Manufacturing method for cultivating diamond seeds at high temperature and high pressure

Abstract

The invention discloses a manufacturing method for cultivating diamond seeds at high temperature and high pressure, which comprises the following steps: S1, collecting diamond blank cutting wastes as raw materials of the diamond seeds; s2, flatly laying and fixing a plurality of raw materials on a first substrate, and cutting to obtain pretreated diamond seeds; s3, after cutting is completed, a second substrate is pasted on the face, away from the pretreated diamond seeds, of the first substrate for reinforcement; s4, after reinforcement is completed, all the pretreated diamond seeds on the first substrate are polished together, and a polished raw material is obtained; s5, the polished raw materials are cleaned and selected, and diamond seeds are obtained; the raw materials are obtained by cutting the diamond blank, the raw materials are directly cut, polished and cleaned, so that the diamond seeds are directly obtained, a traditional cultivation process is not needed, and the obtained crystal seeds are larger in size, more regular in shape, better in size consistency and higher in surface smoothness.

Description

Technical Field

[0001] The present invention belongs to the technical field of cultured diamonds, and in particular relates to a method for manufacturing high-temperature and high-pressure cultured diamond seeds. Background Art

[0002] After years of development, the high-temperature and high-pressure method of artificially growing diamonds has made great improvements in synthesis process, cavity structure, raw material control and other aspects. However, there are still many factors that have an important impact on product quality. Among them, diamond seeds (seeds) are the key materials that affect diamond growth. Traditional seeds are made according to the synthetic block materials of industrial diamonds, and the crystal shape is grown to be close to a cube by means of process control. Among these industrial diamonds, those with complete shape and good clarity are manually selected to be used as seeds for growing cultured diamonds. This kind of seed has poor clarity, yellow color, and poor regularity of shape. Even if there are good clarity and regular shape, they are very rare and cannot meet the needs of mass production. As people's requirements for the quality of cultured diamonds become higher and higher, this traditional seed is difficult to adapt to the needs of market development. The main limitations are reflected in the following points:

[0003] 1. Too many internal impurities: It is easy to cause internal impurities to form in the early stage of diamond growth;

[0004] 2. The surface of the seed crystal is not smooth: This causes different growth rates at different points in the early stages of diamond growth, resulting in a poor crystal shape.

[0005] 3. The shape is uncontrollable: Generally, the seed crystal is close to a cube, but it is only close. It is almost impossible to find two exactly the same seed crystals.

[0006] 4. Large size differences: The cubic diamonds made by industrial diamond methods are screened to control the particle size, but they are only a group of particle sizes. The general side length is 0.6-1.2 mm. When used as seeds, it is necessary to repeatedly select seeds of similar size, which greatly reduces production efficiency. If you don't select carefully, the seed size will vary greatly, and the diamonds grown will also vary greatly.

[0007] 5. Size is limited: Currently, the maximum size of a seed crystal that can be produced using traditional methods is only about 1.5 mm. If it is larger, the quality will be very poor. Therefore, it is almost impossible to produce a larger seed crystal using traditional methods.

[0008] Due to the above limitations, the rate of high-quality crystals of rough diamonds grown by the high-temperature and high-pressure method is currently low, and some companies that do not control well even find it difficult to make a profit. How to make the seed crystal larger, clearer, more regular in shape, more consistent in size, and smoother on the surface has become a technical problem that the industry urgently needs to solve. Summary of the invention

[0009] The object of the present invention is to provide a method for manufacturing high temperature and high pressure cultured diamond seeds to solve at least one of the above technical problems.

[0010] To achieve the above object, the technical solution adopted by the present invention is:

[0011] A method for manufacturing a high temperature and high pressure cultured diamond seed comprises the following steps:

[0012] S1: Collect diamond rough cutting waste as raw materials for diamond seeds;

[0013] S2: laying and fixing a plurality of raw materials on a first substrate for cutting to obtain pre-processed diamond seeds;

[0014] S3: After the cutting is completed, a second substrate is attached to the side of the first substrate facing away from the pre-treated diamond seeds for reinforcement;

[0015] S4: After the reinforcement is completed, all the pre-treated diamond seeds on the first substrate are polished together to obtain polished raw materials;

[0016] S5: Clean and select the polished raw materials to obtain diamond seeds.

[0017] The raw material of the present invention is obtained by cutting diamond roughs. The raw material is directly cut, polished and cleaned, so as to directly obtain diamond seeds, i.e., crystal seeds, without going through the traditional cultivation process. The obtained crystal seeds are larger in size, more regular in shape, better in size consistency and higher in surface finish. Since the raw material is obtained by cutting diamond roughs, the crystal seeds obtained by the method are also higher in clarity. At present, the shapes of diamond roughs cultivated under high temperature and high pressure are all cone-like shapes with a larger bottom and a smaller upper part. When cutting and polishing, the roughs with better clarity and color are first selected for cutting and polishing. The larger part of the bottom of the rough will be completely cut off, and the final diamond yield is generally about 30%. The cut bottom is generally treated as waste. The method uses the waste cut off from the diamond rough when making diamonds as raw materials, does not increase the raw material cost, has low crystal seed production cost, fast speed and high economic benefits.

[0018] The present invention also fixes the raw material through the first substrate. Multiple pieces of raw material can be fixed on the first substrate. Each piece of raw material can also be cut into multiple diamond seeds according to the size of the raw material and the size of the diamond seed, so that a large number of diamond seeds can be prepared at one time.

[0019] Furthermore, the first substrate is a circular iron sheet. Before fixing the raw material onto the first substrate, the first substrate is first polished and flat. The first substrate has a diameter of 50 mm and a thickness of 5 mm, which is convenient for fixing multiple pieces of raw material. The polished first substrate is also conducive to more accurate cutting of the diamond seeds.

[0020] Furthermore, by using an adhesive to fix the raw material on the first substrate, the raw material and the first substrate can be more closely attached and the fixation is more convenient.

[0021] Furthermore, fixing the cut surface of the raw material to the first substrate can make the raw material fixed more stably. When making diamond seeds, an original surface of the raw material can also be used as the bottom surface of the diamond seed, thereby reducing one processing step.

[0022] Furthermore, in step S2, the raw material is cut using a laser cutting machine, and the cutting steps are as follows:

[0023] Carry out thickness cutting of raw materials;

[0024] An array cutting in the X-axis direction and an array cutting in the Y-axis direction are set to cut vertical and horizontal cross lines in the entire range of the first substrate. By cutting in this way, multiple pieces of raw materials can be cut faster to obtain pre-treated diamond seeds. During cutting, the first substrate will be cut, but the first substrate will still be adhered together. The first substrate is reinforced by setting a second substrate, which is convenient for subsequent grinding of a large number of pre-treated diamond seeds at the same time, thereby improving the efficiency of diamond seed production.

[0025] Furthermore, in the cutting step, the cutting thickness is 0.5-1.5 mm, the interval of the array cutting in the X-axis direction is 0.5-3 mm, and the interval of the array cutting in the Y-axis direction is 0.5-3 mm.

[0026] Further, in step S4, the raw material is ground using a grinder in combination with a grinding liquid and abrasive, wherein the grinding liquid is an aqueous grinding liquid, the abrasive is a polycrystalline diamond powder of 3-5 microns, the weight ratio of the diluted grinding liquid to the polycrystalline diamond powder is 1000:5, and the grinding time is 2 hours. By grinding, the surface of the raw material is polished to a mirror effect, which can improve the surface finish of the seed crystal.

[0027] Furthermore, in step S5, before cleaning the polishing raw material, the polishing raw material is first baked in an oven to scorch the adhesive so that the polishing raw material is separated from the first substrate. The baking temperature is 200 degrees Celsius and the baking time is 1 hour. By baking, the adhesive can be scorched, which facilitates the separation of the polishing raw material and the adhesive.

[0028] Furthermore, in step S5, the polished raw material is placed in sulfuric acid, heated and cleaned, and then rinsed with clean water to clean the polished raw material and facilitate washing away impurities attached to the surface of the raw material.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention uses diamond rough cuts as raw materials, for example, waste cut from the diamond production process can be used as raw materials, which greatly reduces the production cost of seed crystals compared to the traditional high temperature and high pressure synthesis method;

[0031] (2) Since the seed crystals are cut by laser, their shape consistency is very good, and the size of each seed crystal is almost the same;

[0032] (3) Since the seed crystal is laser cut, its shape and size can be controlled and can be designed according to the needs, such as square, rectangular, or even more complex shapes such as circle, etc., while traditional solutions cannot achieve such shape control;

[0033] (4) Due to the fine grinding and polishing scheme, the smoothness of the seed crystal growth surface can reach a mirror effect of about 5 microns, which plays a vital role in the uniformity of the initial growth of diamonds;

[0034] (5) Since high-purity diamond rough is used as raw material, the raw material of the seed crystal growth surface is ensured to be highly pure diamond, which provides a reliable premise for improving diamond growth;

[0035] (6) The seed crystal produced by this scheme has significantly improved the consistency and clarity of the blanks produced by a synthetic block, and the comprehensive output efficiency has been improved by 30-50%;

[0036] (7) The present invention can produce a large number of diamond seeds at one time by processing the original diamond seeds fixed on the first substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flow chart of a method for manufacturing high temperature and high pressure cultured diamond seeds in this embodiment;

[0038] Figure 2 This is a schematic diagram of the state of the raw materials being placed on the first substrate in this embodiment;

[0039] Figure 3 This is a schematic diagram of raw material thickness cutting in this embodiment;

[0040] Figure 4 Schematic diagram of array cutting in the X-axis direction and the Y-axis direction in this embodiment;

[0041] In the figure: 1. first substrate; 2. raw material. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] like Figure 1 As shown, this embodiment provides a method for manufacturing a high temperature and high pressure cultured diamond seed, comprising the following steps:

[0044] S1: Collect diamond rough cutting waste as raw material for diamond seeds 2;

[0045] S2: multiple raw materials 2 are laid flat and fixed on the first substrate 1 for cutting to obtain pre-processed diamond seeds;

[0046] S3: After the cutting is completed, a second substrate is attached to the side of the first substrate 1 away from the pre-treated diamond seed for reinforcement;

[0047] S4: After the reinforcement is completed, all the pre-treated diamond seeds on the first substrate 1 are polished together to obtain polished raw materials;

[0048] S5: Clean and select the polished raw materials to obtain diamond seeds.

[0049] The raw material 2 of the present invention is obtained by cutting diamond roughs. The raw material 2 is directly cut, polished and cleaned to directly obtain diamond seeds, i.e., seed crystals, without going through the traditional cultivation process. The seed crystals obtained are larger in size, more regular in shape, better in size consistency, and higher in surface finish. Since the raw material 2 is cut from diamond roughs, the seed crystals obtained by the method are also higher in clarity. Currently, the shapes of diamond roughs cultivated under high temperature and high pressure are all conical shapes with a larger bottom and a smaller top. When cutting and polishing, the roughs with better clarity and color are first selected for cutting and polishing. The larger part of the bottom of the rough will be completely cut off, and the final diamond yield is generally about 30%. The cut bottom is generally treated as waste. The method uses the waste cut off from the diamond rough when making diamonds as the raw material 2, does not increase the cost of the raw material 2, has low seed crystal production cost, fast speed, and high economic benefits.

[0050] The present invention also fixes the raw material 2 by the first substrate 1, such as Figure 2 As shown, a plurality of raw materials 2 can be fixed on the first substrate 1, and each raw material 2 can also be cut into a plurality of diamond seeds according to the size of the raw material 2 and the size of the diamond seeds, so that a large number of diamond seeds can be prepared at one time.

[0051] Furthermore, the first substrate 1 is a circular iron sheet. Before fixing the raw material 2 onto the first substrate 1, the first substrate 1 is first polished and flat. The first substrate 1 has a diameter of 50 mm and a thickness of 5 mm, which is convenient for fixing multiple pieces of raw material 2. The polished first substrate 1 is also conducive to more accurate cutting of the size of the diamond seeds.

[0052] Furthermore, using an adhesive to fix the raw material 2 on the first substrate 1 can make the raw material 2 fit better with the first substrate 1 and make fixation more convenient. The adhesive can be glue, preferably 502 glue, which is easy to solidify and also convenient to separate the polished raw material 2 from the first substrate 1 through subsequent baking.

[0053] Furthermore, fixing the cut surface of the raw material 2 to the first substrate 1 can make the raw material 2 fixed more stably. When making diamond seeds, an original surface of the raw material 2 can also be used as the bottom surface of the diamond seed, thereby reducing one processing step.

[0054] Furthermore, in step S2, the raw material 2 is cut by using a laser cutting machine, and the cutting steps are as follows:

[0055] like Figure 3 As shown, the thickness cutting of the raw material 2 is performed;

[0056] like Figure 4 As shown, array cutting in the X-axis direction and array cutting in the Y-axis direction are set to cut vertical and horizontal cross lines within the entire first substrate 1. By cutting in this way, multiple pieces of raw materials 2 can be cut faster to obtain pre-treated diamond seeds. When cutting, the first substrate 1 will be cut, but the first substrate 1 will still be adhered together. The first substrate 1 is reinforced by setting the second substrate, which is convenient for subsequent grinding of a large number of pre-treated diamond seeds at the same time, thereby improving the efficiency of diamond seed production.

[0057] Furthermore, in the cutting step, the cutting thickness is 0.5-1.5 mm, preferably 1.3 mm; the interval of the array cutting in the X-axis direction is 0.5-3 mm, preferably 2 mm; the interval of the array cutting in the Y-axis direction is 0.5-3 mm, preferably 2 mm.

[0058] Further, in step S4, the raw material 2 is ground using a grinder in combination with a grinding liquid and abrasive, wherein the grinding liquid is an aqueous grinding liquid, the abrasive is a polycrystalline diamond powder with a specification of 3-5 microns, the weight ratio of the diluted grinding liquid to the polycrystalline diamond powder is 1000:5, and the grinding time is 2 hours. By grinding, the surface of the raw material 2 is polished to a mirror effect, which can improve the surface finish of the seed crystal.

[0059] Furthermore, in step S5, before cleaning the polishing raw material, the polishing raw material is first baked in an oven to scorch the adhesive and separate the polishing raw material from the first substrate 1. The baking temperature is 200 degrees Celsius and the baking time is 1 hour. By baking, the adhesive can be scorched, which facilitates the separation of the polishing raw material and the adhesive. The separated polishing raw material is left to cool before being cleaned.

[0060] Further, in step S5, the polished raw material is placed in sulfuric acid, heated and cleaned, and then rinsed with clean water to clean the polished raw material, so as to facilitate washing away impurities attached to the surface of the raw material 2; preferably, when heating and cleaning the polished raw material, the polished raw material can be poured into sulfuric acid and boiled for one hour to achieve a better cleaning effect, so that the graphite on the surface of the polished raw material can be washed away; after cleaning, it is dried, and after drying, it is selected under a microscope to remove irregularly shaped particles, and the polished surface is turned up to check for impurities and cracks, etc., and the defective ones are selected, and the remaining ones can be used as diamond seeds.

[0061] It should be noted that although the present invention is disclosed as above by specific embodiments, the above embodiments are not intended to limit the present invention. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A method for producing high temperature and high pressure cultured diamond seeds, characterized in that: The following steps are involved: S1: Collect diamond rough cutting waste as raw materials for diamond seeds; S2: laying and fixing a plurality of raw materials on a first substrate for cutting to obtain pre-processed diamond seeds; S3: After the cutting is completed, a second substrate is attached to the side of the first substrate facing away from the pre-treated diamond seeds for reinforcement; S4: After the reinforcement is completed, all the pre-treated diamond seeds on the first substrate are polished together to obtain polished raw materials; S5: Clean and select the polished raw materials to obtain diamond seeds.

2. The method for manufacturing high temperature and high pressure cultured diamond seeds according to claim 1, characterized in that: The first substrate is a circular iron sheet. Before fixing the raw material on the first substrate, the first substrate is firstly polished and made flat.

3. The method for manufacturing high temperature and high pressure cultured diamond seeds according to claim 1, characterized in that: In step S2, the raw material is fixed on the first substrate by using an adhesive.

4. The method for manufacturing a high-temperature and high-pressure cultured diamond seed according to claim 1, characterized in that: In step S2, the cut surface of the raw material is fixed to the first substrate.

5. The method for manufacturing high temperature and high pressure cultured diamond seeds according to claim 1, characterized in that: In step S2, the raw material is cut by a laser cutting machine, and the cutting steps are as follows: Carry out thickness cutting of raw materials; Set up array cutting in the X-axis direction and array cutting in the Y-axis direction to cut vertical and horizontal cross lines in the entire first substrate.

6. The method for manufacturing high temperature and high pressure cultured diamond seeds according to claim 5, characterized in that: In the cutting step, the cutting thickness is 0.5-1.5 mm, the interval of the array cutting in the X-axis direction is 0.5-3 mm, and the interval of the array cutting in the Y-axis direction is 0.5-3 mm.

7. The method for manufacturing high temperature and high pressure cultured diamond seeds according to claim 1, characterized in that: In step S4, the raw material is ground using a grinder in combination with a grinding liquid and a grinding material.

8. The method for manufacturing high temperature and high pressure cultured diamond seeds according to claim 3, characterized in that: In step S5, before cleaning the polishing material, the polishing material is first baked in an oven to burn the adhesive, so that the polishing material is separated from the first substrate.

9. The method for manufacturing high temperature and high pressure cultured diamond seeds according to claim 1, characterized in that: In step S5, the polished raw material is placed in sulfuric acid, heated and cleaned, and then rinsed with clean water to clean the polished raw material.

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