1) Sequentially starting vacuum pumps of each stage of the vacuum furnace to perform vacuumizing treatment until reaching 2x10 8 High vacuum degree of Pa; (2) Heating under the vacuum degree for 20min to 300 ℃, preserving heat for 60min at 300 ℃, heating for 60min to 700 ℃, preserving heat for 120min at 700 ℃, and naturally cooling to normal temperature after the heat preservation is finished. The powder vacuum reduction treatment is finished and then packaged, the packaging is to weigh micro powder with certain quality and put the micro powder into a metal wrapping cup, then the hard alloy matrix is placed on the micro powder, then edge sealing treatment is carried out, the whole packaging is finished and then the whole packaging is assembled, all assembling parts are assembled into blocks (heating materials, heat insulation materials, conductive materials and pressure transmission sealing materials) in sequence from inside to outside, and finally the assembling blocks are placed into a pressure cavity of a hexahedral press for high-temperature and high-pressure synthesis, wherein the synthesis conditions are as follows: the pressure is 5.0-5.5GPa, the temperature is 1300-1600 ℃, and the heat preservation time is 5-10min.
Embodiment two:
the mixed diamond micro powder is adopted, wherein the Ti coating diamond micro powder adopts two granularities: coarse grain size is 8-12um, fine grain size is 1-5um. The particle size ratio is respectively 50 weight percent and 30 weight percent. The pure diamond micro powder is prepared from single particle size 0-1um, the mass is proportioned according to 10wt%, the CBN micro powder is prepared from single particle size 4-8um, the mass is proportioned according to 5wt%, the Co powder is prepared from micro powder 1-2um, and the Co powder is proportioned according to 5wt%.
In order to mix materials more uniformly, wet mixing materials are used, alcohol is used as a dispersing agent, the wet materials are mixed in a three-dimensional mixer for 20 hours and then are dried in a vacuum oven, and the specific drying steps are as follows: firstly, placing the wet mixed material in a vacuum oven (vacuum is not pumped firstly), heating to 100 ℃, and pumping when the powder is basically in a dry state after 1 hour, wherein the vacuum degree is as follows: 133Pa, at this time, the temperature is raised to 200 ℃ and redrying is carried out for 2 hours, and after the whole drying process is finished, the powder is placed in a vacuum oven for the next high vacuum reduction.
The mixture is placed in a vacuum furnace for reduction, so as to remove oxygen and moisture adsorbed on the surface of the powder. The specific vacuum reduction steps are as follows: (1) Sequentially starting vacuum pumps of each stage of the vacuum furnace to perform vacuumizing treatment until reaching 2x10 8 High vacuum degree of Pa; (2) Heating under the vacuum degree for 20min to 300 ℃, preserving heat for 60min at 300 ℃, heating for 60min to 700 ℃, preserving heat for 120min at 700 ℃, and naturally cooling to normal temperature after the heat preservation is finished. The powder vacuum reduction treatment is finished and then packaged, the packaging is to weigh micro powder with certain quality and put the micro powder into a metal wrapping cup, then the hard alloy matrix is placed on the micro powder, then edge sealing treatment is carried out, the whole packaging is finished and then the whole packaging is assembled, all the assembled parts are assembled into blocks (heating materials, heat insulation materials, conductive materials and pressure transmission sealing materials) in sequence from inside to outside, and finally the assembled blocks are placed into a pressing cavity of a hexahedral press for high-temperature high-pressure synthesis, wherein the synthesis conditions are as follows: the pressure is 5.0-5.5GPa, the temperature is 1300-1600 ℃, and the heat preservation time is 5-10min.
Comparative example:
the mixed diamond micro powder is adopted, wherein the titanium coating diamond micro powder adopts two particle sizes: the coarse particle size was 10um and the fine particle size was 2um. The particle size ratio is 47wt percent and 28wt percent respectively. The pure diamond micro powder is prepared from single granularity 0.5um, the mass is prepared according to 15t%, the cubic boron nitride micro powder is prepared from single granularity 7um, the mass is prepared according to 5wt%, the cobalt powder is prepared from 2um micro powder according to 5wt% of the cobalt powder.
In order to mix materials more uniformly, a wet mixing method is used for mixing materials, alcohol is used for a dispersing agent, wet materials are mixed in a three-dimensional mixer for 20 hours to obtain wet mixed materials, and the wet mixed materials are dried in a vacuum oven to obtain dry mixed materials. The specific drying steps are as follows: firstly, placing the wet mixed material in a vacuum oven (vacuum is not pumped firstly), heating to 100 ℃, and pumping when the powder is basically in a dry state after 1 hour, wherein the vacuum degree is as follows: 133Pa, at this time, raising the temperature to 200 ℃, and re-drying for 2 hours to obtain a dry mixed material, and after the whole drying process is finished, placing the dry mixed material into a vacuum oven for the next high vacuum reduction.
And (3) placing the dry mixed material into a vacuum furnace for reduction, and removing oxygen and water adsorbed on the surface of the powder material to obtain a reduced mixed material. The specific vacuum reduction steps are as follows: sequentially starting vacuum pumps of each stage of the vacuum furnace to perform vacuumizing treatment until reaching 2x10 8 High vacuum degree of Pa. Heating under the vacuum degree, heating to 300 ℃ within 20min, and then preserving heat at 300 ℃ for 60min; heating to 700 ℃ within 60min, then preserving heat at 700 ℃ for 120min, and naturally cooling to normal temperature after the heat preservation is finished, thus obtaining the reduction mixed material.
Packaging the reduction material, filling the micro powder of the reduction material into a metal wrapping cup, placing the hard alloy matrix on the reduction material, and performing edge sealing treatment. And (3) assembling the reduction mixed material according to the sequence of the heating material, the heat-insulating material, the conductive material and the pressure-transmitting sealing material from inside to outside to obtain an assembly block, and finally placing the assembly block into a pressing cavity of a hexahedral press for high-temperature and high-pressure synthesis to obtain the first diamond-cubic boron nitride composite sheet. The synthesis conditions are as follows: the pressure is 5.2GPa, the temperature is 1400 ℃, and the heat preservation time is 7min.
A conventional PCD composite sheet formed by sintering diamond micropowder, cobalt powder and a hard alloy matrix (WC-Co) at high temperature and high pressure is selected. The conventional PCD compact and the first diamond-cubic boron nitride compact prepared in the comparative example were each laser cut to be identicalA standard type of cutter head is welded in a vacuum brazing furnace (working vacuum degree reaches 5 x10 -2 Pa), and performing a comparison experiment.
When the vacuum brazing temperature is 700 ℃, no graphitization phenomenon exists on the surfaces of the diamond layers of the two cutter heads when the surfaces of the diamond layers of the two cutter heads are observed under a metallographic microscope (black spots of the compact hemp appear on the surface layer of the graphitized PCD cutter head when the surface layer of the cutter head is observed under a metallographic state); when the vacuum brazing temperature is 730 ℃, the conventional PCD blade part is already micro-graphitized, the proportion reaches 30%, and the diamond-cubic boron nitride blade does not find graphitization; when the vacuum brazing temperature was 760 ℃, the conventional PCD inserts were all severely graphitized, whereas the diamond-cubic boron nitride inserts had only a small bit of micro graphitization, accounting for about 20%. Therefore, the diamond-cubic boron nitride composite sheet provided by the application has better high temperature resistance.
When the vacuum brazing temperature is 700 ℃, graphitization phenomenon does not occur on both types of cutter heads; at a vacuum brazing temperature of 730 ℃, slight graphitization of the conventional PCD blade portion was visible to the naked eye, whereas no graphitization was found in the diamond-cubic boron nitride blade; when the vacuum brazing temperature was 760 ℃, the conventional PCD insert was seen to be fully severely graphitized by the naked eye, while only a small bit portion of the diamond-cubic boron nitride insert was slightly graphitized. Therefore, the diamond-cubic boron nitride composite sheet has better high-temperature resistance.
The application provides a diamond-cubic boron nitride composite sheet and a preparation method thereof, wherein the diamond-cubic boron nitride composite sheet consists of titanium coating diamond micro powder, pure diamond micro powder, cubic boron nitride micro powder and cobalt powder, and the titanium coating diamond micro powder is added, and the cubic boron nitride micro powder is added according to a certain proportion, so that the diamond-cubic boron nitride composite sheet with better temperature resistance is obtained. The obtained diamond-cubic boron nitride composite sheet has toughness, wear resistance and temperature resistance, and has good conductivity, and the heat-resistant temperature of the cutter can be obviously improved when the diamond-cubic boron nitride composite sheet is manufactured into a cutting cutter; during high-temperature vacuum welding, the welding temperature range is greatly increased, the vacuum degree condition is lowered, and the probability of PCD graphitization is reduced.
The above-provided detailed description is merely a few examples under the general inventive concept and does not limit the scope of the present application. Any other embodiments which are extended according to the solution of the application without inventive effort fall within the scope of protection of the application for a person skilled in the art.
Claims (8)
1. The diamond-cubic boron nitride composite sheet is characterized by comprising titanium coating diamond micro powder, pure diamond micro powder, cubic boron nitride micro powder and cobalt powder, wherein the titanium coating diamond micro powder comprises coarse-grain titanium coating diamond micro powder and fine-grain titanium coating diamond micro powder, the content of the coarse-grain titanium coating diamond micro powder is 50wt%, the content of the fine-grain titanium coating diamond micro powder is 20wt%, the content of the pure diamond micro powder is 15wt%, the content of the cubic boron nitride micro powder is 10wt%, and the content of the cobalt powder is 5wt%.
2. The diamond-cubic boron nitride composite sheet is characterized by comprising titanium coating diamond micro powder, pure diamond micro powder, cubic boron nitride micro powder and cobalt powder, wherein the titanium coating diamond micro powder comprises coarse-grain titanium coating diamond micro powder and fine-grain titanium coating diamond micro powder, the content of the coarse-grain titanium coating diamond micro powder is 50wt%, the content of the fine-grain titanium coating diamond micro powder is 30wt%, the content of the pure diamond micro powder is 10wt%, the content of the cubic boron nitride micro powder is 5wt%, and the content of the cobalt powder is 5wt%.
3. The diamond-cubic boron nitride compact according to claim 1 or 2, wherein the coarse-grain-size titanium-coated diamond micropowder has a grain size of 8 to 12um and the fine-grain-size titanium-coated diamond micropowder has a grain size of 1 to 5um.
4. A diamond-cubic boron nitride composite sheet according to claim 1 or 2, wherein the cubic boron nitride micro powder has a particle size of 4-8um, the pure diamond micro powder has a particle size of 0-1um, and the cobalt powder has a particle size of 1-2um.
5. A method for preparing a diamond-cubic boron nitride composite sheet, applied to preparing the diamond-cubic boron nitride composite sheet according to any one of claims 1 to 4, comprising:
mixing the titanium-coated diamond micropowder, the pure diamond micropowder, the cubic boron nitride micropowder, the cobalt powder and the alcohol in a three-dimensional mixer for 20 hours to obtain a wet mixed material;
placing the wet mixed material into a vacuum oven for drying to obtain a mixed material;
carrying out high-vacuum reduction on the mixture in a vacuum furnace to obtain a reduced mixture;
and packaging and assembling the reduction mixed material, and synthesizing at high temperature and high pressure to obtain the diamond-cubic boron nitride composite sheet.
6. The method of diamond-cubic boron nitride composite sheet according to claim 5, wherein the placing the wet mix in a vacuum oven for drying specifically comprises:
placing the wet mixed material in a vacuum box, heating to 100 ℃, and drying for 1 hour;
and (3) vacuumizing to 133Pa after 1 hour, raising the temperature to 200 ℃, and drying for 2 hours to obtain the mixture.
7. The diamond-cubic boron nitride compact method of claim 5, wherein the high vacuum reduction comprises:
sequentially starting vacuum pumps of each stage of the vacuum furnace to perform vacuumizing treatment until reaching 2x10 8 Placing the dry blend in a vacuum degree of 2x10 until the high vacuum degree of Pa 8 Heating under Pa, heating to 300 ℃ within 20min, and then preserving heat at 300 ℃ for 60min;
heating from 300 ℃ to 700 ℃ within 60min, and then preserving heat at 700 ℃ for 120min;
naturally cooling to room temperature to obtain the reduced mixed material.
8. The diamond-cubic boron nitride compact method of claim 5, wherein the encapsulating comprises:
placing the reduced mixed material in a metal wrapping cup, placing a hard alloy matrix on the reduced mixed material, and carrying out edge sealing treatment;
assembling the reduction mixed material according to the sequence of the heating material, the heat-insulating material, the conductive material and the pressure-transmitting sealing material from inside to outside to obtain an assembly block;
and placing the assembly blocks into a pressing cavity of a hexahedral top press for synthesis, wherein the synthesis conditions are that the pressure is 5.0-5.5GPa, the temperature is 1300-1600 ℃, and the heat preservation time is 5-10min.
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