Multi-micro-edge diamond and preparation method thereof

Abstract

The preparation method comprises the following steps: carrying out plasma cleaning on the diamond, coating the diamond to obtain a coated diamond, sintering, roasting and cooling the coated diamond to obtain an etched diamond, and immersing the etched diamond into a mixed acid solution for cleaning to obtain the multi-micro-cutting-edge diamond. According to the multi-micro-blade diamond and the preparation method thereof, after plasma cleaning is conducted on the diamond, the surface of the diamond is plated with the carbonized catalytic metal, multi-micro-blade machining of diamond micro powder is achieved under the high-temperature and low-pressure conditions, a uniform and consistent micro-blade layer can be achieved on the surface of the diamond, and the quality of polishing, grinding and the like is improved; uniform and consistent hole structures are manufactured on the surfaces of diamond particles, so that enough cutting edges are formed in the cutting process, abrasive materials with refined structures can form new cutting edges through surface micro-edge crushing, the self-sharpening performance of diamond is greatly improved, and broken pits on the surface of a workpiece are eliminated.

Description

Technical Field

[0001] The invention belongs to the technical field of diamond preparation methods, and relates to a preparation method of a multi-micro-blade diamond. The invention also relates to the multi-micro-blade diamond. Background Art

[0002] Diamond has extremely high hardness, thermal conductivity and chemical stability, and is widely used in abrasive tool manufacturing, grinding, polishing and other fields. Among them, artificial diamond micropowder is widely used in precision grinding and polishing. The diameter of artificial diamond micropowder is generally between 0-50μm, the particles are fine and the surface is smooth. During the polishing process, the micropowder particles are anisotropic due to the different crystal faces, and the existing micropowder cutting edges are few and coarse. When the cutting edge is sharp, the material removal efficiency is high. After the cutting edge is blunted, it is difficult to maintain a high removal efficiency due to poor self-sharpening. In addition, the cutting stress concentration of the coarse cutting edge and the different cutting edge forces on different crystal faces lead to a large number of broken pits on the workpiece surface during polishing, and the cutting texture is deep and rough, which cannot meet the requirements of high-quality workpiece surface polishing processing, such as key components such as turbine blades, bearings and sensors in the aviation field, lenses, reflectors and beam splitters in the optoelectronic field, surgical scalpels, bone drills and endoscopes in the biomedical field, and semiconductor chips, transistors, capacitors and resistors in the microelectronics field. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for preparing multi-micro-edge diamond, which solves the problems of poor self-sharpening, few cutting edges and coarse and deep polishing texture due to the anisotropy of diamond micropowder in the prior art.

[0004] Another object of the present invention is to provide a multi-micro-blade diamond.

[0005] The first technical solution adopted by the present invention is a method for preparing multi-micro-blade diamond, comprising the following steps: Step 1: Plasma cleaning of diamond; Step 2: coating the diamond to obtain coated diamond; Step 3: sintering, roasting, and cooling the coated diamond to obtain etched diamond; Step 4: Immerse the etched diamond in a mixed acid solution for cleaning to obtain a multi-micro-edged diamond.

[0006] The first technical solution of the present invention is also characterized in that: Step 1 is as follows: Place the diamond into the plasma cleaning equipment and pump it to a vacuum degree of no more than 5×10 -3 Pa, start ultrasonic vibration dispersion and introduce argon gas, start plasma cleaning, and clean for 30min-60min after ignition.

[0007] During plasma cleaning, the bias voltage is set to 400v-600v, and the flow rate of argon gas is 50sccm-200sccm.

[0008] Step 2 is as follows: Place the diamond into the PVD magnetron sputtering coating equipment and evacuate the vacuum to a degree not exceeding 5×10 -3 Pa, introduce argon and start ultrasonic vibration, and when the vacuum degree reaches 0.5Pa-2Pa, start the metal target or alloy target for coating to obtain coated diamond.

[0009] In step 2, the flow rate of argon gas is 120sccm-280sccm, the metal target is one of nickel target, iron target, and cobalt target, and the alloy target is an alloy target of any two metals among nickel target, iron target, and cobalt target. The coating is performed at 1200W-2000W for 100s-300s, and the coating thickness is 10nm-50nm.

[0010] Step 3 is specifically as follows: placing the coated diamond in a muffle furnace and sintering for 40-60 minutes, then placing it in a vacuum furnace and evacuating it to a vacuum degree not exceeding 0.1 Pa, and then roasting it, and then naturally cooling it to room temperature after roasting.

[0011] The sintering temperature is 450°C-550°C. After being placed in a vacuum furnace, the temperature is increased to 850°C-950°C at a rate of 5°C / min-10°C / min, and the roasting time is 180min-240min.

[0012] Step 4 is specifically as follows: immersing the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning, wherein the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1-2:6, to obtain a multi-micro-edged diamond.

[0013] The second technical solution adopted by the present invention is to obtain multi-micro-blade diamond by using the preparation method of multi-micro-blade diamond.

[0014] The beneficial effects of the present invention are: The present invention performs plasma cleaning on diamonds and then coats the surface with carbide catalytic metal, and realizes multi-micro-edge processing of diamond micropowder under high temperature and low pressure conditions, so as to realize a uniform micro-edge layer on the diamond surface and improve the quality of polishing and grinding. By manufacturing a uniform hole structure on the surface of diamond particles, sufficient cutting edges are achieved during the cutting process, and the abrasive with a refined structure can be broken by the surface micro-edges to form new cutting edges, which greatly increases the self-sharpening property of diamonds, eliminates the broken pits on the surface of the workpiece, meets the needs of high-quality polishing, and greatly improves the grinding efficiency and quality. The large number of tiny cutting edges on the surface of the abrasive can disperse the grinding heat and stress, so that the grinding lines are refined, thereby maintaining the high-quality and high-efficiency grinding of the abrasive tool, and the diamond surface has richer cutting The cutting edge has a high removal rate and can significantly shorten the process time. Compared with single crystal diamond, the surface of multi-micro-blade diamond has more abundant cutting edges and a high removal rate, which can significantly shorten the process time. Due to the fine and dense cutting edges, while being sharp, the surface of the workpiece after grinding has a higher smoothness, which can significantly reduce the roughness of the workpiece, reduce the grinding process steps, and improve the overall production efficiency. During the grinding and polishing process, the cutting edges are sharp and dense, and the grinding resistance is small, which can reduce the working temperature of the diamond product. After diamond processing, the scratches are fine and the surface smoothness of the workpiece is high. It can effectively grind impurity particles, large grains and other heterogeneous particles in the material, reduce or even avoid defects or edge collapse during grinding and polishing, and the surface of the workpiece after grinding has a higher smoothness. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an electron microscope image of the magnetron sputtering coating of the present invention; Figure 2 This is an electron microscope image of a metal powder premix in the prior art; Figure 3 It is an electron microscope image of the coating in the prior art; Figure 4 This is an electron microscope image of the calcined catalyst in the prior art; Figure 5 This is an electron microscope image of the calcined catalyst of the present invention; Figure 6 This is an electron microscope image of the multi-micro-blade diamond of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] The preparation method of multi-micro-edge diamond comprises the following steps: Step 1: Place the diamond in the plasma cleaning equipment and evacuate to a vacuum of no more than 5×10 -3Pa, start ultrasonic vibration dispersion and introduce 50sccm-200sccm argon, start plasma cleaning and set the bias voltage to 400v-600v, and clean for 30min-60min after ignition to remove organic pollutants and adsorption layers on the diamond surface; Step 2: Place the diamond into the PVD magnetron sputtering coating equipment and evacuate the vacuum to a degree not exceeding 5×10 -3 Pa, introduce 120sccm-280sccm argon and start ultrasonic vibration to make the powder roll and disperse evenly, and when the vacuum degree reaches 0.5Pa-2Pa, start the metal target or alloy target to coat the film for 100s-300s under 1200W-2000W state, and the coating thickness is 10nm-50nm. The metal target is one of nickel target, iron target, and cobalt target, and the alloy target is an alloy target of any two metals among nickel target, iron target, and cobalt target, to obtain coated diamond, thereby coating the catalytic carbide metal on the diamond surface, reducing the reaction conditions and accelerating the reaction rate; see Figure 1 By combining ultrasonic vibration and magnetron sputtering coating, a catalytic metal film with uniform thickness can be formed on the diamond surface. Figure 2 and Figure 3 Conventional metal powder mixing methods cannot effectively and completely cover the diamond surface, and cannot achieve a uniform micro-blade structure after etching; Step 3: Place the coated diamond in a muffle furnace and sinter at 450℃-550℃ for 40min-60min, then place it in a vacuum furnace and heat it to 850℃-950℃ at a rate of 5℃ / min-10℃ / min, then evacuate to a vacuum degree not exceeding 0.1Pa, and then roast it for 180min-240min. After roasting, cool it naturally to room temperature to achieve multi-micro-edge processing and etching of diamond; it can achieve metal oxidation and form a relatively oxygen-rich metal catalytic environment. For comparison of samples in oxygen-rich environment, see Figure 4 and Figure 5 ; Step 4: Immerse the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning. The volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1-2:6. This is used to remove metal elements, oxides, and graphite on the surface of the diamond powder after the reaction is completed. The acidity and oxidizing properties of the mixed acid are used for purification. Figure 6 , and obtain purified multi-micro-edged diamond.

[0018] The glass surface grinding comparison test was carried out on the multi-micro-blade diamond prepared by the present invention and the existing diamond. The results are shown in Table 1: Table 1 Glass surface grinding comparison test table

[0019] It can be seen that the multi-micro-blade diamond prepared by the present invention has a shorter grinding time and good roughness.

[0020] The present invention also provides multi-micro-blade diamond, which is prepared by the above-mentioned preparation method of multi-micro-blade diamond.

[0021] Example 1: The preparation method of multi-micro-edge diamond comprises the following steps: Step 1: Place the diamond in the plasma cleaning equipment and pump it to a vacuum degree of 5×10 -3 Pa, start ultrasonic vibration dispersion and introduce 50sccm argon, start plasma cleaning and set the bias voltage to 400V, and clean for 30 minutes after ignition; Step 2: Place the diamond into the PVD magnetron sputtering coating equipment and evacuate to a vacuum degree of 5×10 -3 Pa, 120 sccm argon gas was introduced and ultrasonic vibration was started. When the vacuum degree reached 0.5 Pa, the nickel target was started to deposit a film at 1200 W for 100 s. The film thickness was 10 nm, and a coated diamond was obtained. Step 3: Place the coated diamond in a muffle furnace and sinter at 450°C for 40 minutes, then place it in a vacuum furnace and heat it to 850°C at a rate of 5°C / min, then evacuate to a vacuum degree of 0.1 Pa, and then roast it for 180 minutes. After roasting, naturally cool it to room temperature; Step 4: Immerse the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning, wherein the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1:6, to obtain a multi-micro-edged diamond.

[0022] Example 2: The preparation method of multi-micro-edge diamond comprises the following steps: Step 1: Place the diamond in the plasma cleaning equipment and pump it to a vacuum of 3×10 -3 Pa, start ultrasonic vibration dispersion and introduce 200 sccm argon, start plasma cleaning and set the bias to 600V, and clean for 60 minutes after ignition; Step 2: Place the diamond into the PVD magnetron sputtering coating equipment and evacuate to a vacuum degree of 3×10 -3 Pa, 280sccm argon gas was introduced and ultrasonic vibration was started. When the vacuum degree reached 2Pa, the nickel and iron alloy target was started to deposit a film at 2000W for 300s. The coating thickness was 50nm, and a coated diamond was obtained; Step 3: Place the coated diamond in a muffle furnace and sinter at 550°C for 50 minutes, then place it in a vacuum furnace and heat it to 950°C at a rate of 10°C / min, then evacuate to a vacuum degree of 0.1 Pa, and then bake it for 240 minutes. After baking, naturally cool it to room temperature; Step 4: Immerse the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning, wherein the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1:3, to obtain a multi-micro-edged diamond. Example 3: The preparation method of multi-micro-edge diamond comprises the following steps: Step 1: Place the diamond in the plasma cleaning equipment and pump it to a vacuum of 2×10 -3 Pa, start ultrasonic vibration dispersion and introduce 150sccm argon, start plasma cleaning and set the bias voltage to 500V, and clean for 45 minutes after ignition; Step 2: Place the diamond into the PVD magnetron sputtering coating equipment and evacuate to a vacuum degree of 2×10 -3 Pa, introduce 200 sccm argon and start ultrasonic vibration, when the vacuum degree reaches 1.5 Pa, start the iron target or alloy target to coat the film at 1600 W for 200 s, and the coating thickness is 30 nm to obtain coated diamond; Step 3: Place the coated diamond in a muffle furnace and sinter at 500°C for 60 minutes, then place it in a vacuum furnace and heat it to 800°C at a rate of 7°C / min, then evacuate to a vacuum degree of 0.05 Pa, and then roast for 210 minutes. After roasting, naturally cool it to room temperature; Step 4: Immerse the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning, wherein the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1:5, to obtain a multi-micro-edged diamond.

[0023] Example 4: The preparation method of multi-micro-edge diamond comprises the following steps: Step 1: Place the diamond in a plasma cleaning device and pump it to a vacuum of 2.5×10 -3 Pa, start ultrasonic vibration dispersion and introduce 120sccm argon, start plasma cleaning and set the bias voltage to 400V, and clean for 35 minutes after ignition; Step 2: Place the diamond into the PVD magnetron sputtering coating equipment and evacuate to a vacuum degree of 4×10 -3 Pa, 180sccm argon gas was introduced and ultrasonic vibration was started. When the vacuum degree reached 1Pa, the cobalt target was started to deposit a film at 1500W for 180s. The film thickness was 30nm, and a coated diamond was obtained. Step 3: Place the coated diamond in a muffle furnace and sinter at 450°C for 45 minutes, then place it in a vacuum furnace and heat it to 900°C at a rate of 8°C / min, then evacuate to a vacuum degree of 0.1 Pa, and then roast it for 240 minutes. After roasting, naturally cool it to room temperature; Step 4: Immerse the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning, wherein the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1:4, to obtain a multi-micro-edged diamond.

[0024] Example 5: The preparation method of multi-micro-edge diamond comprises the following steps: Step 1: Place the diamond in the plasma cleaning equipment and pump it to a vacuum degree of 5×10 -3 Pa, start ultrasonic vibration dispersion and introduce 50sccm of argon, start plasma cleaning and set the bias voltage to 600V, and clean for 50 minutes after ignition; Step 2: Place the diamond into the PVD magnetron sputtering coating equipment and evacuate to a vacuum degree of 5×10 -3 Pa, 120sccm argon gas was introduced and ultrasonic vibration was started. When the vacuum degree reached 2Pa, the iron and cobalt alloy targets were started to coat the diamond at 1200W for 300s. The coating thickness was 50nm, and a coated diamond was obtained. Step 3: Place the coated diamond in a muffle furnace and sinter at 550°C for 50 minutes, then place it in a vacuum furnace and heat it to 850°C at a rate of 10°C / min, then evacuate to a vacuum degree of 0.05 Pa, and then roast it for 180 minutes. After roasting, naturally cool it to room temperature; Step 4: Immerse the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning, wherein the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1:6, to obtain a multi-micro-edged diamond.

[0025] Example 6: The preparation method of multi-micro-edge diamond comprises the following steps: Step 1: Place the diamond in the plasma cleaning equipment and pump it to a vacuum of 2×10 -3 Pa, start ultrasonic vibration dispersion and introduce 100 sccm of argon, start plasma cleaning and set the bias voltage to 500V, and clean for 40 minutes after ignition; Step 2: Place the diamond into the PVD magnetron sputtering coating equipment and evacuate to a vacuum degree of 4×10 -3 Pa, 180sccm argon gas was introduced and ultrasonic vibration was started. When the vacuum degree reached 1Pa, nickel and cobalt alloy targets were started to deposit a film at 1400W for 300s. The coating thickness was 40nm, and a coated diamond was obtained. Step 3: Place the coated diamond in a muffle furnace and sinter at 450°C for 60 minutes, then place it in a vacuum furnace and heat it to 900°C at a rate of 8°C / min, then evacuate to a vacuum degree of 0.1 Pa, and then bake it for 200 minutes. After baking, it is naturally cooled to room temperature; Step 4: Immerse the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning, wherein the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1:5, to obtain a multi-micro-edged diamond.

Claims

1. A method for preparing multi-micro-blade diamond, characterized in that: The following steps are involved: Step 1: Plasma cleaning of diamond; Step 2: coating the diamond to obtain coated diamond; Step 3: sintering, roasting, and cooling the coated diamond to obtain etched diamond; Step 4: Immerse the etched diamond in a mixed acid solution for cleaning to obtain a multi-micro-edged diamond.

2. The method for preparing multi-micro-blade diamond according to claim 1, wherein: The step 1 is specifically as follows: placing the diamond into a plasma cleaning device and pumping the vacuum to a degree not exceeding 5×10 -3 Pa, start ultrasonic vibration dispersion and introduce argon gas, start plasma cleaning, and clean for 30min-60min after ignition.

3. The method for preparing multi-micro-blade diamond according to claim 1 or 2, characterized in that: During the plasma cleaning, the bias voltage is set to 400V-600V, and the flow rate of the argon gas is set to 50sccm-200sccm.

4. The method for preparing multi-micro-blade diamond according to claim 1, characterized in that: The step 2 is specifically as follows: placing the diamond into the PVD magnetron sputtering coating equipment and evacuating the vacuum to a vacuum degree not exceeding 5×10 -3 Pa, introduce argon and start ultrasonic vibration, and when the vacuum degree reaches 0.5Pa-2Pa, start the metal target or alloy target for coating to obtain coated diamond.

5. The method for preparing multi-micro-blade diamond according to claim 4, characterized in that: The flow rate of argon gas introduced in step 2 is 120sccm-280sccm, the metal target is one of a nickel target, an iron target, and a cobalt target, and the alloy target is an alloy target of any two metals among the nickel target, the iron target, and the cobalt target. The coating is performed for 100s-300s at 1200W-2000W, and the coating thickness is 10nm-50nm.

6. The method for preparing multi-micro-blade diamond according to claim 1, characterized in that: The step 3 specifically comprises: placing the coated diamond in a muffle furnace and sintering for 40-60 minutes, then placing it in a vacuum furnace and evacuating the vacuum to a vacuum degree not exceeding 0.1 Pa, performing roasting, and naturally cooling to room temperature after roasting.

7. The method for preparing multi-micro-edge diamond according to claim 6, characterized in that: The sintering temperature is 450° C.-550° C., and after being placed in a vacuum furnace, the temperature is raised to 850° C.-950° C. at a rate of 5° C. / min-10° C. / min, and the sintering time is 180 min-240 min.

8. The method for preparing multi-micro-blade diamond according to claim 1, characterized in that: The step 4 specifically comprises: immersing the etched diamond in a mixed solution of concentrated nitric acid and concentrated sulfuric acid for cleaning, wherein the volume ratio of concentrated nitric acid to concentrated sulfuric acid is 1-2:6, to obtain a multi-micro-edge diamond.

9. Multi-micro-edge diamond, characterized in that: The multi-micro-blade diamond is prepared by the preparation method of the multi-micro-blade diamond according to any one of claims 1-8.

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