A method for processing single crystal diamond

Abstract

The present invention discloses a method for processing single-crystal diamond. The method comprises the following steps: Step 1: uniformly stirring and mixing diamond micropowder with a particle size of 1 to 3 μm and a lipid compound to obtain a grinding medium, wherein the mass ratio of the lipid compound to the diamond micropowder is (2 to 5):1; Step 2: uniformly applying the grinding medium to the surface of a cast iron disc and pushing the disc with a polycrystalline diamond to obtain a cast iron disc inlaid with diamond micropowder; Step 3: grinding and polishing the surface of the single-crystal diamond with the cast iron disc inlaid with diamond micropowder, and adding a mixture of an inorganic aqueous solution and diamond micropowder during the grinding and polishing process. The present invention aims to improve the processing quality of single-crystal diamond.

Description

Technical Field

[0001] The present invention relates to the technical field of diamond material processing, and in particular to a method for processing single crystal diamond. Background Art

[0002] At present, diamond is the hardest material in nature, with high thermal conductivity, chemical inertness and excellent wear resistance. The surface of single-crystal diamond generally prepared by Chemical Vapor Deposition (CVD) will have different degrees of polycrystalline, uneven in terms of crystal orientation and thickness, and the surface is very rough, which cannot be used in related applications. Therefore, before the application of CVD diamond, it needs to be flattened, such as cutting, grinding and polishing. Among them, mechanical grinding is the most important and most widely used processing method for diamond flattening. It is a method of grinding using traditional cast iron discs. Diamond abrasive powder attached to the surface of the iron disc is used to contact the diamond surface to increase friction. During the friction process, the protruding part of the diamond surface collides with the diamond powder and deforms, thereby achieving the effect of flattening the surface.

[0003] Meanwhile, prior art CN110026831A discloses a method for mechanically polishing single-crystal diamond using metal powder. The method employs a mixture of transition metal powder and diamond powder as a polishing medium for mechanical polishing of single-crystal diamond, with a mass ratio of metal powder to diamond powder of 1:0.5 to 1:10. The mixture is evenly applied to the surface of a high-speed rotating cast iron disc. The polishing disc rotates at a speed of 1000 to 5000 r / min, while the cast iron disc rotates at speeds greater than 2800 r / min. During machining, when the diamond contacts the high-speed rotating disc, the surface diamond powder is immediately thrown off, resulting in a low diamond powder content on the disc surface and prolonged machining time. Furthermore, during the automated machining process, high temperatures are continuously generated, and the transition metal powder and diamond powder generate high damping during machining, causing vibration of the diamond disc and causing it to break easily during grinding, thereby affecting the machining quality of the single-crystal diamond. Therefore, there is an urgent need to propose a high-efficiency and high-quality single crystal diamond processing method. Summary of the Invention

[0004] The main purpose of the present invention is to provide a single crystal diamond processing method, aiming to improve the processing quality of single crystal diamond.

[0005] To achieve the above object, the present invention provides a method for processing single crystal diamond, the method comprising the following steps:

[0006] Step 1, uniformly stirring and mixing diamond micropowder with a particle size of 1 to 3 μm and a lipid compound to obtain a grinding medium, wherein the mass ratio of the lipid compound to the diamond micropowder is (2 to 5):1;

[0007] Step 2, evenly applying the grinding medium to the surface of the cast iron disc, and performing a disc pushing operation using polycrystalline diamond to obtain a cast iron disc inlaid with diamond powder;

[0008] Step 3: grinding and polishing the surface of the single crystal diamond with a cast iron disk inlaid with diamond powder, and adding a mixture of an inorganic aqueous solution and diamond powder during the grinding and polishing process, wherein the rotation speed range of the grinding and polishing operation is 2500 to 4500 rpm.

[0009] Optionally, the mass ratio of the lipid compound to the diamond powder in step 1 is 3:1.

[0010] Optionally, the lipid compound includes at least one of petrolatum, animal fat and glycerin.

[0011] Optionally, the inorganic aqueous solution in step 3 includes alcohol or acetone aqueous solution.

[0012] Optionally, the mass ratio of the inorganic aqueous solution to the diamond micropowder is (3-10):1.

[0013] Optionally, the particle size of the diamond powder is 1 μm.

[0014] Optionally, step 2 specifically includes:

[0015] Apply the grinding medium evenly to the surface of the cast iron disc, and adjust the rotation speed of the cast iron disc to a preset value;

[0016] Then, the diamond micropowder attached to the surface of the cast iron disk is pressed by using polycrystalline diamond so that the diamond micropowder is embedded in the surface of the cast iron disk.

[0017] Optionally, before step 3, the method further includes:

[0018] A cast iron disk inlaid with diamond powder is controlled to rotate faster and heat up to a preset value so as to volatilize lipid compounds attached to the surface of the cast iron disk.

[0019] Optionally, the method further comprises inspecting the single crystal diamond after the grinding and polishing operation.

[0020] Optionally, the single crystal diamond is fixed in a fixture with adjustable angle.

[0021] The present invention provides a single crystal diamond processing method. The method comprises the following steps: uniformly stirring and mixing diamond micropowder with a particle size of 1 to 3 μm with a lipid compound to obtain a grinding medium, wherein the mass ratio of the lipid compound to the diamond micropowder is (2 to 5):1; uniformly applying the grinding medium to the surface of a cast iron disc, and pushing the disc with a polycrystalline diamond to obtain a cast iron disc inlaid with the diamond micropowder; and grinding and polishing the surface of the single crystal diamond with the cast iron disc inlaid with the diamond micropowder, and adding a mixture of an inorganic aqueous solution and the diamond micropowder during the grinding and polishing process. It can be seen that in the processing technology of single crystal diamond in the present invention, a mixture of lipid compound and diamond powder is pre-adopted to achieve the embedding of diamond powder on the surface of the cast iron disk, and then the diamond powder is firmly embedded in the surface of the iron disk through the lipid compound, thereby avoiding the loss of diamond powder and the reduction of processing efficiency; at the same time, the particle size of the diamond powder is controlled to be 1 to 3 microns to avoid the powder size being too small, which will cause insufficient removal during the single crystal diamond grinding process, resulting in low grinding efficiency, and the powder size being too large, which will cause the surface of the iron disk to be too rough, causing large vibrations during the grinding process, resulting in cracks or breakage of the diamond, and the powder particle size being too large will also fail to be effectively embedded in the surface of the iron disk, and the powder will roll on the surface of the diamond and the iron disk, affecting the grinding efficiency.

[0022] At the same time, the use of a mixture of inorganic aqueous solution and diamond micropowder during the grinding and polishing operation can, on the one hand, clean the grease on the surface of the iron disc; on the other hand, the mixture of inorganic aqueous solution and diamond micropowder can evaporate rapidly on the surface of the grinding disc as the temperature rises during the grinding and polishing operation, thereby reducing the damping during the grinding and polishing process, reducing the vibration generated during the processing, and preventing the single crystal diamond from breaking during the grinding and polishing operation, thereby improving the processing quality of single crystal diamond. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic flow chart of a single crystal diamond processing method of the present invention;

[0024] Figure 2 This is a microscopic image of the surface of single crystal diamond before processing;

[0025] Figure 3 This is a microscopic image of the surface of single crystal diamond after processing;

[0026] Figure 4 This is a microscopic image of the single crystal diamond surface processed by Comparative Example 1;

[0027] Figure 5 This is a microscopic image of the single crystal diamond surface processed by Comparative Example 2.

[0028] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0029] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] Reference Figure 1 The present invention provides a process diagram of a first embodiment of a single crystal diamond processing method, the method comprising:

[0031] Step 1: Diamond micropowder and a lipid compound are uniformly stirred and mixed to obtain a grinding medium, wherein the mass ratio of the lipid compound to the diamond micropowder is (2-5):1. Preferably, the mass ratio of the lipid compound to the diamond micropowder is 3:1, and the lipid compound includes at least one of petrolatum, animal fat, and glycerin.

[0032] Step 2: Evenly apply the grinding medium to the surface of the cast iron disc, and push the disc with a polycrystalline diamond to obtain a cast iron disc inlaid with diamond powder. Specifically, because lipid compounds have high adhesion, before grinding and polishing, the lipid compound mixed with diamond powder is evenly applied to the surface of the cast iron disc. By turning on the grinding and polishing equipment and adjusting the cast iron disc speed to a slow speed, and using polycrystalline diamond to compact the diamond powder attached to the surface of the cast iron disc, the diamond powder is firmly embedded in the surface of the cast iron disc. In addition, the cast iron disc inlaid with diamond powder is controlled to accelerate and heat up to a preset value to volatilize the lipid compound attached to the surface of the cast iron disc. Generally, a manual disc push can be performed before the automatic grinding and polishing step, waiting for the iron disc surface to heat up, thereby volatilizing the lipid compound attached to the surface of the cast iron disc, and then the fixture equipped with single crystal diamond is dropped to wait for the grinding and polishing operation of step 3 to be performed, wherein the single crystal diamond is fixed in an angle-adjustable fixture and the grinding surface is exposed. In step 2, the lipid compound mainly serves to improve the adhesion of the diamond powder to the surface of the cast iron disk, and thus the particle size of the diamond powder needs to be controlled to 1-3 μm. Preferably, the particle size of the diamond powder is 1 μm.

[0033] Step 3: grinding and polishing the surface of the single crystal diamond with a cast iron disk inlaid with diamond powder, and controlling the rotation speed of the grinding and polishing operation to be in the range of 2500 to 4500 rpm, and adding a mixture of inorganic aqueous solution and diamond powder during the grinding and polishing process.

[0034] Specifically, during the grinding and polishing operation, the surface temperature of the cast iron disc gradually increases, and the inorganic solution will clean the remaining lipid compounds on the surface of the iron disc. At the same time, the inorganic solution will quickly evaporate from the surface of the grinding disc, thereby reducing the friction damping between the diamond and the iron disc during the grinding and polishing process, reducing the vibration generated during the processing, preventing chipping during the operation, and thus improving the processing quality of the single crystal diamond. The inorganic aqueous solution includes an alcohol or acetone aqueous solution. Preferably, the alcohol is 30% alcohol, and the volume ratio of 30% alcohol or acetone to water is controlled to be (3-5):1. The above-mentioned grinding and polishing time is determined according to the size of the product. The larger the product size, the longer the grinding time. The general grinding and polishing time range is 0.2 to 1 hour.

[0035] Furthermore, the mass ratio of the inorganic aqueous solution to the diamond micropowder is (3-10):1. Preferably, the mass ratio of the inorganic aqueous solution to the diamond micropowder is 5:1, and the particle size of the diamond micropowder is 1 to 3 μm.

[0036] Furthermore, after step 3, the single crystal diamond needs to be inspected after the grinding and polishing operation.

[0037] Furthermore, in order to better illustrate the processing method of the present invention, the following is described through specific examples:

[0038] Example 1

[0039] (1) Diamond micropowder with a particle size of 1 μm is mixed with animal fat, wherein the mass ratio of animal fat to diamond micropowder is 3:1, and the mixture is stirred evenly.

[0040] (2) Apply animal fat mixed with diamond powder evenly on the surface of the cast iron disc, turn on the grinding and polishing equipment and adjust the speed of the cast iron disc to slow, and use polycrystalline diamond to press the diamond powder attached to the surface of the iron disc so that the diamond powder is firmly embedded in the surface of the cast iron disc.

[0041] (3) Start manually pushing the plate and wait for the surface of the cast iron plate to heat up so that the animal fat attached to the surface of the cast iron plate can evaporate. Generally, the surface temperature of the cast iron plate can be controlled to rise to 200℃.

[0042] (4) Then the fixture containing the single crystal diamond is dropped to make the single crystal diamond contact with the iron disk. The schematic diagram of the microstructure of the surface of the single crystal diamond before polishing is as follows: Figure 2As shown, the surface of the single-crystal diamond before polishing is uneven and uneven. By starting the automatic polishing process and controlling the polishing speed to 3000 rpm, and adding a mixture of acetone and diamond powder during the polishing process, the surface temperature of the cast iron disc gradually increases during the automatic processing. The acetone solution cleans the grease on the surface of the iron disc and quickly evaporates from the surface of the grinding disc, thereby reducing the friction damping between the diamond and the iron disc during the polishing process, reducing the vibration generated during the processing, and preventing chipping during the operation. The mass ratio of diamond powder to acetone solution is controlled to be 1:5, and the volume ratio of acetone to water in the acetone solution is 3:1.

[0043] (5) Finally, the single crystal diamond after the grinding and polishing process is inspected. If the composite conditions are met, the processing is completed. The schematic diagram of the surface of the single crystal diamond after the grinding and polishing operation is as follows: Figure 3 As shown in the figure, the surface of the single crystal diamond after grinding and polishing is very smooth and flat.

[0044] Example 2

[0045] (1) Diamond micropowder with a particle size of 2 μm is mixed with petrolatum, wherein the mass ratio of petrolatum to diamond micropowder is 2:1, and the mixture is stirred evenly.

[0046] (2) Apply petrolatum mixed with diamond powder evenly on the surface of the cast iron disc, turn on the grinding and polishing equipment and adjust the speed of the cast iron disc to slow, and use polycrystalline diamond to press the diamond powder attached to the surface of the iron disc so that the diamond powder is firmly embedded in the surface of the cast iron disc.

[0047] (3) Start manually pushing the plate and wait for the surface of the cast iron plate to heat up so that the petrolatum attached to the surface of the cast iron plate can evaporate. Generally, the surface temperature of the cast iron plate can be controlled to rise to 300℃.

[0048] (4) The fixture containing the single crystal diamond is then dropped to contact the single crystal diamond with the iron disc, and the automatic grinding and polishing operation is started. The grinding and polishing speed range is controlled to 2500 rpm, and a mixture of acetone aqueous solution and diamond powder is added during the grinding and polishing process, so that the surface temperature of the cast iron disc gradually increases during the automatic processing. The acetone aqueous solution will clean the petrolatum on the surface of the iron disc and quickly evaporate on the surface of the grinding disc, thereby reducing the friction damping between the diamond and the iron disc during the grinding and polishing process, reducing the vibration generated during the processing, and preventing breakage during the operation. Among them, the mass ratio of diamond powder to acetone aqueous solution is controlled to be 1:3, and the volume ratio of acetone to water in the acetone aqueous solution is 5:1.

[0049] (5) Finally, the single crystal diamond after the above grinding and polishing process is inspected. If it meets the composite conditions, the processing is completed.

[0050] The surface effect of the single crystal diamond obtained after grinding and polishing in Example 2 is basically the same as that in Example 1.

[0051] Example 3

[0052] (1) Diamond micropowder with a particle size of 3 μm was mixed with glycerin, wherein the mass ratio of glycerin to diamond micropowder was 4:1, and the mixture was stirred evenly.

[0053] (2) Apply glycerin mixed with diamond powder evenly on the surface of the cast iron disc, turn on the grinding and polishing equipment and adjust the speed of the cast iron disc to slow, and use polycrystalline diamond to press the diamond powder attached to the surface of the iron disc so that the diamond powder is firmly embedded in the surface of the cast iron disc.

[0054] (3) Start manually pushing the plate and wait for the surface of the cast iron plate to heat up so that the glycerin attached to the surface of the cast iron plate can evaporate. Generally, the surface temperature of the cast iron plate can be controlled to rise to 300°C.

[0055] (4) The fixture containing the single crystal diamond is then dropped to contact the single crystal diamond with the iron disc, and the automatic grinding and polishing operation is started. The grinding and polishing speed range is controlled to 4500 rpm, and a mixture of 30% alcohol aqueous solution and diamond powder is added during the grinding and polishing process, so that the surface temperature of the cast iron disc gradually increases during the automatic processing. The alcohol aqueous solution will clean the petrolatum on the surface of the iron disc and quickly evaporate on the surface of the grinding disc, thereby reducing the friction damping between the diamond and the iron disc during the grinding and polishing process, reducing the vibration generated during the processing, and preventing breakage during the operation. Among them, the mass ratio of diamond powder to alcohol aqueous solution is controlled to be 1:10, and the volume ratio of acetone to water in the acetone aqueous solution is 4:1.

[0056] (5) Finally, the single crystal diamond after the above grinding and polishing process is inspected. If it meets the composite conditions, the processing is completed.

[0057] The surface effect of the single crystal diamond obtained after grinding and polishing in Example 3 is basically the same as that in Example 1.

[0058] Example 4

[0059] (1) Diamond micropowder with a particle size of 2 μm is mixed with animal fat, wherein the mass ratio of animal fat to diamond micropowder is 5:1, and the mixture is stirred evenly.

[0060] (2) Apply animal fat mixed with diamond powder evenly on the surface of the cast iron disc, turn on the grinding and polishing equipment and adjust the speed of the cast iron disc to slow, and use polycrystalline diamond to press the diamond powder attached to the surface of the iron disc so that the diamond powder is firmly embedded in the surface of the cast iron disc.

[0061] (3) Start manually pushing the plate and wait for the surface of the cast iron plate to heat up so that the glycerin attached to the surface of the cast iron plate can evaporate. Generally, the surface temperature of the cast iron plate can be controlled to rise to 250°C.

[0062] (4) The fixture containing the single crystal diamond is then dropped to contact the single crystal diamond with the iron disc, and the automatic grinding and polishing operation is started. The grinding and polishing speed range is controlled to 4500 rpm, and a mixture of 30% alcohol aqueous solution and diamond powder is added during the grinding and polishing process, so that the surface temperature of the cast iron disc gradually increases during the automatic processing. The alcohol aqueous solution will clean the grease on the surface of the iron disc and quickly evaporate on the surface of the grinding disc, thereby reducing the friction damping between the diamond and the iron disc during the grinding and polishing process, reducing the vibration generated during the processing, and preventing breakage during the operation. Among them, the mass ratio of diamond powder to alcohol aqueous solution is controlled to be 1:7, and the volume ratio of acetone to water in the acetone aqueous solution is 4:1.

[0063] (5) Finally, the single crystal diamond after the above grinding and polishing process is inspected. If it meets the composite conditions, the processing is completed.

[0064] The surface effect of the single crystal diamond obtained after grinding and polishing in Example 4 is basically the same as that in Example 1.

[0065] Comparative Example 1

[0066] The processing method in Example 1 is used, except that the particle size of the diamond powder used is 6 μm, and the surface effect of the single crystal diamond obtained after the grinding and polishing process does not meet the expected effect. Figure 4 As shown in the figure, the surface of the ground single crystal diamond sheet is broken. The reason is that the micro powder size is too large, which makes the surface of the iron disk too rough, causing large vibrations during the grinding process, resulting in cracks or breakage of the diamond.

[0067] Comparative Example 2

[0068] The processing method in Example 1 is used, except that grease is mixed with diamond powder in step 3, and the surface effect of the single crystal diamond obtained after the grinding and polishing process does not meet the expected effect. Figure 5 As shown in the figure, the surface of the ground single crystal diamond sheet is broken. The principle is that the addition of grease mixed with diamond micropowder during the processing will produce higher damping, which in turn generates vibration, causing the single crystal diamond sheet to break.

[0069] Comparative Example 3

[0070] The processing method of Example 1 was used, except that olive oil and diamond powder were used as the grinding media in step 1. As a result, the surface effect of the single-crystal diamond obtained after the grinding and polishing process did not meet the expected effect. The reason is that olive oil tends to become viscous under high temperature conditions, thereby affecting the grinding effect and causing the surface of the ground single-crystal diamond sheet to crack.

[0071] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0072] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0073] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for processing single crystal diamond, characterized in that: The method comprises the following steps: Step 1, uniformly stirring and mixing diamond micropowder with a particle size of 1 to 3 μm and a lipid compound to obtain a grinding medium, wherein the mass ratio of the lipid compound to the diamond micropowder is (2 to 5):1, and the lipid compound comprises at least one of petrolatum, animal fat, and glycerin; Step 2, evenly applying the grinding medium to the surface of the cast iron disc, and performing a disc pushing operation using polycrystalline diamond to obtain a cast iron disc inlaid with diamond powder; Step 3, grinding and polishing the surface of the single crystal diamond with a cast iron disk inlaid with diamond powder, and adding a mixture of an inorganic aqueous solution and diamond powder during the grinding and polishing process, wherein the grinding and polishing operation is performed at a rotation speed of 2500 to 4500 rpm, the inorganic aqueous solution includes an alcohol or acetone aqueous solution, and the mass ratio of the inorganic aqueous solution to the diamond powder is (3-10):1; The step 2 specifically includes: Apply the grinding medium evenly to the surface of the cast iron disc, and adjust the rotation speed of the cast iron disc to a preset value; Then, the diamond powder attached to the surface of the cast iron disk is pressed tightly by using polycrystalline diamond, so that the diamond powder is embedded in the surface of the cast iron disk; Before step 3, the method further includes: A cast iron disk inlaid with diamond powder is controlled to rotate faster and heat up to a preset value so as to volatilize lipid compounds attached to the surface of the cast iron disk.

2. The method for processing single crystal diamond according to claim 1, characterized in that: The mass ratio of the lipid compound to the diamond powder in step 1 is 3:

1.

3. The method for processing single crystal diamond according to claim 1 or 2, characterized in that: The method further includes inspecting the single crystal diamond after the grinding and polishing operation.

4. The method for processing single crystal diamond according to claim 3, characterized in that: The single crystal diamond is fixed in a fixture with adjustable angle.

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