阅读说明：本技术 一种聚晶金刚石复合片及其制备方法 (Polycrystalline diamond compact and preparation method thereof ) 是由 宇佳莉 黄继庆 樊思成 于 2021-06-25 设计创作，主要内容包括：本发明提供了一种聚晶金刚石复合片及其制备方法,所述聚晶金刚石复合片包括硬质合金基体层,以及覆盖于所述硬质合金基体层端面的聚晶金刚石层,其中,所述聚晶金刚石层包括靠近所述硬质合金基体层端面的内层和远离所述硬质合金基体层端面的外层,所述内层边缘形成的圆的直径大于等于所述硬质合金基体圆柱直径,所述外层边缘形成的圆的直径小于所述硬质合金基体圆柱的直径。本发明通过将聚晶金刚石复合片的聚晶金刚石层设计为多层结构,通过调整聚晶金刚石层的直径,使得在对所述聚晶金刚石复合片进行磨削加工时,可以实现良好的加工精度,满足聚晶金刚石复合片能够装配进高精度配合的钻头,进一步提高聚晶金刚石复合片的使用寿命。(The invention provides a polycrystalline diamond compact and a preparation method thereof, the polycrystalline diamond compact comprises a hard alloy matrix layer and a polycrystalline diamond layer covering the end face of the hard alloy matrix layer, wherein the polycrystalline diamond layer comprises an inner layer close to the end face of the hard alloy matrix layer and an outer layer far away from the end face of the hard alloy matrix layer, the diameter of a circle formed at the edge of the inner layer is larger than or equal to the diameter of a hard alloy matrix cylinder, and the diameter of a circle formed at the edge of the outer layer is smaller than the diameter of the hard alloy matrix cylinder. According to the invention, the polycrystalline diamond layer of the polycrystalline diamond compact is designed into a multilayer structure, and the diameter of the polycrystalline diamond layer is adjusted, so that good processing precision can be realized during grinding of the polycrystalline diamond compact, the polycrystalline diamond compact can be assembled into a drill bit with high-precision fit, and the service life of the polycrystalline diamond compact is further prolonged.)

1. A polycrystalline diamond compact, comprising:

the hard alloy substrate layer and the polycrystalline diamond layer are covered on the end face of the hard alloy substrate layer, wherein the polycrystalline diamond layer comprises an inner layer close to the end face of the hard alloy substrate layer and an outer layer far away from the end face of the hard alloy substrate layer, the diameter of a circle formed at the edge of the inner layer is larger than or equal to the diameter of a hard alloy substrate cylinder, and the diameter of the circle formed at the edge of the outer layer is smaller than the diameter of the hard alloy substrate cylinder.

2. The polycrystalline diamond compact of claim 1, wherein the inner layer completely covers the end surface of the cemented carbide substrate layer, and the outer layer partially covers the inner layer; the inner layer and the outer layer both comprise at least one layer of polycrystalline diamond.

3. The polycrystalline diamond compact of claim 2, wherein the ratio of the diameter of the circle formed by the outer layer edge to the diameter of the cemented carbide cylinder is 50-99.9%.

4. A polycrystalline diamond compact according to claim 2, wherein the polycrystalline diamond layer is composed of diamond powder, a binder, and tungsten carbide powder.

5. A polycrystalline diamond compact according to claim 4, wherein the binder is one or more of Ni, Co, Ti, or an alloy containing at least one of the foregoing elements.

6. The polycrystalline diamond compact of claim 4, wherein the first and second polycrystalline diamond compacts are formed, in parts by weight,

the outer layer includes: 60% -90% of diamond powder, 5% -40% of tungsten carbide and 4% -10% of binder;

the inner layer includes: 10-40% of diamond powder, 60-80% of tungsten carbide and 8-15% of binder.

7. A polycrystalline diamond compact according to claim 4, wherein the diamond powder particles of the outer layer have a particle size of 1 to 20 μm and the diamond powder particles of the inner layer have a particle size of 5 to 40 μm.

8. A polycrystalline diamond compact according to claim 1, wherein the end face of the polycrystalline diamond layer is one or more of a flat face, a spherical face, a convex mesa, a conical face.

9. A method of making a polycrystalline diamond compact according to any one of claims 1 to 8, comprising the steps of:

uniformly mixing diamond powder, a binder and tungsten carbide powder, and filling the mixed powder into a metal cup in layers;

molding the powder in the metal cup, and then filling a hard alloy matrix above the mixed powder in the metal cup to obtain an assembled metal cup component;

vacuum treating the assembled metal cup assembly at a first predetermined temperature for a first predetermined time;

placing the treated metal cup sleeve in a synthetic membrane, and sintering the synthetic membrane in high-temperature and high-pressure equipment at a second preset temperature for a second preset time;

and removing the metal cup, and processing to a target size to obtain the polycrystalline diamond compact.

10. The method of preparing a polycrystalline diamond compact according to claim 9, wherein the first predetermined temperature is 600-800 ℃; the second predetermined temperature is 1300-1500 ℃; the first preset time is 2-10 h; the second preset time is 5-10 min.

Technical Field

The invention relates to the field of drilling tools and superhard materials, in particular to a polycrystalline diamond compact and a preparation method thereof.

Background

The polycrystalline diamond compact is formed by sintering diamond powder and a hard alloy matrix through a binder at high temperature and high pressure. The diamond layer has the characteristics of high hardness, high wear resistance and self-sharpening property, and provides a powerful breakthrough effect for crushing and grinding rocks. However, the composite sheet with high wear resistance is easy to generate the phenomena of large excircle of the diamond layer and small excircle of the hard alloy layer during excircle grinding processing, so that the problems of large excircle processing difficulty and poor precision are caused. When the polycrystalline diamond compact is installed into the drill bit, if the compact and the drill bit mounting hole can not be tightly matched, the service life of the compact can be influenced, and even the compact can directly fail.

Therefore, the prior art has defects and needs to be improved and developed.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a polycrystalline diamond compact and a preparation method thereof, and aims to solve the problem that the service life of the compact is short or the compact fails because the conventional polycrystalline diamond compact cannot be tightly matched with a drill bit mounting hole.

In order to solve the above technical problems, the technical solution adopted by the present invention to solve the above technical problems is as follows:

a polycrystalline diamond compact, comprising:

the hard alloy substrate layer and the polycrystalline diamond layer are covered on the end face of the hard alloy substrate layer, wherein the polycrystalline diamond layer comprises an inner layer close to the end face of the hard alloy substrate layer and an outer layer far away from the end face of the hard alloy substrate layer, the diameter of a circle formed at the edge of the inner layer is larger than or equal to the diameter of a hard alloy substrate cylinder, and the diameter of the circle formed at the edge of the outer layer is smaller than the diameter of the hard alloy substrate cylinder.

The polycrystalline diamond compact is characterized in that the inner layer completely covers the end face of the hard alloy substrate layer, the outer layer partially covers the inner layer, and the inner layer and the outer layer both comprise at least one layer of polycrystalline diamond.

The polycrystalline diamond compact is characterized in that the ratio of the diameter of a circle formed at the edge of the outer layer to the diameter of the hard alloy cylinder is 50% -99.9%.

The polycrystalline diamond compact is characterized in that the polycrystalline diamond layer is composed of diamond powder, a binder and tungsten carbide powder.

The polycrystalline diamond compact is characterized in that the binder is one or more of Ni, Co and Ti, or an alloy containing at least one of the Ni, Co and Ti.

The polycrystalline diamond compact comprises, by weight,

the outer layer includes: 60% -90% of diamond powder, 5% -40% of tungsten carbide and 4% -10% of binder;

the inner layer includes: 10-40% of diamond powder, 60-80% of tungsten carbide and 8-15% of binder.

The polycrystalline diamond compact is characterized in that the grain size of the diamond powder particles on the outer layer is 1-20 microns, and the grain size of the diamond powder particles on the inner layer is 5-40 microns.

The polycrystalline diamond compact is characterized in that the end face of the polycrystalline diamond layer is one or more of a plane, a spherical surface, a convex table surface and a conical surface.

The preparation method of the polycrystalline diamond compact comprises the following steps:

uniformly mixing diamond powder, a binder and tungsten carbide powder, and filling the mixed powder into a metal cup in layers;

molding the powder in the metal cup, and then filling a hard alloy matrix above the mixed powder in the metal cup to obtain an assembled metal cup component;

vacuum treating the assembled metal cup assembly at a first predetermined temperature for a first predetermined time;

placing the treated metal cup sleeve in a synthetic membrane, and sintering the synthetic membrane in high-temperature and high-pressure equipment at a second preset temperature for a second preset time;

and removing the metal cup, and processing to a target size to obtain the polycrystalline diamond compact.

The preparation method of the polycrystalline diamond compact comprises the following steps of, wherein the first preset temperature is 600-800 ℃; the second predetermined temperature is 1300-1500 ℃; the first preset time is 2-10 h; the second preset time is 5-10 min.

Has the advantages that: the invention provides a polycrystalline diamond compact and a preparation method thereof, the polycrystalline diamond compact comprises a hard alloy matrix layer and a polycrystalline diamond layer covering the end face of the hard alloy matrix layer, wherein the polycrystalline diamond layer comprises an inner layer close to the end face of the hard alloy matrix layer and an outer layer far away from the end face of the hard alloy matrix layer, the diameter of a circle formed at the edge of the inner layer is larger than or equal to the diameter of a hard alloy matrix cylinder, and the diameter of a circle formed at the edge of the outer layer is smaller than the diameter of the hard alloy matrix cylinder. According to the invention, the polycrystalline diamond layer of the polycrystalline diamond compact is designed into a multilayer structure, and the diameter of the polycrystalline diamond layer is adjusted, so that good processing precision can be realized during grinding of the polycrystalline diamond compact, the polycrystalline diamond compact can be assembled into a drill bit with high-precision fit, and the service life of the polycrystalline diamond compact is further prolonged.

Drawings

Fig. 1 is a diagram of a polycrystalline diamond compact button according to an embodiment of the present disclosure.

Fig. 2 is a schematic diagram of a polycrystalline diamond compact button layer provided in an embodiment of the invention.

Fig. 3 is a spherical edge view of a polycrystalline diamond compact provided in accordance with an embodiment of the present disclosure.

Fig. 4 is a front view of a polycrystalline diamond compact tapered tooth provided by an embodiment of the present disclosure.

Fig. 5 is a schematic layered view of a polycrystalline diamond compact tapered tooth provided in accordance with an embodiment of the present disclosure.

Fig. 6 is an edge view of a polycrystalline diamond compact tapered tooth provided by an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The polycrystalline diamond compact is formed by sintering diamond powder and a hard alloy matrix through a binder at high temperature and high pressure. The diamond layer has the characteristics of high hardness, high wear resistance and self-sharpening property, and provides a powerful breakthrough effect for crushing and grinding rocks. However, the composite sheet with high wear resistance is easy to generate the phenomena of large excircle of the diamond layer and small excircle of the hard alloy layer during excircle grinding processing, so that the problems of large excircle processing difficulty and poor precision are caused. When the polycrystalline diamond compact is installed into the drill bit, if the compact and the drill bit mounting hole can not be tightly matched, the service life of the compact can be influenced, and even the compact can directly fail.

Based on this, the present invention provides a polycrystalline diamond compact comprising:

the hard alloy substrate layer and the polycrystalline diamond layer are covered on the end face of the hard alloy substrate layer, wherein the polycrystalline diamond layer comprises an inner layer close to the end face of the hard alloy substrate layer and an outer layer far away from the end face of the hard alloy substrate layer, the diameter of a circle formed at the edge of the inner layer is larger than or equal to the diameter of a hard alloy substrate cylinder, and the diameter of the circle formed at the edge of the outer layer is smaller than the diameter of the hard alloy substrate cylinder.

Specifically, the polycrystalline diamond layer of the polycrystalline diamond composite sheet is designed into a multilayer structure, and the diameter of the polycrystalline diamond layer is adjusted, so that the hard alloy matrix layer is not ground more due to the fact that the hardness of the diamond layer is far greater than that of the hard alloy matrix layer when the polycrystalline diamond composite sheet is ground with the same machining force, and the finally machined polycrystalline diamond composite sheet is poor in size precision.

In this embodiment, the inner layer completely covers the end face of the cemented carbide substrate layer, and the outer layer partially covers the inner layer. Meanwhile, the inner layer and the outer layer both comprise at least one layer of polycrystalline diamond.

The polycrystalline diamond compact adopts a unique structural design, namely the polycrystalline diamond layer covering the section of the hard alloy matrix layer is arranged into a plurality of layers, specifically, the polycrystalline diamond layer is arranged into an inner layer which is close to and completely covers the end face of the hard alloy matrix layer and an outer layer which is far away from the end face of the hard alloy matrix layer and partially covers the inner layer, meanwhile, the multilayer structure of the polycrystalline diamond layer can be double layers, three layers or even more, so that the inner layer can be arranged into single-layer polycrystalline diamond or multi-layer polycrystalline diamond, the outer layer can also be arranged into single-layer polycrystalline diamond or multi-layer polycrystalline diamond, the polycrystalline diamond compact can more accurately control the machining size through the multilayer structural design, the thickness of the inner layer is small generally, the influence on the size precision is small, and the outer layer is a main factor influencing the machining precision of the polycrystalline diamond compact, consequently, through carrying out the layering to polycrystalline diamond's structure, reduce outer size and can realize good machining precision, so that work as when polycrystalline diamond compact is installed into the drill bit, polycrystalline diamond compact can realize closely cooperating with the drill bit mounting hole, thereby further ensure polycrystalline diamond compact's life, and make polycrystalline diamond compact can be applicable to the processing of special-shaped terminal surface more.

Specifically, in some embodiments, the ratio of the diameter of the circle formed by the outer layer edge to the diameter of the cemented carbide cylinder is 50% to 99.9%.

In this embodiment, the polycrystalline diamond layer is composed of diamond powder, a binder, and tungsten carbide powder.

Specifically, a polycrystalline diamond compact is generally prepared by sintering and bonding fine diamond particles together in a flow manner on a substrate of sintered tungsten carbide under high temperature and high pressure with the aid of a catalyst material as a binder, wherein the sintered tungsten carbide with the catalyst material as the binder exists as a supporting substrate; in the high-temperature and high-pressure sintering process, the catalyst material in the sintered tungsten carbide substrate can diffuse into the middle of the Diamond particles and can promote the bonding between the Diamond particles as a catalyst, and the Diamond particles are bonded with the Diamond particles through bonds, namely, the Diamond-to-Diamond bonds, which are called D-D bonds for short, so that the polycrystalline Diamond layer is finally formed.

In some embodiments, the catalyst material is one or more of Ni, Co, Ti, or an alloy containing at least one of the foregoing elements, but is not limited thereto.

Specifically, the catalyst material is usually selected from metal, the metal catalyst material can promote graphitization of diamond, and can enable the prepared polycrystalline diamond to have better thermal stability and maintain the original good impact resistance under the condition of proper addition amount, and the finally prepared polycrystalline diamond compact has excellent comprehensive performance and is greatly successful in cutting application, so that the catalyst material is widely applied to various cutting tools.

Further, in some embodiments, the polycrystalline diamond compact of the present disclosure, the outer layer comprises, in parts by weight: 60% -90% of diamond powder, 5% -40% of tungsten carbide and 4% -10% of catalyst material; the inner layer includes: 10% -40% of diamond powder, 60% -80% of tungsten carbide and 8% -15% of catalyst material.

Specifically, the inner layer can be more conveniently processed while the characteristics of high hardness, high wear resistance, self-sharpening property and the like of the polycrystalline diamond compact are maintained by controlling the diamond component contents of the inner layer and the outer layer, the diamond layer of the polycrystalline diamond compact is more difficult to process and has poorer precision when being ground due to the wear resistance of diamond powder, so that the matching tightness degree of the polycrystalline diamond compact and a drill bit mounting hole can be influenced, and the service life of the polycrystalline diamond compact is influenced High wear resistance and self-sharpening.

In some embodiments, the polycrystalline diamond layer has diamond particles sized between 5 and 20 μm, the outer layer has diamond powder particles sized between 1 and 20 μm, and the inner layer has diamond powder particles sized between 5 and 40 μm.

In some embodiments, in order to make the polycrystalline diamond compact applicable to a plurality of drill bits, the end surface of the hard alloy substrate layer coated with the polycrystalline diamond layer may be a plane, a spherical surface, a convex table surface, a conical surface or other irregular shapes, and the polycrystalline diamond layer is correspondingly shaped and covered on the hard alloy substrate layer according to the end surface shape of the hard alloy substrate layer.

The invention also provides a preparation method of the polycrystalline diamond compact, which specifically comprises the following steps:

s100, uniformly mixing diamond powder, a binder and tungsten carbide powder, and filling the mixed powder into a metal cup in a layered manner;

s200, molding the powder in the metal cup, and then filling a hard alloy matrix above the mixed powder in the metal cup to obtain an assembled metal cup assembly;

s300, carrying out vacuum treatment on the assembled metal cup assembly at a first preset temperature for a first preset time;

s400, placing the processed metal cup sleeve in a synthetic membrane, and sintering the synthetic membrane in high-temperature and high-pressure equipment at a second preset temperature for a second preset time;

and S500, removing the metal cup, and processing to a target size to obtain the polycrystalline diamond compact.

Specifically, the first predetermined temperature is 600-; the second predetermined temperature is 1300-1500 ℃; the first preset time is 2-10 h; the second preset time is 5-10 min; the synthetic membrane is made of pyrophyllite.

The present invention will be described in detail below with reference to examples.

Example 1

As shown in fig. 1 to 3, the polycrystalline diamond compact button for the down-the-hole drill includes a cemented carbide substrate 20 and a polycrystalline diamond layer 10 attached to an upper end of the cemented carbide substrate 20: wherein, one end face of the hard alloy matrix 20 is a spherical surface; the polycrystalline diamond layer 10 is two layers: the hard alloy base body comprises an outer layer 101 and an inner layer 102, wherein the outer layer 101 covers the spherical end of the hard alloy base body partially, and the inner layer 102 covers the spherical end completely; the outer layer 101 has a much higher wear resistance than the inner layer 102, and the inner layer 102 has a slightly higher wear resistance than the cemented carbide substrate 20.

As shown in fig. 2, which is a schematic layered view of a polycrystalline diamond compact button provided in an embodiment of the present invention, it can be seen that one end surface of the cemented carbide substrate 20 is a spherical surface; the polycrystalline diamond layer 10 is a bilayer: an outer layer 101 and an inner layer 102.

As shown in fig. 3, which is a spherical edge diagram of the polycrystalline diamond compact provided by the embodiment of the present invention, it can be seen that a difference distance D between the edge of the inner layer 102 and the edge of the outer layer 101 is larger than 0, and D is larger than D.

The preparation method of the polycrystalline diamond composite spherical tooth comprises the following steps;

uniformly mixing diamond particles, a binder and tungsten carbide powder by ball milling through a ball mill, introducing hydrogen into the mixture at the rotating speed of 160r/min at the temperature of 800 ℃ for reduction for 100min, and filling the powder into spherical metal cups made of zirconium or niobium in a layered manner;

molding the powder by using a tool, and then filling a hard alloy matrix above the mixed powder of the metal cup to obtain an assembled metal cup assembly;

carrying out vacuum treatment on the assembled metal cup kit for 6 hours at 750 ℃;

placing the vacuum-treated metal cup kit in a synthetic membrane made of pyrophyllite, and sintering in high-pressure high-temperature equipment at 7.5GPa and 1450 deg.C for 6 min;

and after sintering, releasing pressure, cooling, taking out the polycrystalline diamond compact, removing the metal cup, and processing to a target size to obtain the polycrystalline diamond compact.

Example 2

As shown in fig. 4 to 6, the polycrystalline diamond composite tapered tooth for a down-the-hole drill includes a cemented carbide substrate 20 and a polycrystalline diamond layer 30 attached to an upper end of the cemented carbide substrate 20: wherein, one end surface of the hard alloy matrix 20 is a conical surface; the polycrystalline diamond layer 30 is two layers: the outer layer 301 and the inner layer 302 cover the conical end of the cemented carbide substrate, and are also in the shape of a conical surface, wherein the outer layer 301 is partially covered, and the inner layer 302 is completely covered; the outer layer 301 has a much higher wear resistance than the inner layer 302, and the inner layer 302 has a slightly higher wear resistance than the cemented carbide substrate 20.

As shown in fig. 5, which is a schematic layered view of a polycrystalline diamond compact (pdc) cone tip tooth provided in an embodiment of the present invention, it can be seen that one end surface of the cemented carbide substrate 20 is a conical surface; the polycrystalline diamond layer 30 is a double layer: an outer layer 301 and an inner layer 302.

As shown in fig. 6, which is a spherical edge diagram of the polycrystalline diamond compact provided by the embodiment of the present invention, it can be seen that a difference distance D between the edge of the inner layer 302 and the edge of the outer layer 301 is larger than 0, and D is larger than D.

The preparation method of the polycrystalline diamond compact tapered teeth comprises the following steps;

uniformly mixing diamond particles, a binder and tungsten carbide powder by ball milling through a ball mill, introducing hydrogen into the mixture at the rotating speed of 160r/min at the temperature of 800 ℃ for reduction for 100min, and filling the powder into conical metal cups made of zirconium or niobium in a layered manner;

molding the powder by using a tool, and then filling a hard alloy matrix above the mixed powder of the metal cup to obtain an assembled metal cup assembly;

carrying out vacuum treatment on the assembled metal cup kit for 6 hours at 750 ℃;

placing the vacuum-treated metal cup kit in a synthetic membrane made of pyrophyllite, and sintering in high-pressure high-temperature equipment at 7.5GPa and 1450 deg.C for 6 min;

and after sintering, releasing pressure, cooling, taking out the polycrystalline diamond compact, removing the metal cup, and processing to a target size to obtain the polycrystalline diamond compact.

In summary, the invention provides a polycrystalline diamond compact and a preparation method thereof, the polycrystalline diamond compact comprises a hard alloy substrate layer and a polycrystalline diamond layer covering the end face of the hard alloy substrate layer, wherein the polycrystalline diamond layer is of a multilayer structure. According to the invention, the polycrystalline diamond layer of the polycrystalline diamond compact is designed into a multilayer structure, and corresponding components and structures are set for the inner layer and the outer layer of the polycrystalline diamond layer, so that good processing precision can be realized, the polycrystalline diamond compact can be assembled into a drill bit with high precision, the service life of the polycrystalline diamond compact is further prolonged, and meanwhile, the inner layer of the polycrystalline diamond compact can be processed more easily.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.