Laser cutting method for large-scale polycrystalline diamond
By selecting laser light sources with smaller wavelengths and a scientifically designed cutting process, combined with the use of UV solidified glue, the problems of insufficient flatness, large cutting losses and serious degumming during laser cutting are solved, and high efficiency and low loss cutting effect are achieved, reducing production costs.
Patent Information
- Application Number
- CN202411171654.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-03-18
AI Technical Summary
During the laser cutting process, large-scale polycrystalline diamond blocks have problems such as insufficient flatness, difficulty in controlling cutting losses, and serious degumming and blocking, resulting in long post-polishing time, large material waste and high processing costs.
Using a laser light source with a smaller wavelength, a scientifically designed cutting process, including first-cut sweeping and sample rotation cutting, monitor and control the cutting loss to about 0.10 mm, and the sample surface is coated with UV solidification glue before cutting, ensuring that the laser frequency is within the range of 6-8 Hz.
It significantly improves cutting quality, reduces cutting losses, material collapse and degumming, reduces post-polishing time and material waste, reduces processing costs, and improves the cutting efficiency of polycrystalline diamond.
Smart Images
Figure CN119635004A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of superhard material processing, and in particular to a laser cutting method for large-scale polycrystalline diamond. Background Art
[0002] Large-scale polycrystalline diamond blocks are directly converted from non-diamond carbon at 14-18GPa and 2300-2600K. They have a smooth surface, good light transmittance, Vickers hardness greater than 130GPa, and a wide range of applications. At present, the processing of large-scale polycrystalline diamond blocks mainly adopts laser cutting. Laser cutting uses a high-power density laser beam to irradiate the cut material, so that the material is quickly heated to the vaporization temperature, evaporates to form holes, and as the beam moves on the material, the holes continuously form a very narrow (such as about 0.1mm) slit to complete the cutting of the material. The light source of the laser cutting machine is different, and the cutting loss is also different. At present, the main gem-grade laser cutting machines on the market use infrared lasers, green lasers, and ultraviolet lasers, with wavelengths of about 700 nanometers, 500 nanometers, and 200 nanometers, respectively.
[0003] There is a common drawback when laser cutting is applied to large-diameter blocks, "V" loss. As the name implies, when the laser ablates the gap, the upper part is always ablated more than the lower part. In addition, due to the error of the laser optical path and focal length, the sample obtained by slicing large-diameter polycrystalline diamond blocks is not flat enough, with an upper and lower error difference of 10 wires (0.1 mm).
[0004] The existing large-scale polycrystalline diamond blocks have a diameter greater than or equal to 6 mm, extremely high hardness and wear resistance, and good light transmittance, which bring many problems to laser cutting: the cut blocks are not flat enough, which increases the later polishing time, increases material waste, and increases processing costs; the cutting loss is difficult to control, and the processed samples debond and collapse under high temperature and high-speed laser impact. For this reason, we propose a laser cutting method for large-scale polycrystalline diamond. Summary of the invention
[0005] The main purpose of the present invention is to provide a laser cutting method for large-scale polycrystalline diamond. By setting steps S1-S4, the problems of insufficient flatness of the cut block material, increased later polishing time, increased material waste, and increased processing costs are solved; the cutting loss control is difficult, and the processed samples are debonded and collapsed under high temperature and high-speed laser impact.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] A laser cutting method for large-scale polycrystalline diamond comprises the following steps:
[0008] S1. Light source selection: choose a laser light source with a smaller wavelength to reduce material loss during the cutting process;
[0009] S2, cutting method, first knife sweeping: use the laser cutting machine to make the first cut on the end face of the sample; sample rotation cutting: after completing the sweeping, use the rotation function of the laser cutting machine to rotate the sample 180 degrees, then make the second cut, and then cut normally to obtain a highly flat slice;
[0010] S3, cutting loss control, monitoring the gap loss during the cutting process, controlling it to about 0.10 mm to ensure cutting quality;
[0011] S4, degumming and chipping control, before cutting, apply glue on the sample surface to enhance the adhesion of the sample, and irradiate it under ultraviolet light. After cutting, immerse the sample in hot water to degumming; keep the laser frequency in the range of 6-8 Hz.
[0012] Preferably, the wavelength of the laser light source is 450-500nm.
[0013] Preferably, the surface of the large-scale polycrystalline diamond is evenly colored with a black marker or a fluorescent pen before cutting.
[0014] Preferably, the cutting loss control in step S3 further includes setting the power of the laser generator to 8-10W.
[0015] Preferably, the glue in step S4 is UV curing glue.
[0016] Preferably, the ultraviolet light irradiation power is 1000W, and the irradiation time is 30-90 seconds.
[0017] Preferably, in step S4, the sample is immersed in hot water, the temperature of the hot water is 80° C., and the immersion time is 5 minutes.
[0018] Preferably, the large-scale polycrystalline diamond block is directly converted from non-diamond carbon as a raw material at 14-18 GPa and 2300-2600K.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] In the present invention, by rationally selecting a light source, scientifically designing a cutting process, and using efficient auxiliary materials, the cutting quality can be significantly improved, the cutting loss can be reduced, and the occurrence of material collapse and debonding can be reduced. By implementing the present invention, while ensuring the cutting effect, the production cost can be reduced, the cutting efficiency of polycrystalline diamond can be improved, and a better quality material can be provided for the relevant field. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the first sweeping cutting setting of the present invention;
[0022] Figure 2 This is a schematic diagram of the planar structure of a large-scale polycrystalline diamond after the first cut of the present invention;
[0023] Figure 3 This is a schematic diagram of the second knife cutting setting of the present invention. DETAILED DESCRIPTION
[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.
[0025] Example 1
[0026] like Figure 1-3 As shown, a laser cutting method for large-scale polycrystalline diamond comprises the following steps:
[0027] S1. Light source selection: choose a laser light source with a smaller wavelength to reduce material loss during the cutting process;
[0028] S2, cutting method, first knife sweeping: use the laser cutting machine to make the first cut on the end face of the sample; sample rotation cutting: after completing the sweeping, use the rotation function of the laser cutting machine to rotate the sample 180 degrees, then make the second cut, and then cut normally to obtain a highly flat slice;
[0029] S3, cutting loss control, monitoring the gap loss during the cutting process, controlling it to about 0.10 mm to ensure cutting quality;
[0030] S4, degumming and chipping control, before cutting, glue is applied to the surface of the sample to enhance the adhesion of the sample, and irradiated under ultraviolet light. After cutting, the sample is immersed in hot water to degumming; the laser frequency is maintained at 6 Hz.
[0031] Among them, the wavelength of the laser light source is 450nm.
[0032] Among them, the surface of large-scale polycrystalline diamond is evenly colored with a black marker or fluorescent pen before cutting.
[0033] The cutting loss control in step S3 also includes setting the power of the laser generator to 8-10W.
[0034] The glue in step S4 is UV curing glue.
[0035] Among them, the ultraviolet light irradiation power is 1000W, and the irradiation time is 30-90 seconds.
[0036] In step S4, the sample is immersed in hot water, the temperature of the hot water is 80° C., and the immersion time is 5 minutes.
[0037] Among them, large-scale polycrystalline diamond blocks are directly converted from non-diamond carbon as raw material at 14-18GPa and 2300-2600K.
[0038] Example 2
[0039] The difference from Example 1 is that a large-scale polycrystalline diamond block is synthesized under the conditions of 14 GPa and 2600 K, the large-scale polycrystalline diamond block is placed in a 1000 W UV baking box, baked for 30 seconds, the block is installed on the operating platform of the laser cutting machine, the laser cutting machine output power is set to 8 W, the frequency is 6 Hz, the highest point of the cut sample is used as the focus, the first knife parameters are set, and the cutting is performed. After the first knife cutting is completed, the sample is rotated 180 degrees, the required thickness and the second knife parameters are set, and the cutting is performed to obtain a large-scale polycrystalline diamond slice of the required thickness. The rest is the same as Example 1.
[0040] Example 3
[0041] The difference from Example 1 is that a large-scale polycrystalline diamond block is synthesized under 16GPa and 2500K conditions, the large-scale polycrystalline diamond block is placed in a 1000W UV baking box, baked for 60 seconds, the block is installed on the operating platform of the laser cutting machine, the laser cutting machine output power is set to 9W, the frequency is 7Hz, the highest point of the cut sample is used as the focus, the first knife parameters are set, and the cutting is performed. After the first knife cutting is completed, the sample is rotated 180 degrees, the required thickness and the second knife parameters are set, and the cutting is performed to obtain a large-scale polycrystalline diamond slice of the required thickness. The rest is the same as Example 1.
[0042] Example 4
[0043] The difference from Example 1 is that a large-scale polycrystalline diamond block is synthesized under the conditions of 18 GPa and 2300 K, the large-scale polycrystalline diamond block is placed in a 1000 W UV baking box, baked for 90 seconds, the block is installed on the operating platform of the laser cutting machine, the laser cutting machine output power is set to 10 W, the frequency is 8 Hz, the highest point of the cut sample is used as the focus, the first knife parameters are set, and the cutting is performed. After the first knife cutting is completed, the sample is rotated 180 degrees, the required thickness and the second knife parameters are set, and the cutting is performed to obtain a large-scale polycrystalline diamond slice of the required thickness. The rest is the same as Example 1.
[0044] Comparative Example 1
[0045] The difference from Example 1 is that a large-scale polycrystalline diamond block is synthesized under 13GPa and 2100K conditions, the large-scale polycrystalline diamond block is placed in a 900W UV baking box, baked for 20 seconds, the block is installed on the operating platform of the laser cutting machine, the laser cutting machine output power is set to 7W, the frequency is 6Hz, the highest point of the cut sample is used as the focus, the first knife parameters are set, and the cutting is performed. After the first knife cutting is completed, the sample is rotated 180 degrees, the required thickness and the second knife parameters are set, and the cutting is performed to obtain a large-scale polycrystalline diamond slice of the required thickness. The rest is the same as Example 1.
[0046] Comparative Example 2
[0047] The difference from Example 1 is that a large-scale polycrystalline diamond block is synthesized under the conditions of 14 GPa and 2200 K, the large-scale polycrystalline diamond block is placed in an 1100 W UV baking box, baked for 50 seconds, the block is installed on the operating platform of the laser cutting machine, the laser cutting machine output power is set to 11 W, the frequency is 8 Hz, the highest point of the cut sample is used as the focus, the first knife parameters are set, and the cutting is performed. After the first knife cutting is completed, the sample is rotated 180 degrees, the required thickness and the second knife parameters are set, and the cutting is performed to obtain a large-scale polycrystalline diamond slice of the required thickness. The rest is the same as Example 1.
[0048] Comparative Example 3
[0049] The difference from Example 1 is that a large-scale polycrystalline diamond block is synthesized under the conditions of 19 GPa and 2700 K, the large-scale polycrystalline diamond block is placed in a 1000 W UV baking box, baked for 100 seconds, the block is installed on the operating platform of the laser cutting machine, the laser cutting machine output power is set to 6 W, the frequency is 5 Hz, the highest point of the cut sample is used as the focus, the first knife parameters are set, and the cutting is performed. After the first knife cutting is completed, the sample is rotated 180 degrees, the required thickness and the second knife parameters are set, and the cutting is performed to obtain a large-scale polycrystalline diamond slice of the required thickness. The rest is the same as Example 1.
[0050] Comparative Example 4
[0051] The difference from Example 1 is that a large-scale polycrystalline diamond block is synthesized under the conditions of 18 GPa and 2600 K, the large-scale polycrystalline diamond block is placed in a 1000 W UV baking oven and baked for 30 seconds, the block is mounted on the operating platform of the laser cutting machine, the laser cutting machine output power is set to 8 W, the frequency is 6 Hz, the highest point of the cut sample is used as the focus, the first knife parameters are set, and the cutting is performed. After the first knife cutting is completed, the sample is rotated 180 degrees, the required thickness and second knife parameters are set, and the cutting is performed to obtain a large-scale polycrystalline diamond slice of the required thickness.
[0052] In step S4, the sample is immersed in hot water, the temperature of the hot water is 90° C., and the immersion time is 7 minutes. Other steps are the same as those in Example 1.
[0053] 1. Flatness measurement method
[0054] Measurement method: Use a high-precision surface profiler or laser interferometer for flatness testing.
[0055] step:
[0056] Prepare a standardized substrate and the diamond sample to be measured, ensuring that the sample size is suitable for the measuring instrument.
[0057] Place the sample on the working table of the measuring instrument, making sure that the sample surface is in good contact with the instrument probe.
[0058] Start the instrument to scan and record the height changes on the sample surface.
[0059] The data provided by the instrument shows the height uniformity of the sample surface and calculates the flatness value, which is usually defined as the difference between the maximum and minimum heights of the sample surface.
[0060] Standard: Flatness result should be less than or equal to 0.02 mm.
[0061] 2. Test method for polishing time
[0062] Test method: Use the timing method to test the polishing time and determine the time required to achieve a specific smoothness.
[0063] step:
[0064] The cut diamond samples were pre-treated to ensure that their surfaces were clean and free of obvious scratches.
[0065] Use a standardized polishing machine and polishing agent (such as alumina or silicate) and set the initial polishing conditions (such as speed and pressure).
[0066] Start the polisher and record the start time.
[0067] Check the polishing effect of the sample regularly until the expected smoothness or standard gloss is achieved.
[0068] The total time required to complete the polishing was recorded.
[0069] Standard: Polishing time should be controlled within 30 to 60 minutes.
[0070] 3. Cutting loss test method
[0071] Test method: The weighing method is used to analyze the changes in sample mass before and after cutting.
[0072] step:
[0073] Record the mass of the original diamond block (M1), weigh it and record the specific value.
[0074] Perform diamond cutting operations.
[0075] After cutting is completed, weigh the sample again (M2) and record the mass after cutting.
[0076] Calculate the cutting loss using the formula: loss = M1-M2.
[0077] Standard: Cutting loss should be controlled within the weight change of the sample with a thickness of approximately 0.10 mm.
[0078] 4. Testing method for degumming and block collapse
[0079] Test method: combination of observation method and weighing method.
[0080] step:
[0081] The mass (M1) of the sample was recorded and the surface condition of the sample was checked before cutting.
[0082] Carry out cutting and gluing operations and proceed as described above.
[0083] After cutting, observe the surface of the sample and record whether debonding or block collapse occurs (e.g., observe the surface using a microscope).
[0084] If any fragments occur, record the number and size of the fragments.
[0085] Weigh the sample after cutting (M2) and compare it with the mass before cutting to analyze the material loss.
[0086] Standard: Ensure that the debonding phenomenon of the sample after cutting is minimized and the amount of chipping is controlled within an acceptable range.
[0087] According to the comparison between Comparative Example 1 and Example 1, the synthesis conditions of the large-scale polycrystalline diamond block in Comparative Example 1 are not in the range of 14-18 GPa and 2300-2600 K, the baking time is not in the range of 30-90 seconds, and the output power of the laser cutting machine is not in the range of 8-10 W. In Comparative Example 1, the flatness is poor, the polishing time is long, the cutting loss is also higher than that in Example 1, and the degumming and block collapse phenomenon is also greater than that in Example 1, indicating that the synthesis conditions, baking time and the output power of the laser cutting machine will affect the cutting quality.
[0088] According to the comparison between Comparative Example 2 and Example 2, the synthesis conditions of the large-scale polycrystalline diamond block in Comparative Example 2 are not in the range of 2300-2600K, the UV baking is greater than 1000W, the output power of the laser cutting machine is not in the range of 8-10W, the flatness in Comparative Example 2 is poor, the polishing time is long, the cutting loss is also higher than that in Example 1, and the degumming and chipping phenomenon is also greater than that in Example 1, indicating that the synthesis conditions, baking power and the output power of the laser cutting machine will affect the cutting quality.
[0089] According to the comparison between Comparative Example 3 and Example 3, the synthesis conditions of the large-scale polycrystalline diamond block in Comparative Example 1 are not in the range of 14-18 GPa and 2300-2600 K, the baking time is not in the range of 30-90 seconds, the output power of the laser cutting machine is not in the range of 8-10 W, the frequency is less than 6 Hz, the flatness in Comparative Example 1 is poor, the polishing time is long, the cutting loss is also higher than that in Example 1, and the degumming and block collapse phenomenon is also greater than that in Example 1, indicating that the synthesis conditions and baking time, the output power and frequency of the laser cutting machine will affect the cutting quality.
[0090] According to the comparison between Comparative Example 4 and Example 4, the hot water temperature in Comparative Example 1 is greater than 80°C, the immersion time is greater than 5 minutes, the flatness in Comparative Example 1 is poor, the polishing time is long, the cutting loss is also higher than that in Example 1, and the degumming and block collapse phenomenon is also greater than that in Example 1, indicating that the hot water temperature and the immersion time will affect the cutting quality.
Claims
1. A laser cutting method for large-scale polycrystalline diamond, characterized in that: The following steps are involved: S1. Light source selection: choose a laser light source with a smaller wavelength to reduce material loss during the cutting process; S2, cutting method, first knife sweeping: use the laser cutting machine to make the first cut on the end face of the sample; sample rotation cutting: after completing the sweeping, use the rotation function of the laser cutting machine to rotate the sample 180 degrees, then make the second cut, and then cut normally to obtain a highly flat slice; S3, cutting loss control, monitoring the gap loss during the cutting process, controlling it to about 0.10 mm to ensure cutting quality; S4, degumming and chipping control, before cutting, apply glue on the sample surface to enhance the adhesion of the sample, and irradiate it under ultraviolet light. After cutting, immerse the sample in hot water to degumming; keep the laser frequency in the range of 6-8 Hz.
2. The laser cutting method for large-scale polycrystalline diamond according to claim 1, characterized in that: The wavelength of the laser light source is 450-500nm.
3. The laser cutting method of large-scale polycrystalline diamond according to claim 2, characterized in that: The surface of the large-scale polycrystalline diamond is evenly colored with a black marker or a fluorescent pen before cutting.
4. The laser cutting method of large-scale polycrystalline diamond according to claim 3, characterized in that: The cutting loss control in step S3 also includes setting the power of the laser generator to 8-10W.
5. The laser cutting method of large-scale polycrystalline diamond according to claim 4, characterized in that: The glue in step S4 is UV curing glue.
6. The laser cutting method of large-scale polycrystalline diamond according to claim 5, characterized in that: The ultraviolet light irradiation power is 1000W, and the irradiation time is 30-90 seconds.
7. The laser cutting method of large-scale polycrystalline diamond according to claim 6, characterized in that: In step S4, the sample is immersed in hot water, the temperature of the hot water is 80° C., and the immersion time is 5 minutes.
8. The laser cutting method for large-scale polycrystalline diamond according to claim 7, characterized in that: The large-scale polycrystalline diamond block is directly converted from non-diamond carbon as a raw material at 14-18 GPa and 2300-2600 K.