CN117226108A

CN117226108A - Method for manufacturing multi-material alternately-wrapped PDC substrate by extrusion type additive and application

Info

Publication number: CN117226108A
Application number: CN202311093557.XA
Authority: CN
Inventors: 张伟; 吴金波; 张威; 刘咏; 罗杨; 刘惠仁
Original assignee: Jwe Carbide Co ltd; Central South University
Current assignee: Jwe Carbide Co ltd; Central South University
Priority date: 2023-08-29
Filing date: 2023-08-29
Publication date: 2023-12-15

Abstract

The invention relates to a preparation method of a multi-material alternately-wrapped high-toughness polycrystalline diamond compact substrate based on powder extrusion printing molding; belongs to the technical field of PDC design and preparation. The invention attempts to increase the toughness of PDC by alternately arranging hard layers and soft layers for the first time; during the technology development process, the following steps are found: the ceramic material with alternately arranged hard layers and soft layers has the characteristics of prolonging crack propagation paths and obviously improving fracture toughness and energy absorption capacity of the material, and provides a solution for the high-toughness PDC substrate. The invention adopts powder extrusion printing molding, and obtains a high-quality product with high abrasion ratio and high impact toughness through the synergistic effect of the components and the process. The process of the invention is controllable, and the obtained product has excellent performance and is convenient for large-scale industrialized application.

Description

Method for manufacturing multi-material alternately-wrapped PDC substrate by extrusion type additive and application

Technical Field

The invention relates to a preparation method of a multi-material alternately-wrapped high-toughness polycrystalline diamond compact substrate based on powder extrusion printing molding; belongs to the technical field of PDC design and preparation.

Background

Polycrystalline Diamond Compacts (PDCs) are superhard composites formed from diamond and cemented carbide substrates sintered under High Temperature High Pressure (HTHP) conditions. Because of its excellent low friction, high hardness, high wear resistance, good corrosion resistance and brazing properties, the method is widely applied to the fields of difficult-to-process materials such as coal exploitation, oil gas exploitation, deep well drilling, carbon fiber, titanium alloy and the like. In the high-temperature and high-pressure synthesis process of the PDC, co in the hard alloy gradually melts and sweeps across the diamond layer along with the rise of temperature and pressure, and the densification of the diamond layer and the formation of the polycrystalline diamond layer are promoted. However, co is a major provider of toughness of cemented carbides, and the impact toughness of cemented carbides tends to be severely reduced due to Co migration; in contrast, in PDCs, wear resistance is provided by polycrystalline diamond and toughness is provided by cemented carbide substrates, so in industrial production, the toughness of PDC cemented carbide substrates often fails to meet the high impact toughness requirements of PDCs in increasingly complex and severe service environments.

In order to overcome the problem of the reduction of the impact toughness of the PDC caused by mass migration of Co, the traditional method mainly comprises the step of arranging a Co diffusion barrier layer, such as a W layer, a Ti layer, a Si3N4 layer and the like, between the PDC substrate and the polycrystalline diamond layer. However, the mode often has the problem of poor compatibility of the barrier layer material, hard alloy and diamond, and adds a new problem when introducing a transition layer. In addition, the toughening case of the PDC substrate, namely the hard alloy, mainly comprises the steps of introducing additives and regulating and controlling the morphology and the particle size distribution of WC particles, wherein on one hand, the growth of WC crystal grains is inhibited by the additives, and the yield strength of the material is improved; on the other hand, WC particles with different shapes and particle sizes are added to coordinate with each other, so that energy of crack propagation is absorbed, and the fracture toughness of the material is improved, but the method often faces the problems of high compatibility of the material or high operation difficulty and preparation components, and the like, has limited contribution to the toughness of the hard alloy, and is difficult to realize industrialization.

The search finds that the technology of increasing the toughness of PDC by alternately arranging hard layers and soft layers is still rarely reported at present. There are also few reports on techniques for preparing wrapped PDC substrates with alternating hard and soft layers using extrusion additive manufacturing processes.

Disclosure of Invention

The invention attempts to increase the toughness of PDC by alternately arranging hard layers and soft layers for the first time; during the technology development process, the following steps are found: the ceramic material with alternately arranged hard layers and soft layers has the characteristics of prolonging crack propagation paths and obviously improving fracture toughness and energy absorption capacity of the material, and provides a solution for the high-toughness PDC substrate. The present invention therefore proposes a PDC substrate with a staggered wrapped structure. In the PDC substrate with the staggered wrapping structure, hard alloy layers and soft layers are alternately wrapped layer by layer from a core to the surface, and soft phase layers are distributed between the hard alloy layers in a sandwich mode, and the PDC substrate is of an approximate concentric sphere or concentric cylinder structure. The structure can improve the axial high toughness of the PDC substrate and simultaneously has excellent radial impact resistance, can be suitable for complex stress environments in the PDC service process, is applied to the preparation of the PDC substrate, and is beneficial to improving the impact toughness of the polycrystalline diamond compact and guaranteeing the working efficiency.

Due to the multiple materials and the high complexity, the structure is difficult to prepare by traditional powder metallurgy methods such as die pressing. The additive manufacturing has the advantages in low-cost preparation of customized products with complex shapes and structures, the precise control of composition and structural characteristics in three-dimensional space can be realized, and the external shape and internal gradient distribution of the products are not limited by a die. The material extrusion type additive manufacturing (MEX-AM) based on the mixture of organic matters and powder realizes densification sintering through a treatment process which is highly compatible with the traditional technology, has the characteristics of low-temperature low-stress forming and high-powder filling, and is particularly beneficial to the high-density additive manufacturing of high-melting-point materials such as hard alloy. The extrusion type additive manufacturing also has the characteristic of double nozzles, can realize the customized preparation of various materials and realize the batch production of PDC substrates with staggered wrapping type structures.

The PDC substrate with the wrapped laminated structure is prepared by the extrusion type additive manufacturing method, and the PDC substrate with the complicated structure, which has high hardness and toughness and is suitable for the service environment of the polycrystalline diamond compact, is prepared by the characteristics of high defect tolerance and high energy absorption of the laminated structure, multi-material manufacturing of the extrusion type additive and high structural design flexibility, and the impact resistance of the polycrystalline diamond compact is improved by the high-toughness substrate, so that the service efficiency and service life of the polycrystalline diamond compact in the complicated service environment are improved.

During the synthesis process of the polycrystalline diamond compact, part of liquid-phase Co in the hard alloy substrate sweeps through the diamond layer under the driving of capillary force and interfacial energy, so that the diamond layer is densified and polycrystalline formation is promoted. However, the loss of Co in the hard alloy can lead to the reduction of the toughness of the hard alloy, so that the impact toughness of the PDC is influenced, and the PDC is difficult to use for a long time in a high-requirement service environment. Aiming at the problem, the invention utilizes the characteristic of inhibiting crack initiation and expansion of a wrapped laminated structure, and the extrusion type additive manufacturing method is used for manufacturing the high-toughness PDC substrate with the multi-material alternately wrapped structure, so that the impact resistance of the polycrystalline diamond compact is improved, and the service life of the polycrystalline diamond compact in a complex environment is prolonged.

The invention relates to a method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive, wherein the multi-material alternately-wrapped PDC substrate comprises a working part; the preparation of the working part of the multi-material alternately-wrapped PDC substrate comprises the following steps:

step one of preparation of soft material feed

Selecting soft material, the elastic modulus of the soft material is lower than that of hard alloy, and the thermal expansion coefficient is 3-15 multiplied by 10 ^-6 The melting point is not lower than 1300 ℃, and the amount of the melting point is not more than 50vol.% based on the total volume fraction of the matrix;

Organic polymer binder, soft material powder and metal binder are used as raw materials, and soft material feed is prepared through banburying and granulation; the soft material and the metal binder are mechanically mixed uniformly in advance, and the mass ratio is 70-95:5-30, preferably 80-90:10-20 parts of a base; the loading of soft material powder+metal binder powder is 43-65vol.%, preferably 48-62vol.%; the d90 of the soft material powder and the metal binder is <50 μm,

step two, hard alloy feeding preparation

Preparing hard alloy powder, wherein the hard alloy is WC-Co, the mass fraction of Co is 5-25 wt%, preferably 8-20 wt%, and the mass fraction of WC is 75-95 wt%, preferably 80-92 wt%; taking an organic polymer adhesive and hard alloy powder as raw materials, and preparing hard alloy feed by mixing, banburying and granulating; the volume percentage of the cemented carbide powder in the cemented carbide feed is 43-65vol.%, preferably 48-62vol.%;

in the first and second steps, the organic polymer adhesive comprises a filler, a framework, a plasticizer and a surfactant, wherein the mass ratio of the filler to the framework to the plasticizer to the surfactant is 50-75:15-35:5-20:1-8;

the filler comprises one or more of solid Paraffin (PW), liquid Paraffin (LPW) and Microcrystalline Wax (MW), preferably PW and MW are mixed, and more preferably PW and MW are mixed according to the mass ratio of 3-5: 1, mixing;

The framework comprises one or more of vegetable oil (EO), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP) and ethylene-vinyl acetate copolymer (EVA), preferably HDPE and EVA are mixed, and more preferably HDPE and EVA are mixed according to the mass ratio of 1.0-1.5: 1.0 to 1.5;

the plasticizer is at least one selected from dioctyl phthalate (DOP), dibutyl phthalate (DBP), tricresyl phosphate (TCP), tributyl citrate (TBC), preferably DOP,

the surfactant is at least one of Stearic Acid (SA) and oleic acid (SA), preferably SA;

step three two-dimensional structure construction

According to the modeling of the target three-dimensional structure, converting the three-dimensional structure into a multi-layer two-dimensional structure diagram identifiable by printing equipment through slicing software; the model is composed of hard alloy layers and soft layers, wherein the two materials are alternately wrapped layer by layer from a core part to the surface, the soft layers are distributed between the hard alloy layers in a sandwich mode, the current situation of any soft layer and the corresponding hard alloy layer is similar, the number of the soft layers is more than or equal to 2, and the number of the hard alloy layers is more than or equal to 3; and the outermost layer of the model is a hard alloy layer;

step four print preparation

The soft material feed and the hard alloy feed prepared in the first step and the second step are respectively put into different bins of an extrusion type 3D printer; selecting printing strategy parameters according to the target structure precision, and importing a modeling slice file;

step five extrusion printing forming

Extrusion molding is carried out according to the preset multi-material alternately-wrapped structural hard alloy green body, and the nozzle size is generally selected to be 0.1-0.8mm during extrusion printing molding; when in printing, the thickness of the monolayer layer is 0.1-0.2mm, the extrusion temperature is set to 140-180 ℃, the printing platform temperature is set to 70-100 ℃, the filling flow is set to 50-100%, and other condition parameters are respectively as follows: the filling speed is 10-40mm/s, the wiring width is consistent with the size of the nozzle, the upper and lower layers of wiring directions are 0, 90 DEG, and the single-layer wiring mode is one of straight lines, saw teeth and concentric circles;

in the multi-material alternately-wrapped structural hard alloy green body, the axial thickness of the hard layer and the soft layer is not less than 0.1mm, and the radial thickness is more than or equal to the diameter of the nozzle, wherein the relation between the single-layer radial thickness and the axial thickness is as follows: axial thickness = radial thickness x total height/total diameter of the model; the number of soft phase layers is not less than 2.

Step six, degreasing with solvent

Degreasing a green compact of the PDC substrate with the multi-material alternately-wrapped structure; degreasing for 20-28h at 45-55 ℃ by adopting n-heptane as a degreasing solvent to remove PW, MW and SA, thereby obtaining a degreased composite green body;

Step six, thermal degreasing and vacuum sintering

Placing the composite green body after degreasing in the step five into a vacuum furnace for thermal degreasing, and adopting H with the flow rate of 45-55L/min ₂ Slowly heating to 400-550 ℃ in an atmosphere furnace, and preserving heat for 30-90 min to completely remove the polymer binder. And then continuously heating to 1200-1500 ℃ in a vacuum state, introducing 3-6 bar high-pressure Ar2, preserving heat for 40-90 min, and then cooling the sample along with a furnace to obtain the PDC substrate with the multi-material alternately-wrapped structure.

Preferably, the invention relates to a method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive; the soft material is ceramic particles, and the metal binder is Co; the Co content in the soft material feed is 0.95-1.05 times of the Co content in the hard alloy; the ceramic particles are at least one selected from alumina, zirconia and yttria.

Preferably, the invention relates to a method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive; the particle size of the soft particles is 0.8-2.5 μm, preferably 1-2 μm. The granularity of Co powder mixed with the powder is 0.8 to 1.2 times of soft particle granularity.

Preferably, the invention relates to a method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive; in the soft layer, the proportion of the ceramic particles and Co is less than or equal to the content of Co in the hard alloy.

Preferably, the invention relates to a method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive; the powder particle size of the cemented carbide is 0.5-3 μm, preferably 1.2-2.5 μm.

As a further preferable mode, the adhesive is prepared from PW, MW, EO, EVA, HDPE, DOP, SA and PW by mass ratio: MW: EO: EVA: HDPE: DOP: sa=47:11:4:15:16:5:2.

The multi-material alternately-wrapped PDC substrate can be completely composed of a working part, and can also be used for butt-jointing a support piece made of hard alloy on the working part.

In order to solve the problems of inconsistent impact toughness and poor toughness in all directions, a multi-material alternate wrapping type PDC substrate which is completely composed of working parts is generally adopted, and the effect is better.

In practical application, when the multi-material alternately-wrapped PDC substrate completely composed of the working parts is adopted, the core is made of hard alloy, the soft material is made of Co and alumina, and the hard alloy and the soft material are alternately distributed from inside to outside until the outermost layer is a hard alloy layer.

For industrial application, the thickness of the soft phase layer is not less than 0.1mm in both the longitudinal and transverse directions, and the number of soft phase layers is not less than 2, preferably 3-12, and more preferably 6-10.

Meanwhile, preferably, the equivalent diameter of the hard alloy core is 1-2 times of the radial thickness of other hard alloy layers coated on the soft material; the thickness of the hard alloy layer coated on the soft material in a single layer is 0.2-0.8 mm, preferably 0.45-0.55 mm, and the thickness of the soft material in a single layer is 0.05-0.2 mm, preferably 0.08-0.12 mm.

Preferably, the ratio of the axial thickness of the single cemented carbide layer to the axial thickness of the single soft material is 3 to 6:1, preferably 4 to 5.5:1, and more preferably 4.9 to 5.1:1, in addition to the core material. According to the invention, through control and optimization, except the core material, the ratio of the axial thickness of the single-layer hard alloy layer to the axial thickness of the single-layer soft material is 3-6:1, preferably 4-5.5:1, and more preferably 4.9-5.1:1, so that the abrasion ratio and average impact toughness of the product are remarkably improved.

The invention relates to an application of a method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive, which comprises the steps of assembling a working part in a multi-material alternately-wrapped PDC substrate sintered body and a polycrystalline diamond layer into a high-temperature high-pressure synthetic block, and placing the high-temperature high-pressure synthetic block in a hexahedral press for high-temperature high-pressure synthesis. The synthesis process comprises the following steps: 5-7.5GPa, preferably 6-7GPa, temperature: 1400-1700 ℃, preferably 1450-1550 ℃.

The invention relates to an application of a method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive, wherein after the obtained substrate is compounded with diamond, the PDC abrasion ratio of the product is more than or equal to 37.1 multiplied by 10 ⁴ Flat, flatImpact toughness is 972J or more.

After optimization, the application of the method for manufacturing the multi-material alternately-wrapped PDC substrate by extrusion type additive provided by the invention can obtain a PDC abrasion ratio of 37.4 multiplied by 10 or more after the substrate and diamond are compounded ⁴ The average impact toughness is 1097J or more.

Principle and advantages

According to the invention, the preparation of the high-toughness multi-material alternately-wrapped PDC substrate by extrusion type additive manufacturing is tried for the first time, and the problem that the toughness of the hard alloy substrate is reduced due to Co loss in the high-temperature and high-pressure process, so that the shock resistance of the PDC is reduced is solved.

In the high-temperature and high-pressure synthesis process of the PDC, co in the hard alloy gradually melts and sweeps across the diamond layer along with the rise of temperature and pressure, and the densification of the diamond layer and the formation of the polycrystalline diamond layer are promoted. However, co is a major provider of toughness of cemented carbides, and the impact toughness of cemented carbides tends to be severely reduced due to Co migration; in contrast, in PDCs, wear resistance is provided by polycrystalline diamond and toughness is provided by cemented carbide substrates, so in industrial production, the toughness of PDC cemented carbide substrates often fails to meet the high impact toughness requirements of PDCs in increasingly complex and severe service environments. Therefore, the preparation of the hard alloy substrate with less Co and high hardness and high toughness has great significance for improving the mechanical property and the working efficiency of the polycrystalline diamond.

The invention applies the staggered wrapping type structure to the preparation of the high-hardness high-toughness hard alloy substrate, and by the characteristics of scattering stress waves, promoting crack deflection and the like of the staggered wrapping type structure, the initiation and the expansion of cracks of the hard alloy substrate are restrained in the PDC working process, the fracture toughness of the hard alloy is improved, and meanwhile, the shock resistance and the service life of the polycrystalline diamond compact are improved.

Drawings

FIG. 1 is a schematic illustration of a multi-material alternating pack structure PDC substrate designed in example 1;

FIG. 2 is a schematic diagram of the multi-material alternating pack type structure of example 3 distributed on the working portion of the PDC substrate.

FIG. 3 is a schematic cross-sectional view of a PDC substrate of a multi-material alternating pack structure in accordance with example 1.

Detailed Description

Example 1-globally distributed multi-material alternating wrapped model,

step one

Preparing commercial YG13 hard alloy powder, alumina powder and Co powder; wherein the WC granularity in the commercial YG13 powder is 1.2-1.6 mu m, and the density is 14.2g/cm3; the average grain diameter of the alumina is 1.2 mu m, and the average grain diameter of the Co powder is 1.5 mu m; wherein alumina and Co are weighed and mixed according to the mass ratio of 87:13 to prepare Al ₂ O ₃ -13Co mixed powder.

Step two

Mass ratio, PW: MW: EO: EVA: HDPE: DOP: SA=47:11:4:15:16:5:2, and preparing an organic polymer to obtain a binder; the volume ratio of the binder is as follows: YG13 powder = 43:57, binder: al (Al) ₂ O ₃ -13Co mixed powder = 45:55. And respectively heating the powder and the binder in an internal mixer to 145-160 ℃ for uniform mixing, cooling to ensure that the powder and the organic polymer are fully sheared and kneaded to ensure uniform mixing, crushing and screening the cooled internal mixing material to obtain target feed particles, cooling to 125-30 min for 2h, and granulating the internal mixing feed in a granulator to obtain two molding feeds.

Step three: designing a globally distributed multi-material alternately-wrapped model of YG13 and Al ₂ O ₃ -13Co alternately coated with Al ₂ O ₃ The 13Co layer is sandwiched between YG13 layers. The dimension diameter x height of the model is phi 17.6x8.6mm. Wherein Al is ₂ O ₃ The axial thickness of the 13Co layer is 0.1mm, the radial thickness is obtained by the axial thickness of the 13Co layer multiplied by the total diameter/total height of the model, and is 0.2mm; YG13 layer axial thickness and Al ₂ O ₃ The 13Co layer axial thickness ratio was set to 1:1 (group A), 3:1 (group B), 5:1 (group C), 7:1 (group D). By YG13 layer outside, al ₂ O ₃ -13Co layers are arranged in an inner mode, the two materials are alternately and circularly arranged to the core part of the model from outside to inside, and when the last Al layer is arranged ₂ O ₃ After the-13 Co layer, the model is remainedWhen the space may be arranged in one layer but not enough two layers of YG13, the remaining space of the core is entirely filled with YG 13.

And (3) importing the designed multi-material alternate wrapping model with global distribution into corresponding slicing software and an extrusion printer. YG13 and Al ₂ O ₃ -13Co is respectively provided with two extrusion heads corresponding to each other, and printing strategy parameters corresponding to the two extrusion heads are respectively set in software, wherein the size of a nozzle is 0.1mm, the thickness of a layer is 0.1mm, the extrusion temperature is 165 ℃, the filling flow is 90%, the temperature of a printing platform is 80 ℃, the filling speed is 30mm/s, the wiring width is 0.1mm, the single-layer wiring mode is a straight line, and the wiring direction of an upper limit layer is [0, 90 ]]. Then the YG13 and Al were prepared ₂ O ₃ -13Co feed is placed into two bins of an extrusion type 3D printer respectively, and printing is carried out according to preset parameters.

Step four: solvent degreasing is carried out on the printing green embryo, the solvent degreasing temperature is 50 ℃, the degreasing solvent is n-heptane, and the degreasing time is 24 hours;

step five: and (3) placing the degreased green compact into an H2 atmosphere furnace with the flow rate of 50L/min, slowly heating to 550 ℃, and preserving heat for 1H. Continuously heating to 1400 ℃ in a vacuum state, and introducing 5.8bar high-pressure Ar ₂ And (5) preserving heat for 25min, and then cooling the sample along with a furnace to obtain the multi-material alternately-wrapped PDC substrate sintered body.

Step six

And (3) sequentially placing diamond-4 wt.% Co powder with average diamond grains of 10 mu m and the prepared multi-material alternately-wrapped PDC substrate sintered body into a molybdenum cup, sequentially assembling NaCl, a carbon tube, pyrophyllite, a conductive sheet and a graphite sheet into a high-temperature high-pressure synthetic block, and carrying out high-temperature high-pressure sintering to prepare the polycrystalline diamond compact. The high-temperature and high-pressure process is 1500-9.0 GPa, and the heat preservation time is 10min, so that the Polycrystalline Diamond Compact (PDC) product is prepared.

The prepared multi-material alternately-wrapped PDC substrate green embryo has regular shape, the size deviation is less than 5 percent, and the solvent degreasing does not have bubbling and cracking defects. The radial dimension shrinkage after vacuum sintering (i.e. the step five is completed) is about 16.22%, the axial dimension shrinkage is about 18.31%, and the density is more than 98%. The size of the substrate is not obviously changed after high temperature and high pressure, and the polycrystalline diamond sample is subjected to SiC grinding wheelThe abrasion ratio test is carried out, the PDC anti-dynamic load performance tester is adopted for shock resistance detection, and the detection method comprises the following steps: ten tests were started with an impact energy of 20J; if the sample is not damaged (cracked, layered, etc.), the impact energy is increased to 25J, and the test is continued for ten times; if no damage still occurs, the impact energy is increased again for 5J test ten times, so that the test is stopped after the sample is damaged gradually, the impact energy multiplied by the impact frequency is the impact energy, and the average value of the impact energy multiplied by the impact frequency is obtained after five times of test of each layer. The resulting group A PDC had a wear ratio of 38.9X10 ⁴ An average impact toughness of 972J; group B PDC wear ratio was 40.3X10 ⁴ An average impact toughness of 1089J; group C PDC wear ratio was 37.4X10 ⁴ Average impact toughness 1218J; group D PDC wear ratio of 36.8X10 ⁴ The average impact toughness was 1145J.

EXAMPLE 2 Al ₂ O ₃ -13Co layer thickness is increased from 0.1 to 0.2mm, YG13 layer axial thickness and Al ₂ O ₃ The axial thickness ratio of the-13 Co layer was set to 5:1.

Al in example 1 ₂ O ₃ The layer thickness of the 13Co layer is set to 0.2mm, and the axial thickness of the YG13 layer is equal to Al ₂ O ₃ -13Co layer axial thickness ratio of 5:1, other printing, degreasing and sintering steps and parameters are unchanged. The obtained multi-material alternately-wrapped PDC substrate green embryo has regular appearance, the size deviation is less than 5 percent, and the solvent degreasing does not have bubbling and cracking defects. The radial dimension shrinkage after vacuum sintering (i.e. the step five is completed) is 17.03%, the axial dimension shrinkage is 18.51%, and the density is more than 98%. The substrate size did not change significantly after high temperature and high pressure, and the PDC wear ratio was 37.5X10 according to the test method described in example 1 ⁴ The average impact toughness is 1103J;

EXAMPLE 3 homogeneous basal control group

Additive manufacturing YG13 hard alloy single material green compact with diameter multiplied by height dimension phi 17.6X8.6 mm was prepared, and the molding, degreasing and sintering parameters and steps were the same as those of example 1, so as to prepare the polycrystalline diamond compact with YG13 as a substrate. The radial dimension shrinkage is 17.01 percent, the axial dimension shrinkage is 19.36 percent, and the density is more than 98 percent after the vacuum sintering (namely the step five is completed); after high temperature and high pressure, the composite sheet abrasion ratio was 39.6×10 ⁴ The average impact toughness was 885J.

Example 4-change of Global parcel to working part parcel

And (3) replacing the globally distributed multi-material alternately-wrapped hard alloy substrate in the step (III) with the multi-material alternately-wrapped hard alloy substrate distributed in the axial upper half part. Taking the mold core as a reference, and keeping the mold structure of the part above the core unchanged; al of the lower half of the mold except for the core ₂ O ₃ The 13Co layer shortens and closes the lowest end of the core, the lower part Al ₂ O ₃ The spacing between the 13Co layers, i.e. the lower YG13 layer thickness is equal to Al ₂ O ₃ The layer thickness of the 13Co layer was 0.1mm and the spacer material was YG13. And (3) in the high-temperature and high-pressure process, the other steps and parameters are unchanged, and one end with the semi-wrapping structure is contacted with the diamond powder to synthesize the PDC. The prepared multi-material alternating semi-wrapped PDC substrate green embryo has regular appearance, the size deviation is less than 5 percent, and the solvent degreasing does not have bubbling and cracking defects. After vacuum sintering (i.e. the step five is completed), the radial dimension of the upper half part is contracted by 16.07%, the radial dimension of the lower half part is contracted by 16.93%, the axial dimension is contracted by 17.92%, and the density is more than 98%; the abrasion ratio of the polycrystalline diamond compact obtained after high temperature and high pressure is 38.2 multiplied by 10 ⁴ The average impact toughness was 1097J. According to the scheme, the coverage of the wrapped structure is reduced to the working area of the PDC substrate, so that the original overall multi-material alternating wrapped structure performance is maintained, and meanwhile, the sample manufacturing efficiency is improved.

Example 5 adjustment of the shape of the Soft layer Structure to spherical shape

Adjusting parameters of the globally distributed multi-material alternately-wrapped hard alloy substrate in the third step, YG13 and Al ₂ O ₃ -13Co is alternately arranged in a spherical wrapping type structure in which a single layer of Al is formed ₂ O ₃ The axial thickness of the 13Co layer was 0.1mm, and the axial thickness of the YG13 layer was equal to Al ₂ O ₃ The axial thickness ratio of the-13 Co layer was set to 5:1. By YG13 layer outside, al ₂ O ₃ -13Co layers are arranged in an inner mode, the two materials are alternately and circularly arranged to the core part of the model from outside to inside, and when the last Al layer is arranged ₂ O ₃ After 13Co layers, the mold surplus space may be arranged one layer but not enough two YG13 layers, and the core surplus space is entirely filled with YG 13. Other steps and parameters are unchanged. The abrasion ratio of the prepared polycrystalline diamond compact is 35.7X10 ⁴ The average impact toughness was 1172J.

EXAMPLE 6 adjustment of alumina to cobalt Mass ratio

Al in example 1 ₂ O ₃ The mass ratio of Co is 90:10 weighing and mixing to obtain Al ₂ O ₃ -10Co raw material mixed powder, al ₂ O ₃ The axial thickness of the 13Co layer is 0.1mm, the radial thickness is obtained by the axial thickness of the 13Co layer multiplied by the total diameter/total height of the model, and is 0.2mm; YG13 layer axial thickness and Al ₂ O ₃ The axial thickness ratio of the-13 Co layer is set to be 5:1, and other steps and parameters are unchanged. The prepared PDC green body has regular shape, the size deviation is less than 5 percent, the relative density is 98 percent, and the solvent degreasing does not have bubbling and cracking defects. The radial dimension shrinkage after vacuum sintering is 16.13%, the axial dimension shrinkage is 17.86%, and the microstructure is uniform. After high-temperature high-pressure sintering, the obtained PDC has the abrasion ratio of 37.1 multiplied by 10 ⁴ The average impact toughness was 1033J.

Comparative example 1-verification of insufficient radial impact resistance of simple laminate structure

Step one

Step two

Mass ratio, PW: MW: EO: EVA: HDPE: DOP: SA=47:11:4:15:16:5:2, organic polymer is prepared; the volume ratio of the binder is as follows: YG13 powder = 43:57, binder: al (Al) ₂ O ₃ -13Co mixed powder = 45:55. Respectively heating the powder and the binder in an internal mixer to 145-160 ℃ for uniform mixing, cooling the mixture during the period to ensure that the powder and the organic polymer are fully sheared and kneaded to ensure uniform mixing, and then crushing and screening the cooled internal mixing material to obtain target feeding particlesAnd (3) granulating, wherein the temperature-reducing time is 125-30 min, the total banburying time is 2h, and then feeding the banburying feed into a granulator for granulation to obtain two molding feeds.

Step three

Respectively design YG13 layer and Al ₂ O ₃ -13Co layers from bottom to top and left to right alternating multi-material non-wrapped structural model. The model is YG13 and Al ₂ O ₃ -13Co alternate packing distribution, model size diameter x height is phi 17.6x8.6mm. Wherein a single layer of Al ₂ O ₃ The axial thickness of the 13Co layer is 0.1mm, the radial thickness is obtained by the axial thickness of the 13Co layer multiplied by the total diameter/total height of the model, and is 0.2mm; YG13 layer axial thickness and Al ₂ O ₃ The axial thickness ratio of the-13 Co layer was set to 5:1. By YG13 layer outside, al ₂ O ₃ -13Co layers, the two materials are alternately and circularly arranged from bottom to top (group A) and from left to right (group B) to the other end respectively, and the sample end surface layer is YG13.

Extrusion additive manufacturing and solvent degreasing were then performed according to the steps and parameters described in example 1.

Step four

And (3) placing the degreased green compact into an H2 atmosphere furnace with the flow rate of 50L/min, slowly heating to 550 ℃, and preserving heat for 1H. Continuously heating to 1400 ℃ in a vacuum state, introducing high-pressure Ar2 of 5.8bar, preserving heat for 25min, and then cooling the sample along with a furnace to obtain a group A and a group B non-wrapping structure hard alloy sintered body.

Step five

And (3) carrying out drop hammer impact toughness test on the PDC substrate sintered bodies with the two non-wrapping structures of the group A and the group B obtained in the step four. The impact toughness of the A group (the non-wrapped structure is alternately arranged from top to bottom) of the hard alloy is 1093 and J, B group (the non-wrapped structure is alternately arranged from left to right) of the hard alloy is 726J. The axial impact resistance of the multi-material non-wrapped structure is excellent, but the radial impact resistance is obviously insufficient, and the multi-material non-wrapped structure is not suitable for the complex service environment of the PDC.

In comparative example 1, the impact toughness of an unwrapped structure was tested, the unwrapped structure had strong directionality, the structure distributed in layers from bottom to top exhibited excellent performance in the drop hammer impact toughness test, and the structure distributed from left to right exhibited significant decrease; at this time, the structure from bottom to top represents axial stress, and from left to right represents radial stress.

Comparative example 2 degreasing temperature adjustment

In example 1, step four, the degreasing temperature was adjusted to 70℃in which Al ₂ O ₃ The axial thickness of the 13Co layer is 0.1mm, the radial thickness is obtained by the axial thickness of the 13Co layer multiplied by the total diameter/total height of the model, and is 0.2mm; YG13 layer axial thickness and Al ₂ O ₃ The axial thickness ratio of the-13 Co layer is set to be 5:1, and other steps and parameters are unchanged. The prepared multi-material PDC substrate sintered body green body is bubbling and cracking due to the over-high degreasing rate in the solvent degreasing process. After vacuum sintering, the radial dimension of the sample is shrunk by 17.59%, the axial dimension is shrunk by 19.36%, the dimension shrinkage is slightly increased, and the shape is kept good. The PDC wear ratio obtained after high temperature and high pressure is 36.9X10 ⁴ The impact toughness was 1076J.

Comparative example 3-alumina particle size reduction leads to increased print difficulty;

step one

Preparing commercial YG13 hard alloy powder, alumina powder and Co powder; wherein the alumina powder particle diameter was reduced to 0.5 μm and the Co powder average particle diameter was 1.5 μm as compared with example 1; the WC granularity in the commercial YG13 powder is 1.2-1.6 mu m, and the density is 14.2g/cm3; weighing and mixing alumina and Co according to a mass ratio of 87:13 to obtain Al ₂ O ₃ -13Co mixed powder.

Step two

Mass ratio, PW: MW: EO: EVA: HDPE: DOP: SA=47:11:4:15:16:5:2, organic polymer is prepared; the volume ratio of the binder is as follows: YG13 powder = 43:57, binder: al (Al) ₂ O ₃ -13Co mixed powder = 45:55. And respectively heating the powder and the binder in an internal mixer to 145-160 ℃ for uniform mixing, cooling to ensure that the powder and the organic polymer are fully sheared and kneaded to ensure uniform mixing, crushing and screening the cooled internal mixing material to obtain target feed particles, cooling to 125-30 min for 2h, and granulating the internal mixing feed in a granulator to obtain two molding feeds.

Step three: a globally distributed multi-material alternating wrapped model was designed with model parameters consistent with those described in example 1. And (3) importing the designed multi-material alternate wrapping model with global distribution into corresponding slicing software and an extrusion printer. YG13 and Al ₂ O ₃ -13Co is respectively provided with two extrusion heads corresponding to each other, and printing strategy parameters corresponding to the two extrusion heads are respectively set in software, wherein the size of a nozzle is 0.1mm, the thickness of a layer is 0.1mm, the extrusion temperature is 165 ℃, the filling flow is 90%, the temperature of a printing platform is 80 ℃, the filling speed is 30mm/s, the wiring width is 0.1mm, the single-layer wiring mode is a straight line, and the wiring direction of an upper limit layer is [0, 90 ] ]. Then the YG13 and Al were prepared ₂ O ₃ -13Co feed is placed into two bins of an extrusion type 3D printer respectively, and printing is carried out according to preset parameters.

YG13 prints normally, while Al ₂ O ₃ The 13Co feed was not continuous in the run and was not smooth in extrusion, increasing the extrusion temperature to 175℃and still failing to improve at 100% increase in fill flow, while the feed was not controlled to flow out automatically when the extrusion temperature was adjusted to 180℃due to too high a temperature. When the printing and the blank extrusion are stopped, the screw is rotated for 3-5 seconds to discharge, and the discharged material lines are distributed over obvious holes. This is because the powder has a small particle size, poor compatibility with the feed materials to be dispensed, and is unsuitable for filling with high loadings. The amount of filler and surfactant can be properly adjusted or the powder loading can be reduced.

Comparative example 4-increase in YG13 printing speed, al ₂ O ₃ -13Co mixed powder extrusion temperature

Step one

Step two

Mass ratio, PW: MW: EO: EVA: HDPE: DOP: SA=47:11:4:15:16:5:2, organic polymer is prepared; by volume The ratio is that the adhesive: YG13 powder = 43:57, binder: al (Al) ₂ O ₃ -13Co mixed powder = 45:55. And respectively heating the powder and the binder in an internal mixer to 145-160 ℃ for uniform mixing, cooling to ensure that the powder and the organic polymer are fully sheared and kneaded to ensure uniform mixing, crushing and screening the cooled internal mixing material to obtain target feed particles, cooling to 125-30 min for 2h, and granulating the internal mixing feed in a granulator to obtain two molding feeds.

Step three: designing a globally distributed multi-material alternately-wrapped model of YG13 and Al ₂ O ₃ -13Co alternately coated with Al ₂ O ₃ The 13Co layer is sandwiched between YG13 layers. The dimension diameter x height of the model is phi 17.6x8.6mm. Wherein Al is ₂ O ₃ The axial thickness of the 13Co layer is 0.1mm, the radial thickness is obtained by the axial thickness of the 13Co layer multiplied by the total diameter/total height of the model, and is 0.2mm; YG13 layer axial thickness and Al ₂ O ₃ The axial thickness ratio of the-13 Co layer was set to 5:1. By YG13 layer outside, al ₂ O ₃ -13Co layers are arranged in an inner mode, the two materials are alternately and circularly arranged to the core part of the model from outside to inside, and when the last Al layer is arranged ₂ O ₃ After 13Co layers, the mold surplus space may be arranged one layer but not enough two YG13 layers, and the core surplus space is entirely filled with YG 13.

And (3) importing the designed multi-material alternate wrapping model with global distribution into corresponding slicing software and an extrusion printer. YG13 and Al ₂ O ₃ -13Co feeding is respectively provided with two extrusion heads corresponding to each other, printing strategy parameters corresponding to the two extrusion heads are respectively set in software, the size of a selected nozzle is 0.1mm, the thickness of a layer is 0.1mm, the wiring width is 0.1mm, and the temperature of a printing platform is 80 ℃. The extrusion temperature of the YG13 feed corresponding to the nozzle is 165 ℃, the filling flow is 90%, and the filling speed is 65mm/s; al (Al) ₂ O ₃ 13Co feed was extruded at a temperature of 195℃with a corresponding nozzle, a filling flow of 85% and a filling speed of 30mm/s. The single-layer wiring mode is a straight line, and the upper limit layer wiring direction is 0, 90 DEG]. Then the YG13 and Al were prepared ₂ O ₃ -13Co feed was separately placed into extrusion 3D printingAnd printing according to preset parameters by two bins of the machine.

Due to the too high extrusion temperature, al ₂ O ₃ The 13Co feed was uncontrolled to automatically flow out of the molten filaments from the nozzle and was not printed properly. When the extrusion temperature is reduced to 185 ℃, the diameter of the discharged molten filaments is obviously reduced but still continuously discharged; the uncontrolled outflow is eliminated when the extrusion temperature is continuously reduced to 170 ℃, the nozzle can print normally, and the subsequent operation is carried out normally.

Step four

An inner and outer gradient structure PDC substrate, which was depleted in Co for the outer layer, enriched in Co for the inner layer, and coated on the side and top, was prepared according to the same molding, degreasing, sintering steps and parameters as in example 1, and then placed in a molybdenum cup with diamond-4 wt.% Co powder (4% relative to the total mass of diamond+co) having an average grain size of 10 μm in the order of diamond powder followed by PDC substrate (the top of the prepared gradient structure PDC substrate was contacted with diamond). And assembling NaCl, a carbon tube, pyrophyllite, a conductive sheet and a graphite sheet into a high-temperature high-pressure synthetic block in sequence, and sintering at high temperature and high pressure to obtain the polycrystalline diamond compact. The high-temperature and high-pressure process is 1500-9.0 GPa, and the heat preservation time is 10min, so that the Polycrystalline Diamond Compact (PDC) product is prepared.

The prepared multi-material alternately-wrapped PDC substrate green embryo has regular shape, the size deviation is less than 9 percent, and the solvent degreasing does not have bubbling and cracking defects. The radial dimension shrinkage after vacuum sintering is 17.58%, the axial dimension shrinkage is 18.77%, and the density is about 98%. The substrate size has no obvious change after high temperature and high pressure, the SiC grinding wheel is adopted to carry out abrasion ratio test on the polycrystalline diamond sample, the PDC anti-dynamic load performance tester is adopted to carry out shock resistance detection, and the detection method comprises the following steps: ten tests were started with an impact energy of 20J; if the sample is not damaged (cracked, layered, etc.), the impact energy is increased to 25J, and the test is continued for ten times; if no damage still occurs, the impact energy is lifted to 30 tests for ten times, the test is gradually accumulated until the sample is damaged, the impact energy is multiplied by the impact times, namely the impact energy, and the average value is obtained for five times of test of each layer. The novel PDC wear ratio was 34.2X10 ⁴ Impact toughness was 974J. Due to the filling speed of YG13 corresponding to the nozzleThe degree is large, so that the dimensional accuracy, the relative density and the bonding strength of the green body are reduced to different degrees, and finally, the performance is greatly influenced.

Comparative example 5-set the axial thickness to 0.05, 0.08mm;

step one

Step two

Step three: designing a globally distributed multi-material alternately-wrapped model of YG13 and Al ₂ O ₃ -13Co alternately coated with Al ₂ O ₃ The 13Co layer is sandwiched between YG13 layers. The dimension diameter x height of the model is phi 17.6x8.6mm. Wherein Al is ₂ O ₃ The axial thickness of the 13Co layer was 0.05mm (group a), 0.08mm (group b), the radial thickness being obtained from its axial thickness x the total diameter/total height of the model, 0.2mm; YG13 layer axial thickness and Al ₂ O ₃ The axial thickness ratio of the-13 Co layer was set to 5:1. By YG13 layer outside, al ₂ O ₃ -13Co layers are arranged in an inner mode, the two materials are alternately and circularly arranged to the core part of the model from outside to inside, and when the last Al layer is arranged ₂ O ₃ After 13Co layers, the remaining space of the model can be arranged with one layer but less than two layers of YIn the case of the G13 layer, the core remaining space is entirely filled with YG 13.

And (3) importing the designed multi-material alternate wrapping model with global distribution into corresponding slicing software and an extrusion printer. YG13 and Al ₂ O ₃ -13Co is respectively provided with two extrusion heads corresponding to each other, and printing strategy parameters corresponding to the two extrusion heads are respectively set in software, wherein the size of a nozzle is 0.1mm, the thickness of a layer is 0.1mm, the extrusion temperature is 165 ℃, the filling flow is 90%, the temperature of a printing platform is 80 ℃, the filling speed is 30mm/s, the wiring width is 0.1mm, the single-layer wiring mode is a straight line, and the wiring direction of an upper limit layer is [0, 90 ] ]. Then the YG13 and Al were prepared ₂ O ₃ -13Co feed is placed into two bins of an extrusion type 3D printer respectively, and printing is carried out according to preset parameters.

In the printing process, a and b groups of Al ₂ O ₃ The extrusion wires of the corresponding nozzles of the 13Co layer are not smooth and are distributed in wave-like ripples, the wiring width is also uneven, and the filling flow and the basic temperature are improved to a certain extent after being properly adjusted; however, after the green body is printed to a certain height, the nozzle is easy to scrape the upper layer of melted printing material, so that the green body is lack of material and even deformed, and printing cannot be normally finished; meanwhile, due to the small layer thickness, the green body of group a is slow to print, and is difficult to apply in batches.

Claims

1. A method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive, which is characterized by comprising the following steps of: the multi-material alternately-wrapped PDC substrate comprises a working part; the preparation of the working part of the multi-material alternately-wrapped PDC substrate comprises the following steps:

step one of preparation of soft material feed

Step two, hard alloy feeding preparation

step three two-dimensional structure construction

step four print preparation

step five extrusion printing forming

Extruding and forming according to the preset multi-material alternately-wrapped structural hard alloy green body, and selecting a nozzle with the size of 0.1-0.8mm during extrusion and printing and forming; when in printing, the thickness of the monolayer layer is 0.1-0.2mm, the extrusion temperature is set to 140-180 ℃, the printing platform temperature is set to 70-100 ℃, the filling flow is set to 50-100%, and other condition parameters are respectively as follows: the filling speed is 10-40mm/s, the wiring width is consistent with the size of the nozzle, the upper and lower layers of wiring directions are 0, 90 DEG, and the single-layer wiring mode is one of straight lines, saw teeth and concentric circles;

In the multi-material alternately-wrapped structural hard alloy green body, the axial thickness of the hard layer and the soft layer is not less than 0.1mm, and the radial thickness is more than or equal to the diameter of the nozzle, wherein the relation between the single-layer radial thickness and the axial thickness is as follows: axial thickness = radial thickness x total height/total diameter of the model;

step six, degreasing with solvent

step six, thermal degreasing and vacuum sintering

Placing the composite green body after degreasing in the step five into a vacuum furnace for thermal degreasing, and adopting H with the flow rate of 45-55L/min ₂ Slowly heating to 400-550 ℃ in an atmosphere furnace, and preserving heat for 30-90 min to completely remove the polymer binder. Then continuously heating to 1200-1500 ℃ in a vacuum state, introducing 3-6 bar high-pressure Ar2 for heat preservation for 40-90 min, and then cooling the sample along with the furnaceAnd obtaining the PDC substrate with the multi-material alternately-wrapped structure.

2. The method of extrusion additive manufacturing a multi-material alternating pack PDC substrate of claim 1 wherein: the soft material is ceramic particles, and the metal binder is Co;

The Co content in the soft material feed is 0.95-1.05 times of the Co content in the hard alloy; the ceramic particles are at least one selected from alumina, zirconia and yttria.

3. The method of extrusion additive manufacturing a multi-material alternating pack PDC substrate of claim 1 wherein: the particle size of the soft particles is 0.8-2.5 μm, preferably 1-2 μm; the granularity of Co powder mixed with the powder is 0.8 to 1.2 times of soft particle granularity.

4. A method of extrusion additive manufacturing a multi-material alternating pack PDC substrate of claim 2 wherein: in the soft layer, the proportion of the ceramic particles and Co is less than or equal to the content of Co in the hard alloy.

5. The method of extrusion additive manufacturing a multi-material alternating pack PDC substrate of claim 1 wherein: the powder particle size of the cemented carbide is 0.5-3 μm, preferably 1.2-2.5 μm.

6. The method of extrusion additive manufacturing a multi-material alternating pack PDC substrate of claim 1 wherein: the organic polymer adhesive is prepared from PW, MW, EO, EVA, HDPE, DOP, SA and PW by mass ratio: MW: EO: EVA: HDPE: DOP: sa=47:11:4:15:16:5:2.

7. The method of extrusion additive manufacturing a multi-material alternating pack PDC substrate of claim 1 wherein: the equivalent diameter of the hard alloy core is 1-2 times of the radial thickness of other hard alloy layers coated on the soft material,

the ratio of the axial thickness of the single-layer hard alloy layer to the axial thickness of the single-layer soft material is 3-6:1 except the core material.

8. An application of a method for manufacturing a multi-material alternately-wrapped PDC substrate by extrusion type additive, which is characterized in that: the method comprises the steps of assembling a working part in the prepared multi-material alternately-wrapped PDC substrate sintered body and a polycrystalline diamond layer into a high-temperature high-pressure synthetic block, and placing the high-temperature high-pressure synthetic block in a hexahedral press for high-temperature high-pressure synthesis. The synthesis process comprises the following steps: 5-7.5GPa, preferably 6-7GPa, temperature: 1400-1700 ℃, preferably 1450-1550 ℃.

9. The use of a method of extrusion additive manufacturing multi-material alternating pack PDC substrates of claim 8 wherein: after the obtained substrate is compounded with diamond, the PDC abrasion ratio of the product is more than or equal to 37.1 multiplied by 10 ⁴ The average impact toughness is 972J or more.

10. The use of a method of extrusion additive manufacturing multi-material alternating pack PDC substrates of claim 8 wherein: after the obtained substrate is compounded with diamond, the PDC abrasion ratio of the product is more than or equal to 37.4 multiplied by 10 ⁴ The average impact toughness is 1097J or more.