A method for processing superhard precision coating

Abstract

The present invention relates to the technical field of precision coating processing, and discloses a method for processing super-hard precision coatings, comprising: S1, pre-treating the surface of the coating to be processed; S2, morphologically shaping the pre-treated coating surface so that the peak height and trough of the coating surface meet the design requirements; the morphological shaping includes: initial shaping, iterative shaping, and optimized shaping, the initial shaping makes the initial value of the trough fall within the threshold range, and the iterative shaping gradually reduces the peak height; the optimized shaping fine-tunes the trough; S3, fine-grinding the coating surface after the morphological shaping is completed so that the brightness of the coating surface reaches a predetermined standard. The present application removes macro defects and impurities on the coating surface by pre-treating the coating surface, and performs precise surface morphology control through morphological shaping, thereby achieving precise shaping of the peak height and trough of the coating surface so that it meets the design requirements, and solves the problem that the existing technology cannot accurately control the trough and peak height of the coating surface and cannot meet the design standards.

Description

Technical Field

[0001] The present invention relates to the technical field of precision coating processing, and in particular to a method for processing a superhard precision coating. Background Art

[0002] In the field of precision coating technology, as various industries continue to increase their requirements for product performance and quality, controlling coating surface accuracy has become a critical link. Looking back at the development of existing technologies, early coating surface treatments relied primarily on simple mechanical processing methods. As technology advances, the limitations of traditional methods have become increasingly prominent. As demand grows, a variety of methods have gradually developed, including polishing, coating, and heat treatment.

[0003] In current practical applications, these existing technologies have exposed numerous limitations. For example, mechanical polishing removes microscopic protrusions through friction between the polishing wheel and the workpiece surface. However, on complex coating surfaces, it is difficult to uniformly reduce peak heights and can easily over-remove valleys, compromising the coating's surface integrity. While chemical polishing and electrolytic polishing can improve surface flatness to a certain extent, the control of the chemical reactions and electrolytic processes is challenging, making it difficult to precisely control the effects on valleys and peak heights. For example, in the aerospace sector, coatings on engine components require extremely high surface precision, and traditional polishing processes cannot meet these stringent design standards. Coating techniques such as electroplating, chemical plating, and spraying can fill valleys and reduce surface roughness, but they only provide a surface coating and cannot fundamentally precisely shape valleys and peak heights. In precision instrument manufacturing, if the original valley and peak heights of the coating are not ideal, localized thickness variations may occur after coating, affecting the optical performance and accuracy of the instrument. Heat treatment processes such as quenching, tempering, and normalizing indirectly affect surface micromorphology and mechanical properties by altering the material's microstructure and eliminating internal stresses. However, this control method is not straightforward and difficult to precisely adjust for specific design requirements. In electronic chip manufacturing, the surface accuracy of the chip heat dissipation coating is very demanding, and thermal treatment cannot meet the requirements of precise control of troughs and peaks.

[0004] In summary, existing technologies cannot meet the requirements of precisely controlling the trough and peak heights on the coating surface to meet design standards, which severely limits the application of coatings in high-end manufacturing. A new coating processing method is urgently needed to solve these problems. Summary of the Invention

[0005] This application provides a method for processing superhard precision coatings. By shaping the coating surface morphology, the trough and peak heights of the coating surface can be precisely controlled to meet the design standard requirements. The specific solution is as follows:

[0006] A method for processing a superhard precision coating, comprising the following steps:

[0007] S1, preprocess the surface of the coating to be processed;

[0008] S2, shape the surface of the preprocessed coating so that both the peak height and the trough of the coating surface meet the design requirements;

[0009] The said surface shaping includes: primary shaping, iterative shaping and optimization shaping;

[0010] Through primary shaping, make the initial value of the trough fall within the threshold range, and the said threshold range is determined according to the designed trough Rv

[0019] and the maximum peak height Rp of the profile after pretreatment;

[0011] In the way that the grinding particle size decreases successively, gradually reduce the peak height to the designed peak height Rp design within the error range through iterative shaping;

[0012] Adjust the trough to the designed trough Rv design within the error range through optimization shaping;

[0013] S3, finish fine grinding on the surface of the coating after surface shaping to make the brightness of the coating surface reach the predetermined standard.

[0014] Preferably, in S2, the primary grinding particle size D1 of 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 to ensure that while removing the peak height, the trough is not over-grinded.

[0015] Preferably, in S2, each grinding particle size and the number of grinding times are determined according to the measured peak height after the previous shaping and the average width RSm of the profile unit.

[0016] Preferably, the said 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 the pretreatment of the coating surface.

[0017] Preferably, in S2, the primary shaping, iterative shaping and optimization shaping are specifically as follows:

[0018] a, primary shaping, use the primary grinding particle size D1 as the first grinding particle size to conduct primary shaping on the surface of the preprocessed coating by grinding, so that the initial value of the trough falls within the threshold range;

[0019] b, iterative shaping, use the 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 unit as the next grinding particle size, gradually reduce the peak height, and at the same time keep the trough as the initial value, and conduct iterative shaping in this way until any of the following conditions is met:

[0020] The peak height is completely cut off;

[0021] Peak height reduced to design peak height Rp design ±ΔRp range, where ΔRp is the allowable design peak height error;

[0022] 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, the trough exceeds the designed trough Rv design ±ΔRv range, it enters the optimization shaping stage; if the trough is already in the design trough Rv design If the value is within the range of ±ΔRv, the process directly proceeds to the fine grinding step S3; wherein ΔRv is the allowable design trough error value;

[0023] c. Optimize shaping to match the trough with the designed trough Rv design The difference between the two values ​​is taken as the final grinding particle size D final Fine-tune to adjust the trough to the designed trough Rv design Within the range of ±ΔRv.

[0024] Preferably, the iterative shaping process of b includes:

[0025] i. According to the first measured peak height Rp1 after the initial shaping, the second grinding particle size D2 is selected, and the second grinding and shaping is performed to reduce the peak height to the second measured peak height Rp2, while keeping the trough at the initial value after the initial shaping;

[0026] The second grinding particle size D2 satisfies: D2<Rp1 and D2>1 / 2RSm1, where RSm1 is the average width of the contour unit after the initial shaping;

[0027] ii. Repeat step i, using the grinding particle size D n Subsequent grinding is performed, wherein the grinding particle size D n Satisfied: D n <Rp n-1 and D n >1 / 2 RSm n-1 , where RSm n-1 Rp is the average width of the contour unit after the last shaping. n-1 is the measured peak height after the last shaping.

[0028] Preferably, during the morphology shaping process, the grinding force and the grinding speed are kept uniform.

[0029] Preferably, the coating surface is observed with a magnifying glass after each shaping;

[0030] The coating surface should have uniform texture and no scratches.

[0031] Preferably, the pretreatment in S1 includes: rough grinding of the coating surface, and at least one of cleaning, degreasing or rust removal operations.

[0032] Preferably, cooling treatment is performed during the grinding processes in S1, S2 and S3.

[0033] The beneficial effects of this application are:

[0034] The pretreatment process in S1 of this application removes macro defects and impurities on the coating surface, laying the foundation for the subsequent precise control of troughs and peak heights; the morphology shaping in S2 shapes the morphology of the coating surface after pretreatment, performs precise surface morphology control, and realizes precise control of the peak height and trough of the coating surface, so that the peak height and trough of the coating surface meet the design requirements; the fine grinding stage in S3 ensures good reflection and transmission of light, reduces light scattering and energy loss, thereby realizing the precise control of troughs and peak heights on the coating surface to meet the design standards, effectively overcoming the problem that the coating treatment in the prior art cannot fundamentally shape the morphology of the coating surface, resulting in the inability to accurately control the troughs and peak heights of the coating surface and the inability to meet the design standards.

[0035] In the S2 morphology shaping, the designed trough Rv of the coating surface after pretreatment is used. design The initial grinding particle size D1 is determined by the maximum peak height Rp of the profile, and the subsequent grinding particle size and number are dynamically adjusted according to the peak height after the previous shaping and the average width RSm of the profile unit. This can accurately control the trough and peak height within the design range, achieve precise shaping of the peak height and trough of the coating surface, and meet the stringent requirements of the high-end manufacturing field for coating surface accuracy.

[0036] At the same time, during the morphology shaping process, reasonable grinding particle size selection and dynamic adjustment mechanism avoid over-grinding and unnecessary processing steps. Selecting the appropriate particle size based on the actual situation after each grinding reduces the number of grindings and improves grinding efficiency. Furthermore, inspection of the coating surface after each shaping process can promptly identify problems and make adjustments, reducing scrap rates and lowering production costs. Compared to the existing technology that requires multiple rework and material waste due to the difficulty of precise control, this invention has significant advantages in production efficiency and cost control.

[0037] The cleaning, degreasing or rust removal operations in the S1 pretreatment and the cooling treatment during the entire grinding process (cooling is performed in S1, S2 and S3) improve the adhesion between the coating and the substrate and avoid the degradation of coating performance due to factors such as thermal stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1This is a flow chart of a method for treating a superhard precision coating according to an embodiment of the present application;

[0039] Figure 2 This is a schematic diagram of the surface roughness profile curve of the coating after pretreatment in an embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of the surface roughness profile curve of the coating after morphology shaping in this application embodiment;

[0041] In the attached figure:

[0042] The R curve is the actual roughness profile curve. DETAILED DESCRIPTION

[0043] A method for processing a superhard precision coating, comprising the following steps:

[0044] S1, pre-treating the coating surface to be treated;

[0045] S2, shaping the surface of the pre-treated coating so that the peak height and valley of the coating surface meet the design requirements;

[0046] The shape shaping includes: initial shaping, iterative shaping and optimized shaping;

[0047] The initial value of the trough is made to fall within the threshold range by the initial shaping, and the threshold range is determined according to the design trough Rv. design and the maximum peak height Rp of the profile after preprocessing;

[0048] The peak height is gradually reduced to the designed peak height Rp by iterative shaping in a manner that the grinding particle size is sequentially reduced. design within the margin of error;

[0049] Adjust the trough to the designed trough Rv by optimizing the shaping design within the margin of error;

[0050] S3, fine grinding the coating surface after the morphology shaping is completed, so that the brightness of the coating surface reaches a predetermined standard.

[0051] It should be noted that:

[0052] In this application, the surface of the coating to be treated is systematically pretreated, morphologically shaped and finely ground so that the roughness, peak height, valley and brightness of the coating surface meet specific design requirements.

[0053] Furthermore, in S2, the initial grinding particle size D1 of the initial shaping is adjusted according to the designed trough Rv design And the maximum peak height Rp of the profile is determined, where the initial grinding particle size D1 meets Rv design <D1<Rp。

[0054] It should be noted that:

[0055] In the present application, the selection method where the primary grinding particle size D1 satisfies Rv design < D1 < Rp provides reasonable starting conditions for the subsequent grinding and shaping process. It not only avoids excessive damage to the wave valleys due to too large particle sizes but also ensures that the excessive peak heights can be effectively removed, which helps to precisely control the initial surface topography of the coating, improve the grinding efficiency, reduce unnecessary grinding times, and lower the production cost.

[0056] Furthermore, in S2, each grinding particle size and the number of grinding times are determined according to the actually measured peak height and the average width of the profile units RSm after the previous shaping is completed.

[0057] In the present 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 precisely approach the design requirements, further improving the precision of the coating surface topography shaping and ensuring the consistency and stability of the final coating surface quality.

[0058] Furthermore, the threshold range refers to the data set that is greater than the designed wave valley Rv design and less than the maximum peak height Rp of the profile after the pre-treatment of the coating surface.

[0059] Furthermore, in S2, the primary shaping, iterative shaping, and optimization shaping are specifically as follows:

[0060] a. 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 wave valley fall within the threshold range;

[0061] b. Iterative shaping: Using a particle size that is less than the actually measured peak height after each shaping and greater than 1 / 2 of the average width of the profile units RSm as the next grinding particle size, gradually reduce the peak height while keeping the wave valley at the initial value, and perform iterative shaping in this way until any of the following conditions is met:

[0062] The peak height is completely removed;

[0063] The peak height is reduced to the designed peak height Rp design ±ΔRp range, where ΔRp is the allowable design peak height error value;

[0064] If the peak height is completely removed or the peak height is reduced to the designed peak height Rp design ±ΔRp range and the wave valley exceeds the designed wave valley Rv design ±ΔRv range, then enter the optimization shaping stage; if the wave valley is already within the designed wave valley Rv designIf the value is within the range of ±ΔRv, the process directly proceeds to the fine grinding step S3; wherein ΔRv is the allowable design trough error value;

[0065] c. Optimize shaping to match the trough with the designed trough Rv design The difference between the two values ​​is taken as the final grinding particle size D final Fine-tune to adjust the trough to the designed trough Rv design Within the range of ±ΔRv.

[0066] Furthermore, the iterative shaping process of b includes:

[0067] i. According to the first measured peak height Rp1 after the initial shaping, the second grinding particle size D2 is selected, and the second grinding and shaping is performed to reduce the peak height to the second measured peak height Rp2, while keeping the trough at the initial value after the initial shaping;

[0068] The second grinding particle size D2 satisfies: D2<Rp1 and D2>1 / 2RSm1, where RSm1 is the average width of the contour unit after the initial shaping;

[0069] ii. Repeat step i, using the grinding particle size D n Subsequent grinding is performed, wherein the grinding particle size D n Satisfied: D n <Rp n-1 and D n >1 / 2 RSm n-1 , where RSm n-1 Rp is the average width of the contour unit after the last shaping. n-1 is the measured peak height after the last shaping.

[0070] It should be noted that:

[0071] In this application, the initial grinding particle size D1 is used as the grinding particle size of the first grinding agent to grind the pre-treated coating surface. The initial value of the trough falls within a specific threshold range, which is based on the design trough Rv design This step is the basis for the entire morphology shaping and prepares for subsequent iterative shaping.

[0072] After the initial shaping is complete, the first measured peak height Rp1 is measured. Based on this value, the second grinding particle size D2 is selected. D2 needs to be less than Rp1 and greater than half of the average width of the contour unit after the initial shaping, RSm1. 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 unchanged at the initial value.

[0073] Repeat the above steps of selecting the grinding particle size and grinding, and use the particle size Dn Perform subsequent grinding operations. Among them, D n is selected to satisfy being greater than half of the average width RSm of the contour units after the previous shaping, so as to avoid the grinding particles from contacting the wave valleys, thereby ensuring that the wave valleys remain at the initial value during the iterative grinding process. The iterative process will continue until any one of the following two conditions is met:

[0074] The peak height is completely eliminated, that is, the measured peak height Rp n is 0 μm; or the peak height is reduced to the designed peak height Rp design within the range of ±ΔRp, perform precise shaping of the peak height, and achieve precise control of the peak height step by step through iterative shaping and keep the wave valleys at the initial value. Among them, ΔRp is the allowable design peak height error value.

[0075] Optimized shaping further fine-tunes the wave valleys on the basis of iterative shaping, and adjusts the wave valleys to the designed wave valley Rv design within the range of ±ΔRv; among them, ΔRv is the allowable design wave valley error value. Ensure that the peak height and wave valleys on the final coating surface fully meet the design requirements, greatly improving the accuracy of the coating surface topography and meeting the needs of high-precision applications;

[0076] In this application, by making the initial value of the wave valley (denoted as Rv1) fall within the threshold range (that is, 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, so as to ensure that while removing the peak height, the wave valleys are not over-grinded; adopt iterative shaping with sequentially decreasing grinding particle sizes, 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 contour units after the previous shaping n-1 dynamic adjustment mechanism, which ensures the continuity and effectiveness of the iterative shaping process, protects the wave valleys while gradually reducing the peak height, makes the topography of the coating surface gradually optimize towards the design requirements, improves the controllability and accuracy of the grinding process, and solves the problem that the peak height and wave valleys cannot be synchronously controlled in the prior art.

[0077] Furthermore, during the topography shaping process, the grinding force and grinding speed are kept uniform.

[0078] Furthermore, after each shaping, use a magnifying glass to observe the coating surface;

[0079] The coating surface should meet the requirements of uniform texture and no scratches.

[0080] ​​In this application, by inspecting the coating surface after each shaping, problems that may occur during the grinding process, such as uneven grinding, abnormal lines, etc., can be discovered in a timely manner, so that the grinding parameters can be adjusted in time or remedial measures can be taken to ensure the final coating surface quality and improve production efficiency.

[0081] Furthermore, the pretreatment in S1 includes: rough grinding of the coating surface, and at least one of cleaning, degreasing or rust removal operations.

[0082] In this application, macro 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.

[0083] Furthermore, in S1, S2 and S3, the grinding process is cooled by any one of water cooling and nitrogen cooling.

[0084] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0085] Example:

[0086] The design requirements of this embodiment are: surface roughness: arithmetic mean roughness Ra ≤ 0.1 μm; maximum peak height of profile Rp ≤ 0.2 μm ± ΔRp (ΔRp is 0.05 μm); Rz ≤ 1.0 μm; maximum valley of profile Rv = 0.4 μm ± ΔRv (ΔRv is 0.1 μm); profile support ratio Rmr 70% to 90% (evaluation depth 0.25 Rz); profile skewness: Rsk -0.1 to -3. In this embodiment:

[0087] The maximum peak height Rp of the profile is the maximum vertical distance between the peak top line and the center line of the profile within the sampling length; the maximum trough Rv of the profile is the maximum vertical distance between the bottom line and the center line of the profile within the sampling length; in this embodiment, the maximum peak height Rp of the profile and the maximum trough Rv of the profile are used as the evaluation parameters of peak height and peak valley.

[0088] RSm is the average width of the contour unit: the arithmetic mean of the distances between adjacent contour troughs within the sampling length, reflecting the uniformity of the surface texture;

[0089] Ra is the arithmetic mean roughness, which is the arithmetic mean of the absolute value of the profile deviation within the sampling length, reflecting the average height of the surface micro-roughness. The smaller the value, the smoother the surface. The arithmetic mean roughness Ra is used as the evaluation parameter of the coating surface roughness.

[0090] Rz is the maximum height of the profile, which is the distance between the top line of the profile peak and the bottom line of the profile valley within the sampling length;

[0091] Rak is the arithmetic mean deviation of roughness after specific filtering, which is used to more accurately evaluate surface roughness;

[0092] Rk is the core roughness depth, reflecting the roughness of the core area of ​​the surface;

[0093] Rpk is the reduced peak height, which characterizes the height characteristics of the surface protruding peaks;

[0094] Rvk is the reduced valley depth, which characterizes the depth characteristics of the surface depression valley;

[0095] Rmr is the profile support ratio, which is the ratio of the solid material length of the profile to the evaluation length at a given horizontal position, reflecting the surface bearing capacity;

[0096] Rsk is the profile skewness: it characterizes the symmetry of the peak-valley distribution of the surface profile, and negative values ​​indicate a surface structure dominated by deep valleys;

[0097] Pt is the total height of the profile, which is the distance between the peak line of the profile and the bottom line of the valley of the profile within the evaluation length.

[0098] As attached Figure 1 The following is a method for treating a super-hard precision coating according to this embodiment, and the operation process is as follows:

[0099] S1: Coating surface pretreatment:

[0100] The surface of the coating to be treated is subjected to rough grinding, cleaning, degreasing or rust removal operations to ensure that the surface roughness meets the preliminary design requirements (the preliminary design requirements include rough grinding to remove macro defects, initially reducing the maximum trough Rv of the profile to close to the design range, and the arithmetic average roughness Ra is between 0.25 and 0.40 μm).

[0101] Judgment conditions:

[0102] If the surface roughness after pretreatment meets the preliminary design requirements, enter S2 morphology shaping; if not, return to pretreatment again.

[0103] S2: Surface topography shaping:

[0104] Morphology shaping specifically includes: initial shaping, iterative shaping, and optimized shaping;

[0105] Among them, the initial shaping process:

[0106] Adopt the initial grinding particle size D1 to make the initial value of the wave valley fall within the threshold range, that is: Rv design <the initial value of the wave valley<the maximum peak height Rp of the profile after pretreatment. The initial grinding particle size D1 satisfies Rv design <D1<Rp, and the initial grinding particle size D1 = (Rv design + Rp) / 2 ± 10%.

[0107] Iterative shaping:

[0108] In the way that the grinding particle size decreases sequentially (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 profile unit width RSm after the previous shaping n-1 ), gradually reduce the peak height to the designed peak height Rp design within the error range (±0.05μm), and at the same time keep the wave valley at the initial value.

[0109] Loop condition: If the peak height has not been reduced to the design requirement, return to continue iterative shaping; if any of the following conditions are met:

[0110] The peak height is completely removed (Rp n = 0μm);

[0111] The peak height is reduced to within the designed peak height Rp design ±ΔRp range, where ΔRp is the allowable design peak height error value;

[0112] If the peak height is completely removed or the peak height is reduced to within the designed peak height Rp design ±ΔRp range, and the wave valley exceeds the designed wave valley Rv design ±ΔRv range, then enter the optimization shaping stage; if the wave valley is already within the designed wave valley Rv design ±ΔRv range, then directly enter the fine grinding step S3; where ΔRv is the allowable design wave valley error value;

[0113] Judge whether the peak height and wave valley meet the requirements: Yes, enter the S3 fine grinding process; No, return to iterative shaping or optimization shaping.

[0114] S3: Fine grinding process

[0115] Operation content: Use a fine particle size abrasive to finely grind the coating surface to make the surface brightness of the coating reach the predetermined standard.

[0116] Judgment condition:

[0117] If the brightness meets the standard, the process ends;

[0118] If it does not meet the standards, return it for re-fine grinding.

[0119] The specific implementation steps are:

[0120] S1, preprocessing:

[0121] The surface of the superhard coating was corrected, roughly ground and cleaned to control the surface roughness Ra to 0.25~0.40μm and the maximum valley Rv of the profile was initially reduced to ≤1.0μm. Specifically:

[0122] (1) Trimming:

[0123] 1) Before dressing the grinding wheel, check whether there are cracks on the silicon carbide grinding wheel. If cracks are found, replace it with a new silicon carbide grinding wheel in time.

[0124] 2) Use 60# silicon carbide grinding wheel for correction, with a single-side feed of 0.01mm for rough repair and 0.002mm for fine repair.

[0125] 3) The grinding wheel needs to be dressed once after grinding 2 to 3 parts.

[0126] (2) Coarse grinding:

[0127] 1) Before loading the machine, check the appearance of the workpiece and the chamfer of the inner hole to see if there are any bumps, defects or serious scratches.

[0128] 2) After loading the machine, use a dial indicator to measure the outer circle runout of the non-sprayed coating to within 0.02mm.

[0129] 3) Use a 60# silicon carbide grinding wheel, with a feed rate of 0.005mm per side and a workpiece speed of 90rpm~100rpm. During the process, it is important to ensure that the grinding wheel and parts are adequately cooled to prevent the tool from burning.

[0130] (3) Cleaning:

[0131] Use ultrasonic cleaning (ethanol solvent) and nitrogen drying to ensure that the surface is free of grease and impurities.

[0132] After pretreatment, the coating surface parameters are shown in Table 1; the coating surface roughness measurement diagram is shown in Figure 2 As shown;

[0133] Table 1 Surface parameters of coating after pretreatment

[0134]

[0135] It can be seen from Table 1 that the surface roughness after pretreatment is Ra=0.259μm, which is within the preliminary design requirement of 0.25~0.40μm; but the maximum peak height of the profile is Rp=0.591μm, the maximum height of the profile is Rz=1.587μm, and the maximum valley of the profile is Rv=0.996μm, which has not yet reached the design value of Rp≤0.2μm, Rz≤1.0μm, and Rv≤0.5μm, and needs to be further optimized through morphology shaping.

[0136] S2, morphology shaping:

[0137] Before using the machine, observe the grinding lines on the flame sprayed surface of the workpiece to check for sand drop and vibration marks;

[0138] Use an outside micrometer to check that the outer diameter of the spray coating has a polishing allowance of at least 0.01mm;

[0139] In this embodiment, during the entire morphology shaping stage, diamond grinding is performed in stages. The force and movement speed during the grinding process should be relatively uniform; the grinding pressure is controlled at 50-70N, and the movement speed is uniform (about 10-15mm / s); and after each grinding, a 5x magnifying glass is used to observe the grinding surface texture. The texture is required to be uniform and fine, without pitting, horizontal lines or abnormal grinding marks; water cooling is used throughout the process (18±0.5℃).

[0140] Initial shaping:

[0141] For the first grinding, silicon carbide abrasive with D1=0.55μm is used to grind the pretreated coating surface for the first time, where D1 meets the requirement of being greater than the designed trough Rv design =0.5μm, which is less than the maximum peak height of the profile Rp=0.591μm. In the first grinding, the grinding pressure is 60N and the speed is 250r / min;

[0142] Parameters after initial shaping: initial value of trough (denoted as Rv1) Rv1 = 0.6μm, initial value of trough is within the design trough Rv design =0.5μm and the maximum peak height of the small contour is Rp=0.591μm; the first measured peak height Rp1=0.6μm, and the measured value of the average width RSm1 of the contour unit after the initial shaping is 0.7μm.

[0143] b. Iterative shaping:

[0144] Second grinding: Based on 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 width of the contour unit after the second shaping RSm2 = 0.4μm;

[0145] The third grinding: According to Rp2 = 0.3μm and RSm2 = 0.4μm, the third grinding particle size D3 = 0.22μm is selected, where D3 satisfies < 0.3μm and > 0.2μm); the third measured peak height after grinding Rp3 = 0.15μm ≤ 0.25μm, which meets the design peak height Rp design ±ΔRp, but the third measured trough Rv3=0.6μm is larger than the designed trough Rv design +ΔRv=upper limit of 0.5μm.

[0146] c. Optimize shaping:

[0147] The third measured trough Rv3 = 0.6μm is larger than the designed trough Rv design +ΔRv=0.5μm upper limit, according to the third measured trough Rv3=0.6μm and the designed trough Rv design =0.5μm difference is 0.1μm, select the final grinding particle size The final grinding is carried out with diamond suspension, low pressure grinding is carried out on the valley area, and the final valley Rv final Adjusted to 0.380μm, falling within the 0.3-0.5μm error range.

[0148] After the topography is complete, run the part back and forth 2-3 times before disassembling to eliminate external pressure and residual wear. Check the dimensions and grinding marks, holding the part under sunlight to visually inspect for sand loss and chatter marks. If the requirements are met, proceed to S3.

[0149] After morphology shaping, the coating surface parameters are shown in Table 2; the coating surface roughness measurement diagram is shown in Figure 3 As shown;

[0150] Table 2 Surface parameters of coating after morphology shaping

[0151]

[0152] As can be seen from Table 2, through morphology shaping, the arithmetic average 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 peak height Rp of the profile is 0.110μm, which is within the design standard (Rp≤0.2μm); the maximum valley Rv of the profile is 0.380μm, which falls within the Rv designThe design requirement is 0.4μm±1μm, that is, 0.3~0.5μm; the maximum profile height Rz is 0.491μm, the macro fluctuation is significantly reduced, the surface profile is more uniform, and falls within the design range (Rz≤1.0μm). It can be seen that after the morphology shaping process, the arithmetic mean roughness Ra, the maximum peak height Rp of the profile, and the maximum height Rz of the profile all meet the design requirements; at the same time, it can be seen from Table 2 that after the morphology shaping, Rmr[1] is increased from 52.321% to 84.672%, the support rate is greatly improved, the surface bearing capacity is enhanced, and it can be suitable for high-load scenarios; Rsk is -2.116, the absolute value of the profile deflection increases, and the surface is mainly deep valleys, which is conducive to storing lubricants and reducing friction. It can be seen that after the morphology shaping, the key parameters of the coating surface roughness, peak height, valley, support rate, etc. all meet the design requirements, and the surface microstructure is optimized from "high peak and low support" to "low peak and deep valley and high load", and the functionality is significantly improved.

[0153] Combining Table 1 and Table 2, it can be seen that in the morphology shaping stage, this embodiment achieves the simultaneous reduction of the maximum peak height Rp of the profile from 0.591μm to 0.110μm and the maximum trough of the profile from 0.996μm to 0.380μm through "sequential reduction of the grinding particle size and limitation of the threshold range", which solves the problem that the existing technology cannot synchronously control the peak height and trough; and simultaneously achieves the reduction of the arithmetic mean roughness Ra and the improvement of the profile support rate Rmr, making the coating suitable for precision matching (such as optical components and engine parts); the reduced trough Rvk is reduced from 0.613μm to 0.146μm; the reduced peak height Rpk From 0.155μm to 0.026μm; Rk is reduced from 0.718μm to 0.110μm; it can be concluded that through the ultra-hard precision coating processing method of the present invention, the surface microstructure of the coating is transformed from a disordered rough state of "high peaks and deep valleys" to an ordered smooth state of "low peaks and shallow valleys", which significantly improves the surface accuracy, load-bearing capacity and wear resistance. The deep valley-dominated profile structure Rsk is reduced from -0.654μm to -2.116μm. Combined with the high profile support rate Rmr=84.672%, it shows that the surface is dominated by deep valleys and has a strong load-bearing capacity, which is conducive to storing lubricants and reducing friction, meeting the needs of precision matching scenarios. It can be concluded that this application has achieved precise control of the coating surface roughness, peak height and trough through a systematic process of pretreatment, layered shaping and fine grinding, significantly improving the applicability and reliability of the coating in the field of high-end manufacturing, and effectively solving the shortcomings of the existing technology.

[0154] S3, fine grinding:

[0155] Use 0.05μm cerium oxide polishing liquid, pressure 20N, speed 100rpm. After fine grinding, wipe repeatedly with dust-free paper dipped in alcohol. Use a gloss meter to detect the surface brightness. The brightness value is required to be ≥90GU. During the inspection, it is necessary to observe under bright light or a magnifying glass. The surface should be free of grinding lines, pitting or spots, and should be uniform and fine. A uniform and fine surface is considered qualified for self-inspection.

[0156] In the present embodiment, in S1, S2 and S3, the water cooling system is turned on synchronously and water cooling is used throughout the process. The cooling water flow rate is 50L / min, the temperature is stabilized at 18±0.5°C by a PID controller, the grinding fluid concentration is 0.6%, and the flat nozzle covers the grinding area at a 45° angle to ensure that there is no local overheating. The cooling water is delivered by a cooling pump, wherein the maximum flow rate of the cooling pump is required to be not less than 45L / min, the maximum head is not less than 3.3m, the grinding fluid concentration is between 0.5-0.7%, the water column at the cooling outlet of the machine tool is in a jet shape, and the nozzle is a flat nozzle. During the grinding process, the grinding part is fully covered with water to avoid thermal stress damage.

[0157] In the attached Figure 2 The horizontal axis represents the measured length (mm), and the vertical axis represents the roughness profile height (μm): The P curve (original profile) shows dramatic fluctuations, with a total profile height Pt of 2.454μm and distinct peaks and valleys. The R curve (actual profile) shows irregular fluctuations even after filtering, with a maximum peak height Rp of 0.591μm and a maximum valley Rv of 0.996μm, indicating uneven distribution. The W curve (filtered profile) shows that despite smoothing, the average profile unit width RSm is large, indicating rough surface textures. This indicates that macroscopic defects (such as scratches and protrusions) on the coating surface are not completely removed after pretreatment, and the peak heights and valleys lack precise control, failing to meet the requirements of precision coatings.

[0158] In the attached Figure 3 Middle: P curve (original profile): Total profile height Pt = 0.833μm, peaks are essentially flattened, and valley depths are uniform; R curve (actual profile): The profile is smooth and continuous, with maximum peak height Rp = 0.110μm and maximum valley Rv = 0.380μm within the designed range; W curve (filtered profile): The average width of the profile unit RSm is reduced, and the texture is fine and uniform, with no abnormal protrusions or depressions. This shows that after topography shaping, precise control of peak height and valley depth is achieved, and the surface morphology is transformed from "disordered and rough" to "ordered and smooth."

Claims

1. A method for processing superhard precision coating, characterized in that: The method comprises 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 the peak height and valley of the coating surface meet the design requirements; The shape shaping includes: initial shaping, iterative shaping and optimized shaping; The initial value of the trough is made to fall within the threshold range by the initial shaping, and the threshold range is determined according to the design trough Rv. design and the maximum peak height Rp of the profile after preprocessing; The peak height is gradually reduced to the designed peak height Rp by iterative shaping in a manner that the grinding particle size is sequentially reduced. design within the margin of error; Adjust the trough to the designed trough Rv by optimizing the shaping design within the margin of error; S3, fine grinding the coating surface after the morphology shaping is completed, so that the brightness of the coating surface reaches a predetermined standard; In S2, the initial shaping, iterative shaping, and optimized shaping are specifically as follows: a, initial shaping, using the initial grinding particle size D1 as the first grinding particle size, the pre-treated coating surface is ground for initial shaping, so that the initial value of the trough falls within the threshold range, the threshold range is greater than the designed trough Rv design The range is smaller than the maximum peak height Rp of the profile; b. Iterative shaping: take the particle size smaller than the measured peak height after each shaping and larger than 1 / 2 of the average width of the contour unit RSm as the next grinding particle size, gradually reduce the peak height while keeping the trough as the initial value, and iterate shaping until any of the following conditions are met: The peak height is completely cut off; Peak height reduced to design peak height Rp design ±ΔRp range, where ΔRp is the allowable design peak height error; 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, the trough exceeds the designed trough Rv design ±ΔRv range, it enters the optimization shaping stage; if the trough is already in the design trough Rv design If the value is within the range of ±ΔRv, the process directly proceeds to the fine grinding step S3; wherein ΔRv is the allowable design trough error value; c. Optimize shaping to match the trough with the designed trough Rv design The difference between the two values ​​is taken as the final grinding particle size D final Fine-tune to adjust the trough to the designed trough Rv design Within the range of ±ΔRv.

2. A superhard precision coating processing 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 superhard precision coating processing method according to claim 1, characterized in that: The iterative shaping process of b includes: i. According to the first measured peak height Rp1 after the initial shaping, the second grinding particle size D2 is selected, and the second grinding and shaping is performed to reduce the peak height to the second measured peak height Rp2, while keeping the trough at the initial value after the initial shaping; The second grinding particle size D2 satisfies: D2<Rp1 and D2>1 / 2RSm1, where RSm1 is the average width of the contour unit after the initial shaping; ii. Repeat step i, using the grinding particle size D n Subsequent grinding is performed, wherein the grinding particle size D n Satisfied: D n <Rp n-1 and D n >1 / 2 RSm n-1 , where RSm n-1 Rp is the average width of the contour unit after the last shaping. n-1 is the measured peak height after the last shaping.

4. A method for processing superhard precision coating according to claim 1, characterized in that: During the morphology shaping process, the grinding force and grinding speed are kept uniform.

5. The method for processing superhard precision coating according to claim 1, characterized in that: Use a magnifying glass to observe the coating surface after each shaping; The coating surface should have uniform texture and no scratches.

6. A method for processing superhard precision coating according to claim 1, characterized in that: The pretreatment in S1 includes: rough grinding of the coating surface, and at least one of cleaning, degreasing or rust removal operations.

7. The method for processing superhard precision coating according to claim 1, characterized in that: Cooling treatment is performed during the grinding process in S1, S2 and S3.

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