Superhard precise coating treatment method

Abstract

The invention relates to the technical field of precise coating treatment, and discloses a superhard precise coating treatment method which comprises the following steps: S1, pretreating the surface of a to-be-treated coating; s2, the pretreated surface of the coating is subjected to morphology shaping, so that the peak height and the trough of the surface of the coating meet the design requirements; the shape shaping comprises primary shaping, iterative shaping and optimized shaping, the initial value of a wave trough falls in a threshold value range through the primary shaping, and the peak height is gradually reduced through the iterative shaping; shaping is optimized, and wave troughs are finely adjusted; and S3, the surface of the coating subjected to shape shaping is subjected to accurate grinding, so that the brightness of the surface of the coating reaches a preset standard. According to the method, the surface of the coating is pretreated to remove macroscopic defects and impurities on the surface of the coating, accurate surface morphology control is carried out through morphology molding, accurate molding of the peak height and the trough of the surface of the coating is achieved, the coating meets the design requirements, and the application prospect is wide. The problems that the wave trough and the peak height of the coating surface cannot be accurately controlled and the design standard cannot be met in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of precision coating treatment, and specifically to a super-hard precision coating treatment method. Background Art

[0002] In the technical field of precision coating treatment, with the continuous improvement of the performance and quality requirements of products in various industries, the control of the surface accuracy of the coating has become a key link. Looking back on the development process of the existing technology, in the early stage, simple mechanical processing means were mainly relied on to process the coating surface. With the progress of technology, the limitations of traditional methods have become increasingly prominent. With the growth of demand, various methods such as polishing, coating treatment, and heat treatment have gradually emerged.

[0003] In current practical applications, these existing technologies have exposed many limitations. Taking polishing as an example, mechanical polishing removes micro-protrusions by the friction between the polishing wheel and the workpiece surface. However, on the surface of coatings with complex shapes, it is difficult to ensure uniform reduction of the peak height, and it is easy to cause excessive grinding of the valleys, affecting the integrity of the coating surface. Although chemical polishing and electrolytic polishing can improve the surface flatness to a certain extent, the control of chemical reactions and electrolytic processes is difficult, and it is difficult to precisely control the influence on valleys and peak heights. For example, in the aerospace field, the coatings of engine components have extremely high requirements for surface accuracy, and traditional polishing cannot meet its strict design standards. Coating treatment technologies, such as electroplating, electroless plating, and spraying, can fill the valleys and reduce the surface roughness, but they are only surface coatings and cannot fundamentally and precisely shape the valleys and peak heights. In the manufacturing of precision instruments, if the original valleys and peak heights of the coating are not ideal, uneven local thickness may occur after coating, affecting the optical performance and accuracy of the instrument. The heat treatment process, such as quenching, tempering, and normalizing, indirectly affects the surface micro-topography and mechanical properties by changing the material microstructure and eliminating internal stress. However, this control method is not direct enough and is difficult to precisely adjust according to specific design requirements. In the manufacturing of electronic chips, the surface accuracy requirements for the heat dissipation coatings of chips are extremely strict, and heat treatment is difficult to meet the precise control requirements for valleys and peak heights.

[0004] In summary, the existing technology cannot meet the requirement of precisely controlling the valleys and peak heights on the coating surface to reach the design standard, which severely restricts the application of coatings in the high-end manufacturing field. There is an urgent need for a new coating treatment method to solve these problems. Summary of the Invention

[0005] The present application provides a super-hard precision coating treatment method, which realizes precise control of the valleys and peak heights on the coating surface to meet the design standard requirements by shaping the surface topography of the coating. The specific solution is as follows: A super-hard precision coating treatment method, the method comprising the following steps: S1, pre-treat the surface of the coating to be treated; S2. Perform topography shaping on the surface of the pre-treated coating so that both the peak height and the trough of the coating surface meet the design requirements; The topography shaping includes: primary shaping, iterative shaping, and optimization shaping; Through primary shaping, the initial value of the trough is made to fall within the threshold range, and the threshold range is determined according to the designed trough Rv design and the maximum peak height Rp of the profile after pretreatment; In the way that the grinding particle size decreases sequentially, gradually reduce the peak height to the designed peak height Rp through iterative shaping design within the error range; Adjust the trough to the designed trough Rv through optimization shaping design within the error range; S3. Perform fine grinding on the surface of the coating after topography shaping to make the brightness of the coating surface reach the predetermined standard.

[0006] Preferably, in S2, the primary grinding particle size D1 of the primary shaping is determined according to the designed trough Rv design and the maximum peak height Rp of the profile, where the primary grinding particle size D1 satisfies Rv design < D1 < Rp to ensure that while removing the peak height, excessive grinding of the trough is avoided.

[0007] Preferably, in S2, each grinding particle size and the number of grinding times are determined according to the measured peak height and the average width RSm of the profile units after the previous shaping.

[0008] Preferably, the threshold range refers to the data set that is greater than the designed trough Rv design and less than the maximum peak height Rp of the profile after pretreatment of the coating surface.

[0009] Preferably, in S2, the primary shaping, iterative shaping, and optimization shaping are specifically as follows: a. Primary shaping: Use the primary grinding particle size D1 as the first grinding particle size, and perform primary shaping on the surface of the pre-treated coating by grinding, so that the initial value of the trough falls within the threshold range; b. Iterative shaping: Use a particle size that is less than the measured peak height after each shaping and greater than 1 / 2 of the average width RSm of the profile units as the next grinding particle size, gradually reduce the peak height, and at the same time keep the trough at the initial value, and perform iterative shaping in this way until any of the following conditions is met: The peak height is completely removed; The peak height is reduced to the designed peak height Rp design ±ΔRp range, where ΔRp is the allowable design peak height error value; If the peak height is completely removed or the peak height is reduced to the designed peak height Rp designWithin the range of ±ΔRp, the trough exceeds the designed trough Rv design If it is within the range of ±ΔRv, it enters the optimized shaping stage; if the trough is already within the designed trough Rv design Within the range of ±ΔRv, it directly enters the fine grinding step S3; where ΔRv is the allowable designed trough error value; c. Optimize the shaping, using the difference between the trough and the designed trough Rv design As the final grinding particle size D final Make fine adjustments to adjust the trough to within the range of the designed trough Rv design ±ΔRv.

[0010] Preferably, the iterative shaping process of b includes: i. According to the first measured peak height Rp1 after the initial shaping, select the second grinding particle size D2, and perform the second grinding and shaping to reduce the peak height to the second measured peak height Rp2, while keeping the trough at the initial value after the initial shaping; Where the second grinding particle size D2 satisfies: D2 < Rp1 and D2 > 1 / 2 of RSm1, where RSm1 is the average width of the profile unit after the initial shaping; ii. Repeat step i, and successively use the grinding particle size D n For subsequent grinding, where the grinding particle size D n Satisfies: D n <Rp n-1 And D n >1 / 2 of RSm n-1 Where RSm n-1 Is the average width of the profile unit after the previous shaping, and Rp n-1 Is the measured peak height after the previous shaping.

[0011] Preferably, during the topography shaping process, the grinding force and the grinding speed are kept uniform.

[0012] Preferably, after each shaping, use a magnifying glass to observe the surface of the coating; The surface of the coating should satisfy uniform texture and no scratches.

[0013] Preferably, the pretreatment in S1 includes: rough grinding the surface of the coating, and at least one of cleaning, degreasing or rust removal operations.

[0014] Preferably, cooling treatment is carried out during the grinding processes in S1, S2 and S3.

[0015] The beneficial effects of this application are as follows: In the pretreatment process of this application S1, macroscopic defects and impurities on the coating surface are removed, laying a foundation for subsequent precise control of the wave valleys and peak heights; in the surface topography shaping of S2, the surface topography of the pretreated coating is shaped to perform precise surface topography control, achieving precise control of the peak heights and wave valleys on the coating surface, and making both the peak heights and wave valleys on the coating surface meet the design requirements; in the fine grinding stage of S3, good reflection and transmission of light can be ensured, reducing light scattering and energy loss, thereby realizing the ability to precisely control the wave valleys and peak heights on the coating surface to meet the requirements of the design standard, effectively overcoming the problems in the prior art that the coating treatment cannot fundamentally shape the surface topography of the coating, resulting in the inability to precisely control the wave valleys and peak heights on the coating surface and the inability to meet the design standard.

[0016] Among them, in the surface topography shaping of S2, according to the designed wave valley Rv of the pretreated coating surface design and the maximum profile peak height Rp, the initial grinding particle size D1 is determined, and the particle size and number of each subsequent grinding are dynamically adjusted according to the peak height and the average width of the profile unit RSm after the previous shaping is completed, which can precisely control the wave valleys and peak heights within the design range, achieving precise shaping of the peak heights and wave valleys on the coating surface and meeting the stringent requirements for the surface accuracy of the coating in the high-end manufacturing field.

[0017] At the same time, during the surface topography shaping process, a reasonable grinding particle size selection and dynamic adjustment mechanism avoid over-grinding and unnecessary processing steps. Selecting the appropriate particle size according to the actual situation after each grinding reduces the number of grinding times and improves the grinding efficiency; and the inspection of the coating surface after each shaping can timely detect problems and make adjustments, reducing the rejection rate and lowering the production cost. Compared with the multiple reworks and material waste caused by the difficulty in precise control in the prior art, the present invention has obvious advantages in terms of production efficiency and cost control.

[0018] The cleaning, degreasing or rust removal operations in the S1 pretreatment, as well as the cooling treatment during the entire grinding process (cooling is carried out in S1, S2 and S3), improve the adhesion between the coating and the substrate and avoid the decline of the coating performance caused by factors such as thermal stress. Brief Description of the Drawings

[0019] Figure 1 is a schematic flow chart of a method for treating a superhard precision coating according to an embodiment of this application; Figure 2 is a schematic diagram of the surface roughness profile curve of the coating surface after pretreatment according to an embodiment of this application; Figure 3 is a schematic diagram of the surface roughness profile curve of the coating surface after surface topography shaping according to an embodiment of this application; In the drawings: The R curve is the actual roughness profile curve; the W curve is the roughness curve after filtering; the P curve is the original profile curve. Detailed implementation manners

[0020] A method for treating a super-hard precision coating, the method comprising the following steps: S1, pre-treating the surface of the coating to be treated; S2, shaping the surface of the pre-treated coating so that both the peak height and the trough of the coating surface meet the design requirements; The shaping includes: primary shaping, iterative shaping, and optimization shaping; By primary shaping, the initial value of the trough is made to fall within the threshold range, and the threshold range is determined according to the designed trough Rv design and the maximum peak height Rp of the profile after pre-treatment; In the way that the grinding particle sizes decrease sequentially, the peak height is gradually reduced to the designed peak height Rp design within the error range through iterative shaping; The trough is adjusted to the designed trough Rv design within the error range through optimization shaping; S3, finely grinding the surface of the coating after shaping to make the brightness of the coating surface reach a predetermined standard.

[0021] It should be noted that: In this application, through systematic pre-treatment, shaping, and fine grinding of the surface of the coating to be treated, the roughness, peak height, trough, and brightness of the coating surface all meet specific design requirements.

[0022] Further, in S2, the primary grinding particle size D1 of the primary shaping is determined according to the designed trough Rv design and the maximum peak height Rp of the profile, wherein the primary grinding particle size D1 satisfies Rv design < D1 < Rp.

[0023] It should be noted that: In this application, the selection method in which the primary grinding particle size D1 satisfies Rv design < D1 < Rp provides a reasonable starting condition for the subsequent grinding and shaping process. It not only avoids excessive damage to the trough due to too large particle size, but also ensures that the excessive peak height can be effectively removed, helps to accurately control the initial morphology of the coating surface, improves the grinding efficiency, reduces unnecessary grinding times, and reduces production costs.

[0024] Further, in S2, each grinding particle size and the number of grinding times are determined according to the measured peak height and the average width RSm of the profile unit after the previous shaping ends.

[0025] In this application, through the dynamic adjustment of the grinding process and targeted optimization according to the actual situation after each grinding, it is ensured that each step can more accurately approach the design requirements, further improving the accuracy of coating surface topography shaping and ensuring the consistency and stability of the final coating surface quality.

[0026] Further, the threshold range refers to the data set greater than the designed valley depth Rv design and less than the maximum peak height Rp of the profile after the pre-treatment of the coating surface.

[0027] Further, in S2, the primary shaping, iterative shaping, and optimization shaping are specifically as follows: Primary shaping: Using the primary grinding particle size D1 as the first grinding particle size, perform primary shaping on the pre-treated coating surface to make the initial value of the valley fall within the threshold range; b. Iterative shaping: Using a particle size less than the measured peak height after each shaping and greater than 1 / 2 of the average profile element width RSm as the next grinding particle size, gradually reduce the peak height while keeping the valley at the initial value, and perform iterative shaping in this way until any of the following conditions is met: The peak height is completely removed; The peak height is reduced to the designed peak height Rp design ±ΔRp range; ΔRp is the allowable design peak height error value; If the peak height is completely removed or the peak height is reduced to the designed peak height Rp design ±ΔRp range, and the valley exceeds the designed valley depth Rv design ±ΔRv range, then enter the optimization shaping stage; if the valley is already within the designed valley depth Rv design ±ΔRv range, then directly enter the fine grinding step S3; where, ΔRv is the allowable design valley depth error value; c. Optimization shaping: Using the difference between the valley and the designed valley depth Rv design as the final grinding particle size D final for fine adjustment to adjust the valley to within the designed valley depth Rv design ±ΔRv range.

[0028] Further, the iterative shaping process of b includes: i. According to the first measured peak height Rp1 after primary shaping, select the second grinding particle size D2 and perform the second grinding shaping to reduce the peak height to the second measured peak height Rp2 while keeping the valley at the initial value after primary shaping; where the second grinding particle size D2 satisfies: D2 < Rp1 and D2 > 1 / 2 of the RSm1, where RSm1 is the average profile element width after primary shaping; ii. Repeat step i, successively using the grinding particle size D nPerform subsequent grinding, where the grinding particle size D n satisfies: D n <Rp n-1 and D n >1 / 2 of RSm n-1 , where RSm n-1 is the average width of the contour units after the previous shaping, and Rp n-1 is the measured peak height after the previous shaping.

[0029] It should be noted that: In this application, the initial grinding particle size D1 is used as the grinding particle size of the first abrasive to grind the surface of the pre-treated coating. The initial value of the trough is made to fall within a specific threshold range, which is determined according to the designed trough Rv design and the maximum peak height Rp of the contour after pre-treatment. This step serves as the basis for the entire topography shaping and prepares for subsequent iterative shaping.

[0030] After the initial shaping is completed, the first measured peak height Rp1 is obtained. According to this value, the second grinding particle size D2 is selected. D2 needs to satisfy being less than Rp1 and greater than half of the average width RSm1 of the contour units after the initial shaping. Through the second grinding, the first measured peak height Rp1 is reduced to the second measured peak height Rp2, while ensuring that the trough remains at the initial value.

[0031] Repeat the above steps of selecting the grinding particle size and performing grinding, and successively use the particle size D n to perform subsequent grinding operations. Among them, the selection of D n should satisfy being greater than half of the average width RSm n-1 of the contour units after the previous shaping. This is done to prevent the grinding particles from contacting the trough, thereby ensuring that the trough remains at the initial value during the iterative grinding process. The iterative process will continue until either of the following two conditions is met: The peak height is completely eliminated, that is, the measured peak height Rp n is 0 μm; or the peak height is reduced to within the range of the designed peak height Rp design ±ΔRp, and precise shaping of the peak height is carried out to achieve precise control of the peak height step by step through iterative shaping and keep the trough at the initial value. Among them, ΔRp is the allowable design peak height error value.

[0032] Optimized shaping further fine-tunes the trough on the basis of iterative shaping. The trough is adjusted to within the range of the designed trough Rv design ±ΔRv; among them, ΔRv is the allowable design trough error value. Ensure that the peak height and trough of the final coating surface fully meet the design requirements, greatly improving the precision of the coating surface topography and meeting the needs of high-precision applications; In this application, by making the initial value of the wave valley (denoted as Rv1) fall within the threshold range (i.e., Rv design <Rv1<Rp), it is ensured that the initial value of the wave valley is not lower than the designed wave valley Rv design , and the initial grinding particle size D1 satisfies Rv design <D1<Rp to ensure that while removing the peak height, excessive grinding of the wave valley is avoided; iterative shaping with sequentially decreasing grinding particle sizes is adopted. By selecting a grinding particle size smaller than the measured peak height Rp after the previous shaping n-1 , and greater than half of the average width RSm of the profile units after the previous shaping n-1 , a dynamic adjustment mechanism is guaranteed, ensuring the continuity and effectiveness of the iterative shaping process. While gradually reducing the peak height, the wave valley is protected, enabling the surface morphology of the coating to be gradually optimized in the direction of the design requirements, improving the controllability and accuracy of the grinding process, and solving the problem in the prior art that the peak height and wave valley cannot be controlled synchronously.

[0033] Furthermore, during the morphology shaping process, the grinding force and grinding speed are kept uniform.

[0034] Furthermore, after each shaping, a magnifying glass is used to observe the surface of the coating; The surface of the coating should satisfy uniform texture and no scratches.

[0035] In this application, by inspecting the surface of the coating after each shaping, problems that may occur during the grinding process, such as uneven grinding and abnormal texture, can be detected in a timely manner, so as to adjust the grinding parameters or take remedial measures in a timely manner, ensuring the final surface quality of the coating and improving production efficiency.

[0036] Furthermore, the pretreatment in S1 includes: rough grinding the surface of the coating, and at least one of the operations of cleaning, degreasing, or rust removal.

[0037] In this application, macroscopic defects are removed by rough grinding, and surface impurities are removed by cleaning, degreasing, or rust removal operations, providing a good foundation for subsequent grinding and coating adhesion, improving the adhesion between the coating and the substrate, and enhancing the stability and durability of the coating.

[0038] Furthermore, in S1, S2, and S3, the grinding process is cooled by any one of water cooling or nitrogen cooling.

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] Example 1: The design requirements of this example are as follows: surface roughness: arithmetic mean roughness Ra ≤ 0.1 μm; maximum profile peak height Rp ≤ 0.2 μm ± ΔRp (ΔRp is 0.05 μm); Rz ≤ 1.0 μm; maximum profile valley depth Rv = 0.4 μm ± ΔRv (ΔRv is 0.1 μm); profile bearing ratio Rmr is 70% - 90% (evaluation depth 0.25Rz); profile skewness: Rsk is -0.1 to -3. In this example: The maximum profile peak height Rp is the maximum vertical distance between the profile peak line and the center line within the sampling length; the maximum profile valley depth Rv is the maximum vertical distance between the profile valley bottom line and the center line within the sampling length. In this example, the maximum profile peak height Rp and the maximum profile valley depth Rv are used as the evaluation parameters for peak height and peak valley.

[0041] RSm is the mean width of profile elements: the arithmetic mean of the distances between adjacent profile valleys within the sampling length, reflecting the uniformity of the surface texture; Ra is the arithmetic mean roughness, which is the arithmetic mean of the absolute values of the profile offsets within the sampling length, reflecting the average height of the surface micro-irregularities. The smaller the value, the smoother the surface. The arithmetic mean roughness Ra is used as the evaluation parameter for the surface roughness of the coating; Rz is the maximum profile height, which is the distance between the profile peak line and the profile valley bottom line within the sampling length; Rak is the arithmetic mean deviation of roughness after specific filtering treatment, used to more accurately evaluate the surface roughness; Rk is the core roughness depth, reflecting the roughness of the surface core area; Rpk is the reduced peak height, characterizing the height characteristics of the surface protruding peaks; Rvk is the reduced valley depth, characterizing the depth characteristics of the surface recessed valleys; Rmr is the profile bearing ratio, which is the ratio of the solid material length of the profile at a given horizontal position to the evaluation length, reflecting the surface load-bearing capacity; Rsk is the profile skewness: characterizing the symmetry of the surface profile peak-valley distribution, and a negative value indicates a surface structure dominated by deep valleys; Pt is the total profile height, which is the distance between the profile peak line and the profile valley bottom line within the evaluation length.

[0042] As shown in the attached Figure 1 There is shown a super-hard precision coating treatment method as shown in this example, and the operation process is as follows: S1: Pretreatment of the coating surface: Perform operations such as rough grinding, cleaning, degreasing, or rust removal on the surface of the coating to be processed, so that the surface roughness meets the preliminary design requirements (wherein, the preliminary design requirements include removing macroscopic defects by rough grinding, preliminarily reducing the maximum valley Rv of the profile to be close to the design range, and the arithmetic mean roughness Ra is in the range of 0.25 - 0.40 μm).

[0043] Judgment condition: If the surface roughness after pretreatment meets the preliminary design requirements, enter S2 surface topography shaping; if not, return for re-pretreatment.

[0044] S2: Surface topography shaping: The surface topography shaping specifically includes: primary shaping, iterative shaping, and optimization shaping; Among them, the primary shaping process: Use the primary grinding particle size D1 to make the initial value of the valley fall within the threshold range, that is: Rv design < the initial value of the valley < the maximum peak height Rp of the profile after pretreatment. The primary grinding particle size D1 satisfies Rv design < D1 < Rp, and the primary grinding particle size D1 = (Rv design + Rp) / 2 ± 10%.

[0045] Iterative shaping: In the way of sequentially reducing the grinding particle size (each time the particle size D n < the measured peak height Rp after the previous shaping n-1 and D n > 1 / 2 the average width RSm of the profile unit after the previous shaping n-1 ), gradually reduce the peak height to the designed peak height Rp design within the error range (±0.05 μm), while keeping the valley at the initial value.

[0046] Loop condition: If the peak height has not been reduced to the design requirements, return to continue iterative shaping; if any of the following conditions are met: The peak height is completely removed (Rp n = 0 μm); The peak height is reduced to the designed peak height Rp design ±ΔRp range, where ΔRp is the allowable design peak height error value; If the peak height is completely removed or the peak height is reduced to the designed peak height Rp design ±ΔRp range, and the valley exceeds the designed valley Rv design ±ΔRv range, then enter the optimization shaping stage; if the valley is already within the designed valley Rv design ±ΔRv range, then directly enter the fine grinding step S3; where ΔRv is the allowable design valley error value; Judge whether the peak height and trough meet the requirements. If yes, enter the fine grinding process in S3; if not, return to iterative shaping or optimized shaping (select the loop node according to the specific deviation).

[0047] S3: Fine grinding process Operation content: Use a fine-grained abrasive to finely grind the coating surface to make the surface brightness of the coating reach the predetermined standard.

[0048] Judgment condition: If the brightness meets the standard, the process ends; If not, return for re-fine grinding.

[0049] The specific implementation steps are as follows: S1, Pretreatment: Perform correction, rough grinding, and cleaning on the surface of the superhard coating respectively to control the surface roughness Ra within 0.25 - 0.40 μm and initially reduce the maximum profile trough Rv to ≤ 1.0 μm. Specifically: (1) Trimming: 1) Before trimming the grinding wheel, check whether the silicon carbide grinding wheel has cracks. When cracks are found, replace the new silicon carbide grinding wheel in time.

[0050] 2) Use a 60# silicon carbide grinding wheel for correction, with a roughing unilateral feed of 0.01 mm and a finishing feed of 0.002 mm.

[0051] 3) Trim the grinding wheel once for every 2 - 3 parts ground.

[0052] (2) Rough grinding: 1) Observe the appearance of the workpiece and whether there are bumps, defects, and severe scratches at the inner hole chamfer before mounting on the machine.

[0053] 2) After mounting on the machine, use a dial indicator to measure the outer circle runout of the non-sprayed coating within 0.02 mm.

[0054] 3) Use a 60# silicon carbide grinding wheel with a unilateral feed of 0.005 mm and a workpiece rotation speed of 90 rpm - 100 rpm; during the process, pay attention to sufficient cooling of the grinding wheel and the part to prevent tool burning.

[0055] Cleaning: Use ultrasonic cleaning (ethanol solvent) and nitrogen drying to ensure that the surface has no grease and impurities.

[0056] After pretreatment, the coating surface parameters are shown in Table 1; the schematic diagram of the coating surface roughness measurement is as Figure 2 shown; Table 1 Coating surface parameter table after pretreatment

[0057] As can be seen from Table 1, the surface roughness Ra = 0.259μm after pretreatment is within the preliminary design requirement of 0.25 - 0.40μm; however, the maximum profile peak height Rp = 0.591μm, the maximum profile height Rz = 1.587μm, and the maximum profile valley Rv = 0.996μm have not reached the design values of Rp ≤ 0.2μm, Rz ≤ 1.0μm, and Rv ≤ 0.5μm, and further optimization is required through topography shaping.

[0058] S2, topography shaping: Before loading onto the machine, observe the grinding marks on the surface of the workpiece after flame spraying to check for sand dropping and chatter marks. Use an outside micrometer to check that there is at least 0.01mm of polishing allowance on the sprayed outer diameter. In the entire topography shaping stage of this embodiment, diamond grinding is carried out in stages with a belt. During the grinding process, the force and the moving speed should be relatively uniform; the grinding pressure is controlled at 50 - 70N, and the moving speed is uniform (about 10 - 15mm / s); and after each grinding, a 5x magnifying glass is used to observe the grinding marks on the surface, and the marks are required to be uniform and delicate, without pitting, horizontal lines, or abnormal grinding marks; water cooling is used throughout the process (18 ± 0.5°C).

[0059] Initial shaping: For the initial grinding, silicon carbide abrasive with D1 = 0.55μm is selected to perform the first grinding on the surface of the pretreated coating, where D1 satisfies being greater than the designed valley Rv design = 0.5μm and less than the maximum profile peak height Rp = 0.591μm. During the first grinding, the grinding pressure is 60N and the rotational speed is 250r / min. Parameters after initial shaping: The initial value of the valley (denoted as Rv1) Rv1 = 0.6μm, and the initial value of the valley is within the range of the designed valley Rv design = 0.5μm and the small maximum profile peak height Rp = 0.591μm; the first measured peak height Rp1 = 0.6μm, and the measured value of the average profile element width RSm1 after initial shaping is 0.7μm.

[0060] b, iterative shaping: Second grinding: According to Rp1 = 0.5μm and RSm1 = 0.7μm, the second grinding particle size D2 = 0.4μm is selected, where D2 satisfies < 0.5μm and > 0.35μm); after the second grinding, the second measured peak height Rp2 = 0.3μm, the second measured valley Rv2 = 0.6μm, and the average profile element width RSm2 after the second shaping is 0.4μm; Third grinding: According to Rp2 = 0.3μm and RSm2 = 0.4μm, the particle size of the third grinding D3 = 0.22μm is selected accordingly, where D3 satisfies < 0.3μm and > 0.2μm); after grinding, the actually measured peak height of the third time Rp3 = 0.15μm ≤ 0.25μm, meeting the designed peak height Rp design ±ΔRp, but the actually measured valley of the third time Rv3 = 0.6μm is greater than the designed valley Rv design +ΔRv = 0.5μm upper limit value.

[0061] c, Optimization of shaping: The actually measured valley of the third time Rv3 = 0.6μm is greater than the designed valley Rv design +ΔRv = 0.5μm upper limit value. According to the difference between the actually measured valley of the third time Rv3 = 0.6μm and the designed valley Rv design = 0.5μm which is 0.1μm, select the final grinding particle size D final = ∣Rv3 - Rv design ∣ = 0.1μm diamond suspension for final grinding. For low-pressure grinding in the valley area, the final valley Rv final is adjusted to 0.380μm, falling within the error range of 0.3 - 0.5μm.

[0062] After the shape shaping is in place, before disassembling the parts, the parts should be run empty for 2 - 3 round trips to eliminate the external circle pressure and local residual grinding allowance. Self-check the dimensions and check the grinding lines, and it is necessary to take it to the sun to visually check whether there is sand loss and chatter marks. After meeting the requirements, perform S3.

[0063] After the shape shaping, the surface parameters of the coating are shown in Table 2; the schematic diagram of the surface roughness measurement of the coating is as Figure 3 shown; Table 2 Surface parameters of the coating after shape shaping

[0064] It can be seen from Table 2 that through shape shaping, the arithmetic mean roughness Ra is 0.049μm, meeting the design requirement ≤ 0.1μm, the roughness is significantly reduced, and the surface smoothness is greatly improved; the maximum profile peak height Rp is 0.110μm, falling within the design standard (Rp ≤ 0.2μm); the maximum profile valley Rv is 0.380μm, falling within Rv designThe design requirements are 0.4μm ± 1μm, that is, 0.3 - 0.5μm; the maximum profile height Rz is 0.491μm, the macroscopic undulation is significantly reduced, the surface profile is more uniform, and it is adjusted to the design range (Rz ≤ 1.0μm). It can be seen that after the topography shaping process, the arithmetic mean roughness Ra, the maximum profile peak height Rp, and the maximum profile height Rz all meet the design requirements; at the same time, it can be known from Table 2 that after the topography shaping, Rmr[1] is increased from 52.321% to 84.672%, the support rate is greatly increased, the surface load-bearing capacity is enhanced, and it can be suitable for high-load scenarios; Rsk is -2.116, the absolute value of the profile skewness increases, and the surface is mainly deep valleys, which is beneficial to storing lubricants and reducing friction. It can be seen that after the topography shaping, the key parameters such as the surface roughness, peak height, trough, and support rate of the coating all meet the design requirements, and the surface microstructure is optimized from "high peak and low support" to "low peak, deep valley, and high load-bearing", and the functionality is significantly improved.

[0065] Combining Table 1 and Table 2, it can be seen that in the topography shaping stage of this embodiment, through "successively reducing the grinding particle size and limiting the threshold range", the maximum profile peak height Rp is synchronously reduced from 0.591μm to 0.110μm and the maximum profile trough is reduced from 0.996μm to 0.380μm, solving the problem that the prior art cannot synchronously control the peak height and trough; and the reduction of the arithmetic mean roughness Ra and the increase of the profile support rate Rmr are synchronously achieved, making the coating suitable for precision fits (such as optical elements, engine components); the reduced valley depth Rvk is reduced from 0.613μm to 0.146μm; the reduced peak height Rpk is reduced from 0.155μm to 0.026μm; Rk is reduced from 0.718μm to 0.110μm; it can be concluded that through the superhard precision coating treatment method of the present invention, the surface microstructure of the coating changes from the disordered rough state of "high peak and deep valley" to the ordered smooth state of "low peak and shallow valley", significantly improving the surface accuracy, load-bearing capacity and wear resistance. The deep valley-dominated profile structure Rsk is reduced from -0.654μm to -2.116μm. Combining with the high profile support rate Rmr = 84.672%, it shows that the surface is mainly deep valleys and has a strong load-bearing capacity, which is beneficial to storing lubricants and reducing friction, meeting the requirements of precision fit scenarios.

[0066] Therefore, it can be concluded that through the systematic processes of pretreatment, layered shaping and fine grinding of this application, the precise control of the surface roughness, peak height and trough of the coating is realized, the applicability and reliability of the coating in the high-end manufacturing field are significantly improved, and the deficiencies of the prior art are effectively solved.

[0067] S3, fine grinding: Use a cerium oxide polishing solution with a particle size of 0.05 μm, a pressure of 20 N, and a rotation speed of 100 rpm. After fine grinding, wipe it repeatedly with a lint-free paper dipped in alcohol. Use a gloss meter to detect the surface brightness, and the brightness value is required to be ≥ 90 GU. When detecting, it is necessary to observe under bright light or a magnifying glass. The surface should have no grinding marks, pits or spots, be uniform and delicate. A uniform and delicate surface is considered qualified for self-inspection.

[0068] In S1, S2, and S3 of this embodiment, the water cooling system is synchronously started and water cooling is used throughout the process. The cooling water flow rate is 50 L / min, and the temperature is stabilized at 18 ± 0.5 °C by a PID controller. The grinding fluid concentration is 0.6%. The flat nozzle covers the grinding area at an angle of 45°, ensuring no local overheating. The cooling water is transported by a cooling pump. It is required that the maximum flow rate of the cooling pump is not less than 45 L / min and the maximum head is not less than 3.3 m. The grinding fluid concentration is between 0.5 - 0.7%. The water column at the cooling water outlet of the machine tool is in a jet shape, and a flat nozzle is selected as the nozzle. The water spray fully covers the grinding area during the grinding process to avoid thermal stress damage.

[0069] In the attachment Figure 2 where the abscissa is the measurement length (mm) and the ordinate is the roughness profile height (μm): P curve (original profile): The total height of the undulating profile Pt is 2.454 μm, with obvious peaks and deep valleys; R curve (actual profile): Irregular fluctuations can still be seen after filtering. The maximum peak height Rp of the profile is 0.591 μm, and the maximum valley depth Rv of the profile is 0.996 μm, with uneven distribution; W curve (filtered profile): Although smoothed, the average width of the profile elements RSm is large, and the surface texture is rough. It can be seen that after pretreatment, the macroscopic defects (such as scratches and protrusions) on the coating surface are not completely removed, and the peak height and valley depth lack precise control, unable to meet the requirements of precision coatings.

[0070] In the attachment Figure 3 where: P curve (original profile): The total height of the profile Pt = 0.833 μm, the peak tops are basically flattened, and the valley depths are uniform; R curve (actual profile): The profile line is smooth and continuous, and the maximum peak height Rp = 0.110 μm and the maximum valley depth Rv = 0.380 μm are controlled within the design range; W curve (filtered profile): The average width of the profile elements RSm decreases, the texture is delicate and uniform, and there are no abnormal protrusions or depressions. It can be seen that after topography shaping, precise control of the peak height and valley depth is achieved, and the surface topography changes from "disordered and rough" to "ordered and smooth".

Claims

1. A method for ultra-hard precision coating treatment, characterized in that, The method includes the following steps: S1, pre-treat the surface of the coating to be processed; S2, perform topography shaping on the pre-treated coating surface so that both the peak height and trough of the coating surface meet the design requirements; The topography shaping includes: primary shaping, iterative shaping, and optimization shaping; The initial value of the wave valley falls within the threshold range through initial shaping, and the threshold range is determined according to the designed wave valley Rv design and the maximum peak height Rp of the preprocessed profile; Gradually reduce the peak height to the designed peak height Rp through iterative shaping in the order of decreasing grinding particle size design within the error range; Adjust the wave trough to the designed wave trough Rv by optimizing shaping design Within the error range; S3, perform fine grinding on the coating surface after topography shaping so that the brightness of the coating surface reaches a predetermined standard.

2. A super-hard precision coating treatment method according to claim 1, characterized in that In S2, the initial grinding particle size D1 of the initial shaping is determined according to the designed valley Rv design and the maximum peak height Rp of the profile, where the initial grinding particle size D1 satisfies Rv design < D1 < Rp to ensure that while removing the peak height, excessive grinding of the valley is avoided 。 3. A super-hard precision coating treatment method according to claim 1, characterized in that, In S2, the grinding particle size and the number of grinding times for each time are determined according to the actually measured peak height and the average width RSm of the profile units after the previous shaping.

4. A method for treating a superhard precision coating according to claim 1, characterized in that, The threshold range refers to a data set that is greater than the designed wave valley Rv design and less than the maximum peak height Rp of the profile after pre-treatment of the coating surface.

5. A super-hard precision coating treatment method according to claim 1, characterized in that In S2, the primary shaping, iterative shaping, and optimization shaping are specifically as follows: a. Initial shaping: Using the initial grinding particle size D1 as the first grinding particle size, perform initial shaping on the surface of the pre-treated coating by grinding, so that the initial value of the wave valley falls within the threshold range, and the threshold range is an interval greater than the designed wave valley Rv design and less than the range of the maximum peak height Rp of the profile; b, iterative shaping, use a particle size smaller than the actually measured peak height after each shaping and larger than 1 / 2 of the average width RSm of the profile units as the grinding particle size for the next time, gradually reduce the peak height, and at the same time keep the trough at the initial value, and perform iterative shaping in this way until any of the following conditions is met: The peak height is completely removed; The peak height is reduced to the designed peak height Rp design within the range of ±ΔRp, where ΔRp is the allowable error value of the designed peak height; If the peak height is completely cut off or the peak height is reduced to the designed peak height Rp design within the range of ±ΔRp and the trough exceeds the designed trough Rv design within the range of ±ΔRv, enter the optimization shaping stage; if the trough is already within the range of the designed trough Rv design within the range of ±ΔRv, directly enter the fine grinding step S3; where ΔRv is the allowable designed trough error value; c. Optimize the shaping, and use the difference between the trough and the designed trough Rv design as the final grinding particle size D final for fine adjustment to adjust the trough to the designed trough Rv design within the range of ±ΔRv.

6. A super-hard precision coating treatment method according to claim 5, characterized in that The iterative shaping process of b includes: i. According to the first actually measured peak height Rp1 after primary shaping, select the second grinding particle size D2, perform the second grinding shaping, reduce the peak height to the second actually measured peak height Rp2, and at the same time keep the trough at the initial value after primary shaping; Among them, the second grinding particle size D2 satisfies: D2 < Rp1 and D2 > 1 / 2 of RSm1, where RSm1 is the average width of the profile units after primary shaping; ii. Repeat step i and successively perform subsequent grinding using the grinding particle size D n where the grinding particle size D n satisfies: D n <Rp n-1 and D n >1 / 2 of RSm n-1 where RSm n-1 is the average width of the contour units after the previous shaping, and Rp n-1 is the measured peak height after the previous shaping.

7. A super-hard precision coating treatment method according to claim 5, characterized in that During the topography shaping process, the grinding force and the grinding speed are kept uniform.

8. A super-hard precision coating treatment method according to claim 5, characterized in that, Observe the coating surface with a magnifying glass after each shaping; The coating surface should meet the requirements of uniform texture and no scratches.

9. A super-hard precision coating treatment method according to claim 1, characterized in that, The pre-treatment in S1 includes: rough grinding the coating surface and at least one of the operations of cleaning, degreasing, or rust removal.

10. A superhard precision coating treatment method according to claim 1, characterized in that, Cooling treatment is performed during the grinding processes in S1, S2, and S3.

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