A diamond polishing and parameter control method based on temperature feedback control

Abstract

The present invention discloses a diamond polishing and parameter control method based on temperature feedback control. According to the processing stage, i.e., rough polishing or fine polishing, priority is given to processing quality or processing efficiency without affecting reaction conditions. The sequence is taken into consideration when adjusting parameters. This solves the problem that the processing force and processing temperature cannot be measured simultaneously in large-size wafer processing. Furthermore, it solves the problem of using processing temperature as a constraint in end face polishing, thereby further improving the polishing efficiency while ensuring polishing quality.

Description

Technical Field

[0001] The invention belongs to the technical field of large-size CVD polycrystalline diamond polishing, and in particular relates to a diamond polishing and parameter control method based on temperature feedback control. Background Art

[0002] Diamond possesses exceptional physical, chemical, optical, and thermal properties, including extremely high hardness, excellent chemical stability, high thermal conductivity, high elastic modulus, large electrical resistivity, wide bandgap, wide optical transmission range (from infrared to ultraviolet), and low friction coefficient. It is considered one of the most promising engineering materials of the 21st century, with broad applications in high-tech fields. Due to its high hardness and brittleness, high-tech applications, particularly in high-tech fields, require not only minimal surface roughness but also high surface accuracy and surface integrity. Diamond is the hardest material known in nature and is typically difficult to process and process, which presents significant challenges for its processing.

[0003] Mechanical polishing is currently the only method capable of processing large-scale CVD polycrystalline diamond. The material removal rate during diamond machining is affected by grinding pressure and polishing speed. Achieving higher material removal rates requires increasing pressure and line speed, but this also requires controlling the grinding temperature. This is because increasing grinding temperature, under high loads and line speeds, can lead to thermal cracking and stress concentration, increasing the risk of sample breakage.

[0004] Furthermore, to improve material removal rates, many grinding methods, such as dynamic friction and chemical mechanical polishing, are not performed at room temperature. These methods, such as dynamic friction and chemical mechanical polishing, only achieve high material removal rates at temperatures of 100 to 200°C or even higher. Due to growth, the rough surface of diamond sheets is not flat, with varying thicknesses and warping. At the beginning of grinding, the contact area between the sample and the grinding wheel is relatively small, resulting in high pressure per unit area. As the grinding process continues, the contact area between the sample and the grinding wheel gradually increases. This change in contact area causes changes in grinding temperature and pressure per unit area. Conventional grinding processes are typically performed under constant parameters, such as rotational speed and feed rate, or rotational speed and pressure. This can lead to reduced grinding efficiency and sample breakage during the grinding process, failing to meet practical production requirements. Therefore, timely adjustment of processing parameters is necessary to control the grinding temperature and achieve high material removal rates without breaking the sample.

[0005] The patent disclosed in Chinese patent CN104742018A is only applicable to surface grinding or plunge grinding. For large-size wafers, especially end face grinding, it is impossible to measure temperature and force at the same time when the workpiece and grinding wheel rotate at the same time, and it is also impossible to adjust the parameters. Summary of the Invention

[0006] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and provide a diamond polishing and parameter control method based on temperature feedback control, which can adjust the processing parameters while ensuring the safety of the sample, optimize the processing time of different processes, improve processing efficiency and save production costs.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A diamond polishing and parameter control method based on temperature feedback control, wherein the polishing device includes a polishing disc, a polishing fixture, a temperature sensor, and a dynamometer mounted on a machine tool spindle. The polishing fixture is fixed to the dynamometer via a T-shaped fixture. The polishing fixture and the T-shaped fixture are respectively provided with mounting holes for passing a temperature measuring unit of the temperature sensor. The temperature measuring unit is in direct contact with the sample to be processed, and the temperature sensor is controllably connected to the machine tool control system.

[0009] The control method includes the following steps:

[0010] (1) The diamond sheet is attached to the fixture, the fixture is mounted on the wireless rotary dynamometer, and the rotary dynamometer is mounted on the spindle of the machine tool;

[0011] (2) The temperature sensor is built into the spindle of the machine tool and rotates synchronously with the rotor of the spindle of the machine tool. The temperature sensing unit of the temperature sensor is set on both sides of the fixture to directly contact the diamond piece to be polished, and the temperature signal is transmitted to the control system of the machine tool via wireless signal;

[0012] (3) The polishing process was explored through single-factor experiments. The load, temperature, grinding wheel speed, and material removal rate were recorded to obtain the variation pattern of polishing temperature with the change of load and polishing speed. The upper limit of the optimal range of polishing temperature was defined as T1, and the lower limit of the optimal range was defined as T0.

[0013] (4) Monitor polishing temperature through the control system:

[0014] a. When the polishing temperature is between T0 and T1, the polishing pressure and speed remain unchanged;

[0015] b. Rough polishing stage:

[0016] When the temperature is lower than T0, first increase the pressure and then increase the speed according to the temperature rise.

[0017] After the machining speed stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1;

[0018] As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases.

[0019] When the temperature is higher than T1, the machine control system first reduces the speed and then reduces the pressure according to the temperature drop to ensure the material removal rate;

[0020] After the polishing pressure stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1;

[0021] c. Fine polishing stage:

[0022] When the temperature is lower than T0, first increase the speed and then reduce the polishing pressure according to the temperature rise.

[0023] After the polishing pressure stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1;

[0024] As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases.

[0025] When the temperature is higher than T1, the machine control system first reduces the polishing pressure and then increases the speed according to the temperature drop to ensure the processing accuracy;

[0026] After the rotation speed stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1;

[0027] (5) Polishing: Stop the machine every 1-4 hours to check. When the entire surface of the sample to be processed is in contact with the polishing disc, check the surface roughness.

[0028] If the roughness does not meet the index requirements, repeat step (4) until the index requirements are met;

[0029] If the roughness meets the index requirements, the polishing is completed and the sample is removed from the polishing fixture.

[0030] In the rough polishing stage of step (4),

[0031] When the temperature is lower than T0, first increase the pressure and then increase the speed according to the temperature rise. Increase the polishing pressure through the machine tool control system. The single polishing pressure increase is 5-10% of the initial load. When the processing temperature stabilizes, if the processing temperature is still lower than T0, increase the processing speed by 5-10%;

[0032] After the machining speed stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1;

[0033] As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases.

[0034] When the temperature is higher than T1, the machine control system first reduces the speed and then reduces the pressure according to the temperature drop to ensure the material removal rate;

[0035] First, reduce the speed through the machine control system, and reduce the processing speed by 5-10% of the initial speed at a time. When the processing temperature stabilizes, if the processing temperature is still higher than T1, reduce the polishing pressure by 5-10%;

[0036] After the polishing pressure stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1.

[0037] Step (4) of the fine polishing stage:

[0038] When the temperature is lower than T0, first increase the speed and then reduce the polishing pressure according to the temperature rise. Increase the speed through the machine control system, and increase the processing speed by 5-10% of the initial speed at a time. When the processing temperature stabilizes, if the processing temperature is still lower than T0, reduce the polishing pressure by 5-10%;

[0039] After the polishing pressure stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1;

[0040] As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases.

[0041] When the temperature is higher than T1, the machine control system first reduces the polishing pressure and then increases the speed according to the temperature drop to ensure the processing accuracy;

[0042] First, reduce the polishing pressure through the machine control system, and reduce the polishing pressure by 5-10% of the initial pressure at a time. When the processing temperature stabilizes, if the processing temperature is still higher than T1, increase the speed by 5-10%;

[0043] After the rotation speed stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1.

[0044] The sample to be processed, i.e. the diamond sheet, is glued to the polishing fixture using high temperature resistant glue.

[0045] The temperature measuring units of the temperature sensor are symmetrically arranged on both sides of the polishing fixture, and the temperature sensor is built into the main shaft of the machine tool and rotates synchronously with the main shaft.

[0046] The temperature sensor transmits data to the control system of the machine tool via Bluetooth.

[0047] The beneficial effects of the present invention are:

[0048] The present invention discloses a diamond polishing and parameter control method based on temperature feedback control. According to the processing stage, i.e., rough polishing or fine polishing, priority is given to processing quality or processing efficiency without affecting reaction conditions. The sequence is taken into consideration when adjusting parameters. This solves the problem that the processing force and processing temperature cannot be measured simultaneously in large-size wafer processing. Furthermore, it solves the problem of using processing temperature as a constraint in end face polishing, thereby further improving the polishing efficiency while ensuring polishing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the experimental device structure of the present invention;

[0050] Figure 2 is a flow chart of the optimization method of the present invention;

[0051] Figure 3 is the relationship between the polishing temperature and the material removal rate of the present invention;

[0052] Figure 4 is the relationship between the polishing speed and temperature of the present invention;

[0053] Figure 5 The relationship between the polishing pressure and temperature of the present invention;

[0054] Figure 6 The relationship between the polishing pressure, surface roughness and material removal rate of the present invention;

[0055] Figure 7 The relationship between the grinding wheel speed, surface roughness and material removal rate of the present invention is:

[0056] Figure 8 The surface roughness test results after polishing corresponding to implementation cases 1-4 are shown;

[0057] Figure 9 Statistical results of roughness at different locations for implementation cases 1-4. DETAILED DESCRIPTION

[0058] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0059] The present invention provides a diamond polishing and parameter control method based on temperature feedback control, such as Figures 1 to 9 shown.

[0060] A diamond polishing and parameter control method based on temperature feedback control, the polishing device includes a polishing disc, a polishing fixture, a temperature sensor and a dynamometer installed on the spindle of a machine tool, and the polishing fixture is fixed to the dynamometer by a T-shaped fixture, and the polishing fixture and the T-shaped fixture are respectively provided with mounting holes for passing a temperature measuring unit of the temperature sensor, the temperature measuring unit is in direct contact with the workpiece to be polished, and the temperature sensor is controlled and connected to the control system of the machine tool.

[0061] The sample to be tested, i.e., the diamond sheet, is glued to the polishing fixture using high-temperature resistant glue, such as high-temperature resistant metal glue. The polishing fixture is installed on the wireless rotary dynamometer, and the rotary dynamometer is installed on the machine tool spindle through an interface that is adapted to the machine tool spindle. The temperature measuring units of the temperature sensor are symmetrically arranged on both sides of the polishing fixture, and the temperature sensor is built into the machine tool spindle and rotates synchronously with the spindle. In this embodiment, the temperature sensor transmits data to the machine tool control system via Bluetooth.

[0062] The diamond polishing and parameter control method comprises the following steps:

[0063] (1) The diamond sheet is attached to a fixture, the fixture is mounted on a wireless rotary dynamometer, and the rotary dynamometer is mounted on the spindle of a machine tool;

[0064] (2) The temperature sensor is built into the spindle of the machine tool and rotates synchronously with the rotor of the spindle of the machine tool. The temperature sensing units of the temperature sensor are set on both sides of the fixture to directly contact the diamond piece to be polished, and the temperature signal is transmitted to the control system of the machine tool via wireless signal;

[0065] (3) In order to obtain the optimal temperature range of the reaction grinding wheel for diamond polishing, as well as the influence of grinding load and grinding wheel speed on polishing temperature, a single-factor experiment was conducted to explore the polishing process. The load, temperature, grinding wheel speed and material removal rate were recorded, and the variation law of polishing temperature with the change of load and polishing speed was obtained. The upper limit of the optimal range of polishing temperature was defined as T1, and the lower limit of the optimal range was defined as T0. Diamond grinding wheels with different bond types and different grits have different speeds and loads within the optimal temperature range.

[0066] (4) Monitor polishing temperature through control system:

[0067] a. When the polishing temperature is between T0 and T1, the polishing pressure and speed remain unchanged;

[0068] b. Rough polishing stage:

[0069] When the temperature is lower than T0, first increase the pressure and then increase the speed according to the temperature rise.

[0070] After the machining speed stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1;

[0071] As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases.

[0072] When the temperature is higher than T1, the machine control system first reduces the speed and then reduces the pressure according to the temperature drop to ensure the material removal rate;

[0073] After the polishing pressure stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1;

[0074] c. Fine polishing stage:

[0075] When the temperature is lower than T0, first increase the speed and then reduce the polishing pressure according to the temperature rise.

[0076] After the polishing pressure stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1;

[0077] As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases.

[0078] When the temperature is higher than T1, the machine control system first reduces the polishing pressure and then increases the speed according to the temperature drop to ensure the processing accuracy;

[0079] After the rotation speed stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1;

[0080] (5) Polishing should be stopped every 1-4 hours to check the surface roughness of the sample when the entire surface is in contact with the polishing disc.

[0081] If the roughness does not meet the index requirements, repeat step (4) until it meets the index requirements;

[0082] If the roughness meets the index requirements, the polishing is completed and the sample is removed from the polishing fixture.

[0083] More specifically, in the rough polishing stage in step (4),

[0084] When the temperature is lower than T0, first increase the pressure and then increase the speed according to the temperature rise. Increase the polishing pressure through the machine tool control system. The single polishing pressure increase is 5-10% of the initial load. When the processing temperature stabilizes, if the processing temperature is still lower than T0, increase the processing speed by 5-10%;

[0085] After the machining speed stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1;

[0086] As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases.

[0087] When the temperature is higher than T1, the machine control system first reduces the speed and then reduces the pressure according to the temperature drop to ensure the material removal rate;

[0088] First, reduce the speed through the machine control system, and reduce the processing speed by 5-10% of the initial speed at a time. When the processing temperature stabilizes, if the processing temperature is still higher than T1, reduce the polishing pressure by 5-10%;

[0089] After the polishing pressure stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1.

[0090] And the fine polishing stage in step (4):

[0091] When the temperature is lower than T0, first increase the speed and then reduce the polishing pressure according to the temperature rise. Increase the speed through the machine control system, and increase the processing speed by 5-10% of the initial speed at a time. When the processing temperature stabilizes, if the processing temperature is still lower than T0, reduce the polishing pressure by 5-10%;

[0092] After the polishing pressure stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1;

[0093] As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases.

[0094] When the temperature is higher than T1, the machine control system first reduces the polishing pressure and then increases the speed according to the temperature drop to ensure the processing accuracy;

[0095] First, reduce the polishing pressure through the machine control system, and reduce the polishing pressure by 5-10% of the initial pressure at a time. When the processing temperature stabilizes, if the processing temperature is still higher than T1, increase the speed by 5-10%;

[0096] After the rotation speed stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1.

[0097] The following describes the specific embodiment of the present invention in detail with reference to the technical solution and the accompanying drawings. The processing object is a 4-inch MPCVD polycrystalline diamond sheet 1. The final processing requirement is a surface roughness of less than 1nm. The processing steps are roughing and finishing. The roughing processing accuracy requirement is a surface roughness of less than 5nm. The roughing polishing uses an alloy polishing disc 7 containing 10μm diamond powder, and the processing method is end face grinding. Figure 1 Schematic diagram of the experimental device principle of the present invention.

[0098] The diamond sheet 1 is adhered to the circular fixture 2 by a high-temperature resistant glue with high thermal conductivity. The high-temperature resistant glue can withstand temperatures above 300 degrees Celsius without failure. The circular fixture is fixed on the T-type fixture. The T-type fixture has a cylindrical structure and is fixed to the wireless rotary dynamometer with a CNC machine tool handle using a spring collet. The interface of the dynamometer is the same as the national standard tool handle. The dynamometer 3 is installed on the machine tool spindle 6. There are two small holes of corresponding size and position on the circular fixture and the T-type fixture. The two small holes are symmetrically arranged and located at 1 / 2 of the fixture radius. The temperature measuring unit 5 of the temperature sensor is directly connected to the sample to be processed through the two holes. The temperature sensor is built into the machine tool rotor 4 and is transmitted to the machine tool control system 9 via wireless signal transmission 8. During processing, the sample to be processed is end-face ground with the alloy polishing disk 7. The temperature and force signals are transmitted to the control end of the machine tool. The processing method is dry polishing. The feed of the machine tool is fed back through the loading force. The process of adjusting the processing parameters is as follows. Figure 2 shown.

[0099] Through preliminary experiments, it has been determined that the optimal processing parameters for reaction grinding wheels are as follows:

[0100] Figure 3 The figure shows the influence of polishing temperature on material removal rate. The temperature with the highest processing efficiency is 220℃-260. The grinding pressure of the 4-inch diamond sheet is 120N, the workpiece speed is a fixed speed of 19RPM, the polishing disc speed is 1000RPM, and the surface roughness after processing is less than 5nm. Then the lower limit of temperature T0=220℃, and the upper limit of temperature is T1=260℃. Enter the parameters into the control system of the machine tool. The polishing stage is rough polishing. The influence of pressure and speed on polishing temperature is tested through single-factor experiments, such as Figure 4 and Figure 5 As shown in the figure, it can be seen that the polishing temperature increases with the increase of polishing pressure and grinding wheel speed during polishing.

[0101] Use the above parameters to perform polishing and monitor the processing temperature in real time. According to the influence of polishing pressure and speed on polishing temperature in the previous test, Figure 6 and Figure 7 As shown in the figure, with the increase of polishing pressure, the surface roughness of the polished surface does not change significantly, but the material removal rate is significantly improved. With the increase of polishing speed, the surface roughness of the polished surface is significantly reduced, and the material removal rate of the polished surface is also improved. However, through Figure 3 It can be seen that the polishing temperature also increases significantly. In order to ensure that the polishing temperature is in the optimal processing range and surface quality, while taking into account the material removal rate of rough processing.

[0102] The following is specifically described in conjunction with the embodiments:

[0103] Implementation Case 1:

[0104] The initial polishing temperature was 243°C. Between T0 and T1, the polishing pressure and speed remained constant, and the temperature fluctuation was less than 5°C, indicating equilibrium. The polishing was stopped every four hours for inspection. When the entire surface of the sample was contacted, the surface roughness was tested. If the roughness was less than 5nm, polishing was terminated and the sample was removed from the fixture.

[0105] Implementation Case 2:

[0106] The grinding wheel is trimmed at the beginning of polishing. The polishing temperature is relatively low. After the temperature stabilizes, the temperature is measured to be 205°C. In order to ensure that the polishing temperature is in the optimal processing range and surface quality, while taking into account the material removal rate of rough processing, the polishing pressure is increased to 130N through the machine tool control unit. The interval of a single increase is 8.3% of the initial load. After waiting for 10 minutes, the temperature reaches a steady state of 228°C. The polishing is stopped every 4 hours for inspection. When the entire surface of the sample is in contact, the surface roughness is tested. If the roughness is less than 5nm, the polishing is ended and the sample is removed from the fixture.

[0107] Implementation Case 3:

[0108] The grinding wheel is trimmed at the beginning of polishing. The polishing temperature is relatively low. After the temperature stabilizes, the temperature is measured to be 198°C. In order to ensure that the polishing temperature is in the optimal processing range and surface quality, while taking into account the material removal rate of rough processing, the polishing pressure is increased to 135N through the machine tool control unit. The processing temperature is 215°C after the pressure is adjusted to 135N and stabilized. The temperature is still lower than T0, so the processing speed is increased to 1100prm. After waiting for 10 minutes, the temperature stabilizes at 225°C, which meets the requirements; then the polishing is stopped every 4 hours for inspection. When the entire surface of the sample is contacted, the surface roughness is tested. If the roughness is less than 5nm, the polishing is ended and the sample is removed from the fixture.

[0109] Implementation Case 4:

[0110] The grinding wheel is dressed at the beginning of polishing. The polishing temperature is relatively low. After the temperature stabilizes, the temperature is measured to be 215°C. In order to ensure that the polishing temperature is within the optimal processing range and surface quality, while taking into account the material removal rate of rough processing, the polishing pressure is increased to 125N through the machine tool control unit. After the pressure is adjusted to 125N and stabilized, the processing temperature is 235°C, and the polishing process is continued.

[0111] As the grinding process progresses, the abrasive grains of the grinding wheel will be consumed and the sharpness will decrease. After the grinding temperature stabilizes at 265°C, the speed is first reduced to 900rpm through the machine tool control unit. After waiting for 10 minutes, the processing temperature basically remains stable at 253°C, and the temperature fluctuation is less than 5°C. It is considered that equilibrium has been reached; then the polishing is stopped every 4 hours for inspection. When the entire surface of the sample is in contact, the surface roughness is tested. If the roughness is less than 5nm, polishing is ended and the sample is removed from the fixture.

[0112] Figure 8 and Figure 9 The figure shows the surface roughness results of different samples. Four samples were processed continuously using the same grinding wheel, and the polishing roughness was consistent, all less than 5nm, meeting the processing requirements. Compared with the minimum parameters, the processing efficiency was significantly improved, and the polishing time of a single diamond was greatly shortened.

[0113] If the terms "first" and "second" are used in this patent to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of describing the present invention and simplifying the description, and the above terms have no special meaning.

[0114] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications are possible without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the claimed invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0115] In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "center", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the protection content of the present invention.

Claims

1. A diamond polishing and parameter control method based on temperature feedback control, characterized in that: The polishing device includes a polishing disc, a polishing fixture, a temperature sensor, and a dynamometer mounted on the spindle of a machine tool. The polishing fixture is fixed to the dynamometer via a T-shaped fixture. The polishing fixture and the T-shaped fixture are provided with mounting holes for passing a temperature measuring unit of the temperature sensor. The temperature measuring unit is in direct contact with the sample to be processed, and the temperature sensor is connected to the control system of the machine tool. The control method includes the following steps: (1) The diamond sheet is attached to a fixture, the fixture is mounted on a wireless rotary dynamometer, and the rotary dynamometer is mounted on the spindle of a machine tool; (2) The temperature sensor is built into the spindle of the machine tool and rotates synchronously with the rotor of the spindle of the machine tool. The temperature sensing units of the temperature sensor are set on both sides of the fixture to directly contact the diamond piece to be polished, and the temperature signal is transmitted to the control system of the machine tool via wireless signal; (3) The polishing process was explored through single-factor experiments. The load, temperature, grinding wheel speed, and material removal rate were recorded to obtain the variation pattern of polishing temperature with the change of load and polishing speed. The upper limit of the optimal range of polishing temperature was defined as T1, and the lower limit of the optimal range was defined as T0. (4) Monitor polishing temperature through control system: a. When the polishing temperature is between T0 and T1, the polishing pressure and speed remain unchanged; b. Rough polishing stage: When the temperature is lower than T0, first increase the pressure and then increase the speed according to the temperature rise. After the machining speed stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1; As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases. When the temperature is higher than T1, the machine control system first reduces the speed and then reduces the pressure according to the temperature drop to ensure the material removal rate; After the polishing pressure stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1; c. Fine polishing stage: When the temperature is lower than T0, first increase the speed and then reduce the polishing pressure according to the temperature rise. After the polishing pressure stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1; As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases. When the temperature is higher than T1, the machine control system first reduces the polishing pressure and then increases the speed according to the temperature drop to ensure the processing accuracy; After the rotation speed stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1; (5) Polishing should be stopped every 1-4 hours to check. When the entire surface of the sample to be processed is in contact with the polishing disc, the surface roughness should be checked. If the roughness does not meet the index requirements, repeat step (4) until it meets the index requirements; If the roughness meets the index requirements, the polishing is completed and the sample is removed from the polishing fixture.

2. The diamond polishing and parameter control method based on temperature feedback control according to claim 1, characterized in that: In the rough polishing stage of step (4), When the temperature is lower than T0, first increase the pressure and then increase the speed according to the temperature rise. Increase the polishing pressure through the machine tool control system. The single polishing pressure increase is 5-10% of the initial load. When the processing temperature stabilizes, if the processing temperature is still lower than T0, increase the processing speed by 5-10%; After the machining speed stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1; As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases. When the temperature is higher than T1, the machine control system first reduces the speed and then reduces the pressure according to the temperature drop to ensure the material removal rate; First, reduce the speed through the machine control system, and reduce the processing speed by 5-10% of the initial speed at a time. When the processing temperature stabilizes, if the processing temperature is still higher than T1, reduce the polishing pressure by 5-10%; After the polishing pressure stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1.

3. The diamond polishing and parameter control method based on temperature feedback control according to claim 1, characterized in that: Step (4) of the fine polishing stage: When the temperature is lower than T0, first increase the speed and then reduce the polishing pressure according to the temperature rise. Increase the speed through the machine control system, and increase the processing speed by 5-10% of the initial speed at a time. When the processing temperature stabilizes, if the processing temperature is still lower than T0, reduce the polishing pressure by 5-10%; After the polishing pressure stabilizes, if the polishing temperature is stable and still lower than T0, repeat the above steps until the polishing temperature is between T0 and T1; As the grinding process progresses, the grinding wheel abrasive is consumed, the sharpness decreases, and the grinding temperature increases. When the temperature is higher than T1, the machine control system first reduces the polishing pressure and then increases the speed according to the temperature drop to ensure the processing accuracy; First, reduce the polishing pressure through the machine control system, and reduce the polishing pressure by 5-10% of the initial pressure at a time. When the processing temperature stabilizes, if the processing temperature is still higher than T1, increase the speed by 5-10%; After the rotation speed stabilizes, if the polishing temperature is stably higher than T1, repeat the above steps until the polishing temperature is between T0 and T1.

4. The diamond polishing and parameter control method based on temperature feedback control according to claim 1, characterized in that: The sample to be processed, i.e. the diamond sheet, is glued to the polishing fixture using high temperature resistant glue.

5. The diamond polishing and parameter control method based on temperature feedback control according to claim 1, characterized in that: The temperature measuring units of the temperature sensor are symmetrically arranged on both sides of the polishing fixture, and the temperature sensor is built into the main shaft of the machine tool and rotates synchronously with the main shaft.

6. The diamond polishing and parameter control method based on temperature feedback control according to claim 1, characterized in that: The temperature sensor transmits data to the control system of the machine tool via Bluetooth.

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