CA2768933A1 - Surface-modified polycrystalline diamond and processing method thereof - Google Patents
Surface-modified polycrystalline diamond and processing method thereof Download PDFInfo
- Publication number
- CA2768933A1 CA2768933A1 CA2768933A CA2768933A CA2768933A1 CA 2768933 A1 CA2768933 A1 CA 2768933A1 CA 2768933 A CA2768933 A CA 2768933A CA 2768933 A CA2768933 A CA 2768933A CA 2768933 A1 CA2768933 A1 CA 2768933A1
- Authority
- CA
- Canada
- Prior art keywords
- polycrystalline diamond
- holes
- diamond body
- catalyst metal
- modified
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/24—After-treatment of workpieces or articles
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C26/00—Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Polishing Bodies And Polishing Tools (AREA)
- Catalysts (AREA)
Abstract
A surface-modified polycrystalline diamond and a processing method thereof are provided in the present disclosure. The polycrystalline diamond comprises a polycrystalline diamond body, holes are formed on the polycrystalline diamond body after a catalyst metal is removed, and the holes are embedded with a non-catalyst metal.
According to the surface-modified polycrystalline diamond and the processing method thereof of the present disclosure, the catalyst metal is removed from the polycrystalline diamond body, and the non-catalyst metal is embedded into the holes that are formed in a surface of the polycrystalline diamond after the catalyst metal is removed therefrom. Thus, thermal damage and stress damage to the polycrystalline diamond during operations at a high temperature are eliminated, improve the thermal conductivity of the surface of the polycrystalline diamond, reduce the temperature of the area around the operating point of the polycrystalline diamond and, therefore, the service life of the polycrystalline diamond is prolonged.
According to the surface-modified polycrystalline diamond and the processing method thereof of the present disclosure, the catalyst metal is removed from the polycrystalline diamond body, and the non-catalyst metal is embedded into the holes that are formed in a surface of the polycrystalline diamond after the catalyst metal is removed therefrom. Thus, thermal damage and stress damage to the polycrystalline diamond during operations at a high temperature are eliminated, improve the thermal conductivity of the surface of the polycrystalline diamond, reduce the temperature of the area around the operating point of the polycrystalline diamond and, therefore, the service life of the polycrystalline diamond is prolonged.
Description
SURFACE-MODIFIED POLYCRYSTALLINE DIAMOND AND PROCESSING
METHOD THEREOF
FIELD OF INVENTION
[00011 The present disclosure relates to improvement of properties of polycrystalline diamonds, and more particularly, to a surface-modified polycrystalline diamond and a processing method thereof.
BACKGROUD OF INVENTION
[00021 Polycrystalline diamond compacts (briefly called PDCs) are made from a diamond powder incorporating a certain amount of sintering aids therein and a cemented carbide substrate , which are assembled together and then sintered on a special diamond hydraulic press at an high temperature under an ultra-high pressure. A PDC is composed of a polycrystalline diamond layer and the cemented carbide substrate .
Because the polycrystalline diamond layer has high hardness and good wear resistance and the substrate is excellent in toughness and weldability, the PDCs are widely applied in the fields of oil drilling, geological drilling, coal field exploitation, cutting, and so on.
[00031 When PDCs or integrated polycrystalline diamonds are manufactured, cobalt, nickel, or iron is usually used as the sintering aids to sinter the diamond powder at an high temperature under an ultra-high pressure. The most common catalyst metal is cobalt or an alloy thereof, and the common pressure for sintering at an high temperature under an ultra-high pressure is 4.5 GPa to 6 GPa. Under this condition, the aforesaid sintering aids need to be used so that the diamond particles can be directly sintered with each other to form a diamond-diamond (D-D) combination structure, thereby achieving a polycrystalline diamond layer having excellent properties. The microstructure of the polycrystalline diamond consists of a diamond phase having frameworks connected with each other and a dispersed islet-shaped metal phase.
[00041 After the diamond particles are sintered into the frameworks, the properties of 22205305.2 1 the entire polycrystalline diamond totally depend on the combination of the diamond frameworks. The greater the diamond particles are combined with each other and the larger the combination area is, the better the strength and wear resistance of the polycrystalline diamond will be. The strength is substantially unrelated to the metal phase dispersed in interstices between the frameworks. On the contrary, existence of iron group metal phases is detrimental to the performance of the polycrystalline diamond, including causing thermal damage and stress damage to the performance of the polycrystalline diamond.
[0005] When the PDC operates as a tool, there is often very high operating temperature around the operating point where the PDC contacts with a workpiece, and the temperature may be about 700 C to 800 C, or even over 1000 C at some points. As shown by researches, cobalt, nickel or iron, which is used as a catalyst metal for catalyzing transformation of graphite into the diamond under a high pressure, also catalyzes transformation of the diamond into graphite under the normal pressure.
Consequently, the iron group metal phase in the PDC can degrade the wear resistance of the PDC
to some extent depending on different high temperatures at operating points, thereby causing a thermal damage.
[0006] A thermal expansion coefficient of the diamond is only one tenth of cobalt.
When the operating temperate is very high, the cobalt phase expands to an extent much greater than that of the diamond frameworks, thereby generating a thermal stress. After reaching a certain value, the thermal stress will destroy the diamond frameworks to cause cracks in the polycrystalline diamond, thereby leading to a stress damage.
[0007] Accordingly, the structure of the existing polycrystalline diamond body and the method of processing the polycrystalline diamond body in the art need further improvement and enhancement.
22205305.2 2 SUMMARY OF THE INVENTION
[0008] In view of the shortcomings of the prior art, an objective of the present disclosure is to provide a surface-modified polycrystalline diamond and a processing method thereof, in which a catalyst metal is removed from a polycrystalline diamond body to form holes and a non-catalyst metal having a high thermal conductivity is embedded into the holes. Thus, thermal damage and stress damage to the polycrystalline diamond body during operations at a high temperature are eliminated.
[0009] To achieve the aforesaid objective, the present disclosure provides the following technical solutions:
[0010] A surface-modified polycrystalline diamond, which comprises a polycrystalline diamond body, wherein holes are formed on the polycrystalline diamond body after a catalyst metal is removed, and the holes are embedded with a non-catalyst metal.
[0011] The surface-modified polycrystalline diamond, wherein the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof.
[0012] The surface-modified polycrystalline diamond, wherein each of the holes has a depth of 0.1 mm to 1 mm.
[0013] The present disclosure further provides a method of processing a surface-modified polycrystalline diamond, which comprises the following steps of:
[0014] removing a catalyst metal from a surface of the polycrystalline diamond body and forming holes in the surface of the polycrystalline diamond body; and [0015] embedding a non-catalyst metal into the holes.
[0016] The method of processing a surface-modified polycrystalline diamond, wherein the steps of removing the catalyst metal from the surface of the polycrystalline diamond body and forming the holes in the surface of the polycrystalline diamond body comprise:
[0017] boiling the polycrystalline diamond body in an aqua regia for 20 to 60 hours;
and [0018] taking the polycrystalline diamond body out of the aqua regia and rinsing the 22205305.2 3 polycrystalline diamond body until the polycrystalline diamond body becomes neutral.
[00191 The method of processing a surface-modified polycrystalline diamond, wherein the steps of embedding the non-catalyst metal into the holes comprise:
[00201 putting a copper wheel rotating at a rotating speed of 1400 revolutions per second (rps) into contact with the surface of the polycrystalline diamond body; and 100211 feeding the copper wheel by 0.1 mm to 0.4 mm for strong friction so that the surface of the polycrystalline diamond body is covered by copper.
[00221 The method of processing a surface-modified polycrystalline diamond, wherein the polycrystalline diamond body is boiled in the aqua regia for 10 to 110 hours; and the polycrystalline diamond body is taken out of the aqua regia and rinsed until the polycrystalline diamond body becomes neutral.
[00231 The method of processing a surface-modified polycrystalline diamond, wherein the step of embedding the non-catalyst metal into the holes comprises: placing the polycrystalline diamond body into a copper mould for electrodeposition, with the mould being used as a cathode, a copper sulfate solution being used as an electrolyte, and a pure copper plate being used as an anode.
[00241 The method of processing a surface-modified polycrystalline diamond, wherein the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof.
[00251 The method of processing a surface-modified polycrystalline diamond, wherein each of the holes has a depth of 0.1 mm to 1 mm.
[00261 According to the surface-modified polycrystalline diamond and the processing method thereof provided in the present disclosure, the catalyst metal is removed from the polycrystalline diamond body, and the non-catalyst metal is embedded into the holes formed in the surface of the polycrystalline diamond after the catalyst metal is removed.
Thus, thermal damage and stress damage to the polycrystalline diamond during operations at a high temperature are eliminated and, therefore, the service life of the polycrystalline diamond is prolonged.
22205305.2 4 BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Fig. 1 is a schematic structural view of a polycrystalline diamond according to an embodiment of the present disclosure;
[0028] Fig. 2 is a schematic structural view of the polycrystalline diamond according to an embodiment of the present disclosure after a catalyst metal is removed therefrom; and [0029] Fig. 3 is a flowchart diagram of a method of processing the polycrystalline diamond according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0030] The present disclosure provides a surface-modified polycrystalline diamond and a processing method thereof. To make the objectives, technical solutions, and efficacies of the present disclosure clearer, the present disclosure will be further described hereinbelow with reference to the attached drawings and embodiments thereof. It shall be understood that, the embodiments described herein are only intended to illustrate but not to limit the present disclosure.
[0031] Referring to Fig. 1 and Fig. 2, a surface-modified polycrystalline diamond according to an embodiment of the present disclosure comprises a polycrystalline diamond body 11 installed on a cemented carbide matrix 21. A plurality of holes 111 are formed on the polycrystalline diamond body 11 after a catalyst metal is removed therefrom, and the holes 111 are embedded with a non-catalyst metal.
[0032] The catalyst metal is one of iron, cobalt, and nickel, and the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof. Each of the holes 111 preferably has a depth of 0.1 mm to 1 mm; that is, only the catalyst metal at the depth of 0.1 mm to 1 mm from a surface of the polycrystalline diamond body 11 is removed in the present disclosure. According to the present disclosure, the holes 111 are formed in the surface of the polycrystalline diamond body 11 after iron, cobalt, or nickel is removed;
and then 22205305.2 5 copper, silver, or aluminum is embedded into the holes 111. In this way, the heat resistance of the polycrystalline diamond is improved and, thus, the service life of the polycrystalline diamond is prolonged.
[0033] None of copper, silver, and aluminum is a catalyst metal of the synthetic diamond and can catalyze reverse transformation of the diamond into graphite.
Copper has a thermal conductivity of 397 W/mK, silver has a thermal conductivity of 429 W/mK, aluminum has a thermal conductivity of 217 W/mK, and cobalt has a thermal conductivity of only 96 W/mK. Replacing cobalt, nickel, or iron with one of copper, silver, aluminum, and alloys thereof is beneficial to improvement of the overall thermal conductivity of the polycrystalline diamond, and this makes it easier to dissipate heat from the surface of the polycrystalline diamond body 11 so that the operating temperature at the operating point of the polycrystalline diamond body 11 can be reduced.
[0034] In this embodiment, although the thermal conductivity of silver is slightly higher than that of copper, silver is much expensive than copper. Therefore, copper or an alloy thereof is preferably used in the present disclosure to replace cobalt.
Another choice is to use aluminum or an alloy thereof. Specifically, aluminum has a low melting point, so it is easier to embed aluminum into the holes 111; and additionally, at the operating point under a temperature above 700 C, the molten aluminum will overflow from the surface, thereby achieving the purpose of heat dissipation through "sweating".
Therefore, in this embodiment of the present disclosure, the non-catalyst metal having a high thermal conductivity is adopted to replace cobalt, nickel, and iron so as to eliminate thermal damage and stress damage to the polycrystalline diamond.
[0035] Correspondingly, an embodiment of the present disclosure further provides a method of processing a surface-modified polycrystalline diamond. Referring to Fig. 3, the processing method comprises the following steps of:
[0036] S110: coating an anticorrosion paint on the cemented carbide matrix of the polycrystalline diamond compact (PDC);
22205305.2 6 [0037] S210: removing a catalyst metal from a surface of the polycrystalline diamond body and forming holes in the surface the polycrystalline diamond body;
[0038] S3 10: embedding the non-catalyst metal into the holes; and [0039] S410: sanding the surface of the polycrystalline diamond body by using an abrasive paper or an abrasive cloth so as to remove a redundant part of the non-catalyst metal from the surface of the polycrystalline diamond body.
[0040] In the step S210, the catalyst metal is iron, cobalt, or nickel, which is corroded from the surface of the polycrystalline diamond body mainly by an acid boiling method;
however, the diamond has strong acid and alkali resistance and, thus, will not change after being treated with an acid or an alkali. After the catalyst metal is removed from the surface of the polycrystalline diamond body, the microstructure of the polycrystalline diamond body comprises a single diamond phase and dispersed holes.
[0041] In the step S3 10, the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof. Copper, silver, or aluminum is only filled in the holes that are formed after iron, cobalt, or nickel is removed, and is particularly flexible and only located in the surface. Therefore, there can be very small thermal stress generated due to a difference between a thermal expansion coefficient of copper, silver or aluminum and that of the diamond during operations at a high temperature, thereby eliminating thermal damage and stress damage.
[0042] The step S410 is optional, and may be executed by using a mechanical polishing method to polish the polycrystalline diamond until the surface thereof is exposed. In this case, it can be observed by means of a microscope that the microscopic holes in the surface of the polycrystalline diamond body have been filled by copper, silver, or aluminum. In practical implementations, a surface grinder of model M7132 may be adopted, in which a 240/270 fine diamond grinding wheel is slowly fed to grind off the surface of the polycrystalline diamond body by a thickness of about 0.01 mm, thereby grinding the surface into a polished surface. If there is no requirement on the appearance 22205305.2 7 of the polycrystalline diamond body but much attention is paid to the use effect of the polycrystalline diamond body, it is advantageous to maintain the copper layer in the surface of the polycrystalline diamond body.
[0043] As shown by researches, the larger the depth in the surface of the polycrystalline diamond body by which cobalt is removed and copper is filled is, the better the effect of the polycrystalline diamond body in practical applications will be and, thus, the longer the service life of the polycrystalline diamond will become. However, in case the depth by which cobalt is removed is over 0.5 mm, both the speed of removing cobalt and that of filling copper will be remarkably reduced, and this will significantly increase the manufacturing cost. Accordingly, in this embodiment of the present disclosure, the depth by which cobalt is removed is 0.1 mm to 1 mm, and preferably 0.3 mm to 0.5 mm.
[0044] Hereinafter, the method of processing the surface-modified polycrystalline diamond according to this embodiment of the present disclosure will be described in detail with reference to examples thereof.
Embodiment 1 [0045] First step: enclosing the cemented carbide matrix of the polycrystalline diamond body with an anticorrosion fixture;
[0046] second step: boiling the polycrystalline diamond body in an aqua regia for 20 to 60 hours, and removing cobalt from the surface of the polycrystalline diamond body by a depth of 0.3 mm to 0.4 mm;
[0047] third step: after the aqua regia is cooled, taking the polycrystalline diamond body out of the aqua regia and rinsing the polycrystalline diamond body until the polycrystalline diamond body becomes neutral;
[0048] fourth step: putting a copper wheel rotating at a rotating speed of revolutions per second (rps) into contact with the surface of the polycrystalline diamond body;
[0049] fifth step: feeding the copper wheel by 0.1 mm to 0.4 mm for strong friction so 22205305.2 8 r that the surface of the polycrystalline diamond body is covered by copper; and [00501 sixth step: sanding the surface of the polycrystalline diamond body by using a common No. 180 abrasive cloth or abrasive paper to remove the redundant purplish red copper layer until the surface of the black polycrystalline diamond body layer is exposed.
[0051] In practical implementations, given that a red copper wheel is used as an abrasion wheel on a surface grinder, the copper wheel rotating at a rotating speed of 1400 rps is put into contact with the surface of the polycrystalline diamond that has been treated with an acid, and then fed by 0.2 mm for strong friction until the entire surface of the polycrystalline diamond is covered by the copper layer.
Embodiment 2 [0052] First step: coating an anticorrosion paint on the cemented carbide matrix of the polycrystalline diamond body;
[0053] second step: boiling the polycrystalline diamond body in an aqua regia for 10 to 110 hours, and removing cobalt from the surface of the polycrystalline diamond body by a depth of 0.4 mm to 0.6 mm;
[0054] third step: taking the polycrystalline diamond body out of the aqua regia and rinsing the polycrystalline diamond body until the polycrystalline diamond body becomes neutral;
[0055] fourth step: placing the polycrystalline diamond body into a copper mould for electrodeposition, with the mould being used as a cathode, a copper sulfate solution being used as an electrolyte, and a pure copper plate being used as an anode; and [0056] fifth step: sanding the surface of the polycrystalline diamond body by using a common No. 180 abrasive cloth or abrasive paper to remove the redundant purplish red copper layer until the surface of the black polycrystalline diamond body layer is exposed.
[0057] In the process of plating copper in an electrodeposition device, the polycrystalline diamond body is placed into a copper mould for electrodeposition, with the 22205305.2 9 mould being used as a cathode, a copper sulfate solution being used as an electrolyte, and a pure copper plate being used as an anode. The electrolyte consists of 250 g/L of copper sulfate (CuSO4.5H2O) and 0.1 g/L of polyethylene glycol solution. In practical implementations, after the polycrystalline diamond body is placed into the electrolyte, the electrolyte is supplied with a current of 10 A/dm and is stirred at a speed of 150 r/min for electrodeposition of 20 hours at the normal temperature (i.e., 25 C).
Embodiment 3 [00581 This embodiment differs from the second embodiment only in that, copper is filled into the holes by using an electroless copper plating method in the fourth step, wherein the electroless copper plating is accomplished by reducing copper ions under the action of a reducing agent on a surface having a catalytically active material, so that a copper plated layer is formed in the surface of the polycrystalline diamond body, with the solution being a CuSO4 solution or a CuC12 solution.
Embodiment 4 [00591 This embodiment differs from the second embodiment only in that, copper is evaporated into vapor by using a vacuum evaporation method in the fourth step so that a copper film is plated in the surface of the polycrystalline diamond body.
100601 According to the above descriptions, in the surface-modified polycrystalline diamond and the processing method thereof provided in the present disclosure, the catalyst metal is removed from the polycrystalline diamond body, and the non-catalyst metal is embedded into the holes that are formed in the surface of the polycrystalline diamond after the catalyst metal is removed. Thus, thermal damage and stress damage to the polycrystalline diamond during operations at a high temperature are eliminated and, therefore, the service life of the polycrystalline diamond is prolonged.
[00611 It can be understood that, for those skilled in the art, equivalents or 22205305.2 10 modifications can be made on basis of the technical solution and the inventive concept provided in the present disclosure, and any of these equivalents and modifications shall also fall within the scope of the present disclosure.
22205305.2 11
METHOD THEREOF
FIELD OF INVENTION
[00011 The present disclosure relates to improvement of properties of polycrystalline diamonds, and more particularly, to a surface-modified polycrystalline diamond and a processing method thereof.
BACKGROUD OF INVENTION
[00021 Polycrystalline diamond compacts (briefly called PDCs) are made from a diamond powder incorporating a certain amount of sintering aids therein and a cemented carbide substrate , which are assembled together and then sintered on a special diamond hydraulic press at an high temperature under an ultra-high pressure. A PDC is composed of a polycrystalline diamond layer and the cemented carbide substrate .
Because the polycrystalline diamond layer has high hardness and good wear resistance and the substrate is excellent in toughness and weldability, the PDCs are widely applied in the fields of oil drilling, geological drilling, coal field exploitation, cutting, and so on.
[00031 When PDCs or integrated polycrystalline diamonds are manufactured, cobalt, nickel, or iron is usually used as the sintering aids to sinter the diamond powder at an high temperature under an ultra-high pressure. The most common catalyst metal is cobalt or an alloy thereof, and the common pressure for sintering at an high temperature under an ultra-high pressure is 4.5 GPa to 6 GPa. Under this condition, the aforesaid sintering aids need to be used so that the diamond particles can be directly sintered with each other to form a diamond-diamond (D-D) combination structure, thereby achieving a polycrystalline diamond layer having excellent properties. The microstructure of the polycrystalline diamond consists of a diamond phase having frameworks connected with each other and a dispersed islet-shaped metal phase.
[00041 After the diamond particles are sintered into the frameworks, the properties of 22205305.2 1 the entire polycrystalline diamond totally depend on the combination of the diamond frameworks. The greater the diamond particles are combined with each other and the larger the combination area is, the better the strength and wear resistance of the polycrystalline diamond will be. The strength is substantially unrelated to the metal phase dispersed in interstices between the frameworks. On the contrary, existence of iron group metal phases is detrimental to the performance of the polycrystalline diamond, including causing thermal damage and stress damage to the performance of the polycrystalline diamond.
[0005] When the PDC operates as a tool, there is often very high operating temperature around the operating point where the PDC contacts with a workpiece, and the temperature may be about 700 C to 800 C, or even over 1000 C at some points. As shown by researches, cobalt, nickel or iron, which is used as a catalyst metal for catalyzing transformation of graphite into the diamond under a high pressure, also catalyzes transformation of the diamond into graphite under the normal pressure.
Consequently, the iron group metal phase in the PDC can degrade the wear resistance of the PDC
to some extent depending on different high temperatures at operating points, thereby causing a thermal damage.
[0006] A thermal expansion coefficient of the diamond is only one tenth of cobalt.
When the operating temperate is very high, the cobalt phase expands to an extent much greater than that of the diamond frameworks, thereby generating a thermal stress. After reaching a certain value, the thermal stress will destroy the diamond frameworks to cause cracks in the polycrystalline diamond, thereby leading to a stress damage.
[0007] Accordingly, the structure of the existing polycrystalline diamond body and the method of processing the polycrystalline diamond body in the art need further improvement and enhancement.
22205305.2 2 SUMMARY OF THE INVENTION
[0008] In view of the shortcomings of the prior art, an objective of the present disclosure is to provide a surface-modified polycrystalline diamond and a processing method thereof, in which a catalyst metal is removed from a polycrystalline diamond body to form holes and a non-catalyst metal having a high thermal conductivity is embedded into the holes. Thus, thermal damage and stress damage to the polycrystalline diamond body during operations at a high temperature are eliminated.
[0009] To achieve the aforesaid objective, the present disclosure provides the following technical solutions:
[0010] A surface-modified polycrystalline diamond, which comprises a polycrystalline diamond body, wherein holes are formed on the polycrystalline diamond body after a catalyst metal is removed, and the holes are embedded with a non-catalyst metal.
[0011] The surface-modified polycrystalline diamond, wherein the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof.
[0012] The surface-modified polycrystalline diamond, wherein each of the holes has a depth of 0.1 mm to 1 mm.
[0013] The present disclosure further provides a method of processing a surface-modified polycrystalline diamond, which comprises the following steps of:
[0014] removing a catalyst metal from a surface of the polycrystalline diamond body and forming holes in the surface of the polycrystalline diamond body; and [0015] embedding a non-catalyst metal into the holes.
[0016] The method of processing a surface-modified polycrystalline diamond, wherein the steps of removing the catalyst metal from the surface of the polycrystalline diamond body and forming the holes in the surface of the polycrystalline diamond body comprise:
[0017] boiling the polycrystalline diamond body in an aqua regia for 20 to 60 hours;
and [0018] taking the polycrystalline diamond body out of the aqua regia and rinsing the 22205305.2 3 polycrystalline diamond body until the polycrystalline diamond body becomes neutral.
[00191 The method of processing a surface-modified polycrystalline diamond, wherein the steps of embedding the non-catalyst metal into the holes comprise:
[00201 putting a copper wheel rotating at a rotating speed of 1400 revolutions per second (rps) into contact with the surface of the polycrystalline diamond body; and 100211 feeding the copper wheel by 0.1 mm to 0.4 mm for strong friction so that the surface of the polycrystalline diamond body is covered by copper.
[00221 The method of processing a surface-modified polycrystalline diamond, wherein the polycrystalline diamond body is boiled in the aqua regia for 10 to 110 hours; and the polycrystalline diamond body is taken out of the aqua regia and rinsed until the polycrystalline diamond body becomes neutral.
[00231 The method of processing a surface-modified polycrystalline diamond, wherein the step of embedding the non-catalyst metal into the holes comprises: placing the polycrystalline diamond body into a copper mould for electrodeposition, with the mould being used as a cathode, a copper sulfate solution being used as an electrolyte, and a pure copper plate being used as an anode.
[00241 The method of processing a surface-modified polycrystalline diamond, wherein the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof.
[00251 The method of processing a surface-modified polycrystalline diamond, wherein each of the holes has a depth of 0.1 mm to 1 mm.
[00261 According to the surface-modified polycrystalline diamond and the processing method thereof provided in the present disclosure, the catalyst metal is removed from the polycrystalline diamond body, and the non-catalyst metal is embedded into the holes formed in the surface of the polycrystalline diamond after the catalyst metal is removed.
Thus, thermal damage and stress damage to the polycrystalline diamond during operations at a high temperature are eliminated and, therefore, the service life of the polycrystalline diamond is prolonged.
22205305.2 4 BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Fig. 1 is a schematic structural view of a polycrystalline diamond according to an embodiment of the present disclosure;
[0028] Fig. 2 is a schematic structural view of the polycrystalline diamond according to an embodiment of the present disclosure after a catalyst metal is removed therefrom; and [0029] Fig. 3 is a flowchart diagram of a method of processing the polycrystalline diamond according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0030] The present disclosure provides a surface-modified polycrystalline diamond and a processing method thereof. To make the objectives, technical solutions, and efficacies of the present disclosure clearer, the present disclosure will be further described hereinbelow with reference to the attached drawings and embodiments thereof. It shall be understood that, the embodiments described herein are only intended to illustrate but not to limit the present disclosure.
[0031] Referring to Fig. 1 and Fig. 2, a surface-modified polycrystalline diamond according to an embodiment of the present disclosure comprises a polycrystalline diamond body 11 installed on a cemented carbide matrix 21. A plurality of holes 111 are formed on the polycrystalline diamond body 11 after a catalyst metal is removed therefrom, and the holes 111 are embedded with a non-catalyst metal.
[0032] The catalyst metal is one of iron, cobalt, and nickel, and the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof. Each of the holes 111 preferably has a depth of 0.1 mm to 1 mm; that is, only the catalyst metal at the depth of 0.1 mm to 1 mm from a surface of the polycrystalline diamond body 11 is removed in the present disclosure. According to the present disclosure, the holes 111 are formed in the surface of the polycrystalline diamond body 11 after iron, cobalt, or nickel is removed;
and then 22205305.2 5 copper, silver, or aluminum is embedded into the holes 111. In this way, the heat resistance of the polycrystalline diamond is improved and, thus, the service life of the polycrystalline diamond is prolonged.
[0033] None of copper, silver, and aluminum is a catalyst metal of the synthetic diamond and can catalyze reverse transformation of the diamond into graphite.
Copper has a thermal conductivity of 397 W/mK, silver has a thermal conductivity of 429 W/mK, aluminum has a thermal conductivity of 217 W/mK, and cobalt has a thermal conductivity of only 96 W/mK. Replacing cobalt, nickel, or iron with one of copper, silver, aluminum, and alloys thereof is beneficial to improvement of the overall thermal conductivity of the polycrystalline diamond, and this makes it easier to dissipate heat from the surface of the polycrystalline diamond body 11 so that the operating temperature at the operating point of the polycrystalline diamond body 11 can be reduced.
[0034] In this embodiment, although the thermal conductivity of silver is slightly higher than that of copper, silver is much expensive than copper. Therefore, copper or an alloy thereof is preferably used in the present disclosure to replace cobalt.
Another choice is to use aluminum or an alloy thereof. Specifically, aluminum has a low melting point, so it is easier to embed aluminum into the holes 111; and additionally, at the operating point under a temperature above 700 C, the molten aluminum will overflow from the surface, thereby achieving the purpose of heat dissipation through "sweating".
Therefore, in this embodiment of the present disclosure, the non-catalyst metal having a high thermal conductivity is adopted to replace cobalt, nickel, and iron so as to eliminate thermal damage and stress damage to the polycrystalline diamond.
[0035] Correspondingly, an embodiment of the present disclosure further provides a method of processing a surface-modified polycrystalline diamond. Referring to Fig. 3, the processing method comprises the following steps of:
[0036] S110: coating an anticorrosion paint on the cemented carbide matrix of the polycrystalline diamond compact (PDC);
22205305.2 6 [0037] S210: removing a catalyst metal from a surface of the polycrystalline diamond body and forming holes in the surface the polycrystalline diamond body;
[0038] S3 10: embedding the non-catalyst metal into the holes; and [0039] S410: sanding the surface of the polycrystalline diamond body by using an abrasive paper or an abrasive cloth so as to remove a redundant part of the non-catalyst metal from the surface of the polycrystalline diamond body.
[0040] In the step S210, the catalyst metal is iron, cobalt, or nickel, which is corroded from the surface of the polycrystalline diamond body mainly by an acid boiling method;
however, the diamond has strong acid and alkali resistance and, thus, will not change after being treated with an acid or an alkali. After the catalyst metal is removed from the surface of the polycrystalline diamond body, the microstructure of the polycrystalline diamond body comprises a single diamond phase and dispersed holes.
[0041] In the step S3 10, the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof. Copper, silver, or aluminum is only filled in the holes that are formed after iron, cobalt, or nickel is removed, and is particularly flexible and only located in the surface. Therefore, there can be very small thermal stress generated due to a difference between a thermal expansion coefficient of copper, silver or aluminum and that of the diamond during operations at a high temperature, thereby eliminating thermal damage and stress damage.
[0042] The step S410 is optional, and may be executed by using a mechanical polishing method to polish the polycrystalline diamond until the surface thereof is exposed. In this case, it can be observed by means of a microscope that the microscopic holes in the surface of the polycrystalline diamond body have been filled by copper, silver, or aluminum. In practical implementations, a surface grinder of model M7132 may be adopted, in which a 240/270 fine diamond grinding wheel is slowly fed to grind off the surface of the polycrystalline diamond body by a thickness of about 0.01 mm, thereby grinding the surface into a polished surface. If there is no requirement on the appearance 22205305.2 7 of the polycrystalline diamond body but much attention is paid to the use effect of the polycrystalline diamond body, it is advantageous to maintain the copper layer in the surface of the polycrystalline diamond body.
[0043] As shown by researches, the larger the depth in the surface of the polycrystalline diamond body by which cobalt is removed and copper is filled is, the better the effect of the polycrystalline diamond body in practical applications will be and, thus, the longer the service life of the polycrystalline diamond will become. However, in case the depth by which cobalt is removed is over 0.5 mm, both the speed of removing cobalt and that of filling copper will be remarkably reduced, and this will significantly increase the manufacturing cost. Accordingly, in this embodiment of the present disclosure, the depth by which cobalt is removed is 0.1 mm to 1 mm, and preferably 0.3 mm to 0.5 mm.
[0044] Hereinafter, the method of processing the surface-modified polycrystalline diamond according to this embodiment of the present disclosure will be described in detail with reference to examples thereof.
Embodiment 1 [0045] First step: enclosing the cemented carbide matrix of the polycrystalline diamond body with an anticorrosion fixture;
[0046] second step: boiling the polycrystalline diamond body in an aqua regia for 20 to 60 hours, and removing cobalt from the surface of the polycrystalline diamond body by a depth of 0.3 mm to 0.4 mm;
[0047] third step: after the aqua regia is cooled, taking the polycrystalline diamond body out of the aqua regia and rinsing the polycrystalline diamond body until the polycrystalline diamond body becomes neutral;
[0048] fourth step: putting a copper wheel rotating at a rotating speed of revolutions per second (rps) into contact with the surface of the polycrystalline diamond body;
[0049] fifth step: feeding the copper wheel by 0.1 mm to 0.4 mm for strong friction so 22205305.2 8 r that the surface of the polycrystalline diamond body is covered by copper; and [00501 sixth step: sanding the surface of the polycrystalline diamond body by using a common No. 180 abrasive cloth or abrasive paper to remove the redundant purplish red copper layer until the surface of the black polycrystalline diamond body layer is exposed.
[0051] In practical implementations, given that a red copper wheel is used as an abrasion wheel on a surface grinder, the copper wheel rotating at a rotating speed of 1400 rps is put into contact with the surface of the polycrystalline diamond that has been treated with an acid, and then fed by 0.2 mm for strong friction until the entire surface of the polycrystalline diamond is covered by the copper layer.
Embodiment 2 [0052] First step: coating an anticorrosion paint on the cemented carbide matrix of the polycrystalline diamond body;
[0053] second step: boiling the polycrystalline diamond body in an aqua regia for 10 to 110 hours, and removing cobalt from the surface of the polycrystalline diamond body by a depth of 0.4 mm to 0.6 mm;
[0054] third step: taking the polycrystalline diamond body out of the aqua regia and rinsing the polycrystalline diamond body until the polycrystalline diamond body becomes neutral;
[0055] fourth step: placing the polycrystalline diamond body into a copper mould for electrodeposition, with the mould being used as a cathode, a copper sulfate solution being used as an electrolyte, and a pure copper plate being used as an anode; and [0056] fifth step: sanding the surface of the polycrystalline diamond body by using a common No. 180 abrasive cloth or abrasive paper to remove the redundant purplish red copper layer until the surface of the black polycrystalline diamond body layer is exposed.
[0057] In the process of plating copper in an electrodeposition device, the polycrystalline diamond body is placed into a copper mould for electrodeposition, with the 22205305.2 9 mould being used as a cathode, a copper sulfate solution being used as an electrolyte, and a pure copper plate being used as an anode. The electrolyte consists of 250 g/L of copper sulfate (CuSO4.5H2O) and 0.1 g/L of polyethylene glycol solution. In practical implementations, after the polycrystalline diamond body is placed into the electrolyte, the electrolyte is supplied with a current of 10 A/dm and is stirred at a speed of 150 r/min for electrodeposition of 20 hours at the normal temperature (i.e., 25 C).
Embodiment 3 [00581 This embodiment differs from the second embodiment only in that, copper is filled into the holes by using an electroless copper plating method in the fourth step, wherein the electroless copper plating is accomplished by reducing copper ions under the action of a reducing agent on a surface having a catalytically active material, so that a copper plated layer is formed in the surface of the polycrystalline diamond body, with the solution being a CuSO4 solution or a CuC12 solution.
Embodiment 4 [00591 This embodiment differs from the second embodiment only in that, copper is evaporated into vapor by using a vacuum evaporation method in the fourth step so that a copper film is plated in the surface of the polycrystalline diamond body.
100601 According to the above descriptions, in the surface-modified polycrystalline diamond and the processing method thereof provided in the present disclosure, the catalyst metal is removed from the polycrystalline diamond body, and the non-catalyst metal is embedded into the holes that are formed in the surface of the polycrystalline diamond after the catalyst metal is removed. Thus, thermal damage and stress damage to the polycrystalline diamond during operations at a high temperature are eliminated and, therefore, the service life of the polycrystalline diamond is prolonged.
[00611 It can be understood that, for those skilled in the art, equivalents or 22205305.2 10 modifications can be made on basis of the technical solution and the inventive concept provided in the present disclosure, and any of these equivalents and modifications shall also fall within the scope of the present disclosure.
22205305.2 11
Claims (14)
1. A surface-modified polycrystalline diamond, comprising a polycrystalline diamond body, wherein holes are formed on the polycrystalline diamond body after a catalyst metal is removed therefrom, and the holes are embedded with a non-catalyst metal.
2. The surface-modified polycrystalline diamond of claim 1, wherein the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof.
3. The surface-modified polycrystalline diamond of claim 1, wherein each of the holes has a depth of 0.1 mm to 1 mm.
4. A method of processing the surface-modified polycrystalline diamond of claim 1, comprising the following steps of:
removing a catalyst metal from a surface of the polycrystalline diamond body and forming holes in the surface of the polycrystalline diamond body; and embedding a non-catalyst metal into the holes.
removing a catalyst metal from a surface of the polycrystalline diamond body and forming holes in the surface of the polycrystalline diamond body; and embedding a non-catalyst metal into the holes.
5. The method of processing the surface-modified polycrystalline diamond of claim 4, wherein the steps of removing the catalyst metal from the surface of the polycrystalline diamond body and forming the holes in the surface of the polycrystalline diamond body comprise:
boiling the polycrystalline diamond body in an aqua regia for 20 to 60 hours;
and taking the polycrystalline diamond body out of the aqua regia and rinsing the polycrystalline diamond body until the polycrystalline diamond body becomes neutral.
boiling the polycrystalline diamond body in an aqua regia for 20 to 60 hours;
and taking the polycrystalline diamond body out of the aqua regia and rinsing the polycrystalline diamond body until the polycrystalline diamond body becomes neutral.
6. The method of processing the surface-modified polycrystalline diamond of claim 5, wherein the steps of embedding the non-catalyst metal into the holes comprise:
putting a copper wheel rotating at a rotating speed of 1400 revolutions per second (rps) into contact with the surface of the polycrystalline diamond body; and feeding the copper wheel by 0.1 mm to 0.4 mm for strong friction so that the surface of the polycrystalline diamond body is covered by copper.
putting a copper wheel rotating at a rotating speed of 1400 revolutions per second (rps) into contact with the surface of the polycrystalline diamond body; and feeding the copper wheel by 0.1 mm to 0.4 mm for strong friction so that the surface of the polycrystalline diamond body is covered by copper.
7. The method of processing the surface-modified polycrystalline diamond of claim 4, wherein:
boiling the polycrystalline diamond body in an aqua regia for 10 to 110 hours;
and taking the polycrystalline diamond body out of the aqua regia and rinsing the polycrystalline diamond body until the polycrystalline diamond body becomes neutral.
boiling the polycrystalline diamond body in an aqua regia for 10 to 110 hours;
and taking the polycrystalline diamond body out of the aqua regia and rinsing the polycrystalline diamond body until the polycrystalline diamond body becomes neutral.
8. The method of processing the surface-modified polycrystalline diamond of claim 7, wherein the step of embedding the non-catalyst metal into the holes comprises:
placing the polycrystalline diamond body into a copper mould for electrodeposition, with the mould being used as a cathode, a copper sulfate solution being used as an electrolyte, and a pure copper plate being used as an anode.
placing the polycrystalline diamond body into a copper mould for electrodeposition, with the mould being used as a cathode, a copper sulfate solution being used as an electrolyte, and a pure copper plate being used as an anode.
9. The method of processing the surface-modified polycrystalline diamond of claim 4, wherein the non-catalyst metal is one of copper, silver, aluminum, and alloys thereof.
10. The method of processing the surface-modified polycrystalline diamond of any of claim 4, wherein each of the holes has a depth of 0.1 mm to 1 mm.
11. The method of processing the surface-modified polycrystalline diamond of any of claim 5, wherein each of the holes has a depth of 0.1 mm to 1 mm.
12. The method of processing the surface-modified polycrystalline diamond of any of claim 6, wherein each of the holes has a depth of 0.1 mm to 1 mm.
13. The method of processing the surface-modified polycrystalline diamond of any of claim 7, wherein each of the holes has a depth of 0.1 mm to 1 mm.
14. The method of processing the surface-modified polycrystalline diamond of any of claim 8, wherein each of the holes has a depth of 0.1 mm to 1 mm.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110050119.6 | 2011-03-02 | ||
| CN2011100501196A CN102126257B (en) | 2011-03-02 | 2011-03-02 | Surface modified polycrystalline diamond and processing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2768933A1 true CA2768933A1 (en) | 2012-09-02 |
| CA2768933C CA2768933C (en) | 2015-05-19 |
Family
ID=44264670
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2768933A Expired - Fee Related CA2768933C (en) | 2011-03-02 | 2012-02-22 | Surface-modified polycrystalline diamond and processing method thereof |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US20120222362A1 (en) |
| CN (1) | CN102126257B (en) |
| CA (1) | CA2768933C (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103623747B (en) * | 2013-12-03 | 2016-03-02 | 深圳市海明润超硬材料股份有限公司 | A kind of diamond compact with high thermal conductivity and preparation method thereof |
| EP3374541B1 (en) | 2015-11-12 | 2023-11-29 | National Oilwell DHT, L.P. | Downhole drill bit with a cutting element coated with a nanodiamond polycrystalline containing coating |
| CN108314463B (en) * | 2018-04-10 | 2021-01-29 | 衢州学院 | Electrolytic copper filled porous diamond grinding tool and preparation method thereof |
| CN110757912B (en) * | 2019-11-20 | 2022-03-11 | 聊城纬特新材料科技有限公司 | Polycrystalline diamond compact and preparation method thereof |
| CN111963064A (en) * | 2020-08-27 | 2020-11-20 | 重庆北思卡新材料有限公司 | Cobalt-removing diamond drilling tooth and ultra-deep cobalt removing process thereof |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4224380A (en) * | 1978-03-28 | 1980-09-23 | General Electric Company | Temperature resistant abrasive compact and method for making same |
| US5127923A (en) * | 1985-01-10 | 1992-07-07 | U.S. Synthetic Corporation | Composite abrasive compact having high thermal stability |
| US5723168A (en) * | 1997-01-13 | 1998-03-03 | Xerox Corporation | Solventless coating method employing aramid fibers |
| AU7423001A (en) * | 2000-09-20 | 2002-04-02 | Schlumberger Holdings | Polycrystalline diamond with a surface depleted of catalyzing material |
| US6592985B2 (en) * | 2000-09-20 | 2003-07-15 | Camco International (Uk) Limited | Polycrystalline diamond partially depleted of catalyzing material |
| US7726421B2 (en) * | 2005-10-12 | 2010-06-01 | Smith International, Inc. | Diamond-bonded bodies and compacts with improved thermal stability and mechanical strength |
| GB0612176D0 (en) * | 2006-06-20 | 2006-08-02 | Reedhycalog Uk Ltd | PDC cutters with enhanced working surfaces |
| GB2453135B (en) * | 2007-09-27 | 2011-08-10 | Reedhycalog Uk Ltd | Bonding method and component for use therein |
| PL2262600T3 (en) * | 2008-04-08 | 2014-07-31 | Element Six Ltd | Cutting tool insert |
| KR101220647B1 (en) * | 2008-09-03 | 2013-01-10 | 스미토모 덴키 고교 가부시키가이샤 | Seal structure, method of forming seal structure, wiring body, and electronic apparatus |
| CA2683260A1 (en) * | 2008-10-20 | 2010-04-20 | Smith International, Inc. | Techniques and materials for the accelerated removal of catalyst material from diamond bodies |
| CN101476445A (en) * | 2008-12-24 | 2009-07-08 | 陈继锋 | CVD diamond layer overlapped diamond composite sheet for drilling and its production method |
-
2011
- 2011-03-02 CN CN2011100501196A patent/CN102126257B/en active Active
-
2012
- 2012-02-22 CA CA2768933A patent/CA2768933C/en not_active Expired - Fee Related
- 2012-03-02 US US13/410,682 patent/US20120222362A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| CN102126257B (en) | 2012-01-18 |
| CN102126257A (en) | 2011-07-20 |
| US20120222362A1 (en) | 2012-09-06 |
| CA2768933C (en) | 2015-05-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2768933C (en) | Surface-modified polycrystalline diamond and processing method thereof | |
| EP2647470B1 (en) | Cemented carbide base outer-diameter blade cutting wheel and manufacturing method thereof | |
| US3850590A (en) | An abrasive tool comprising a continuous porous matrix of sintered metal infiltrated by a continuous synthetic resin | |
| EP2647469B1 (en) | Super hard alloy baseplate outer circumference cutting blade and manufacturing method thereof | |
| JP5630389B2 (en) | Cemented carbide base plate outer peripheral cutting blade and manufacturing method thereof | |
| Qi et al. | Vacuum brazing diamond grits with Cu-based or Ni-based filler metal | |
| EP2612728B1 (en) | Method of manufacturing an outer blade cutting wheel | |
| JP2015155143A (en) | Method for manufacturing super hard alloy baseplate outer circumference cutting blade | |
| JP2016211727A (en) | Slide member | |
| CN104985536A (en) | Metal-bonded diamond grinding wheel | |
| CN109676541A (en) | A kind of grinding of silicon ingot is with being excused from a college course reduction conjunction binding agent ultra hard grinding wheel and its preparation method and application | |
| JP2015140456A (en) | Composite material, semiconductor device, and method for manufacturing composite material | |
| CN103447531B (en) | A kind of silver-tungsten disulfide brush in composite material-slip ring system | |
| CN103203453B (en) | Grinding wheel manufacturing method of edge-sharpening single crystal diamond tool | |
| US3820966A (en) | Diamond grinding layer for honing segments | |
| JP5734730B2 (en) | Polishing cloth dresser | |
| CN104175237A (en) | Diamond grinding wheel adopting rare-earth modified tungsten-based bond and manufacturing method thereof | |
| CN106041089B (en) | The unrestrained manufacturing method for oozing burning Ti-Al-Cu-Sn-Ni micropore skives | |
| JP2011073113A (en) | Double-coated diamond abrasive particle and method of manufacturing the same | |
| CN102490127A (en) | Grinding material of grinding disc fixed with grinding material | |
| CN112570686A (en) | Method for optimizing tungsten carbide particle reinforced iron-based composite material interface | |
| JP2011079929A (en) | Double coating diamond polishing agent particle and production method thereof | |
| JP5880652B2 (en) | Cemented carbide base plate outer peripheral cutting blade and manufacturing method thereof | |
| JP2010076094A (en) | Metal bond diamond grinding wheel and method of manufacturing the same | |
| CN115401202B (en) | WC hard alloy matrix diamond compact combined by high-entropy alloy and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20210831 |
|
| MKLA | Lapsed |
Effective date: 20200224 |